Skin & Breast

Question 1

what are the layers of the epidermis?

Answer 1

• stratum basale
• stratum spinosum
• stratum granulosum
• stratum lucidum
• stratum corneum

Question 2

where are melanocytes found in the skin?

Answer 2

epidermis

- stratum basale

Question 3

what is the function of melanocytes?

Answer 3

• synthesise melanin
• transfer melanin to surrounding keratinocytes in melanosomes
• absorb UV light

Question 4

what stimulates melanocytes?

Answer 4

• MSH

- ACTH

Question 5

where is most of the melanin found?

Answer 5

keratinocytes

Question 6

what does skin colour depend on?

Answer 6

amount and type of melanin synthesised

Question 7

what is normally the largest layer of the epidermis?

Answer 7

stratum spinosum

Question 8

what is found in the stratum spinosum?

Answer 8

• keratinocytes
• langerhans cells
• merkel cells

Question 9

what is the function of langerhans cells and are they seen readily on H&E?

Answer 9

• antigen recognition

- no

Question 10

what is the function of merkel cells and are they seen readily on H&E?

Answer 10

• sensory

- no

Question 11

describe the structure of the stratum granulosum

Answer 11

• flattened squames

Question 12

what happens in the stratum granulosum?

Answer 12

• keratin formation

- epidermal keratinocytes mature

Question 13

where is keratin formed?

Answer 13

stratum granulosum

Question 14

where do epidermal keratinocytes mature?

Answer 14

stratum granulosum

Question 15

which layer of the epidermis is visible on palms and soles?

Answer 15

stratum lucidum

Question 16

describe the appearance of the stratum lucidum

Answer 16

thin and pale

Question 17

what is the stratum corneum?

Answer 17

acellular plates of keratin (as dead keratinised squames)

Question 18

where is the stratum corneum particularly thick and why?

Answer 18

• palms and soles

- helps to resist abrasive forces

Question 19

what is the epidermal adnexae?-

Answer 19

downgrowths of the epidermis into underlying layers of the skin (dermis and subcutis)

Question 20

what is found in the epidermal adnexae?

Answer 20

• hair follicles
• eccrine sweat glands
• apocrine sweat glands

Question 21

where do hairs arise from?

Answer 21

germinative epithelium within hair bulb

Question 22

what is responsible for the pigmentation of hair and where are they found?

Answer 22

melanocytes

- germinative epithelium within the hair bulb

Question 23

where does hair lengthen?

Answer 23

within a root sheath composed of epidermis

Question 24

what surrounds hair follicles?

Answer 24

collagenous follicle sheath

Question 25

what muscule causes hairs to 'stand on end'?

Answer 25

erector pili

Question 26

where are the erector pili muscles found?

Answer 26

collagenous follicle sheath surrounding hair follicles

Question 27

are erector pili muscles stimulated sympathetically or parasympathetically?

Answer 27

sympathetically

Question 28

what is the function of the sebaceous glands associated with hair follicles?

Answer 28

lubricate and waterproof hair

Question 29

what provides surface lubrication to the face and groin?

Answer 29

hairless follicles

Question 30

what are apocrine glands?

Answer 30

specialised sweat glands

Question 31

where are apocrine glands found?

Answer 31

- armpits - groins - genitals - around anus

Question 32

what produces ear wax?

Answer 32

ceruminous glands in external auditory canal

Question 33

describe the structure of apocrine glands

Answer 33

- simple coiled tubular glands | - eosinophilic cytoplasm with surface budding

Question 34

what do eccrine glands secrete?

Answer 34

thin watery secretion associated with sweat

Question 35

what are the most common sweat glands?

Answer 35

eccrine glands

Question 36

where are eccrine glands found?

Answer 36

everwhere (in dermis)

Question 37

what are the 2 layers of eccrine glands:

Answer 37

inner: secretory outer: myoepithelial

Question 38

what are rete pegs?

Answer 38

downwards protrusion of the epidermis into the dermis

Question 39

what is the function of the rete pegs?

Answer 39

help to anchor epidermis onto underlying dermis

Question 40

what is the papillary dermis?

Answer 40

space between ridges of the rete pegs

Question 41

what is the dermis?

Answer 41

irregular loose connective tissue layer

Question 42

what are the 2 elements of the dermis?

Answer 42

papillary dermis - between rete pegs reticular dermis - rest of dermis

Question 43

what does the dermis contain?

Answer 43

- fibrous connective tissue (with elastin) - downgrowth of adnexal organs of epidermis - fibroblasts - collagen - glycosaminoglycan matrix

Question 44

what are the Meissner's corpuscles?

Answer 44

elongated receptors formed by a connective tissue capsule that comprises several lamellae of Schwann cells

Question 45

where are meissner's corpuscles found?

Answer 45

between dermal papillae beneath epidermis of fingers, palms and soles

Question 46

what is the function of meissner's corpuscles?

Answer 46

fine touch

Question 47

what frequency of vibrations are meissner's corpuscles effecting in transducing?

Answer 47

low frequency | e.g. when textured objects are moved across skin

Question 48

what are pacinian corpuscles?

Answer 48

large encapsulated sensory receptors

Question 49

where are pacinian corpuscles found?

Answer 49

- subcutaneous tissues - interosseous membranes of gut mesentery (in deep dermis)

Question 50

what is the function of the onion-like capsule of pacinian corpuscles?

Answer 50

acts as a filter | - only allows high frequencies to activate nerve endings

Question 51

what is the function of pacinian corpuscles?

Answer 51

discrimination of fine surface textures / other moving stimuli that produce high frequency vibration of the skin

Question 52

do meissner's corpuscles or pacinian corpuscles adapt more rapidly?

Answer 52

pacinian corpuscles

Question 53

do meissner's corpuscles or pacinian corpuscles have a higher response threshold?

Answer 53

meissner's corpuscles

Question 54

what is the function of the subcutis?

Answer 54

- shock absorber - insulation - food store

Question 55

what does the subcutis contain?

Answer 55

- white adipose connective tissue | - fibrovascular septa

Question 56

what are nails composed of?

Answer 56

compacted keratin

Question 57

what do nails arise from?

Answer 57

nail matrix cells under cuticle

Question 58

what are breasts?

Answer 58

myoepithelial system of ducts and lobules set in fibroadipose connective tissue

Question 59

where do ducts of the breast empty?

Answer 59

nipple

Question 60

what does male breast tissue contain?

Answer 60

ductal system

Question 61

what are the functional components of the breasts?

Answer 61

terminal duct lobular units

Question 62

what is the arrangement in terminal duct lobular units?

Answer 62

secretory lobules arranged around terminal ducts | - et in loose fibrous connective tissue stroma

Question 63

what are the ducts and lobules in terminal duct lobular units lined by?

Answer 63

outer: - contractile myoepithelial cells inner: - columnar epithelial cells

Question 64

which cells in breasts adapt to produce milk?

Answer 64

columnar epithelial cells

Question 65

what is the distinguishing factor of lactating breast?

Answer 65

inner layer of secretory cells become markedly vacuolated

Question 66

what are the 3 principle histological layers of the skin?

Answer 66

- epidermis - dermis - subcutis

Question 67

what are sweat glands and hair follicles?

Answer 67

downgrowths of epidermis