1: Histology of Skin - Patestas

Question 1

what is the integument?

Answer 1

• skin
• sweat glands
• sebaceous glands
• hair
• nails

Question 2

functions of skin

Answer 2

• protection
• regulation of body temp
• reception
• absorption
• excretion

Question 3

describe epidermis

Answer 3

stratified squamous keratinized avascular epithelium

Question 4

what are the nonkeratinocytes?

Answer 4

langerhans cells (APC)
merkel cells (mechanoreceptors)
melanocytes

Question 5

main location of langerhans cells

Answer 5

stratum spinosum and superficial dermis

reside in all layers of dermis

Question 6

where do langerhans cells derive from

Answer 6

precursors in bone marrow

Question 7

membrane bound birbeck granules indicate …

Answer 7

langerhans cell

Question 8

location of merkel cells

Answer 8

• base of hair follicles and fingertips
• attach to keratinocytes by desmosomes
• stratum basale*

Question 9

melanocytes arise from…

Answer 9

neural crest

Question 10

location melanocytes

Answer 10

stratum basale* and superficial dermis

Question 11

what aa becomes melanin?

Answer 11

tyrosine via tyrosinase

melanin granules reside in cell processes of melanocyte

Question 12

what causes different skin pigmentation

Answer 12

• tyrosinase activity
• number melanin granules
• size
• distribution
• rate of breakdown
• NOT total number melanocytes

Question 13

decrease or total loss of melanocytes

Answer 13

vitiligo

albinism = melanocytes do not synthesize melanin due to defect or absence of tyrosinase

Question 14

strata of thin skin bottom –> top

Answer 14

stratum basale "cell renewal"
stratum spinosum "binding, protection"
stratum granulosum "waterproofing"
stratum lucidum "clear"
stratum corneum

Question 15

pearly papule and subepidermal blood vessels

Answer 15

basal cell carcinoma

Question 16

strata of thick skin bottom –> top

Answer 16

basale
spinosum
corneum

• absence of definite stratum lucidum and granulosum although individual cells are present

Question 17

“fish like scales”

Answer 17

ichthyosis

- hyperkeratosis (excessive keratin buildup)

Question 18

dermal papilla correlates with…

Answer 18

epidermal ridge

• areas that are subject to increased mechanical stress display prominent epidermal ridges, dermal papillae and true dermal ridges

Question 19

layers of dermis

Answer 19

papillary layer - defense against foreign invaders

reticular layer - tensile strength

Question 20

is hypodermis (superficial fascia) a part of skin

Answer 20

NO

skin = epidermis and dermis

Question 21

receptors
free nerve endings
pacinian corpuscles
meissner's corpuscles
krause end bulbs

Answer 21

• pain and temp
• pressure, vibration
• mechanoreceptors, discriminatory, fine touch
• function unclear

Question 22

where are apocrine sweat glands located?

Answer 22

axilla, areola, anal region
- merocrine secretory product

normal sweat glands = eccrine

Question 23

reasons why there is a loss of hair from leg and/or foot:

Answer 23

PAD
diabetes
low thyroid hormone levels

Question 24

arrector pili muscle

Answer 24

smooth muscle

attaches to hair follicle midway, obliquely and cradles sebaceous gland

Question 25

nail growth

Answer 25

fingernail - 3.47 mm/mo | toenail - 1.62 mm/mo

Question 26

pemphigus vulgaris pemhigus foliaceus epidermolysis bullosa

Answer 26

- auto ab against desmogelein 1 and 3 - auto ab against desmoglein 1 - genetic mutation encoding for structural prtns such as keratins, collagen type VII or laminin (non-inflammatory blistering disorder)

Question 27

layer burned in superficial/1st degree burns

Answer 27

epidermis full thickness burns (aka 3rd degree) extend into subcutaenosu tissue (hypodermis)

Question 28

epithelial cells aka

Answer 28

keratinocytes | these desquamate every 20-30 days

Question 29

glues and anchors the epidermis to underlying dermis

Answer 29

basement membrane

Question 30

true dermal ridges

Answer 30

oriented parallel to and lie in between dermal papillae dermal ridges are genetically unique = fingerprints

Question 31

reticular fibers

Answer 31

type III collagen fibers in papillary layer of dermis

Question 32

where are meissner corpuscles and krause end bulb located?

Answer 32

papillary layer of dermis

Question 33

where are pacinian (pressure ribration) and ruffini corpuscles (tensile forces) located?

Answer 33

reticular layer of dermis

Question 34

surgical incisions oriented parallel to __________ produce minimal scaring

Answer 34

langer's lines | - type I collagen bundles with regular orientation in reticular layer of dermis

Question 35

describe eccrine sweat glands histologically

Answer 35

- simple coiled tubular glands - secretory segment = simple cuboidal to low columnar - duct segment = stratified cuboidal epithelium

Question 36

nail growth occurs here

Answer 36

nail matrix | forms keratin which forms nail plate

Question 37

proximal nail fold

Answer 37

eponychium (cuticle, consists of stratum corneum)

Question 38

crescent shaped area at base of nail, appears white

Answer 38

lunula

Question 39

3 stages of cutaneous wound healing

Answer 39

inflammatory proliferative maturation