Skin

Question 1

functions of skin?

Answer 1

1. barrier
2. prevent dehydration
3. largest sensory organ
4. thermoregulation
5. metabolic functions
6. immune functions
7. communications.

Question 2

what are the layers of skin?

Answer 2

epidermis, dermis, subcutaneous layer (hypodermis)

Question 3

Features of epidermis?

Answer 3

avascualar.

Question 4

Features of dermis?

Answer 4

blood vessels, nerves, hair follicles, sweat glands.

Question 5

features of hypodermis?

Answer 5

fatty layer, adipose tissue, energy reserve, thermoregulation.

Question 6

how thick is skin?

Answer 6

0.5mm –> 5mm

Question 7

What is the thinnest skin?

Answer 7

eyelid (0.5mm)

Question 8

what is the most sensitive skin?

Answer 8

lips.

Question 9

what are the thickest skin?

Answer 9

soles, palms.

Question 10

how is skin innervated?

Answer 10

• dermamyotome.

- derma cells become the dermis and drag nerve supply with them so cutaneous nerves are segmental.

Question 11

what is a dermatome?

Answer 11

area of skin innervated by fibres from a single root.

Question 12

What are angiosomes?

Answer 12

regions of skin, superficial fascia, deep fascia and possibly even underlying muscle that share common blood supply.

Question 13

What is the histology of epidermis? from most deep to superficial.

Answer 13

• stratum basale.
• stratum spinosum.
• stratum granulosum
• stratum lucidum
• stratus corneum.

Question 14

features of stratum spinosum?

Answer 14

-spiny looking cells as they have shrunked a little bit and have a border around them still have nuclei, come from stratum basale.

Question 15

features of stratum granulosum?

Answer 15

• develop granules inside them called keratohyalin granules.
• start laying down of keratin and other proteins that make the skin water resistant.
• have nuclei.

Question 16

features of stratum lucidum?

Answer 16

• no nuclei, almost dead, fill up with protein (mostly keratin)
• only found in thick skin.

Question 17

features of stratum corneum?

Answer 17

-dead, forms protective layer mainly consisting of keratin.

Question 18

how do the cells in the deepest level of the epidermis function?

Answer 18

extremely active and divide constantly to make more and more new cells.

Question 19

What happens to the new cells made in the deepest level of the epidermis?

Answer 19

they are pushed upward through the other levels of the epidermis and toward the surface of the skin.

Question 20

What is the blood supply for epidermis?

Answer 20

no direct blood supply, all nutrient that feed these cells come from the dermis

Question 21

What are cell types in epidermis?

Answer 21

• keratinocytes
• malanocytes
• langerhan cells
• merkel cells

Question 22

what is the primary function of keratinocytes.

Answer 22

-responsible for forming tight junctions with the nerves of the skin.

Question 23

what does the epidermis primarily consist of?

Answer 23

keratinocytes.

Question 24

what is a secondary fucntion of keratinocytes?

Answer 24

keep langerhan cells of the epidermis and lymphocytes of the dermis in place.

Question 25

what do melanocytes do?

Answer 25

make melanin.

Question 26

what do melanocytes appear as?

Answer 26

appear as small cells, usually in or near stratum basale.

Question 27

what do langerhan cells do?

Answer 27

participate in the surveillance of immune system.

Question 28

what do langerhan cells look like?

Answer 28

smaller than keratinocytes, with clear cytoplasm, usually located within the stratum spinosum or stratum basale.

Question 29

what do merkel cells do?

Answer 29

- small cells associated with nerve endings in epidermis. | - involved in tactile sensation.

Question 30

what is the dermis?

Answer 30

thick layer of connective tissue to which the epidermis is attached.

Question 31

what are the 2 sublayers of the dermis?

Answer 31

- papillary layer | - reticular layer with thicker elastin fibres and bundles of collagen

Question 32

what does papillary layer adhere to?

Answer 32

epidermis.

Question 33

what does reticular layer adhere to?

Answer 33

subcutaneous tissue.

Question 34

what are tension lines determined by?

Answer 34

alignment of dermal connective tissue and effect of underlying muscle

Question 35

why does skin bounce back?

Answer 35

elastin.

Question 36

Where are sebaceous glands derived from?

Answer 36

epidermis.

Question 37

where are sebaceous glands located?

Answer 37

dermis.

Question 38

what is the shape of seb glands?

Answer 38

flask-shaped and packed solidly with cells that often have a foamy appearance ins sections.

Question 39

where are seb glands found?

Answer 39

found everywhere in the body.

Question 40

what do seb glands do?

Answer 40

produce a substance called sebum which keeps cells and skin moisturised.

Question 41

structure of seb glands?

Answer 41

a duct from each gland opens into an associated hair follicle.

Question 42

where is sebum found?

Answer 42

most of the body except palms and soles.

Question 43

what do eccrine sweat glands secrete?

Answer 43

produce mostly NaCl and water.

Question 44

where are apocrine glands found?

Answer 44

mostly in axilla and groins.

Question 45

what do apocrine glands secrete?

Answer 45

milky secretion directly into hair follicles.

Question 46

what is the size of apocrine sweat glands compared to eccrine sweat glands?

Answer 46

apocrine are much larger.

Question 47

what do ceruminous glands secrete?

Answer 47

ear wax.

Question 48

what do mammary glands secrete?

Answer 48

milk.

Question 49

what muscle is arrector pili muscle?

Answer 49

smooth muscle.

Question 50

what is innervation of arrector pili muscle?

Answer 50

sympathetic. part of flight or fight.

Question 51

what is hyperhidrosis?

Answer 51

excessive sweating in hands and feet.

Question 52

where are hair follicels located?

Answer 52

dermis.

Question 53

metabolic function of skin?

Answer 53

vitamin d3 is made in the skin. important for bone health/calcium metabolism.ski

Question 54

5 skin sensations?

Answer 54

fine, vibration, light touch, temp, pain

Question 55

where are langerhan cells found?

Answer 55

epidermis.

Question 56

where are mast cells found?

Answer 56

underneath epidermis, under blood vessels.

Question 57

where are macrophages found?

Answer 57

dermis.

Question 58

where are melanocytes found?

Answer 58

basal layer of the epidermis.

Question 59

how many melanocytes do different people have?

Answer 59

same number.