This document provides an overview of the anatomy of skin and basic skin lesions. It describes the layers of skin - epidermis, dermis and subcutaneous tissue. It details the cells and structures found in the epidermis and dermis, including hair follicles, sebaceous glands, sweat glands, blood and nerve supply. It also classifies and describes common primary skin lesions such as macules, papules, nodules, plaques, vesicles and bullae.
The skin is composed of two main layers - the epidermis and dermis. The epidermis is made up of stratified squamous epithelium with the basal layer containing keratinocytes that divide and push outward. As they move upward through the granular and stratum corneum layers, the keratinocytes produce more keratin and eventually shed their nuclei. The dermis lies below and contains collagen, fibers and vasculature that provide strength and nutrients to the epidermis. The basement membrane separates the two layers and is important for structural integrity of the skin.
This document summarizes melanogenesis and melanin production. It discusses the key events including the origin and function of melanocytes, melanosome formation and function, and melanin biosynthesis and regulation. The major types of melanin include eumelanin and pheomelanin. Core regulatory pathways influencing melanin production include the melanocortin 1 receptor and SCF-KIT receptor tyrosine kinase pathways. Enzyme activity is regulated by factors such as alpha-MSH, MITF, protein kinase C, and Sox family transcription factors.
Melanocytes are neural crest-derived cells located in the epidermis that synthesize melanin in organelles called melanosomes. There are two types of melanocytes - secretory melanocytes that transfer melanosomes to surrounding keratinocytes to provide UV protection, and non-secretory melanocytes that redistribute melanosomes within their dendrites. Melanin synthesis involves the transcription of proteins, melanosome biogenesis, sorting of proteins into melanosomes, transport of mature melanosomes to dendrite tips, and transfer to keratinocytes. The two main types of melanin produced are eumelanin (brown/black) and pheomelanin (red/yellow). UV irradiation and keratinocyte factors can stimulate
This document discusses skin pigmentation and disorders of pigmentation. It begins by explaining the basis of skin pigmentation including melanosomes, melanin synthesis and transport. It then discusses different types of chromophores and pigments that determine skin color. The document further describes melanocyte development, migration and function. It provides details on melanin types, melanosome biogenesis and transfer. Finally it discusses various disorders of hypopigmentation and hyperpigmentation.
This document discusses scabies and pediculosis (head lice). Scabies is caused by the human itch mite Sarcoptes scabiei and affects 300 million people worldwide annually. It is transmitted through direct skin-to-skin contact. Clinical features include a characteristic rash and burrows. Treatment involves topical scabicides like permethrin or oral ivermectin. Pediculosis involves infestation by head lice, body lice, or pubic lice. It causes itching and nits/lice can be seen on hair and clothing. Topical pediculocides or oral medications like ivermectin are used for treatment. Other parasitic
This document provides an overview of acne at different stages of life. It discusses neonatal acne, infantile acne, acne in childhood, adolescence, adulthood, pregnancy, and in ethnic skin. Treatment options are presented for each group, including topical retinoids, oral antibiotics, and isotretinoin. Updates are provided on the use of isotretinoin, including its efficacy, safety profile, and the new iPLEDGE registry system required for its prescription in the US.
The skin is composed of two main layers - the epidermis and dermis. The epidermis is made up of stratified squamous epithelium with the basal layer containing keratinocytes that divide and push outward. As they move upward through the granular and stratum corneum layers, the keratinocytes produce more keratin and eventually shed their nuclei. The dermis lies below and contains collagen, fibers and vasculature that provide strength and nutrients to the epidermis. The basement membrane separates the two layers and is important for structural integrity of the skin.
This document summarizes melanogenesis and melanin production. It discusses the key events including the origin and function of melanocytes, melanosome formation and function, and melanin biosynthesis and regulation. The major types of melanin include eumelanin and pheomelanin. Core regulatory pathways influencing melanin production include the melanocortin 1 receptor and SCF-KIT receptor tyrosine kinase pathways. Enzyme activity is regulated by factors such as alpha-MSH, MITF, protein kinase C, and Sox family transcription factors.
Melanocytes are neural crest-derived cells located in the epidermis that synthesize melanin in organelles called melanosomes. There are two types of melanocytes - secretory melanocytes that transfer melanosomes to surrounding keratinocytes to provide UV protection, and non-secretory melanocytes that redistribute melanosomes within their dendrites. Melanin synthesis involves the transcription of proteins, melanosome biogenesis, sorting of proteins into melanosomes, transport of mature melanosomes to dendrite tips, and transfer to keratinocytes. The two main types of melanin produced are eumelanin (brown/black) and pheomelanin (red/yellow). UV irradiation and keratinocyte factors can stimulate
This document discusses skin pigmentation and disorders of pigmentation. It begins by explaining the basis of skin pigmentation including melanosomes, melanin synthesis and transport. It then discusses different types of chromophores and pigments that determine skin color. The document further describes melanocyte development, migration and function. It provides details on melanin types, melanosome biogenesis and transfer. Finally it discusses various disorders of hypopigmentation and hyperpigmentation.
This document discusses scabies and pediculosis (head lice). Scabies is caused by the human itch mite Sarcoptes scabiei and affects 300 million people worldwide annually. It is transmitted through direct skin-to-skin contact. Clinical features include a characteristic rash and burrows. Treatment involves topical scabicides like permethrin or oral ivermectin. Pediculosis involves infestation by head lice, body lice, or pubic lice. It causes itching and nits/lice can be seen on hair and clothing. Topical pediculocides or oral medications like ivermectin are used for treatment. Other parasitic
This document provides an overview of acne at different stages of life. It discusses neonatal acne, infantile acne, acne in childhood, adolescence, adulthood, pregnancy, and in ethnic skin. Treatment options are presented for each group, including topical retinoids, oral antibiotics, and isotretinoin. Updates are provided on the use of isotretinoin, including its efficacy, safety profile, and the new iPLEDGE registry system required for its prescription in the US.
Acne scarring can be classified as icepick, boxcar, or rolling scars based on their width, depth, and architecture. Treatment options include topical agents, superficial and medium-depth peels, dermabrasion, fillers, fat transfer, needling, fractional photothermolysis, and surgical techniques like excision, grafting, and subcision. Superficial peels improve boxcar scars but may require multiple sessions. Dermabrasion is effective for acne scars but requires proper patient selection and technique. Fillers and fat transfer work best for atrophic depressed scars. Needling induces collagen without damage to induce healing. Surgical techniques are best for deep
Barrier function & biomechanical properties of the skin Ahmed Amer
This document summarizes the structure and function of the skin barrier. It describes the epidermis, stratum corneum, dermis, and basement membrane zone. The stratum corneum consists of corneocytes bound by lipid mortar, forming the skin's barrier against water loss and insults. Defects in corneocytes or lipids cause skin diseases. The dermis contains collagen, elastin, and glycosaminoglycans that provide mechanical strength, elasticity, and resistance to compression. Inherited disorders impact these structures, altering the skin's biomechanical properties.
This document summarizes the anatomy and physiology of the various glands in skin - sweat glands, sebaceous glands and apocrine glands. It describes the two main types of sweat glands - eccrine and apocrine, as well as apoeccrine glands. Details are provided on the structure, development, distribution and functions of each gland type. The hormonal control of sebaceous gland activity is also summarized, noting the effects of androgens, estrogens and other hormones.
Anatomy & physiology of sweat glands, sebaceousAhmed Amer
1. The document describes the anatomy and physiology of sweat glands, sebaceous glands, hair, and nails. It discusses the structure, development, innervation, function, and disorders of eccrine and apocrine sweat glands.
2. Sebaceous glands are described in relation to their sites of occurrence, development linked to androgen levels, and role in secreting sebum.
3. The stages of the hair follicle from infundibulum to bulb and the cycle of hair growth and shedding are outlined. The structure and pigmentation of the hair shaft is also covered.
4. Nail anatomy includes the nail plate, proximal nail fold, nail bed, nail
Rosacea and lymphocytic infiltration disordersRohit Singh
This document provides information on rosacea, including its definition, diagnostic criteria, pathogenesis, classification, clinical presentation, histopathology, and differential diagnosis. Rosacea is a chronic inflammatory skin condition of the central face characterized by flushing, permanent erythema, papules and pustules, telangiectasias, and occasionally nodules and plaques. It primarily affects fair-skinned individuals. The pathogenesis involves various factors such as solar irradiation, neurogenic mechanisms, oxidative stress, antimicrobial peptides, vasoactive mediators, and Demodex mites. It is classified into subtypes based on clinical features and has varying presentations ranging from mild flushing to severe inflammatory lesions.
This presentation is on functions of skin and physiology of skin including thermoregulatory function, barrier function, vitamin D synthesis, cosmetic functions.
- The epidermis maintains homeostasis through balanced cell production and loss in the basal layer. Three cell populations exist: stem cells, transient amplifying cells, and post-mitotic cells.
- Stem cells give rise to the epidermis and reside in the basal layer and hair follicle bulge. Transient amplifying cells can undergo limited proliferation.
- Keratinocytes take 12-19 days to transit from basal layer to stratum corneum, and 14 more days to transit through the stratum corneum. A variety of growth factors regulate epidermopoiesis.
This document discusses various types of excessive sweating conditions (hyperhidrosis) including their causes, presentations, and treatments. It describes primary cortical (emotional) hyperhidrosis which commonly affects the axillae and palms. Secondary causes include hyperhidrosis related to the hypothalamus or gustatory system. Treatment options mentioned are topical antiperspirants, oral medications like glycopyrrolate, and botulinum toxin injections for select cases.
The document provides information on the pilosebaceous unit, which is composed of hair follicles, hair shafts, arrector pili muscles, and sebaceous glands. It discusses the anatomy and histology of hair and sebaceous glands. Sebaceous glands develop from the hair follicle and are holocrine glands composed of lobules that produce an oily secretion called sebum. The document outlines the locations of sebaceous glands on the body, their functions, and how their activity is regulated by hormones such as androgens and estrogens. Common diseases associated with abnormalities in sebaceous glands are also mentioned.
This document discusses various hair shaft abnormalities and their causes. It provides detailed descriptions and microscopic images of trichoptilosis, trichoschisis, trichorrhexis nodosa, monilethrix, pili torti, uncombable hair syndrome, trichothiodystrophy, loose anagen syndrome, anagen effluvium hairs, and other conditions. It also covers hair findings associated with infections like pediculosis and piedra.
This document discusses various surgical techniques for treating vitiligo, including grafting techniques like minipunch grafting, suction blister grafting, and thin split thickness skin grafting. It also covers non-grafting techniques like dermabrasion and micropigmentation. For cellular grafts, it describes autologous non-cultured epidermal cell suspension and cultured melanocyte transplantation. Key factors in selecting a surgical approach include the type and extent of vitiligo lesions as well as equipment and surgeon expertise. Complications, advantages, and disadvantages of each technique are also reviewed.
This document summarizes epidermal kinetics and dynamics. It discusses the structure of the epidermis, epidermal proliferation units, cell cycle kinetics like turnover time and labeling index. Disturbances in epidermal kinetics like acanthosis, parakeratosis and dyskeratosis are described. Kinetics in normal skin versus psoriasis are compared. Epidermal differentiation and terminal differentiation involving keratinization are outlined. Drugs acting on epidermal cells like retinoids, vitamin D analogues, and salicylic acid are mentioned. Cancers of the epidermis are briefly described.
This document discusses post inflammatory scarring, specifically acne scarring. It defines different types of scarring such as hypertrophic, keloid, and atrophic scarring. It further classifies atrophic scarring into icepick, boxcar, and rolling scars. The document then discusses various treatment options for acne scarring including chemical peels, microdermabrasion, subcision, and skin needling. It provides details on how these procedures work and reviews studies showing their effectiveness in improving acne scarring.
This document provides an overview of facial melanosis and approaches to patients presenting with it. It begins with the anatomy and physiology of melanocytes and Fitzpatrick skin types. It then classifies the three main types of facial hypermelanosis as brown, blue, or mixed. Common causes of facial melanosis include melasma, freckles, lentigines, periorbital melanosis, seborrheic melanosis, and exogenous ochronosis. Melasma is described as the most common cause, with classifications based on location and patterns of pigmentation. Freckles and lentigines are also briefly discussed.
This document discusses topical keratolytics and topical steroids. It defines keratolytics as drugs that cause mild peeling of the skin or mucous membrane when applied locally by removing the pathologic desquamated keratin layer. Common keratolytics include salicylic acid, urea, benzoyl peroxide, and tretinoin. Topical steroids are defined as medicines used to treat skin conditions like eczema and psoriasis. They are anti-inflammatory and immunosuppressive. Common indications for topical steroids include recurrent aphthous ulcers, Behcet's syndrome, and pemphigus vulgaris. Potent topical steroids like bet
Melasma is a common skin condition that causes brown or gray-brown patches on the face. It is caused by overproduction of melanin in response to sun exposure and hormonal factors like pregnancy. Symptoms include dark, well-demarcated patches on areas like the forehead, cheeks and upper lip. Diagnosis is usually made by visual examination, though a biopsy can rule out other conditions. Treatment focuses on reducing melanin production using topical creams with hydroquinone, retinoids, and corticosteroids. Managing melasma requires daily sun protection and gentle skin care.
Skin = integument
Skin+ accessory organs = integumentary system.
The integumentary system comprises the skin and its appendages acting to protect the body from various kinds of damage, such as loss of water or damages from outside.
It includes hair, glands and nails.
It has a variety of additional functions; it may serve to waterproof, and protect the deeper tissues, excrete wastes, and regulate body temperature, and is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature,vitamin D synthesis.
skin and its layuer
Epidermis
Dermis
Hypodermis ( subcutaneous layer)
Epidermis
Most superficial layer of the skin
Approx 10 to 30 cells thick ( epithelial)
Cell types
Keratinocytes -90%
Melanocytes
Merkel cells 10%
Langerhens
stratum basale
Stratum germinativum
Deepest epidermal layer
Attaches to basal lamina
Cells bond to dermis via collagen fibres
Finger like projection called dermal papillae in dermis
Helps in stronger connection
Cells- cuboidal shaped keratinocytes
Grows constantly ,mitosis
Pushed up old cells
Applied aspects
Cells – merkel cell – function as receptor- stimulating sensory nerve fibres
Found in hairless skin.
Abundant on surface of hand and feet.
Melanocytes- produces pigment melanin
- gives hair and skin its color
-protect from u rays
Note: skin color influenced by ,melanin and carotene – carrot, oxygenated haemoglobin
Fingerprints-epidermal ridges
Stratum spinosum
Spiny in appearance
Desmosomsis protruding cell
Interlock between cells
Composed of 8to 10 layers of keratinocytes
Applied aspects
Langerhans cell –as a macrophage by engulfing bacteria and foreign body and damaged cell.
Keratinocytes synthesise keratin and prevent water loss
Stratum granulosam
Has a grainy appearance
Cells become flattened,and cell membrane thicken, and generate large amount of protein keratin and keratohyalin
After cell dies , keratin ,keratohyalin and cell membrane forms stratum lucidum
And accessory structures of hair and nail
Stratum lucidum
Smooth translucent layer
It is found only in thick skin of palms ,soles,digits
Cells are densely packed with eleidin , a clear protein rich in lipids,
Transparent appearance
Stratum corneam
Most superficial layer of epidermis
The increased keratinization of cell
It has 15 to 30 layers of cells
Water is lost from skin in 2 ways
Insensible perspiration
water diffuses from stratum corneum and evaporates from skin
-500 ml per day
Sensible perspiration
Water excreted by sweat glands.
clinical application
Some medications are toxic if swallowed, but safe if used topically (applied to surface of skin)
• Certain topical antibiotics are fairly toxic if taken by mouth, butcan be applied to skin with minimal risk of systemic absorption;they are polar molecules that cannot pass through epidermis toreach blood vessels in dermis; allows for local effect only
• Nonpolar substances cross epidermis much more easily;provides a c
The skin has three main layers - the epidermis, dermis, and subcutaneous layer. The epidermis is made of epithelial tissue in 5 layers (stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum) and contains four main cell types. The dermis is made of connective tissue and contains hair follicles, sebaceous glands, sweat glands, and nerves. The skin provides protection from external factors, regulates body temperature, and serves important sensory functions.
Acne scarring can be classified as icepick, boxcar, or rolling scars based on their width, depth, and architecture. Treatment options include topical agents, superficial and medium-depth peels, dermabrasion, fillers, fat transfer, needling, fractional photothermolysis, and surgical techniques like excision, grafting, and subcision. Superficial peels improve boxcar scars but may require multiple sessions. Dermabrasion is effective for acne scars but requires proper patient selection and technique. Fillers and fat transfer work best for atrophic depressed scars. Needling induces collagen without damage to induce healing. Surgical techniques are best for deep
Barrier function & biomechanical properties of the skin Ahmed Amer
This document summarizes the structure and function of the skin barrier. It describes the epidermis, stratum corneum, dermis, and basement membrane zone. The stratum corneum consists of corneocytes bound by lipid mortar, forming the skin's barrier against water loss and insults. Defects in corneocytes or lipids cause skin diseases. The dermis contains collagen, elastin, and glycosaminoglycans that provide mechanical strength, elasticity, and resistance to compression. Inherited disorders impact these structures, altering the skin's biomechanical properties.
This document summarizes the anatomy and physiology of the various glands in skin - sweat glands, sebaceous glands and apocrine glands. It describes the two main types of sweat glands - eccrine and apocrine, as well as apoeccrine glands. Details are provided on the structure, development, distribution and functions of each gland type. The hormonal control of sebaceous gland activity is also summarized, noting the effects of androgens, estrogens and other hormones.
Anatomy & physiology of sweat glands, sebaceousAhmed Amer
1. The document describes the anatomy and physiology of sweat glands, sebaceous glands, hair, and nails. It discusses the structure, development, innervation, function, and disorders of eccrine and apocrine sweat glands.
2. Sebaceous glands are described in relation to their sites of occurrence, development linked to androgen levels, and role in secreting sebum.
3. The stages of the hair follicle from infundibulum to bulb and the cycle of hair growth and shedding are outlined. The structure and pigmentation of the hair shaft is also covered.
4. Nail anatomy includes the nail plate, proximal nail fold, nail bed, nail
Rosacea and lymphocytic infiltration disordersRohit Singh
This document provides information on rosacea, including its definition, diagnostic criteria, pathogenesis, classification, clinical presentation, histopathology, and differential diagnosis. Rosacea is a chronic inflammatory skin condition of the central face characterized by flushing, permanent erythema, papules and pustules, telangiectasias, and occasionally nodules and plaques. It primarily affects fair-skinned individuals. The pathogenesis involves various factors such as solar irradiation, neurogenic mechanisms, oxidative stress, antimicrobial peptides, vasoactive mediators, and Demodex mites. It is classified into subtypes based on clinical features and has varying presentations ranging from mild flushing to severe inflammatory lesions.
This presentation is on functions of skin and physiology of skin including thermoregulatory function, barrier function, vitamin D synthesis, cosmetic functions.
- The epidermis maintains homeostasis through balanced cell production and loss in the basal layer. Three cell populations exist: stem cells, transient amplifying cells, and post-mitotic cells.
- Stem cells give rise to the epidermis and reside in the basal layer and hair follicle bulge. Transient amplifying cells can undergo limited proliferation.
- Keratinocytes take 12-19 days to transit from basal layer to stratum corneum, and 14 more days to transit through the stratum corneum. A variety of growth factors regulate epidermopoiesis.
This document discusses various types of excessive sweating conditions (hyperhidrosis) including their causes, presentations, and treatments. It describes primary cortical (emotional) hyperhidrosis which commonly affects the axillae and palms. Secondary causes include hyperhidrosis related to the hypothalamus or gustatory system. Treatment options mentioned are topical antiperspirants, oral medications like glycopyrrolate, and botulinum toxin injections for select cases.
The document provides information on the pilosebaceous unit, which is composed of hair follicles, hair shafts, arrector pili muscles, and sebaceous glands. It discusses the anatomy and histology of hair and sebaceous glands. Sebaceous glands develop from the hair follicle and are holocrine glands composed of lobules that produce an oily secretion called sebum. The document outlines the locations of sebaceous glands on the body, their functions, and how their activity is regulated by hormones such as androgens and estrogens. Common diseases associated with abnormalities in sebaceous glands are also mentioned.
This document discusses various hair shaft abnormalities and their causes. It provides detailed descriptions and microscopic images of trichoptilosis, trichoschisis, trichorrhexis nodosa, monilethrix, pili torti, uncombable hair syndrome, trichothiodystrophy, loose anagen syndrome, anagen effluvium hairs, and other conditions. It also covers hair findings associated with infections like pediculosis and piedra.
This document discusses various surgical techniques for treating vitiligo, including grafting techniques like minipunch grafting, suction blister grafting, and thin split thickness skin grafting. It also covers non-grafting techniques like dermabrasion and micropigmentation. For cellular grafts, it describes autologous non-cultured epidermal cell suspension and cultured melanocyte transplantation. Key factors in selecting a surgical approach include the type and extent of vitiligo lesions as well as equipment and surgeon expertise. Complications, advantages, and disadvantages of each technique are also reviewed.
This document summarizes epidermal kinetics and dynamics. It discusses the structure of the epidermis, epidermal proliferation units, cell cycle kinetics like turnover time and labeling index. Disturbances in epidermal kinetics like acanthosis, parakeratosis and dyskeratosis are described. Kinetics in normal skin versus psoriasis are compared. Epidermal differentiation and terminal differentiation involving keratinization are outlined. Drugs acting on epidermal cells like retinoids, vitamin D analogues, and salicylic acid are mentioned. Cancers of the epidermis are briefly described.
This document discusses post inflammatory scarring, specifically acne scarring. It defines different types of scarring such as hypertrophic, keloid, and atrophic scarring. It further classifies atrophic scarring into icepick, boxcar, and rolling scars. The document then discusses various treatment options for acne scarring including chemical peels, microdermabrasion, subcision, and skin needling. It provides details on how these procedures work and reviews studies showing their effectiveness in improving acne scarring.
This document provides an overview of facial melanosis and approaches to patients presenting with it. It begins with the anatomy and physiology of melanocytes and Fitzpatrick skin types. It then classifies the three main types of facial hypermelanosis as brown, blue, or mixed. Common causes of facial melanosis include melasma, freckles, lentigines, periorbital melanosis, seborrheic melanosis, and exogenous ochronosis. Melasma is described as the most common cause, with classifications based on location and patterns of pigmentation. Freckles and lentigines are also briefly discussed.
This document discusses topical keratolytics and topical steroids. It defines keratolytics as drugs that cause mild peeling of the skin or mucous membrane when applied locally by removing the pathologic desquamated keratin layer. Common keratolytics include salicylic acid, urea, benzoyl peroxide, and tretinoin. Topical steroids are defined as medicines used to treat skin conditions like eczema and psoriasis. They are anti-inflammatory and immunosuppressive. Common indications for topical steroids include recurrent aphthous ulcers, Behcet's syndrome, and pemphigus vulgaris. Potent topical steroids like bet
Melasma is a common skin condition that causes brown or gray-brown patches on the face. It is caused by overproduction of melanin in response to sun exposure and hormonal factors like pregnancy. Symptoms include dark, well-demarcated patches on areas like the forehead, cheeks and upper lip. Diagnosis is usually made by visual examination, though a biopsy can rule out other conditions. Treatment focuses on reducing melanin production using topical creams with hydroquinone, retinoids, and corticosteroids. Managing melasma requires daily sun protection and gentle skin care.
Skin = integument
Skin+ accessory organs = integumentary system.
The integumentary system comprises the skin and its appendages acting to protect the body from various kinds of damage, such as loss of water or damages from outside.
It includes hair, glands and nails.
It has a variety of additional functions; it may serve to waterproof, and protect the deeper tissues, excrete wastes, and regulate body temperature, and is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature,vitamin D synthesis.
skin and its layuer
Epidermis
Dermis
Hypodermis ( subcutaneous layer)
Epidermis
Most superficial layer of the skin
Approx 10 to 30 cells thick ( epithelial)
Cell types
Keratinocytes -90%
Melanocytes
Merkel cells 10%
Langerhens
stratum basale
Stratum germinativum
Deepest epidermal layer
Attaches to basal lamina
Cells bond to dermis via collagen fibres
Finger like projection called dermal papillae in dermis
Helps in stronger connection
Cells- cuboidal shaped keratinocytes
Grows constantly ,mitosis
Pushed up old cells
Applied aspects
Cells – merkel cell – function as receptor- stimulating sensory nerve fibres
Found in hairless skin.
Abundant on surface of hand and feet.
Melanocytes- produces pigment melanin
- gives hair and skin its color
-protect from u rays
Note: skin color influenced by ,melanin and carotene – carrot, oxygenated haemoglobin
Fingerprints-epidermal ridges
Stratum spinosum
Spiny in appearance
Desmosomsis protruding cell
Interlock between cells
Composed of 8to 10 layers of keratinocytes
Applied aspects
Langerhans cell –as a macrophage by engulfing bacteria and foreign body and damaged cell.
Keratinocytes synthesise keratin and prevent water loss
Stratum granulosam
Has a grainy appearance
Cells become flattened,and cell membrane thicken, and generate large amount of protein keratin and keratohyalin
After cell dies , keratin ,keratohyalin and cell membrane forms stratum lucidum
And accessory structures of hair and nail
Stratum lucidum
Smooth translucent layer
It is found only in thick skin of palms ,soles,digits
Cells are densely packed with eleidin , a clear protein rich in lipids,
Transparent appearance
Stratum corneam
Most superficial layer of epidermis
The increased keratinization of cell
It has 15 to 30 layers of cells
Water is lost from skin in 2 ways
Insensible perspiration
water diffuses from stratum corneum and evaporates from skin
-500 ml per day
Sensible perspiration
Water excreted by sweat glands.
clinical application
Some medications are toxic if swallowed, but safe if used topically (applied to surface of skin)
• Certain topical antibiotics are fairly toxic if taken by mouth, butcan be applied to skin with minimal risk of systemic absorption;they are polar molecules that cannot pass through epidermis toreach blood vessels in dermis; allows for local effect only
• Nonpolar substances cross epidermis much more easily;provides a c
The skin has three main layers - the epidermis, dermis, and subcutaneous layer. The epidermis is made of epithelial tissue in 5 layers (stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum) and contains four main cell types. The dermis is made of connective tissue and contains hair follicles, sebaceous glands, sweat glands, and nerves. The skin provides protection from external factors, regulates body temperature, and serves important sensory functions.
The document provides an overview of the integumentary system, including the structure and functions of the skin and its derivatives. It defines key terms and discusses the layers of the epidermis and dermis. Accessory organs like sweat glands, sebaceous glands, hair, and nails are described. The functions of skin include protection, regulation of body temperature, sensation, excretion, absorption, immunity, and synthesis of vitamin D. Skin color and various markings are also covered.
1. Introduction to dermatology Year 5.2023.pptxDakaneMaalim
This document provides an introduction to dermatology, covering the structure and functions of the skin, its derivatives like hair and nails, and common terminology used to describe skin lesions. The skin consists of three layers - the epidermis, dermis, and subcutaneous tissue. It has structures like hair follicles, sebaceous glands, eccrine and apocrine sweat glands. The skin acts as a barrier, regulates temperature, has sensory functions, and plays a role in vitamin D production and immunity. Common skin conditions are described.
The anatomy of the skin consists of three main layers - the epidermis, dermis and subcutaneous fat. The epidermis contains five layers and produces keratinocytes, melanocytes, Merkel cells and Langerhans cells. The dermis lies underneath and contains collagen, elastin and ground substance. It is divided into the papillary and reticular layers. Skin appendages include hair follicles, sebaceous and eccrine glands. The skin has blood and lymphatic vessels, nerves and muscles like the arrector pili. Skin thickness and structure varies in different areas and changes with ageing.
Structure and function of Skin (Integumentary system) - mypharmaguidePankaj Saha
Dermatology – defined as ‘the branch of medicine concerned with the diagnosis & treatment of skin disorders’
However, dermatologists do not confine themselves purely to a study of intrinsic disorders of the skin
Must also study internal medicine & the many environmental & occupational factors that so frequently cause skin problems
Visit - MyPharmaGuide.Com for more or Download MyPharmaGuide app from Google Play Store
This document summarizes the key types of body membranes and skin structures. It discusses the three main types of epithelial membranes - cutaneous, mucous and serous. It then describes each membrane in more detail, including their composition, location and functions. The document also outlines the layers of skin, skin appendages like hair and glands, pigmentation, and some imbalances like infections, burns and allergies.
The document discusses the different types of epithelial and connective tissue membranes in the body. It covers cutaneous, mucous, serous, and synovial membranes. Cutaneous membranes form the skin and are composed of stratified squamous epithelium. Mucous membranes line body cavities and are moist. Serous membranes form double-layered membranes around organs in body cavities. Synovial membranes line joints.
The document provides information about human skin anatomy, organization, histology, function and diagnosis. It discusses the key components and layers of the skin including the epidermis, dermis and skin appendages. The epidermis is composed of the basal, spinous, granular and stratum corneum layers. The dermis contains collagen, elastic and ground substance fibers. The skin has important protective, sensory and temperature regulating functions. Common skin lesions and their characteristics are also defined.
The document provides information on the integumentary system, skeletal system, and joints. It includes sections on the structure and functions of skin, as well as the structure of the skull, vertebral column, thoracic cage, and types of bones. Key points covered are the layers of the skin (epidermis and dermis), structures in the skin (sweat glands, hair follicles, sebaceous glands), functions of skin (protection, temperature regulation, sensation), and divisions of the skeletal system into the axial skeleton and appendicular skeleton.
The document discusses the anatomy and functions of the integumentary system. It describes the two main layers of skin - the epidermis and dermis. The dermis contains blood vessels, hair follicles, sweat and sebaceous glands. The dermis regulates body temperature through blood vessel dilation and constriction. Keratinization occurs as cells move from the stratum basale to the stratum corneum. The skin protects the body, regulates temperature and sensation, and produces Vitamin D.
Normal histology of skin with pathological skin conditions.pptxDr.Sunil mitran
The skin has three main layers - the epidermis, dermis, and hypodermis. The epidermis is made of stratified squamous epithelium and contains keratinocytes, melanocytes, Langerhans cells, and Merkel cells. It is divided into five layers from superficial to deep: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. The dermis lies below the epidermis and contains fibroblasts, mast cells, and adipocytes. It is divided into the papillary and reticular dermis. Skin appendages include hair follicles, sweat glands, sebaceous glands, and nails
The skin is the largest organ of the body and has three main layers - the epidermis, dermis, and subcutaneous tissue. The epidermis is made of stratified squamous epithelium and contains keratinocytes, melanocytes, Langerhans cells, and Merkel cells. The dermis lies below the epidermis and contains collagen, elastic fibers, hair follicles, sweat and sebaceous glands. The skin acts as a protective, sensory, synthetic and temperature regulating organ.
The skin is the largest organ of the body, protecting underlying tissues and regulating temperature. It consists of three layers - the epidermis, dermis, and hypodermis. The epidermis contains keratinocytes, melanocytes, Langerhans cells, and Merkel cells. The dermis contains hair follicles, sweat and sebaceous glands, nerves, and blood vessels. The skin protects the body, regulates temperature, and produces vitamin D. Skin disorders include acne, psoriasis, skin cancer, and infections.
The skin is the largest organ of the body that protects us from damage and regulates body temperature. It is made up of three main layers - the epidermis, dermis, and hypodermis. The epidermis is the outermost layer and contains keratinocytes that produce keratin, while the dermis lies underneath and contains structures like hair follicles, sebaceous glands, and sweat glands.
The document discusses the structure and function of the integumentary system, specifically the skin. It describes the three main layers of skin - the epidermis, dermis and hypodermis. The epidermis contains keratinocytes, melanocytes, Langerhans cells and Merkel cells. It has several layers with different functions. The dermis contains collagen, elastic fibers, blood vessels and glands. It is made up of papillary and reticular layers. The hypodermis contains fat and connective tissue. Skin color is determined by melanin, hemoglobin and carotene. Hair, nails and glands are important accessory structures of the skin.
This document summarizes the structure and functions of human skin. It discusses that skin is the largest organ, weighs 4 kg and has an area of 2 m2. It then describes the three layers of skin - epidermis, dermis and subcutaneous tissue. It provides detailed information about the structure and cells within the epidermis and dermis layers. It also discusses the blood supply, lymphatics, nerves and immune system of skin. Finally, it summarizes the different types of immune reactions that can occur in the skin, including immediate, humoral, immune-complex mediated and delayed hypersensitivity reactions.
The integumentary system is an organ system consisting of the skin, hair, nails, and exocrine glands. The skin is only a few millimeters thick yet is by far the largest organ in the body. The average person's skin weighs 10 pounds and has a surface area of almost 20 square feet.
The skin has three layers - the epidermis, dermis, and hypodermis. The epidermis is made of stratified squamous epithelium and contains keratinocytes, melanocytes, Langerhans cells, and Merkel cells. It provides protection, regulates temperature and moisture, and produces vitamin D. The dermis contains dense connective tissue, hair follicles, sweat and sebaceous glands. It provides strength and elasticity to the skin. The hypodermis is a layer of adipose tissue that acts as insulation for the body. The skin comes in thick and thin varieties and has eccrine and apocrine sweat glands that help regulate temperature and release scent compounds.
Similar to Chapter_01_Anatomy_of_Skin[1].pptx (20)
Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased risk of fractures. Key points:
- It is defined as a bone density 2.5 standard deviations or more below the mean bone density of healthy young adults.
- It occurs more frequently with age and is more common in women, especially after menopause due to estrogen loss.
- Risk factors include family history, smoking, low weight, inactivity, excessive alcohol, and certain medical conditions or medications.
- It is usually asymptomatic until a fracture occurs. Treatment focuses on lifestyle changes, calcium/vitamin D supplementation, and medications to increase bone density
An electrocardiogram (ECG) records the electrical activity of the heart on paper. It is recorded at a rate of 25mm/s, with each large square measuring 0.2 seconds and containing 5 small squares of 0.04 seconds each. The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization. Various intervals between the P, QRS, and T waves provide information about electrical conduction through the heart. Abnormalities in the ECG patterns can provide clues about conditions affecting different areas of the heart muscle.
This document discusses the concept of mobilization with movement (MWM), as developed by Brian Mulligan. MWM involves applying a sustained accessory mobilization by the therapist while the patient performs an active movement. It is based on the idea that minor positional faults in joints can cause pain and limited range of motion, and that correcting these faults through MWM can provide fast pain relief and improved function. Specific MWM techniques discussed for the spine include natural apophyseal glides, reverse natural apophyseal glides, and sustained natural apophyseal glides, while movement with mobilizations is described as the extremity technique. The principles, indications, contraindications and applications of MWM are outlined.
This document discusses mumps, measles, rubella, polio, and congenital viral infections. It covers the causative viruses, symptoms, complications, diagnosis, prophylaxis, and laboratory tests for each. Mumps is caused by mumps virus and causes parotitis. Measles is caused by measles virus and causes rash and Koplik's spots. Rubella is caused by rubella virus and causes German measles. Poliovirus can cause paralysis. Congenital infections transmitted during pregnancy can cause defects like deafness, cataract, or cardiac issues. Vaccines for mumps, measles, and rubella include the live attenuated MMR vaccine.
Mr. Xyz is a 15-year-old male who presented with pain in his left elbow and inability to fully bend or extend it for 2.5 months following a supracondylar fracture from a fall from his bed that was managed conservatively. Examination found disunity in the supracondylar region of the left humerus, reduced range of motion and muscle strength in the left elbow, and altered posture. He has moderate difficulty lifting objects and requires assistance with dressing and eating due to pain and weakness in his left arm.
Mr. XYZ, a 48-year-old carpenter, complains of pain in his right forearm and tingling in his right thumb and index finger for 4 weeks. Clinical investigations show reduced nerve conduction velocity. Repetitive pronation from his work causes increased muscle bulk in the pronator teres muscle, compressing the median nerve. On examination, there is increased muscle mass of the pronator teres muscle entrapping the median nerve. The patient has weakness of right finger flexion due to median nerve compression between the two heads of the pronator teres muscle. He has difficulty lifting objects and writing due to tingling and weakness in his right thumb and index finger. Support from family and motivation to recover facilitate his
This document discusses the biomechanics and examination of the sacroiliac joint. It covers topics like the resting position, capsular patterns on stressing joints, close and loose pack positions involving nutation and counternutation. It describes tests like the gait cycle, pelvic angles, and special tests to assess the sacroiliac joint like SLR, Gaenslen's, and Trendelenburg's sign. Examination findings related to posture, skin, muscles, and movements are also outlined.
This document discusses parasites and provides details about Entamoeba histolytica and intestinal amoebiasis. It defines parasites as organisms that thrive on another host and obtain nutrition. It describes the different types of parasites, including ectoparasites that live on the skin and endoparasites that live inside the body. It then focuses on E. histolytica, noting that it is a protozoan parasite found worldwide that can cause intestinal or extraintestinal amoebiasis via ingestion of cysts in contaminated food or water. Symptoms of intestinal amoebiasis include ulcers and abscesses in the liver from trophozoites spreading via the bloodstream. Diagnosis involves microscopy of stool
The document summarizes the structure and biomechanics of the cervical spine. It describes the seven cervical vertebrae and their typical and atypical features. It discusses the distinctive structures of the atlas and axis vertebrae. It also outlines the articulations between vertebrae including the atlanto-occipital and atlantoaxial joints. Additionally, it summarizes the ligaments of the craniovertebral region and the motions and couplings between vertebrae in the cervical spine.
This document discusses several connective tissue diseases:
- Lupus erythematosus can present as cutaneous, subacute, or chronic forms and is characterized by a butterfly rash. Systemic lupus erythematosus can involve multiple organ systems.
- Scleroderma involves skin thickening and fibrosis. It can be limited or diffuse and also cause lung, heart, gastrointestinal and renal involvement.
- Dermatomyositis is characterized by a violaceous rash over the knuckles, elbows and back along with progressive symmetric muscle weakness.
This document discusses types of thoracic spine abnormalities including kyphosis which can present as a round back, Dwagers hump, flat back or hump back. It also mentions scoliosis and different types of chest deformities such as pigeon chest, funnel chest and barrel chest.
This document discusses various movement disorders including chorea, athetosis, and dystonia. It describes the basal ganglia pathways and how they relate to movement. It defines different types of dystonia such as focal, segmental, and generalized dystonia. It also describes specific forms of dystonia like blepharospasm, cervical dystonia, and oromandibular dystonia. Treatment options for dystonia and chorea are discussed including physical therapy, medications, botulinum toxin injections, and deep brain stimulation. The causes of chorea are outlined including genetic disorders like Huntington's disease.
Immobilization and prolonged bed rest can lead to significant physiological changes and health risks. It causes fluid shifts, reduced cardiac function, muscle and bone loss, increased risk of infection and blood clots. Specific problems include dehydration, low blood pressure with standing, muscle and joint stiffness, lung function decline, and bone loss or fractures over time. Those who are already ill or elderly are most vulnerable to the negative effects of immobilization.
Pulmonary function tests measure lung volumes, gas flow rates, gas diffusion, and gas distribution to evaluate the integrity of the airways, respiratory musculature, and lung tissues. The results of these tests can classify pulmonary diseases into three categories: obstructive, restrictive, or a combination of both. Pulmonary function testing involves measurements of dynamic gas flow, lung volumes and capacities, and gas diffusion to provide a quantitative assessment of lung function.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
1. Anatomy of Skin and Basic Skin Lesions
Digital Lecture Series : Chapter 01
2. CONTENTS
Introduction
Embryology
Layers of Skin
Epidermis
• Cells of Epidermis
• Function of Epidermis
• Epidermal Appendages
A. Hair
B. Sebaceous Gland
C. Sweat Gland
D. Eccrine Sweat Gland
E. Apocrine Gland
Dermis
• Structure
• Dermo -Epidermal Junction
• Nerves
• Blood Supply
Basic Skin Lesion
• Primary
• Secondary
• Special
MCQs
Photoquiz
3. Anatomy of Skin
Largest organ system
Measures about 2.12 Sq m, Weighing 4.2kg
Hair, Sebaceous and Eccrine glands, Nails, Mucous membranes make
important components with specialized physiological functions
4. Embryology of Skin
All constituents are derived from ectoderm and mesoderm
Ectoderm and mesoderm begin to proliferate and differentiate at 4th
week of intrauterine life
The specialized structures of skin, teeth, hair, nails and glands begin
to appear at this time
8. Epidermis
Stratum corneum :
Flattened, anuclear, eosinophilic corneocytes,
Dead layer shed during epidermal turnover
Stratum lucidum :
Clear layer found in palms and soles in between stratum corneum and
stratum granulosum
Epidermal turnover/ transit time :
Time taken for a cell to pass from basal layer to surface of skin is 52-
75 days (normal skin)
9. Other Cells in Epidermis
Melanocyte
Langerhans cell
Merkel cell
10. Melanocytes
Neural crest derived Dendritic cells
Synthesize and secrete melanin containing organelles called
melanosomes
Located in basal cell layer; 1:10 ratio
Epidermal Melanin Unit : A single melanocyte supplies
melanosomes to 36 keratinocytes (1:36)
Melanosomes vary in distribution and size according to skin type.
However, the density of melanocytes in different races is the same.
11. Melanocytes - Melanogenesis
Melanin formed through mediation of tyrosinase and DOPA from tyrosine
Controlled by :
• Genetic factors
• UVR
• Hormones (e.g. MSH)
Phenylalanine Tyrosine DOPA
DOPAquinone
Pheomelanin Eumelanin
12. Melanocytes - Functions
Melanin:
Impart colour to skin and hair
Protect the skin from UV radiation
Biochemical neutralizer of toxic, free radical oxygen derivatives
13. Langerhans cells and Merkel Cells
Langerhans cells
• Dendritic cells
• Type of macrophage
• Role in various immune processes like - allergic contact dermatitis,
immune tolerance, surveillance against viral infections and
neoplasia
Merkel cell
• Non-Dendritic cells lying in or near basal layer or hair follicles
• Neuritic cells
• Fine touch receptors
• Detect mechanical deformities of epidermis
14. Functions of Epidermis
Cornification
Barrier function
Permeability
Maintenance of fluid and electrolyte balance
Thermoregulation
Pigmentation
Immune function
Sensory receptor
Vitamin D Synthesis
16. Hair
Found over the entire surface of the body except palms, soles, glans penis,
clitoris, labia minora, mucocutaneous junction and distal portions of the
fingers and toe.
Types of Hair
Lanugo hair : Fine, soft hair in fetus
Vellus hair : Fine, short, non-medulated hair over most parts of the
body
Terminal hair : Long, coarse, medulatd hair over scalp, beard, and
body depending on age and gender
19. Hair Growth Cycle
Hair cycle consists of three phases:
Anagen : Phase of growth and activity, lasts for 2-10 years
About 90% of hair are in anagen at a given time
Catagen : Phase of transition, lasts for 1-3 weeks.
About 1% hair are in catagen
Telogen : Resting phase lasts for about 3 months.
About 10% hair are in telogen
Telogen hair is shed and anagen hair replaces it
Average hair loss is 100/day
20. Sebaceous Glands
Lipid producing holocrine, multi-lobed glands
Arise from the hair follicle at the junction of the infundibulum and the
isthmus
Distributed all over the body except the palms and soles
Numerous, large and productive over the face and scalp
Stimulated by androgens and mature at puberty
21. Sebaceous Glands
Consists of lobules of epithelial cells that differentiate toward lipid
producing cells in a centripetal manner
Enlarged, vacuolated cells in the center of the lobule disintegrate into
an amorphous mass – the sebum
Major components of sebum : Triglycerides, wax esters, squalene,
cholesterol esters, and cholesterol
Acne, Rosacea, Seborrheic dermatitis
22. Sweat Glands
Depending on mode of secretion these are –
Eccrine sweat glands and Apocrine sweat glands
Apo-eccrine glands have features of both
All have 2 parts
• Secretary coil
• Duct
23. Eccrine Sweat Glands
These are present all over body except over the lips, external ear canal
and labia minora
Most concentrated in the palms, soles and axillae
The secretary coil lies deep in the dermis that connects with the
surface by a duct
Major role is in Thermoregulation
Control of sweating
Innervated by sympathetic cholinergic nerve fibers
The central control of sweating lies in preoptic hypothalmic sweat
centre
Temperature, Emotions, Hormones (antidiuretic hormone,
aldosterone), Gustatory (hot spicy foods)
24. Apocrine Sweat Glands
These are mainly present in axillae, nipples, peri-umblical skin,
perineum and genitalia
Modified apocrine glands are -Ceruminous glands (external ear canal),
Moll’s glands (eyelids) and Mammary glands
The secretary coil lies at junction of dermis and subcutis
The duct opens into the mid part of hair follicle just above the
entrance of sebaceous gland
Innervated by adrenergic sympathetic nerve fibers
Vestigial sexual function and represent Scent glands
25. Dermis
Constitute 15-20% of body weight
Papillary dermis - thin zone beneath epidermis
Reticular dermis - thick zone which extends from base of papillary
dermis to the surface of subcutaneous fat
The upward projection of dermis, the dermal papillae, strongly inter
digitate with the downward , the rete pegs, of epidermis to form
Dermo-epidermal junction.
3 components : Cells, Fibers and Ground substance.
26. Dermis - Structure
Cellular contents
Fibroblasts, mast cells, histiocytes, Langerhans cells, lymphocytes and
eosinophils
Non-cellular connective tissue
Collagen (80%), elastic fibers (2%) and ground substance
(mucopolysaccharides, glycoproteins, chondroitin sulphate)
Embedded nerves, blood vessels, lymph vessels, muscles and pilo
sebaceous, apocrine and eccrine units
27. Dermis - Variation in thickness
Difference of thickness of the skin is dependent largely on dermal
thickness, with the palms and soles being thickest (1.5 mm) and
thinnest in the eyelids and post-auricular region (0.05 mm).
Males have thicker skin than females
Children and elderly have thinner skin than adults
29. Dermo-epidermal Junction
Functions
Attachment of dermis to epidermis
Mechanical support to epidermis
Regulation of permeability for nutrients and exogenous substances
Influence growth, differentiation and migration of basal keratinocytes
Autoantibodies to proteins in the dermo-epidermal junction
responsible for Bullous pemphigoid
Inherited defect in Epidermolysis bullosa
30. Nerves & Innervation
Rich network of nerves with 2 types of sensory endings – ‘The
Corpuscles (Mecahno-receptors)’ and ‘Free nerve endings
(Nociceptors)’
Mechano-receptors
Light touch : Merkel cells of the epidermis, Meissner’s corpuscles in
dermal papillae
Pressure : Pacinian corpuscles in deep dermis or subcutaneous tissue
31. Nerves & Innervation
Nociceptors
Pain and Itch : Transmitted through naked fine free nerve endings
located in the basal layer of the epidermis close to the dermo-
epidermal junction
Temperature :
• Krause bulbs detect cold, Ruffini end organs detect heat
• Heat, cold and proprioception also located in the superficial dermis
Adjacent dermatomes often overlap, important for local anesthesia
32. Blood & Lymphatic Supply
Extensive subdermal and dermal plexuses
Dermal plexus: 2 horizontal plexuses connected by vertical
communicating vessels–
Superficial horizontal plexus lies in the papillary dermis, feeding
arterioles/capillary loops in dermal papillae
Deep horizontal plexus lies deep just above the subcutis, supplies
to sweat gland and hair follicles
Cutaneous vasculature important in thermoregulation
Cutaneous lymphatics parallels the blood supply
36. Macule
Definition: Circumscribed alteration in the colour of the skin of any size or
shape that is non-palpable and without depression and has no alteration
in the skin texture or scaling within the lesion
Macule > 1-2cm in diameter is “LARGE MACULE”
Macule > 2cm in diameter is “AREA”
Margins can be well defined or ill defined
Shape can be circular, oval, or irregular
Colour of Macule : Erythematous, Hypopigmented (e.g. Nevus
hypochromicus), Hyperpigmented (e.g. Melasma), depigmented (e.g.
Vitiligo)
39. Papule
Definition : Small, solid, elevated, palpable lesion up to 0.5 cm in size
formed either by localized proliferation of tissue cells or infiltration with
inflammatory cells.
Papules sized 1-2 mm are called “Micropapules”
Shape : Sessile, Pedunculated, Dome-shaped, Flat-topped,
Filiform, Acuminate, Umbilicated
41. Nodule
Definition : Solid, elevated, palpable lesion >0.5 to 1 cm in size formed
either by localized proliferation of tissue cells or infiltration with
inflammatory cells.
A nodule sized >1.0 cm is better be called a “Large nodule”
Shape : Ellipsoid or Globular, Pedunculated or Sessile
Surface : Smooth, Keratotic, Ulcerated, or Fungating
Types : Depending anatomical component involved -
Epidermal, Epidermal-dermal, Dermal,
Dermal-subdermal or Subcutaneous
Other features : Depending on underlying pathology –
Warm, Hard, Soft, Fluctuant, Tender, Movable, or Fixed
Examples : Neurofibroma, Leprosy, Erythema nodosum
42. Papules and Nodules of varied Morphology
and Size in neurofibromatosis
Shiny, Pearly Umblicated Papules
in Molluscum contagiosum
43. Plaque
Definition : Solid, elevated, palpable lesion >1 cm in diameter with a flat
plateau like surface. =
Plaque sized >2cm are “Large plaques”
Shape : Round, Oval, Discoid (uniformly thickened), or Annular with
regular or irregular borders
Types : Depending on anatomical component involved –
Epidermal, Epidermal-dermal, Dermal,
Dermal-subdermal or Subcutaneous
Surface changes : Depending on underlying pathology –
Scaling, Necrosis, Erosion, Ulceration, Crusting, Eschcar formation
Examples : Psoriasis, Leprosy, Granuloma annulare
45. Vesicles and Bulla (Blister)
Definitions :
Vesicle: An elevated fluid-filled lesion
sized < 0.5 cm
Bulla: Fluid filled lesion sized > 0.5 cm
Formation : Vesicles or bullae arise from the
cleavage at either intraepidermal or sub
epidermal level by -
• Formation of cavity
• Collection of fluid
In Bulla, the fluid in the cavity exerts
equal pressure in all directions giving
spherical shape
Contents of vesicle: Clear, Serous, Turbid,
Haemorrhagic
Examples : Herpes simplex, Pemphigus,
Scalds, Bullous pemphigoid, eczema
46. Pustule
Definition : A circumscribed raised Pus
filled lesion.
Pustules may vary in size and in
certain conditions like pustular
psoriasis they may coalesce to give
“lake of pus” appearance
Purulent exudate contain : either cellular
debris, leukocytes, or bacteria or may be
sterile
They can be located at the opening of
hair follicles as in folliculitis
Pustules are superficial- heal without
scarring
Examples : Bacterial (folliculitis), Pustular
psoriasis Pustules in pustular psoriasis
47. Cyst
Definition : A closed cavity or sac
(normal or abnormal) that has an
epithelial, endothelial or
membranous lining and contain
fluid or semisolid material
Examples : Sebaceous cyst,
Epidermal cyst (Milia), Pilar cyst
Abscess
Definition : It is localized
accumulation of pus deep in dermis
or sub cutis. Usually not visible on
the surface of skin.
It is erythematous, warm, tender,
fluctuant nodule
From Staphylococcal, Streptococcal
infections
49. Scale
It is visible exfoliation of flake of
stratum corneum
Morphology varies with type of skin
disease
Examples –
• Silvery, loose scales - Psoriasis
• Fine powdery scales - Pityriasis
versicolor
• Fish-like scales - Ichthyosis
• Collarette scales - Pityriasis
rosea, Seborrhoeic dermatitis
Ichthyotic Scales
50. Crust
Crust is dried up exudates (blood,
serum, pus)
Removal of crusts leave moist
surface/ erosion beneath
Colour of crust varies with nature of
exudate:
• Yellow-brown - dried serous
secretions
• Turbid yellow-green - purulent
secretion
• Reddish black - hemorrhagic
secretion
Hemorrhagic Crusts
51. Erosion
Raw, moist lesion left from a
complete or partial loss of epidermis
or mucosal epithelium
Results from trauma, rupture of
vesicles or bullae, or epidermal
necrosis
Heal without scar unless secondarily
infected
Examples : in Pemphigus, SJS-TEN
Erosions in a Pemphigus patient
52. Ulcer
Ulcer forms from breach and
destruction of skin (epidermis,
dermis with basal layer, adnexal
structures) or Mucosa
Heals with scarring.
May be superficial or deep.
Margins of ulcer : overhanging-
tubercular Punched out - gumma
Light pink granulation tissue at floor-
healing
Ulcer
53. Excoriations
Linear or circumscribed erosions
formed from surface excavations of
epidermis due to scratching
Frequent finding in patients having
disorders with pruritus
Linear and punctate excoriations on
the back induced by scratching.
54. Fissure
It is a linear, triangular crack in the
skin/mucosa
Results from excessive tension or
decreased elasticity of the involved
tissue
Can be superficial or deep
Deep fissures are painful
Common over palms and soles due
to thick Stratum corneum
Examples : In Palmoplantar
psoriasis, Keratodermas, Irritant CD
Fissures of heels
55. Sinus
It is a tract connecting a deep cavity
to the surface of the skin
Contents of the deep cavity are
usually pus, epithelial debris
These contents drain to the surface
when such a channel exits
Multiple sinuses in Nocardiosis
56. Scar
It is the proliferation of fibrous
tissue that replaces the normal
collagen after the ulcer involving the
reticular dermis heals
Epidermis is thinned and wrinkled,
and adnexa like hair are destroyed
Hypertrophic scars : typically take
form of plaques or nodules. It does
not grow beyond the limit of original
lesion
Keloid : exceeds the limit of original
lesion
Keloid
57. Lichenification
Definition : Thickening of skin due to
repeated and prolonged rubbing/
scratching of skin characterized by:
Thickening of epidermis/dermis
Accentuated of skin markings
Hyperpigmentation
Examples : Lichen simplex chronicus
(LSC), Lichenified chronic (atopic)
dermatitis
Lichenification (LSC)
58. Atrophy
Definition : A loss of cutaneous mass
from diminution in size of any of the
components of skin.
Epidermal atrophy: Glossy,
transparent, cigarette-paper like
thinning and wrinkling, loss of
normal skin lines
Dermal atrophy: Circumscribed area
of depressed skin, normal in colour
and surface
Subcutaneous atrophy: Substantial
depression of skin
Epidermal atrophy
60. Erythema and Purpura
Erythema : Blanches redness of skin, and
is due to vascular congestion or increased
perfusion e.g. Facial erythema in Rosacea,
Purpura : Non-blanching reddish to
purple discolouration of skin due to
extravasation of RBCs in dermis e.g.
Vasculitis, Bleeding disorders
Petechiae : 1-2 mm small pupuric lesions,
Occur in crops e.g. Clotting disorders
Ecchymosis : Larger purpuric lesions from
extrvasation of blood
Diascopy : differentiates erythema from
purpura
Vasculitis- purpura
61. Wheal (Hives, Urticaria) & Angioedema
Definition : An evanescent (lasting 48-72 hrs) erythematous, elevated
lesion due to edema of dermis (Wheal) frequently with central pallor,
or dermo-hypodermis with loose dermal tissue e.g. lips, eyelids,
scrotum (Angioedema)
Results due to vasodilatation and increased permeability of dermal
capillaries leading to edema
Specific of Urticaria
62. Burrow
Definition : It is wavy, thread like tunnel excavated in the stratum
corneum by Scabies mite
It measures only few mm in length
Characteristic of Scabies and particularly seen over palms and soles,
wrists, and genitalia in infants and very young children
63. Comedo (Pl. Comedones)
Definition : A dilated pilosebaceous
orifice plugged by keratin and sebum
Open Comedo : Pilosebaceous
opening is open to the surface of
skin by black keratinous plug
Closed Comedo : Closed
pilosebaceous opening is
unapparent, accumulates the
whitish keratin
Characteristic and primary lesion of
acne
Comedones in acne
64. Milium
Definition : A tiny white superficial cyst
with epidermal lining containing
lamellated keratin.
Sometimes arise on blistered or
damaged skin e.g. after dystrophic
epidermolysis bullosa, Porphyria,
Dermabrasion.
65. Telangiectasias
Definition : Visible and persistent
dilatations of small capillaries in the
superficial dermis that appear as fine,
bright non-pulsatile, net like pattern on
the skin
May or may not disappear with
diascopy
Types : Mat-like, Punctate, Linear
Examples : In - rosacea, Collagen
vascular diseases
66. Sclerosis
Definition: A diffuse induration and hardening of skin due to dermal
fibrosis. The skin feels firm board like, immobile and difficult to pick up
Examples: Morphea, Systemic sclerosis.
67. Poikiloderma
Definition : A dappled appearance of
skin from combination of atrophy,
telangiectasia, and pigment changes
(hypo or hyperpigmentation)
Example : Rothmund Thompson
syndrome, Xeroderma pigmentosa
Poikiloderma in Xeroderma
pigmentosa
68. Target Lesions
Definition : These have 3 zones:
Central: dusky, blistered or purpuric
zone
Middle: pale zone of edema
Outer: Erythematous zone with well
defined edge
Example : Erythema multiforme
69. Further Description
Shape of lesions : The shape of each lesion - Dome-shaped, Flat
topped, Umbilicated, Acuminate, Pedunculated, Verrucous,
Distribution of lesions : The overall distribution of lesions - Scattered,
Disseminated, Wide spread, Confluent, Symmetrical or Asymmetrical,
Acral
Pattern of lesions : The arrangement of individual lesions - Annular,
Arcuate, Linear, Grouped, Discoid, Reticulate, Gyrate,
Colour of skin and of lesions : e.g. Purplish (LP), yellowish
(xanthoma), etc
70. Further Description
Arrangement : Linear, Grouped, Dermatomal, Serpiginous
Zosteriform : Grouped vesicles arranged in a dermatome
Corymbose : grouped arrangement with a central cluster of lesions
beyond which are scattered individual lesions
Un-patterned grouped lesions : As in Verruca plana, Lichen planus,
Urticaria, Insect bites(often in groups of three).
Spared areas : As in Photodermatitis
71. MCQ’S
Q.1) One Keratinocyte-Melanin Unit comprises
A. One melanocyte and 10 keratinocytes
B. One melanocyte and 36 keratinocytes
C. One melanocyte and 40 keratinocytes
D. None of the above
E. Answer “A” and “B” above are correct
Q.2) Langerhans cells -
A. are non-dendritic cells
B. are a fine touch receptors
C. are involved skin immune surveillance
D. are Neuritic cells
E. detect mechanical deformities of epidermis
72. MCQ’S
Q.3) Average hair loss is?
A. About 200 per day
B. About 100 per day
C. No hair are shed normally
D. All are true
E. None is true
Q.4) Eccrine sweat gland are most concentrated over
A. Trunk
B. Extremities
C. Scalp
D. Palms, sole and axillae
E. Groins
73. MCQ’S
Q.5) Downward projections of epidermis are called?
A. Reticular dermis
B. Papillae
C. Rete pegs
D. Stratum spinosum
E. Stratum corneum
74. Q. Identify the lesion over forehead of the child in the image?
Photo Quiz