skin structure

Question 1

epidermis

Answer 1

outer layer

stratified squamous epithelium

Question 2

layers of skin at 16 weeks

Answer 2

keratin layer
granular layer
prickle cell layer
basal layer
dermis

Question 3

what is the developmental growth pattern of skin

Answer 3

blaschko’s lines

Question 4

what does skin consist of (layers)

Answer 4

epidermis
dermis
dermis is thicker

Question 5

whats different about skin in the armpit

Answer 5

additional glands

Question 6

differentiation

Answer 6

keratinocytes migrate from basement membrane

continuous regeneration

Question 7

prickle cell layer

Answer 7

larger polyhedral cells

Question 8

desmosomes

Answer 8

cell contact

allow cells to move about

Question 9

if you dont have the filaggrin protein what happens

Answer 9

skin gets very dry

-excema

Question 10

what cells in keratin layer

Answer 10

corneocytes

lamellar granules release lipid

Question 11

what are the mucosal membranes

Answer 11

oral mucosa

ocular mucosa

Question 12

name some epidermal cells

Answer 12

melanocytes
langerhans cells
merkel cells

Question 13

what are melanocytes

Answer 13

pigment producing dendritic cells

Question 14

whats loss of pigment called

Answer 14

vitiligo

Question 15

merkel cells

Answer 15

basal
between keratinocytes and nerve fibres
mechanoreceptors

Question 16

whats merkel cell cancer caused by

Answer 16

viral infection

Question 17

phases of hair follicle growth

Answer 17

anagen - growing
catagen - involuting
telogen - resting

Question 18

dermo-epidermal junction

Answer 18

interface between epidermis and dermis

key role in epithelial-mesenchymal interactions

Question 19

role of dermo-epidermal junction

Answer 19

support, anchorage, adhesion, growth and differentiation of basal cells
semi-permeable membrane acting as barrier and filter

Question 20

what can happen when this junction goes wrong

Answer 20

bullous pemphigoid

Question 21

what is dermis derived form

Answer 21

mesoderm

Question 22

what cells are in the dermis

Answer 22

mainly fibroblasts, macrophages, mast cells, lymphocytes, langerhans cells

Question 23

what fibres are in dermis

Answer 23

collagen and elastin

Question 24

what is the function of blood vessels in the dermis

Answer 24

supply greater then metabolic needs

vessel walls well supported

Question 25

flow of the blood vessels in dermis

Answer 25

arteriole - precapillary sphincters - arterial - venous capillaries - post-capillary venules - collecting venules

Question 26

immune functions of lymphatic vessels in dermis

Answer 26

immune surveillance by circulating lymphocytes and langerhans cells channelling of micro-organisms/toxins

Question 27

what nerves are in the dermis

Answer 27

``` somatic sensory -free nerve endings -special receptors (pacinian and meissners) automatic nerve supply -blood vessels, nerves and glands ```

Question 28

pacinian

Answer 28

pressure nerve receptors

Question 29

meissners

Answer 29

vibration nerve receptors

Question 30

what is the pilosebaceous unit composed of

Answer 30

hair follicle hair shaft arrector pili muscle sebaceous glands

Question 31

three segments of hair follicle

Answer 31

infundibulum isthmus hair bulb

Question 32

what are the three types of skin gland

Answer 32

sebaceous apocrine eccrine

Question 33

sebaceous glands

Answer 33

holocrine secretion opening into pilary canal face chest back when you hit puberty produce sebum control moisture loss and protection from fungal infection

Question 34

apocrine sweat glands

Answer 34

develop as part of pilosbaceous unit | axillae, groin, eyelids, ears, mammary and perineal regions

Question 35

eccrine sweat glands

Answer 35

whole skin surface | sympathetic cholinergic nerve supply

Question 36

what absorbs UV rays to protect DNA?

Answer 36

melanin

Question 37

what are the main functions of the skin

Answer 37

``` barrier metabolism and detoxification thermoregulation immune defence communication sensory functions ```

Question 38

where do splits cause blistering

Answer 38

dermo-epidermal junction

Question 39

what different tissue groups are found in the skin?

Answer 39

``` epithelium nervous tissue connective tissue glands muscle hair adipose tissue ```

Question 40

Found over the whole body except the lips & genitals. | Coiled tubular structures which regulate heat and salt loss. What are these glands?

Answer 40

eccrine glands

Question 41

Limited to axillae/nipple/genitals. | Develop at puberty and open into hair follicles. What are these glands?

Answer 41

apocrine glands

Question 42

structure of a nail

Answer 42

nail plate matrix cuticle hyponychium

Question 43

stage 1 of wound healing

Answer 43

inflammation Platelets form the initial clot and release inflammatory mediators. Leucocytes debride the wound bed by phagocytosing bacteria and scavenging cellular debris. Inflammation gradually decreases as keratinocyte proliferation and new tissue formation becomes predominant.

Question 44

stage 2 of wound healing

Answer 44

cells divide to re-epithelialise the wound surface. granulation tissue formation is stimulated fibroblasts lay down matrix, and contract the wound endothelial cells develop into new blood vessels

Question 45

stage 3 of wound healing

Answer 45

tissue remodelling -new tissue is converted into mature scar tissue over a period of months. fibroblasts lay down collagen to improve the tensile strength of the scar and restore the normal dermal matrix

Question 46

what is a surface slough

Answer 46

a mixture of dead cells, polymorphs and bacteria

Question 47

what is stage 1 of pressure sore development

Answer 47

Skin is unbroken but shows a pink or reddened area .May look like a mild sunburn. Skin may be tender, itchy or painful

Question 48

what is stage 2 of pressure sore development

Answer 48

Skin is red, swollen and painful. Blisters that may be broken or intact may be present. Upper layers of skin begin to die

Question 49

stage 3 of pressure sore development

Answer 49

Sore has broken through the skin and wound extends down to deeper layers of skin tissue. Crater-like ulcers are present. Wound is prone to infection

Question 50

stage 4 of pressure sore development

Answer 50

Sore extends past the skin and into fat, muscle and bone tissue . Blackened dead tissue called eschar may be seen in deep opened wounds