ECG

Question 1

what term is used to describe contraction of the heart

Answer 1

myogenic

Question 2

where does it start

Answer 2

SA node

Question 3

1 step

Answer 3

SA node generates electrical excitation and spreads over both atria so they contract

Question 4

special feature of AV node

Answer 4

delay

Question 5

when does AV node start contracting

Answer 5

when muscles of atria finishes contracting

Question 6

where does AV node pass the excitation

Answer 6

down the nerves of the bundle of his to the apex
then transmitted ro purkunjie fibres

Question 7

where can you find purkunjie fibres

Answer 7

in the ventricle walls

Question 8

why does it contract from the apex

Answer 8

pushes the blood up to the aorta and pulmonary artery empting ventricles completley

Question 9

What is the line between the T and P wave

Answer 9

isoelectric line

Question 10

what is atrial fibrilation

Answer 10

rapid heart rate that may lack a P wave

Question 11

rapid heart rate that may lack a P wave

Answer 11

atrial fibrilation

Question 12

how can you tell theyve had a prevoius heart attack

Answer 12

wide qrs complex

Question 13

what does enlarged ventricle walls show

Answer 13

qrs complex showing greater voltage charge

Question 14

what is changes in the height of st and t wave show

Answer 14

insufficient blood = blocked cornoary arteries

Question 15

what is the sign of blocked cornoary arteries

Answer 15

changes in height of ST segment or T wave

Question 16

how is the frequency and force of heartbeat modified to the bodys needs

Answer 16

stimulation by nervous system of heart muscle increases and adrenaline activity increases

Question 17

what happens during P wave

Answer 17

sends excitations across both atrias from SA node

contracts atria

Question 18

what happens in the QRS complex

Answer 18

AV node transmits elecrical implse
passes throgh bundle of his
depolarisatin of ventricles - causes contractions

Question 19

T wave meaning

Answer 19

repolarisation of ventricles

Question 20

how would PQRST complex change if person doing exercise

Answer 20

shorter PR segment would be shorter

less time between atrial systole + ventricular systole

Question 21

where is blood pressure highest

Answer 21

aorta
large arteries

Question 22

% of plasma mewn blood

Answer 22

55

Question 23

main function of heamgoblin

Answer 23

transport oxygen from the lungs to respiring tissues

Question 24

2 ways erythrocytes are different

Answer 24

1 - biconcave discs
2 - reduces diffuson distance
3 - no nucleus

Question 25

what is in plasma

Answer 25

glucose amino acids vit B + C mineral ions

Question 26

what are in plasma proteins

Answer 26

blood clotting proteins antibodies

Question 27

what is haemoglobin

Answer 27

quaternary protein

Question 28

transport of oxygen equation

Answer 28

oxygen + haemoglobin = oxyhaemoglobin

Question 29

what is good about heamoglobin

Answer 29

can change its affinity for oxygen because it changes its shape

Question 30

how many haem groups does haemoglobin have

Answer 30

4

Question 31

how many oxgyen molescules can bind to each iron ion

Answer 31

1 so can bind 4 oxyegn

Question 32

what happens for the first molecule with oxygen binding

Answer 32

changes the shape of haemoglbin molecule making it easier for the second mol to attach

Question 33

what is the attacthment of oxygen mols changing shape of haemoglobin called

Answer 33

cooperative binding

Question 34

what does coorperative binding allow

Answer 34

haemoglobin to pick up oxygen very rapidly

Question 35

when does it not change shape for oxygen binding

Answer 35

third mol

Question 36

how does it bind fourth oxygen mol

Answer 36

large increase in oxygen partial pressure to bind the fourth oxygen molecule

Question 37

what is the partial pressure of a gas

Answer 37

pressure it would exert if it were the only one present

Question 38

shape of graph because of cooperative binding

Answer 38

haemoglobin exposed to increasing partial pressures of oxygen shows a simoid (S shaped) curve

Question 39

what happens at very low oxygen partial pressure

Answer 39

difficult for haemoglobin to load oxygen

Question 40

what happens at high partial pressures of oxygen

Answer 40

percentage saturation of oxygen is very high

Question 41

what does a very small decrease in oxygen partial pressure lead to

Answer 41

lot of oxygen dissasociating from haemoglobin

Question 42

what would higher partial pressure of oxygen lead to

Answer 42

oxygen affinity would too low, oxygen would be readily released and wouldnt rwach respiring tissues

Question 43

what is partial pressure of oxygen linked to

Answer 43

oxygen affinity

Question 44

lower partial pressure of oxygen is linked to

Answer 44

too high oxygen affinity, oxygen would not be released in respirign tissues even at low oxygen partial pressures

Question 45

how does fetus absorb oxygen

Answer 45

from maternal haemogobin at the placenta

Question 46

whats the difference in fetal haemoglobin

Answer 46

2 of the 4 polypeptide chains from the haemoglobin of an adult

Question 47

what does the difference in fetal haemoglobin allow

Answer 47

higher affinity for oxygen at the same partial pressure of oxygen

Question 48

percentage saturation of fetus blood vs maternal

Answer 48

higher

Question 49

where is haemoglobin found

Answer 49

blood only

Question 50

how many oxygen molecules can be joined in haemoglobin at one time

Answer 50

4

Question 51

haemoglobin oxygen affinity compared to myoglobin

Answer 51

low

Question 52

saturation of haemoglobin

Answer 52

never reaches 100% oxygen saturation

Question 53

where is myoglobin found

Answer 53

in muscle tissues

Question 54

how many oxygen mols can myoglobin takes

Answer 54

one

Question 55

oxygen affinity of myoglobin compared to haemoglobin

Answer 55

higher

Question 56

saturation levels of myoglobin

Answer 56

can resch 100%

Question 57

what happens when co2 conc increases

Answer 57

haemoglobin releases oxygen more readily

Question 58

whats the bohr effect

Answer 58

curve moving to the right because of higher CO2 conc

Question 59

what would a move to the left on a bohr effect mean

Answer 59

low co2 conc

Question 60

how many ways is there for co2 to be transported

Answer 60

3

Question 61

3 ways co2 can be transported

Answer 61

in plasma as hydrogen carbonate bound to haemoglobin

Question 62

how does c02 get into a red blood cell

Answer 62

- diffuses in - carbonic anhydrase catalyses the combo of c02 and water to make carbonic acid

Question 63

what happens when c02 changed into carbonic acid in the blood cell

Answer 63

dissolves into H+ and HC03- ions Hc03- ions diffuses out

Question 64

whats the chloride shift

Answer 64

to balance outflow of neg ions (hc03-) chloride ions diffuse in

Question 65

what do the H+ ions from c02 which has diffused into blood cells do

Answer 65

cause oxyhaemoglobin - oxygen + haemoglobin h ions combine with haemoglobin to make haemoglobonic acid oxygen diffuses out of the cell

Question 66

explination cause of c02 why bohr effect happens

Answer 66

more c02 produces more H+ ions so more oxygen is released from oxyhaemoglobin

Question 67

just reminder o'r tissue fluid thing its in your medical notes