The skin has three main layers - the epidermis, dermis and hypodermis. The epidermis is the outermost layer and provides a protective barrier. It has five sublayers including the stratum corneum. The dermis lies beneath the epidermis and contains hair follicles, sweat glands, vessels and nerves. The hypodermis is made of adipose and connective tissue and contains larger blood vessels and nerves. The skin functions to protect the body, regulate temperature, produce vitamin D, detect sensations and store fat.

1. STRUCTURE AND FUNCTION OF SKIN
Prepared by
Suman Das
Roll no.:- 29
B.Pharm 8th semester
Dept. of pharmaceutical Sciences
Dibrugarh University
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2. CONTENTS
 INTRODUCTION TO SKIN
 STRUCTURE OF SKIN
 FUNCTION OF SKIN
 BIBLIOGRAPHY
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3. INTRODUCTION
 Skin is the body’s largest and primary protective organ
 It covers entire external surface of the body
 It has a surface area about 1.5-2 m2
 It contains accessory glands, hairs and nails
 Serves as 1st order physical barrier against the environment
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4. STRUCTURE OF SKIN
Contd……
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5.  skin is made up of 3 layers
 Epidermis: The outermost layer of skin, provides a water barrier and contributes
to skin tone
 Dermis: Found beneath the epidermis, contains connective tissue, hair follicles,
blood vessels, lymphatic vessels and sweat glands
 Hypodermis: Deep to the dermis, not exactly the part of skin, it is the
subcutaneous layer comprising of areolar and adipose tissue. Also contains larger
vessels and nerves.
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6. 1. STRATUM CORNEUM
Most differentiated top superficial
layer, consists of 25-30 layers of
flattened keratinocytes that contains
mostly keratin
2. STRATUM LUCIDERM
Lies below the stratum corneum.
It is only present in the thick skin
of fingereprints, palms and soles
3. STRATUM GRANULOSUM
Middle and superficial layer of
the epidermis. It is non-
keratinized. 1-3 cells thick
spindle shaped cells enriched
with keratohyaline.
4. STRATUM SPINOSUM
This layer contain 8-10 layers of
cells. The cells have lots of
desmosomes, which anchors the
cells to each other.
5. STRATUM GERMINATIVUM
It is the deepest layer of
epidermis. Cells are non-
nucleated. This layer contain
melanocytes.
EPIDERMIS
It composed of stratified keratinised squomous epithelium, it contains four principle type of
cells such as keratinocytes(90%), melanocytes, langerhans cells and merkel cells.
It is divided into 5 distinct layers
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7. DERMIS
 Dermis is the second deepest region lying in betweeen Epidermis and
Hypodermis
 It is formed from connective tissue containing collagen and elastin fibres
 The principal cells found in this layer are fibroblasts, macrophages and
adipocytes
Blood vessels, nerve fibre and hair follicles are embedded in this layer
The superficial portion dermis called papillary layer , consist of areolar
connective tissue containing elastin fibres
 the surface area is greatly increased by small finger like projections called
dermal papilae
 this dermal papilae contain tactile receptors called corpuscles of touch or
meissner corpuscles that are sensitive to touch
 The reticular region of dermis attached to the hypodermis consist of dense
irregular connective tissue, collagen and elastic fibres
This collagen and elastin fibres provides strength, extensibility and elasticity to
the skin
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8. HYPODERMIS
 It is the subcutaneous layer which lies deep to the dermis
It is not part of the skin
 This layer consist of areolar and adipose tissue
 This layer also contains nerve endinngs called
lamellate(panician) corpuscles that are sensitive to pressure
 It serves as storage for fat
 Contains large blood vessels that supply the skin
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9. FUNCTIONS OF SKIN
2. SENSONY FUNCTION: Free nerve endings on the skin are
sensitive to pain, touch, heat and cold.
1. PROTECTION: acts as a barrier preventing entry of
pathogens
3. TEMPERATURE REGULATION: Regulation of body
temperature at about 36.9o
with a variation 0.50 and 0.750 is
one of the important function
4. PRODUCTION OF VITAMIN D: Sunlight action on fatty
tissue within skin causes the production of vit. D, essential
for calcium absorption from the diet.
5. OTHER : Storage of fat, excretion of water, salts and very
small amout of urea
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10. BIBLIOGRAPHY
 https://www.ncbi.nlm.nih.gov/books/NBK470464/ (29/04/2022; 12.10 A.M.)
 https://www.slideshare.net/docjikisha/structure-of-skin-124339625
(29/04/2022; 3.15 P.M.)
 A text book of cosmetic science; Dr. Aijaz Sheikh, Dr. Subhash Deshmane et
al.; S.Vikas and Company; 2019; 1st edition; page no.:- 29-35
 Cosmetic Sciences: concepts and principles; Dr. Kamala pathak, Dr. Ankur
Vandya; Nirali Prakashan; 2018; 1st edition; page no. 4.1- 4.5
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