Derm- physiology and pathophysiology

Question 1

what is the largest vital organ in body

Answer 1

skin

Question 2

What is the outermost layer of skin called?

Answer 2

epidermis

Question 3

Blaschko’s lines

Answer 3

developmental growth pattern of skin

Question 4

type of epithelium in epidermis

Answer 4

stratified cellular epithelium

Question 5

dermis location

Answer 5

beneath epidermis

Question 6

subcutis skin

Answer 6

fat layer beneath dermis

Question 7

what are melanocytes

Answer 7

pigment producing cells from neural crest- migrate to epidermis in first three months of foetal development

Question 8

Which germ layer forms epidermis

Answer 8

ectoderm

Question 9

which germ layer forms dermis

Answer 9

formed from mesoderm below ectoderm

Question 10

which makes up 95% of epidermis

Answer 10

keratinocytes

Question 11

In foetal skin development, which layers are formed after 16 weeks

Answer 11

Keratin layer
granular layer
prickle cell layer
basal layer

Question 12

melanocytes convert _____ to melanin pigment

Answer 12

tyrosine

Question 13

eumelanin colour

Answer 13

brown or black

Question 14

phaeomelanin colour

Answer 14

red, yellow

Question 15

function of langerhans cells

Answer 15

involved in the skin immune system

Question 16

keratin layer of epidermis

Answer 16

non-specific
physical barrier to pathogens

Question 17

keratinocytes produce…

Answer 17

Produce antimicrobial peptides (AMPs) that can directly kill pathogens

Question 18

what are langerhans cells

Answer 18

antigen presenting cells

Question 19

which ig mediates type I hypersensitivity reactions (allergy)

Answer 19

IgE

Question 20

which ig mediates type II and type III hypersensitivity reactions

Answer 20

IgM, IgG

Question 21

which cell mediates type IV hypersensitivity reactions

Answer 21

TH1 cell mediated

Question 22

dermo-epidermal junction

Answer 22

interface between epidermis and dermis

Question 23

immune cells of the dermis

Answer 23

dendritic cells- dermal DC, plasmacytoid DC
fibroblasts
macrophages
neutrophils
mast cells

Question 24

Major histocompatability complex (MHC)- chromosome _

Answer 24

chromosome 6

Question 25

Major histocompatability complex (MHC) roles

Answer 25

Control the immune response through recognition of self and non-self Responsible for immunological recognition and transplant rejection

Question 26

MHC class I found-

Answer 26

Found on almost all cells

Question 27

MHC class II found-

Answer 27

Found on antigen presenting cells (dendritic cells, B cells, macrophages)

Question 28

antigen presenting cells

Answer 28

dendritic cells B cells macrophages

Question 29

MHC class I present endogenous/exogenous antigens to _____

Answer 29

Present endogenous antigens to cytotoxic T cells

Question 30

MHC class II present endogenous/exogenous antigens to _____

Answer 30

Present exogenous antigens to TH cells

Question 31

three types of skin glands

Answer 31

sebaceous apocrine eccrine

Question 32

sebaceous glands functions

Answer 32

control moisture loss- provide lubrication protect from fungal infection

Question 33

largest sebaceous glands found where?

Answer 33

face and chest

Question 34

sebaceous glands produce sebums-

Answer 34

squalene wax esters triglycerol free fatty acids

Question 35

mechanism of secretion in sebaceous glands

Answer 35

holocrine secretion

Question 36

hormonal control of sebaceous glands

Answer 36

increased in puberty

Question 37

what are sebaceous glands

Answer 37

specialized exocrine glands in the skin that produce and secrete an oily substance called sebum

Question 38

where are apocrine sweat glands found

Answer 38

axillae groin eyelids ears mammary and perineal regions

Question 39

apocrine sweat glands activated by ___

Answer 39

hormones- androgen

Question 40

most abundant type of sweat gland in body

Answer 40

eccrine sweat gland

Question 41

control of eccrine sweat glands

Answer 41

sympathetic cholinergic nerve supply

Question 42

pilosebaceous unit

Answer 42

half follicle hair shaft arrector pili muscle sebaceous glands

Question 43

Which layer of skin are langerhans cells found

Answer 43

prickle cell layer

Question 44

where do langerhans cells derive from

Answer 44

bone marrow

Question 45

which layer of skin are melanocytes found

Answer 45

basal layer

Question 46

hair phases of growth

Answer 46

anagen catagen telogen

Question 47

anagen hair phase of growth

Answer 47

growing

Question 48

catagen hair phase of growth

Answer 48

involuting

Question 49

telogen hair phase of growth

Answer 49

resting

Question 50

is skin metabolically active?

Answer 50

yes

Question 51

main role of vitamin D

Answer 51

increase the flow of calcium into the bloodstream

Question 52

vitamin D2 present in

Answer 52

plants

Question 53

vitamin D3 present/made in

Answer 53

small amounts of some foods eg oily fish, meat skin from sunlight

Question 54

thyroid hormone metabolism

Answer 54

thyroxine (T4)- triiodothyronine (T3)

Question 55

where does T4-T3 conversion occur?

Answer 55

20% in thyroid gland 80% in peripheral tissues including skin

Question 56

which cells are important in the skins immune defence

Answer 56

langerhans cells and T cells

Question 57

functions of skin (7)

Answer 57

barrier function metabolism and detoxification thermoregulation communication sensory function wound healing immunisation

Question 58

keratin layer aka

Answer 58

stratum corneum

Question 59

granular layer aka

Answer 59

stratum granulosum

Question 60

prickle cell layer aka

Answer 60

stratum spinosum

Question 61

basal cell layer aka

Answer 61

stratum basale

Question 62

what are langerhans cells characterised by

Answer 62

the birbeck granule ("tennis racquet")

Question 63

pruritoceptive

Answer 63

something (usually dryness/inflammation) in skin triggers itch

Question 64

where do melanocytes derive from

Answer 64

neural crest

Question 65

cytotoxic T cells aka

Answer 65

CD8 + T cells

Question 66

TH cells aka

Answer 66

CD4 + T cells

Question 67

what are merkel cells

Answer 67

mechanoreceptors that aid sensation

Question 68

where are merkel cells found

Answer 68

between keritanocytes and nerve fibres

Question 69

what do TH1 cells do

Answer 69

activate macrophages to destroy microorganisms

Question 70

what do TH2 cells do

Answer 70

help B cells make antibodies

Question 71

ratio of melanocytes:basal cells

Answer 71

1:10

Question 72

what is an allergy

Answer 72

hypersensitivity disorder of the immune system

Question 73

allergic reactions occur when-

Answer 73

a persons immune system reacts to normally harmless substances in the environment

Question 74

how long does allergic reaction occur after exposure to allergen in type I allergy

Answer 74

immediate- occurs within minutes and up to two hours after exposure

Question 75

how long does allergic reaction occur after exposure to allergen in type IV allergy

Answer 75

delayed- 12-24 hours

Question 76

which cells produce collagen

Answer 76

fibroblasts

Question 77

what is the function of Meissners corpuscles

Answer 77

vibration sensation

Question 78

what is the function of paninian corpuscles

Answer 78

pressure sensation

Question 79

how many days does it take for a cell to migrate from the basal layer to the keratin layer

Answer 79

28 days

Question 80

which layer of the epidermis is the most metabolically active

Answer 80

the basal layer

Question 81

which layer of the epidermis are odland bodies associated with

Answer 81

granular layer

Question 82

which layer of the epidermis are corneocytes associated with

Answer 82

keratin layer

Question 83

where is energy stored

Answer 83

subcutaneous fat

Question 84

layers of the scalp from outside to inside of the body- SCALP

Answer 84

skin connective tissue aponeurosis loose connectie tissue periosteum