CHAPTER 5 INTEGUMENTARY SYSTEM Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
THE INTEGUMENTARY SYSTEM MADE OF SKIN, HAIR, NAILS & GLANDS. FUNCTIONS FOR:- PROTECTION. EXCRETION. TEMPERATURE REGULATION. SENSORY PERCEPTION VITAMIN D SYNTHESIS.
STRUCTURE OF THE SKIN EPIDERMIS IS THE THINNER OUTER LAYER COMPOSED OF STRATIFIED SQUAMOUS EPITHELIUM THAT FORM TWO CELL LAYERS. STRATUM CORNEUM:- SURFACE LAYER MADE OF DEAD FLAT KERATINIZED CELLS. STRATUM BASALE:- INNER LAYER THAT DIVIDE CONTINUOUSLY TO MAKE NEW CELLS.
STRUCTURE OF THE SKIN EPIDERMIS THE EPIDERMIS FORMS HAIR FOLICLES, HAIR, SEBACEOUS GLANDS AND SWEAT GLANDS THAT PENETRATE INTO THE DERMIS OR HYPODERMIS LAYERS. EPIDERMIS FUNCTION FOR PROTECTION AGAINST PATHOGENS, ULTRAVIOLET RADIATION & EXCESSIVE WATER LOSS.
Figure 05.01
STRUCTURE OF THE SKIN DERMIS THE THICKER INNER LAYER COMPOSED OF FIBROUS CONNECTIVE TISSUE THAT PROVIDE STRENGTH AND ELASTICITY. CONTAIN BLOOD VESSELS, NERVES AND SENSORY RECEPTORS. DERMAL PAPILLAE CONTAIN BLOOD VESSELS THAT SUPPLY NUTRIENTS TO THE EPIDERMIS AND PRODUCE THE FINGERPRINTS.
STRUCTURE OF THE SKIN
STRUCTURE OF THE SKIN HYPODERMIS IS NOT PART OF THE SKIN BUT CLOSELY ASSOCIATED WITH IT. COMPOSED OF LOOSE CONNECTIVE AND ADIPOSE TISSUE THAT ATTACHES THE SKIN TO THE UNDERLYING STRUCTURES. IT ALSO SERVES AS A HEAT INSULATOR AND A STORAGE SITE FOR FATS.
SKIN COLOR SKIN COLOR IS INHERITED & PRODUCED FROM THREE DIFFERENT PIGMENTS:- HEMOGLOBIN:- PINKISH CAUCASIAN SKIN. CAROTENE:- YELLOWISH ASIAN SKIN. MELANIN:- DARK SKIN IN COLORED RACES. MELANIN IS PRODUCED BY MELANOCYTES FOUND IN DEEPER EPIDERMIS LAYERS.
HAIR & HAIR FOLLICLES HAIR IS FORMED OF KERATINIZED CELLS THE SHAFT PROJECT ABOVE THE SKIN SURFACE. THE ROOT IS BELOW THE SKIN SURFACE IN A HAIR FOLLICLE. THE ARRECTOR PILI MUSCLE MAKE THE HAIR STAND & PRODUCE GOOSE BUMPS. THE SEBACEOUS GLANDS SECRETE OIL INTO THE HAIR FOLLICLES.
NAILS NAILS ARE MADE OF KERATINIZED CELLS CONSIST OF A BODY {VISIBLE PART} & A ROOT {INSERTED INTO THE DERMIS}. THE LUNULA IS THE WHITISH CRESENT-SHAPED AREA NEAR THE ROOT. NAILS ARE COLORLESS BUT APPEAR PINK DUE TO THE NAIL BED BLOOD VESSLES. NAILS FUNCTION IS PROTECTION.
SKIN GLANDS THREE TYPES OF EXOCRINE GLANDS ARE ASSOCIATED WITH THE SKIN:- SEBACEOUS GLANDS:- PRODUCE AN OILY SEBUM INTO THE HAIR FOLLICLE. SUDORIFEROUS GLANDS:- SWEAT. CERUMINOUS GLANDS:- EAR WAX.
TEMPERATURE REGULATION
CUTANEOUS MALIGNANT MELANOMA