Exam 3: Integumentary System

Question 1

Integumentary system as protective barrier?

Answer 1

mechanical damage
toxins
dehydration - levels in 3rd degree burns
uv light - vitamin D
infection

Question 2

Integumentary system and homeostasis and excretion

Answer 2

homeostasis: fluid, thermoregulation
excretion: glands

Question 3

integumentary system in immunological and endocrine aspects

Answer 3

immunological: antigen processing
endocrine: growth factors

Question 4

Integumentary system as vitamin production and sensory

Answer 4

vitamin production: vitamin D

sensory - thermoreceptors, pain receptors

Question 5

Integumentary Components

Answer 5

skin - cutaneous membrane (epidermis, dermis)

accessory structures - glands, hair, nails

Question 6

embryo covered by a single layer of ectodermal cells over mesenchymal tissue

Answer 6

embryo - first month

Question 7

two layers of ectoderm form; deep basal layer will give rise to the epidermis
- the superficial layer forms the periderm

Answer 7

embryo - 2nd month

Question 8

3 germ cell layers

Answer 8

endoderm, mesoderm, ectoderm

Question 9

what layer is superficial?

Answer 9

periderm

Question 10

periderm function

Answer 10

protect you from fluid environment of the amniotic fluid

Question 11

deep layer

Answer 11

basal

Question 12

what does the basal layer give rise to?

Answer 12

epidermis

Question 13

when does the periderm stay until?

Answer 13

keratin can be made by your own cells

Question 14

multiple layers form, proliferation of basal layer

Answer 14

fetus - 3rd and 4th month

Question 15

keratinocytes differentiate
keratinization occurs
confined layers appear
periderm breaks down once keratinization is present

Answer 15

5th month plus

Question 16

keratinocytes

Answer 16

produce keratin

prevent from drying out, irritation

Question 17

3 key points of the dermis

Answer 17

1. dermis development lags behind epidermis by 1-2 weeks
2. dermis development influences epidermal development by secreting epidermal growth factor
3. proliferation in epidermis causes response in dermis - thickens

Question 18

feedback between the dermis and epidermis

Answer 18

as epidermis thickens above the dermis, pressure inc in the dermis and the dermis thickens by secreting growth factor
- dermis sends signals for epidermis to get thicker, then causing dermis thickening underneath it

Question 19

example of epidermis and dermis interactions

Answer 19

calluses on hands

- not system wide, just where the pressure is

Question 20

the dermis originates from how many sites?

Answer 20

4

3 mesodermal and 1 ectodermal

Question 21

dermis of back

Answer 21

derived from paraxial somites

Question 22

dermis of ventral body and appendages

Answer 22

lateral mesoderm

Question 23

dermis of cranium

Answer 23

superior somites

Question 24

dermis of face and ventral neck

Answer 24

ectoderm

• same place you get epidermis from
• may see inc in glandular concentration since all ectoderm

Question 25

somites

Answer 25

segmented regions lateral to the neural tube | - give rise to muscle, nerve, vertebrae, and skin of the region

Question 26

what is the skin severed by the nerve known as

Answer 26

dermatome

Question 27

most of the dermis is....

Answer 27

mesoderm

Question 28

skin development of dermis - 2nd month embryo

Answer 28

dermis begins secretion of growth factors | - locks dermis into epidermis

Question 29

when does the dermis thicken and differentiate into corium and subcorium

Answer 29

fetus 3-4 months

Question 30

corium

Answer 30

forms dermal papillae that push into epidermis

Question 31

sub corium

Answer 31

contains adipose and will separate into the subcutaneous layer

Question 32

fetus 5th month + dermis

Answer 32

dermis reticular layer develops - most dense irregular connective tissue that locks into papillae

Question 33

where can dermatomes be seen (example)

Answer 33

shingles - lysogenic, dormant in peripheral nerve. when it goes lysogenic you see rash in dermis of dermatome associated with that nerve - not bilateral dermatome: skin and nerves innervate skin

Question 34

5 epidermal layers of skin

Answer 34

basale, spinosum, granulosum, lucisum, corneum

Question 35

2 dermal layers of skin

Answer 35

dermal papillae | reticular

Question 36

basale

Answer 36

deepest layer, mitotically active cells, stem cells (keratinocytes), germinativum

Question 37

spinosum

Answer 37

several layers, cells enlarge, put out projections and attach by desmosomes dehydration gives cells spiked appearance

Question 38

granulosum

Answer 38

produces keratohyalin granules grainy appearance precursor to hydrophobic fiber

Question 39

lucidum

Answer 39

subdivision of corneum layer visible in thick skin - palm of hand, sole of feet (hard for hair to pass through thick skin) thin skin - no lucidum layer

Question 40

corneum

Answer 40

cells are anucleated; keratohyalin is transformed into keratin filaments; deeper layers have extra-cellular lipid barrier for water-proofing

Question 41

dermal papillae

Answer 41

fingerlike projections that lock the dermis into epidermal ridges (areolar connective tissue)

Question 42

reticular

Answer 42

thicker portion dese, irregular connective tissue bundles oriented along tension lines (langer's lines)

Question 43

Langer lines

Answer 43

correspond to mechanical tension on skin - fiber bundles in dermis line up on these lines - surgical incisions made parallel to the lines to heal with little scarring

Question 44

melanocytes

Answer 44

begin migration from neural crest at 2 months - infiltrate stratum basale at 3 months - dendritic cells connecting to basale and deeper spinosum keratinocytes - pigment is produced by tyrosinase and located in melanosomes

Question 45

langerhans cells

Answer 45

originate in mesenchyme of bone marrow precursors - infiltrate spinosum - immunological outposts - has both mhc I and II - have receptors for complement and Fc - can present antigens

Question 46

merkel's discs

Answer 46

migrate from neural crest at 4 months - infiltrates basale and interacts with free nerve endings in dermis - tactile receptor

Question 47

accessory structures that infiltrate dermis

Answer 47

hair, glands, nails

Question 48

what is the development of hair initiated by? | where does localized thickening of epidermis occur?

Answer 48

- signal from dermal fibroblasts | - occurs in placodes

Question 49

what do underlying dermal mesenchymal cells aggregate?

Answer 49

condensates

Question 50

the peg epithelial cells envelope the _____ which becomes the _____

Answer 50

dermal condensate dermal papilla - cells in contact become matrix - mitotic region

Question 51

eumelanin

Answer 51

black or brown hair

Question 52

pheomelanin

Answer 52

blonde, red hair

Question 53

dermal papilla contains the ___

Answer 53

blood supply

Question 54

matrix produces cells that differentiate into all hair structures...

Answer 54

medulla cortex cuticle

Question 55

outer root sheath

Answer 55

protective and in contact with basement memrbane

Question 56

inner root sheath

Answer 56

forms channel

Question 57

structure of hair

Answer 57

like a pencil - inner portion medulla - around medulla = cortex - outer = cuticle

Question 58

cuticle

Answer 58

single, overlapping layers of transparent cells

Question 59

cortex

Answer 59

main bulk of hair - contains pigment and protein fibrils | - determines strength and elasticity

Question 60

macrofibril

Answer 60

complex of interconnnected fibrils that run length of the shaft

Question 61

medulla

Answer 61

central hollow core | may be absent or fragmented