Unit 4 Integumentary

Question 1

function

Answer 1

1. mechanical protection
2. protection from fluid loss
3. physical barrier
4. thermoregulation
5. receptor organ

Question 2

structure

Answer 2

1. epidermis
2. dermis
3. hypodermis (not truly skin)

Question 3

epidermis

Answer 3

a) from surface ectoderm

b) stratified squamous keratinized epithelium

Question 4

dermis

Answer 4

a) mostly from mesoderm

b) dense irregular connective tissue

Question 5

hypodermis

Answer 5

a) loose connective tissue

b) forms superficial fascia

Question 6

epidermis types

Answer 6

1. thick (glabrous; smooth, nonhairy)

2. thin (hairy)

Question 7

epidermis layers

Answer 7

1. stratum basale
2. stratum spinous
3. stratum granulosum
4. stratum lucidum
5. stratum corneum

Question 8

stratum basale

Answer 8

a) one layer thick
b) rests on basal lamina
c) highly mitotic
d) cuboidal to columnar cells

Question 9

stratum spinous

Answer 9

a) cuboidal cells
b) extensive desmosomes – “prickle cells”
c) tonofilaments – keratin

Question 10

stratum granulosum

Answer 10

a) keratohyalin granules – protein; no membrane
b) lamellar bodies – lipid; membrane-bound
(1) sealant effect; water proofing
(2) cells above die

Question 11

stratum lucidum

Answer 11

only in thick skin

Question 12

stratum corneum

Answer 12

a) dead cells
b) no organelles
c) high molecular weight keratin tonofilaments

Question 13

cells

Answer 13

1. keratinocytes
2. langerhan’s cells
3. melanocytes

Question 14

keratinocytes

Answer 14

predominant cell type

Question 15

langerhan’s cells

Answer 15

1. originate in bone marrow

2. antigen presenting cells

Question 16

melanocytes

Answer 16

a) from neural crest
b) make melanin
c) transfer melanin to cells of stratum basale and stratum spinosum

Question 17

epidermis pigmentation

Answer 17

1. blood
2. carotene
3. melanin

Question 18

dermis structure

Answer 18

1. dense irregular connective tissue
2. variable thickness
3. fibers – type I collagen and elastic; provide strength and elasticity
4. cells – fibroblasts and macrophages
5. ground substance rich in hyaluronic acid, dermatin sulfate and chondroitin
   sulfate

Question 19

dermis layers

Answer 19

1. papillary dermis

2. reticular dermis

Question 20

dermis blood supply

Answer 20

1. arterial plexuses and venous plexuses between papillary and reticular dermis and between reticular dermis and hypodermis
2. arteriovenous shunts can bypass superficial capillaries to conserve heat and increase blood pressure

Question 21

nerve endings

Answer 21

1. encapsulated

2. free

Question 22

encapsulated nerve endings

Answer 22

a) Meissner’s corpuscles

b) Pacinian corpuscles

Question 23

Meissner’s corpuscles

Answer 23

in papillary dermis; touch

Question 24

Pacinian corpuscles

Answer 24

deep dermis and hypodermis; deep pressure and vibration

Question 25

free nerve endings

Answer 25

a) fine touch; temperature

b) abundant around hair follicles

Question 26

eccrine sweat glands

Answer 26

1. wide distribution
2. simple, coiled tubular glands
3. secretory cells – simple cuboidal
4. duct – stratified cuboidal
5. merocrine secretion

Question 27

hair

Answer 27

1. in thin skin
2. hair follicle – epidermal origin
3. sebacous gland
4. arrestor pili muscle

Question 28

sebaceous gland

Answer 28

a) outgrowth of hair follicle
b) secretes sebum into follicle
c) holocrine secretion

Question 29

arrestor pili muscle

Answer 29

a) smooth muscle innervated by sympathetic division of ANS

b) contraction causes hair to stand up