Revision

Question 1

what does transcellular fluid include

Answer 1

cerebrospinal fluid
synovial fluid
ocular fluid

Question 2

pH in plasma vs intracellularly

Answer 2

plasma - 7.4

intracellularly 7.1 = double the [H+]

Question 3

protein conc intracellularly

Answer 3

10mM

Question 4

Cl- conc intracellularly

Answer 4

5mM

Question 5

what happens to the cell if the solution is hypertonic

Answer 5

it shrinks

Question 6

what happens to the cell if the solution is hypotonic

Answer 6

it swells

Question 7

how does tonicity define the strength of solution

Answer 7

as how it affects the final volume of the cell

Question 8

how are substances exchanged through the endothelium

Answer 8

via pores in the cells

Question 9

what causes oedema

Answer 9

increased permeability of the capillary walls to plasma proteins

Question 10

what does it mean that APs are non-decremental

Answer 10

size of the AP is maintained throughout transmission

Question 11

when is Ca returned to the sarcoplasmic reticulum

Answer 11

simultaneous to its release

the rate of active transport back in is lower than the rate of release

Question 12

what does recruitment mean in terms of muscles

Answer 12

increasing the number of active motor units

Question 13

what is a motor unit

Answer 13

a single motor neuron and all its fibres

Question 14

size of cardiac cells compared to SM cells

Answer 14

cardiac are larger

Question 15

what innervates sm cells

Answer 15

autonomic nerves

Question 16

are both sm and cardiac cells spontaneously active

Answer 16

yes

Question 17

what is salbutamol

Answer 17

an agonist

Question 18

how do tyrosine kinases work

Answer 18

phosphorylating the AA tyrosine

eg GF receptors eg insulin, epidermal and platelet derived

Question 19

describe G proteins

Answer 19

heterotrimeric
a B and y subunits
have 7 transmembrane couple receptors which when activated stimulate the exchange of GDP to GTP

Question 20

mechanisms to switch off the intracellular signal

Answer 20

receptor inactivation
receptor down regulation - breakdown by lysosomes
the production of inhibitory proteins
inactivation of intracellular signalling proteins

Question 21

components of the epidermis

Answer 21

squamous epithelium composed of

keratinocytes, melanocytes, langherhans and merkel cells

Question 22

what is the dermis

Answer 22

forms the structural foundation of skin containing bv, nerves and adnexal structures - hair follicles, sweat glands and sebaceous glands

Question 23

what is the hypodermis

Answer 23

a deep subcutaneous adipose layer

acts as fat and heat store

Question 24

melanin

Answer 24

pigment found in epidermis but not secreted

Question 25

layers of the epidermis

Answer 25

``` cells that gradually keritinise to form the waterproofing layer From deep to superficial: stratum basale stratum spinosum stratum granulosum stratum corneum ```

Question 26

stratum basale

Answer 26

deepest layer large nuclei dense cytoplasm

Question 27

stratum spinosum

Answer 27

intracellular spines

Question 28

stratum granulosum

Answer 28

granules containing precureser filaggrin - help bind keratin filaments

Question 29

stratum corneum

Answer 29

contains dead, flattened cells filled with keratin

Question 30

hemidesmosomes

Answer 30

on basal surface of epithelial cells present in dermo-epidermal junctions attach a single cell to the ECM

Question 31

desmosomes

Answer 31

attach 2 cells together

Question 32

adhesion belts

Answer 32

control the assembly of other junctions

Question 33

tight junctions

Answer 33

form tight seal s between adjacent cells

Question 34

gap junctions

Answer 34

form continuous pores on adjacent cells allowing for passage of ions between cells

Question 35

where is hair not found

Answer 35

glaborus skin of palms, soles, glans penis, vulval introitus

Question 36

lanugo hair

Answer 36

fine and long formed in foetus at 20weeks - lost at birth happen with malnutrition - anorexia

Question 37

vellus hair

Answer 37

short fine light coloured all over the body

Question 38

terminal hair

Answer 38

longer thicker pigmented found on scalp, eyebrow and eyelashes and pubic, axillary and beard areas

Question 39

what happens in catagen

Answer 39

cell division slows and stops shaft keratinises and forms a club shape dermal papilla and club move to muscle insertion 4-6wks

Question 40

telogen

Answer 40

hair actively shed and next anaphase begins

Question 41

time frame of hair growth

Answer 41

anagen 2-6wks catagen 2-3wks telogen 2-3 months

Question 42

nail matrix

Answer 42

contains dividing cells which mature, keratinise and move to form nail plate can contain melanocytes

Question 43

nail root

Answer 43

where the nail begins | embedded underneath the skin at the base of the nail

Question 44

other word for eponychium

Answer 44

cuticle

Question 45

what is the eponchium

Answer 45

acts as a barrier to the external environment | ensheaths the nail plate from above and below

Question 46

what is the hyponychium

Answer 46

thickened epidermis that underlies the free margin of the nail

Question 47

nail bed

Answer 47

produces a small amount of keratin and is adherent to the nail plate

Question 48

normal morphology of the nail

Answer 48

angle between proximal nail fold and nail plate <180degrees | nail curved in 2 planes and has longitudinal ridges in a proximal to distal direction