Name some functions of the skin.
Protection, Sensation, Thermo-regulation and Homeostasis, Metabolism of Vitamin-D, Excretion of Salts and Wastes
Epidermis consists of what four cell types?
Keratinocytes, Melanocytes, Langerhans Cells, Merkel Cells
Produce keratin, a protein that hardens and waterproofs the skin. Mature keratinocytes at the skin surface are dead and filled almost entirely with keratin
Produce Melanin, a pigment that protects cells from ultraviolet radiation. Melanin from the melanocytes is transferred to the keratinocytes.
Phagocytic microphages that interact with white blood cells during an immune response.
They occur at the epidermis-dermis boundary. They form merkel discs which, in conjunction with nerve endings, serve a sensory function.
The five layers of the epidermis:
Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, Stratum Basale
Function of the Dermis:
Provides strength, extensibility (stretchability), elasticity (ability to return to original form).
A thin, outer layer of the dermis with finger like projections called dermal papillae that protrude into the epidermis. The dermal papillae create epidermal ridges, which are responsible for finger prints.
Hypodermis (Subcutaneous Layer):
Layer between the dermis and underlying tissues and organs. Storage site for most body fat.
Functions of the Hypodermis:
Thermal Insulation, Shock Absorption, fastens skin to underlying surface
Elongated filaments of keratinized epithelial cells that arise and emerge from the skin of mammals.
Bottom of the hair follicle located inside the bulb where cells actively divide, producing new cells and causing hair growth.
Smooth muscle that is attached to the hair follicle. Muscle contracts, hair becomes erect, goosebumps are produced.
Sudoriferous (Sweat) Glands
Secrete sweat. Sweat consists of water, various salts, and other substances
Four Types Of Sudoriforous Glands:
Eccrine Glands, Apocrine Glands, Ceruminous Glands, Mammary Glands
Glands under most skin surfaces that secrete a watery substance through the pores, which serves to cool the skin as it evaporates
Found under skin surfaces of the armpits and pubic region, these glands secrete a solution into the hair follicles in response to stress and sexual excitement.
Secretes cerumen (ear wax) into the external ear canal. wax helps impede entrance of foreign bodies.