The document summarizes key aspects of the integumentary system including the skin, hair, nails, and glands. It describes the two main layers of the skin - the epidermis and dermis, and provides details on their structure and functions. Important topics like skin color, friction ridges, flexure lines, aging changes, and common skin conditions are concisely discussed.

1. The Intgumentary system: Skin,
superficial & deep fascia
 Author: Dr. A. Bose
Associate Professor
Department Of Anatomy
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2. Introduction
 Cutis (L), derma(G), Integument
 Largest organ of the body
 Surface area of skin-1.5-2 sq.mtr.
(A= W X H X 71.84)
 General covering of whole external
surface of body.
 Continuous with mucus membrane at
orifices of body
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3. 3

4. The Integument
The skin covers your body.
Skin is also known as the cutaneous
membrane.
Integumentary system consists of the
skin and its derivatives—nails, hair,
sweat glands, and sebaceous glands.
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5. The Integument
Is the body’s largest organ.
Its surface is covered by an epithelium that
protects underlying body layers.
The connective tissues contain blood vessels
that provide nutrients and provide
strength and resilience to the skin.
Smooth muscle controls both blood
vessel diameter and hair position.
Neural tissue supports and monitors
sensory receptors in the skin
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6. 2 Distinct Layers
 A layer of stratified squamous epithelium
called the epidermis.
 A deeper layer of dense irregular connective
tissue called the dermis.
 deep to the dermis is a layer of areolar and
adipose connective tissue called the
subcutaneous layer, or hypodermis
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7. 7

8. Thick Skin
Thick epidermis is found on the
palms of the hands, the soles of the
feet, and corresponding surfaces of the
fingers and toes.
All five epidermal strata occur in thick
skin.
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9. Thin Skin
Thin epidermis covers most of the
body.
Lacks the stratum lucidum
Has only four specific layers.
Contains the following accessories:
hair follicles, sebaceous glands, and
sweat glands.
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10. Functions of Skin
Protection
Prevention of water loss
Temperature regulation
Absorption
Secretion- sweat, sebum
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11. Functions of Skin
 Sensory reception
 Excretion
 Synthesis of vitamin D
 Regulation of pH
 Storage of chlorides
 Reparative –of wounds
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12. Skin Color
 Hemoglobin is an oxygen-binding protein
present in red blood cells. Upon binding
with oxygen, hemoglobin exhibits a bright
red color.
 Melanin is a pigment produced and stored
in cells called melanocytes.
 The two types of melanin occur in various
yellow, reddish, tan, brown, and black
shades
 Carotene comes primarily from diet.
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13. Skin pigments
 Atleast 5 pigments at different levels of skin:
 Melanin- brown-in germinative zone of
epidermis
 Melanoid- like melanin
 Carotene- yellow to orange- in stratum
corneum & fat cells of dermis
 Haemoglobin-purple
 Oxyhaemoglobin-red
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14. Friction Ridges/papillary ridges
 Found on the fingers, palms, soles, and toes.
 Formed from large folds and valleys of both
dermal and epidermal tissue.
 Help us grasp objects, and they
 Increase friction so that items do not slip
easily from our hands.
 Our feet do not slip on the floor when we
walk.
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15. Friction Ridges/papillary ridges
Friction ridges can leave noticeable
prints on touched surfaces.
Each individual has a unique pattern of
friction ridges.
Fingerprints have become a valuable
tool for law enforcement in identifying
individuals.
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16. Flexure lines(Langer lines) /skin
creases/skin joints
 Permanent lines along which the skin folds
chiefly during flexion of joints
 Skin here is thin and firmly bound to deep
fascia
 Very prominent opposite flexure of joints,
specially on palms , soles & digits
 Are longitudinal in limbs &horizontal in
trunk & neck
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17. Lines of Cleavage
Tension lines in the skin identify the
predominant orientation of collagen
fiber bundles.
Clinically and surgically significant
because cuts can result in slow healing
and increased scarring.
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18. Importance of Langer’s lines
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19. Skin Markings
 Nevus (mole)
 Freckles
 Hemangioma
 capillary hemangiomas (“strawberry-
colored birthmarks”)
 cavernous hemangiomas (“port-wine
stains”)
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20. Layers of the Dermis
Composed of
Cells of the connective tissue
proper and
Primarily of collagen fibers,
although both
Elastic and reticular fibers are also
present.
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21. Layers of the Dermis
 Other components of the dermis are
 Blood vessels,
 Sweat glands,
 Sebaceous glands,
 Hair follicles,
 Nail roots,
 Sensory nerve endings, and
 Muscular tissue.
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22. 2 Major Regions of Dermis
 Superficial papillary layer
 Deeper reticular layer
 Dermis is the real skin
 When dried it makes green hide
 When tanned it makes leather
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23. Innervation and Blood Supply
 The dermis has extensive innervation.
 Monitor sensory receptors in the dermis and
epidermis, and control both blood flow and gland
secretion rates.
 Tactile corpuscles and tactile (Merkel) cells
perceive touch sensations, and work with a variety
of other sensory nerve endings in the skin.
 This rich innervation allows us to be very aware of
our surroundings and to differentiate among the
different kinds of sensory signals from receptors in
the skin.
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24. Nails
 Scale like modifications of the epidermis
that form on the dorsal surfaces of the tips
of the fingers and toes.
 Protect the exposed distal tips and prevent
damage or distortion during jumping,
kicking, catching, or grasping.
 Hard derivatives formed from the stratum
corneum layer of the epidermis.
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25. 25

26. 26

27. Applied Anatomy of nails
• In anaemia nails pale, thin, brittle, spoon
shaped(koilonychia)
• In chronic lung diseases-Hypertrophy of
nail bed (clubbing)
 In cardiac diseases- blue nails(cyanosis)
 Rate of nail growth- 0.1 mm/day
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28. Hair
 Found almost everywhere on the body
except the palms of the hands, the sides and
soles of the feet, the lips, the sides of the
fingers and toes, and portions of the
external genitalia.
 Most of the hairs on the human body are on
the general body surface rather than the
head.
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29. Parts of hair
 Implanted part – root
 Projecting part – shaft
 Root surrounded by hair follicle & expanded
to form hair bulb
 Arrectores pilorum muscles connect under
surface of follicles to superficial part of
dermis
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30. 30

31. 3 Kinds of Hair
 During our lives, we produce three kinds of
hair:
 Lanugo(primary hair)
 vellus (Secondary hair)
 terminal hair
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32. Functions of Hair
 Protection
 Heat retention
 Prevents the loss of conducted heat from the scalp
to the surrounding air
 Facial expression
 Sensory reception
 Visual identification
 Chemical signal dispersal
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33. Hair Color
 Result of the synthesis of melanin in the
matrix adjacent to the papillae.
 Variations in hair color reflect genetically
determined differences in the structure of
the melanin.
 Environmental and hormonal factors
 Age
 Gray hair
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34. Hair Growth and Replacement
 Sometimes hair loss may be temporary as a
result of one or more of the following
factors: exposure to drugs, dietary factors,
radiation, high fever, or stress.
 Thinning of the hair, called alopecia can
occur in both sexes, usually as a result of
aging.
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35. Applied Anatomy of hair
In mal nutrition-hairs thin sparse & dry
In hypothyroidism-hair is coarse & dry
Excessive growth of hair- hirsutism
Loss of hair- alopacia
Rate of hair growth is 1.5-2.2mm/week
Life span of hair- 4months to 4 years
Foetal hair is fine- called lanugo hair.
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36. Exocrine Glands of the Skin
Sweat (sudoriferous) glands produce
a watery solution that performs
several specific functions.
 Merocrine (eccrine) sweat glands
 Apocrine sweat glands
Sebaceous glands produce an oily
material that coats hair shafts and the
epidermal surface. 5-36

37. 37

38. Other Integumentary Glands
Ceruminous glands
Mammary glands
modified apocrine sweat glands
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39. Aging of the Integument
Skin repair processes take longer due to
reduced number and activity of stem cells.
Skin forms wrinkles and becomes less
resilient.
Skin’s immune responsiveness is
diminished.
Skin becomes drier due to decreased
sebaceous gland activity.
Altered skin and hair pigmentation.
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40. Aging of the Integument
Sweat production diminishes.
Blood supply to the dermis is reduced
leading to impaired thermoregulation.
Hair thinning and loss.
Integumentary production of vitamin
D3 diminishes.
Development of skin cancers.
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41. Skin Cancer
The most common type of cancer.
The greatest risk factor is exposure to
UV rays of the sun.
The highest incidence is in people who
have had severe sunburns, especially as
children.
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42. Applied anatomy of skin
 Skin dry in ‘Datura’poisoning,heat stroke,
diabetic coma
 Unusually moist in hypoglycemic coma,
heart failure
 Abnormally dry skin- Ichthyosis
 Excessive oilyness- seborrhoea
 Acne vulgaris- skin infection due to
seborrhoea
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43. Applied anatomy of skin
Dermatitis/ eczema
Albinism
Herpes zoster
Pressure sores
Benign pigmented mole / naevus
Boil
Sebaceous cyst
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44. Applied anatomy of skin
Keloid
Fungal infection of skin
Vitiligo- white patches on skin
Baldness
Scabies
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