Integumentary System (skin, hair, nails)

Question 1

what is it?

Answer 1

Epithelium tissue, a boundary between internal and external enviroments

Question 2

key characterstics (5)

Answer 2

1. Pliable
2. Tough
3. Stretchable
4. Waterproof
5. Self-repairing

Question 3

keratinised vs non keratinised

Answer 3

Keratinised: contains a layer of dead cells containing no nucleus + ketarin (skin)
Non-Keteranised: all live cells w. nuclei but no Ketarin found internally (pharynx, oesphagus, anus, vagina)

Question 4

anatomy of integument

Answer 4

1. Epidermis
2. Dermis
3. Subcutaneous tissue (hypo-dermis)

Question 5

role of integumentry system (5)

Answer 5

1. Protection
2. Sensory interaction
3. Metabolic functions
4. Excretion
5. Temperature regulation

Question 6

Function: Protection

Answer 6

provides a physical (waterproof, containing proteins and keratin to provide resistence to abrasion), chemical (melanin protecting against UV radiation, slightly acidic bacteria secetions preventing bacteria growth) and biological (immue cells )barrier

Question 7

Function: Sensory interaction

Answer 7

has sensory receptors which respond to: pressure, heat, pain, cold, touch, and displacement of hair-shafts

Question 8

Function: Metabolic

Answer 8

creation of Vit D from sunlight via reactions with modified chorlestrol in BVs, help regulate calcuim homeostasis

Question 9

Function: Excretion

Answer 9

secretion via sweat of nitrogen-containing waste (e.g. ammonia, urea, uric acid)

Question 10

Temperature set point

Answer 10

humans are petuathermatic and so must keep body temp in small range (arround 37degrees), homeostasis mechanisms help regulate temp

Question 11

when hyper-thermic

Answer 11

nervous system signals to dermal BVs to dialate and sweat glands to excrete

Question 12

when hypo-thermic

Answer 12

nervous system signals to dermal BVs to contrict and inactivate sweat glands, if continuing low temp nervous system will signal muscles to contract involuntarily (shiver) to generate heat

Question 13

Epidermis

Answer 13

stratified squamous epithelium, is constantly lost + replaced

Question 14

types of cells in epidermis (4)

Answer 14

keratinocytes, melanocytes, merkel cells, langerhans’ cells

Question 15

dermis

Answer 15

dense irregular connective tissue

Question 16

cells within dermis (4)

Answer 16

fibroblasts, macrophages, mast cells, WBC (which are surrounded by collogen, elastin, and reticular fibres)

Question 17

compoents of dermis (4) except cells

Answer 17

hair, BVs, Nerves, glands: sweat + oil