1. STRUCTURE AND FUNCTION OF SKIN
Prepared by
Suman Das
Roll no.:- 29
B.Pharm 8th semester
Dept. of pharmaceutical Sciences
Dibrugarh University
30-05-2022 1
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
30-05-2022 3
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.
30-05-2022 5
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
30-05-2022 6
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
30-05-2022 7
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
30-05-2022 8
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
30-05-2022 9
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
30-05-2022 10