LECTURE 1 integument

Question 1

functions of integumentary system (6)

Answer 1

protection (mechanical, thermal, chemical, UV, physical), cushions and insulates deeper organs, prevention of water loss, thermoregulation, excretion (salts, urea, water), sensory reception

Question 2

layers of the skin (3)

Answer 2

epidermis, dermis, hypodermis

Question 3

epidermis

Answer 3

most superficial, epithelium

Question 4

dermis

Answer 4

deep to epidermis/superficial to hypodermis, loose and dense CT, highly innervated, highly vascularized, collagen and elastic fibers

Question 5

hypodermis

Answer 5

aka subcutis or superficial fascia, most deep, loose CT, areolar and adipose CT, anchors skin to bone or muscle, stores fat, insulation

Question 6

skin appendages

Answer 6

outgrowths of epidermis (produced by epithelial cells), eg: hair follicles, sweat and sebaceous glands, nails

Question 7

cell layers of epidermis

Answer 7

stratum corneum: most superficial, dead keratinocytes; stratum lucidum: only in “thick” skin, dead keratinocytes; stratum granulosum: water proofing; stratum spinosum: resists tears and tension; stratum basale: most deep, regenerative germ layer, sensory receptors, melanocytes, keratinocytes

Question 8

keratinocytes

Answer 8

found in all layers of epidermis (alive or dead), if dead can protect by taking microorganisms off body’s surface when they fall off

Question 9

cell layers of dermis

Answer 9

papillary layer: 20%, areolar CT, collagen and elastic fibers, innervation, hair follicles; reticular layer: 80%, dense irregular CT, glands (usually exocrine), smooth muscle fibers, innervation