physiology

Question 1

what is a cream, what does it contain

Answer 1

semi-solid emulsion of oil in water

contains emulsifier and preservative

Question 2

what is a ointment

Answer 2

semi-solid grease/oil containing no preservative

Question 3

what is a lotion

Answer 3

suspension or solution of medication in water, alcohol, or other liquids

Question 4

what is a gel

Answer 4

semi-solid containing high molecular weight polymers e.g. methylcellulose

Question 5

what is a paste semisolids containing finely powdered material e.g. ZNO

Answer 5

semi-solids containing finely powdered material e.g. ZNO

Question 6

when are pastes commonly used

Answer 6

in cooling and drying bandages

Question 7

what is a foam

Answer 7

colloid with two to three phases, usually hydrophilic liquid in continuous phase with a foaming agent dispersed in gaseous phase

Question 8

what is the use of emollients

Answer 8

enhance the rehydration of the epidermis

Question 9

what is the epidermis

Answer 9

outer layer, 1.5mm thick

Question 10

what is the epidermis made of

Answer 10

stratified cellular epidermis

Question 11

what is the epidermis formed from

Answer 11

ectoderm

Question 12

what are the 4 layers of the epidermis

Answer 12

keratin layer
granular layer
prickle cell layer
basal layer

Question 13

what is the main cell found in the epidermis

Answer 13

95% = keratinocyte

Question 14

what do keratinocytes contain

Answer 14

structural keratins

Question 15

what is the function of the keratin layer

Answer 15

tight, waterproof barrier

Question 16

what cell makes up the keratin layer, describe them

Answer 16

corneocytes

overlapping, non-nucleated cell remnants

Question 17

Describe the granular layer

Answer 17

2-3 layers of flatter cells

Question 18

what cells makes up the granular layer, what do they contain

Answer 18

keratohyalin granules which contains structural filaggrin and involucrin proteins

Question 19

Describe the prickle cell layer

Answer 19

larger polyhedral cells with lots of desmosomes

Question 20

describe the basal layer

Answer 20

one cell thick, small and cuboidal with lots of intermediate filaments (keratin)

Question 21

what layer is the most metabolically active

Answer 21

prickle cell layer

Question 22

in what day is skin formed. what is this known as

Answer 22

days 7-10

gastrulation

Question 23

what are Blaschko’s lines

Answer 23

developmental growth pattern of skin not following vessels, nerves, or lymphatics

Question 24

what other cells are found in the epidermis

Answer 24

melanocytes
langerhans cells
merkle cells

Question 25

what are melanocytes

Answer 25

pigment producing dendritic cells

Question 26

where are melanocytes formed

Answer 26

neural crest

Question 27

what do melanocytes contain, what role do these play

Answer 27

melanosomes convert tyrosine to melanin pigment

Question 28

what is the role of melanin pigment

Answer 28

absorbs light

Question 29

what are the two types of melanin, what colour are they

Answer 29

``` eumelanin = brown/black phaeomelanin = red/yellow ```

Question 30

what layer of the epidermis are melanocytes found

Answer 30

basal

Question 31

what are ephilides, what causes them

Answer 31

freckles patchy increase in melanin pigmentation which occurs after UV exposure

Question 32

what are actinic lentigines, what causes them

Answer 32

age spots/ liver spots increase in melanin and basal melanocytes in response to UV exposure over many years

Question 33

what are langerhan cells

Answer 33

antigen presenting cells

Question 34

what layer of the epidermis are langerhan cells found

Answer 34

prickle cell layer

Question 35

what are langerhan cells formed from

Answer 35

bone marrow

Question 36

where else in the body are langerhan cells found

Answer 36

dermis | lymph nodes

Question 37

what are merkle cells

Answer 37

mechanoreceptor for touch

Question 38

where are merkle cells found

Answer 38

basal layer

Question 39

what is the dermo-epidermal junction

Answer 39

interface between the epidermis and dermis

Question 40

what is the role of the dermo-epidermal junction

Answer 40

adhesion, growth and differentiation of basal cells

Question 41

what is the dermis

Answer 41

"ground substance"

Question 42

what cells make up the dermis

Answer 42

mostly fibroblasts immune cells collagen and elastin fibres

Question 43

what immune cells are located in the dermis

Answer 43

macrophages mast cells lymphocytes langerhan cells

Question 44

what else is located in the dermis

Answer 44

``` blood vessels muscles nerves lymphatics glands ```

Question 45

what is the dermis formed by

Answer 45

mesoderm

Question 46

what is photoaging

Answer 46

skin damage caused by prolonged sun exposure, specifically UVA and UVB.

Question 47

what types of nerves are found in the dermis, what do they sense

Answer 47

pacinian corpuscle = pressure | meissner's corpuscle = vibration

Question 48

what are the 3 types of skin glands

Answer 48

sebaceous eccrine apocrine

Question 49

what does sebaceous glands produce

Answer 49

sebum

Question 50

what is the function of sebaceous glands

Answer 50

control moisture loss | protect from fungal infection

Question 51

what is the function eccrine glands

Answer 51

cooling via evaporation | moisten palms/soles for grip

Question 52

what are eccrine glands stimulated by

Answer 52

thermal mental gustatory

Question 53

where are apocrine glands located

Answer 53

armpit | perineum

Question 54

what controls apocrine glands

Answer 54

androgen dependant

Question 55

what do apocrine glands produce

Answer 55

oily fluid which gains a smell after bacterial decomposition

Question 56

what are langerhan cells characterised by

Answer 56

birbeck granule

Question 57

what is the function of keratinocytes

Answer 57

sense pathogens via cell surface receptors and mediate an immune response

Question 58

what immune response do keratinocytes mediate

Answer 58

produce antimicrobial peptides that can kill directly produce cytokines produce chemokines