Integumentary System

Question 1

skin consists of…

Answer 1

epidermis: - epithelial tissue from ectoderm
- avascular

dermis: - CT from mesoderm
- nerves, glands + hair follicle
- vascular

Question 2

epidermis layers

Answer 2

1) stratum Basale: single layer
2) stratum Spinosum: several cell layers
3) stratum Granulosum: dark granular layer
4) stratum Lucidum: apparent in thick skin
5) stratum Corneum: outermost layer

Beautiful Skin Gets Lovely Compliments

Question 3

epidermis: stratum basale

Answer 3

• single layer furthest from outside (basal layer)
• 90% keratinocytes
• 8% melanocytes

Question 4

stratum spinosum

Answer 4

• several layer thick
• melatin granules scattered
• keratinocytes layered

Question 5

stratum granulosum

Answer 5

• dark granules

- 3-5 layers thick

Question 6

stratum lucidium

Answer 6

• in thick skin

- flat, dead cells (2-3 layers)

Question 7

stratum corneum

Answer 7

• outermost layer
• protection + moisture retention (waterproof)
• 30 layers
• flat filled with keratin

Question 8

thick + thin skin

Answer 8

thick: stratum lucidum present (clear layer)
- no hair follicle, hair or sebaceous glands

thin: has hair follicle, sweat glands + sebaceous glands

Question 9

dermis layer

Answer 9

• formed from CT proper
• consists of fibroblasts, fibrocytes + matrix

layers:
1) papillary
2) reticular

Question 10

papillary layer

Answer 10

• loose, areolar CT
• dermal papillae: upwards projections into epidermis
• vascular
• dermal ridges > epidermal ridges > fingerprints

Question 11

dermis: reticular layer

Answer 11

• deepest of the dermis
• 80% of dermis
• dense irregular CT
• stretching > tear in dermis > stretch marks

Question 12

hypodermis

Answer 12

• subcutaneous layer
• connective tissue below skin
• contains half of body’s adipose
  superficial fascia: binds skin to muscle

Question 13

skin colour

Answer 13

• melanin (melanocytes) formed in stratum basale + spinosum
• sun stimulates melanin production
• pink tinge comes from hemoglobin in vascular layer

Question 14

hair

Answer 14

• dead keratinized cells

- shaft is above surface > keratinization complete

Question 15

hair follicle

Answer 15

• hair bulb at deepest point
• in dermis

hair papilla: dermal tissue produces hair bulb (knot of capillaries)

Question 16

nails

Answer 16

• keratinized epidermal cells from stratum corneum

Question 17

sebaceous gland

Answer 17

• produce sebum

- connected to hair follicle

Question 18

ceruminous gland

Answer 18

• modified sweat gland in ear

- produce ear wax

Question 19

mammary gland

Answer 19

• modified sweat gland

- produce milk

Question 20

sudoriferous gland

Answer 20

• produce sweat (contains lysosome > antibiotic)

- removes waste such as urea

Question 21

cutaneous sense receptors

Answer 21

• nerve ending of sensory neurons

- touch receptors, pressure receptor, thermoreceptors, nociceptors

Question 22

touch receptors

Answer 22

• free nerve endings in epidermis

meissner’s corpuscles: in dermal papillae

Question 23

pressure receptors

Answer 23

• free nerve endings respond to pressure

pacinian corpuscles: dermis of hypodermis

Question 24

thermoreceptors

Answer 24

• free nerve endings

- detect cold more than hot

Question 25

nociceptors

Answer 25

• detect pain

- free nerve endings