2. Main functions
Multiple roles in homeostasis
(e.g. temperature change, dehydration)
Protects against invasion of infectious organisms, sunburn
Protects the body’s internal tissues and organs
Maintains the body’s form
Generates vitamin D
Stores fats, water, glucose and vitamin D
4. Skin
It's your body's largest organ
Average surface area 1.8-2.0m² (19.4-21.5ft² )
Releases around three gallons of sweat in a hot day
There are at least five types of receptors in the skin that
respond to pain and to touch
White skin appeared just 20,000 to 50,000 years ago, as
dark-skinned humans migrated to colder climes and lost
much of their melanin pigment.
5. Three layers or structures of the skin
Epidermis
Dermis and hypodermis
Sweat and oil glands; hair and nails
8. Cells of epidermis
95% cells are keratinocytes
Major function is the defense against environmental damage
(pathogens, heat, UV radiation and water loss)
Melanocytes ( melanin-producing cells )
Langerhans cells (antigen-presenting immune
cells)
Merkel cells (oval receptor cells )
Inflammatory cells (a cell participating in the
inflammatory response to a foreign substance. )
9. First and last layers of epidermis
basal/germinal layer
Cell growth of keratinocytes, attached to basement
membrane. Melanocytes and Merkel cells also can be found
in this layer.
cornified layer
Keratinocytes are presented at final step of differentiation
(corneocytes), surrounded by keratin proteins envelope. Most
of the barrier function are here
11. Stratum papillare
This region is composed of loose connective tissue with
network of blood capillaries and Meissner's corpuscles
(type of mechanoreceptors sensitive to light touch)
Stratum reticulare
Is composed of dense irregular connective tissue with
collagen, elastic and reticular fibers (strength, extensibility,
and elasticity)
13. Hypodermis or
subcutaneous tissue
In hypodermis fibroblasts, adipose cells
and macrophages can be found
Is used mainly for fat storage
In arthropods, the hypodermis is an epidermal
layer of cells that secretes the chitinous cuticle
15. Sebaceous Glands
Secrete an oily/waxy
matter, called sebum,
to lubricate and
waterproof the skin
and hair
Greatest abundance on
the face and scalp
16. Sebaceous Glands Diseases
Acne
Hyperplasia - disorder of the sebaceous
glands in which they become enlarged
Sebaceous cysts
Sebaceous adenoma - a slow-
growing tumour
Sebaceous gland carcinoma -
aggressive malignant cutaneous tumor
18. Apocrine glands
produce a viscous and
odorous secretion.
They begin secreting at
puberty
discharge in the canals
of hair follicles
may also
contain pheromones
19. Eccrine glands
smaller than apocrine
sweat glands, and
they do not extend as
deep into the dermis
discharge their
secretions directly
onto the surface of
the skin
• highest density (>250 glands/cm2) being on soles,
palms, and scalp
20. Sweat Glands Diseases
Hidradenitis - The inflammation of a
sweat gland (usually of the apocrine type)
Hyperhidrosis - Excessive sweating
Hypohidrosis - diminished or absent
perspiration
Miliaria - A syndrome of cutaneous
changes associated with sweat retention
and extravasation of sweat at different
levels in the skin.
22. Ceruminous glands diseases
Benign tumors
(e.g. ceruminous adenoma - tumour of the
external auditory canal in adults, 1% of all
external ear tumors)
Malignant tumors
(e.g. Mucoepidermoid carcinoma - most
common type of malignancy in adults. Can
also be found in other organs, as bronchi,
lacrimal sac and thyroid.
24. Mammary Glands Diseases
Fat necrosis - firm nodule in the
breast
Fibrocystic change - most
common disorder
Gynecomastia - bilateral breast
enlargement in the male
Fibroadenoma: most common
benign tumor
Breast cancer - most common
type of cancer in women
25. Some other common Skin
Diseases
Melanoma
Eczema
Otitis Externa
Skin Cancer
26. Hair facts
The fastest growing tissue in the body
90% of scalp hairs are growing and 10% are resting
Female hair grows more slowly
Lifespan of hair: 2 to 7 years
A single hair has a thickness of 0.02 - 0.04mm
The average scalp has 100,000 hairs
It is normal to lose 100 hairs per day from the scalp
A single hair can support up to 100 grams in weight and a whole head of hair
could support up to 12 tonnes - the equivalent of two African elephants!
27. Hair Parts
the hair root
the hair shaft
Hair is composed primarily
of proteins (88%). These
proteins are of a hard fibrous
type known as keratin.
31. Hair diseases and disorders
Mainly associated with the follicles of
the hair
Hypertrichosis - an abnormal
amount of hair growth on the body
Alopecia Areata - one of the most
prevalent hair loss diseases
32. Nails
Actually the same as hair
Nails grow at the rate of 0.1 mm daily
Women's nails grow slowly
Toe nails are about twice thicker than finger nails
The fastest growing nail is on the middle finger.
The slowest – on the thumbnail
Nails reflect your health status
33. (I) Nail structure 6 parts:
The root (germinal matrix) - produces most of the
volume of the nail and the nail bed.
Nail bed (sterile matrix) - part of the nail matrix.
Contains the blood vessels, nerves, and melanocytes.
Adds material to the undersurface of the nail making it
thicker
Nail plate - actual
fingernail, made of
translucent keratin
34. (II) Nail structure 6 parts :
Eponychium (cuticle) – fuse
skin and nail plate, providing
waterproof barrier
Perionychium (paronychial
edge) - the skin that overlies
the nail plate on its sides
Hyponychium -the area
between the nail plate and the
fingertip
35. Nail diseases
Fungal infection
(Onychomycosis)
Beau's Lines
Nail Lifting (Onycholysis)
Nail Splitting
(Onychoschizia)
Bacterial infection
(Paronychia)
36. Integumentary System Functions
Multiple roles in homeostasis
(e.g. temperature change, dehydration)
Protects against invasion of infectious organisms, sunburn
Protects the body’s internal tissues and organs
Maintains the body’s form
Generates vitamin D
Stores fats, water, glucose and vitamin D
Skin
Hair
Nail