Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OCR A Biology > 3.1.2 transport in animals > Flashcards

3.1.2 transport in animals Flashcards

1
Q

what is a closed system

A

blood is enclosed in blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a single closed system and what animals are they found in

A

one circuit around the body straight to and from the heart
fish and worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a double closed system

A

two circuits going from heart to lungs to heart to body
mammals and birds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is an open system

A

blood flows from heart to haemocoel (few vessels contain transport medium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the blood vessels attached to the heart

A

vena cava
aorta
pulmonary artery
pulmonary vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the valves in the heart

A

atrioventricular (tricuspid and bicuspid)
semi-lunar valves (pulmonary and aortic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

summarise blood flow through the right side of the heart

A

blood into vena cava
enters right atrium
goes through tricuspid valves
into right ventricle
goes through pulmonary valves
into pulmonary artery
into lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

summarise blood flow through the left side of the heart

A

blood into pulmonary vein from lungs
enters left atrium
goes through bicuspid valves
into left ventricle
goes through aortic valves into aorta
into body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the word for the heart being able to stimulate it’s own contraction

A

myogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

explain how the heart’s basic rhythm is stimulated

A

SAN causes atria to contract
AVN delays slightly then stimulates bundle of His
conducts excitational wave through to apex
purkinje fibres spread it to ventricle walls
ventricles contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a healthy electrocardiogram trace

A

typical PQRST trace

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when does systole occur on the ECG

A

QRS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

when does diastole begin on the ECG

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is bradycardia

A

increased stroke volume of the heart that decreases beats per min
athletes or disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is tachycardia

A

ver fast heart rate greater than 100bpm
fear, panic, excersise or SAN issues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is an ectopic heartbeat

A

extra beat as heart contracts before the first contraction finishes then there’s a short pause
very common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is atrial fibrillation

A

irregular waves of electrical impulses in atria that causes rapid contraction (arrythmia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does the cardiac cycle consist of

A

passive filling, systole and diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

explain the process of systole in the cardiac cycle

A

atria contract so pressure in atria increases - atrioventricular valves OPEN
blood goes down pressure gradient into ventricles
atria relax
ventricles contract
pressure in ventricles increases above pressure in atria
atrioventricular valves CLOSE
pressure in ventricles gets higher than in arteries - semi-lunar valves OPEN
blood forced into arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

explain the process of diastole in the cardiac cycle

A

ventricles relax
when pressure in ventricles drops below arteries semi-lunar valves CLOSE
when pressure in ventricles drops below atria atrioventricular valves OPEN again to allow for passive filling

21
Q

what do arteries transport

A

oxygenated blood away from heart

22
Q

what do veins transport

A

deoxygenated blood to heart

23
Q

what do capillaries do

A

exchange oxygen, nutrients and waste between blood and cells

24
Q

describe an artery

A

small lumen maintains high pressure
thick, smooth muscular wall provides strength and can contract/relax to cope with changing pressure
collagen elastic fibres to recoil and provide strength
folded endothelium lining

25
Q

describe a vein

A

large lumen to allow a greater volume of blood through at low pressure
thin wall as less support is needed
valves to prevent backflow of blood

26
Q

describe a capillary

A

squamous endothelial cell thick for short diffusion pathway
large surface area for more diffusion

27
Q

what are arterioles and venules

A

smaller versions of arteries and veins that link to capillaries to provide deoxygenated/oxygenated blood

28
Q

what is tissue fluid

A

allows transport between blood and cells via diffusion

29
Q

what is hydrostatic pressure

A

generated by heart
exerted by fluid in vessels

30
Q

what is oncotic pressure

A

exerted by plasma proteins in blood
make a water potential gradient

31
Q

describe hydrostatic pressure at the arterial end of the capillary

A

higher in the arterial end than venous end
forces fluid out of capillaries through tiny gaps in capillary walls
a smaller hydrostatic pressure forces some pressure back into capillaries

32
Q

what moves with fluid in arterial end of capillaries

A

dissolved gases and nutrients

33
Q

describe oncotic pressure in the arterial end of the capillary

A

oncotic pressure means water potential of capillaries becomes more negative as hydrostatic pressure pushes blood and fluid out so water moves into capillaries down the gradient

34
Q

is hydrostatic pressure greater in the arterial end or the venous end of the capillary

A

arterial

35
Q

what happens to excess fluid in vessels

A

not all goes through capillaries, net excess is drained into vessels of lymphatic system

36
Q

what is lymph fluid

A

made in lymph nodes
contains lymphocytes which produce antibodies and remove bacteria and pathogens

37
Q

why do people with high blood pressure produce less tissue fluid

A

net outward pressure from the arteriole end increases
forces tissue fluid out of capillary
decreases net hydrostatic pressure at venous end

38
Q

how does haemoglobin behave with oxygen generally

A

it has a high affinity for oxygen
can carry 4 oxygen molecules

39
Q

how does haemoglobin behave with oxygen in the lungs

A

oxygen diffuses into plasma
then into erythrocytes
binds to haemoglobin to maintain concentration gradient

40
Q

how does haemoglobin behave with oxygen in respiring tissue

A

oxygen dissociates from oxyhaemoglobin so it can diffuse out into respiring cells

41
Q

describe the shape of the oxygen dissociation curve

A

sigmoidal as % saturation of haemoglobin is not directly proportionate to po2

42
Q

explain why the oxygen dissociation curve is shaped like that

A

hard for 1st oxygen molecule to bind due to structure of Hb
conformation then changes
after 1st oxygen molecule associates conformation changes
conformational change makes it easy for 2nd and 3rd to associate
po2 rises, gradient steepens, more o2 diffuses into Hb
more difficult to associate 4th o2 molecule as Hb gets full and gradient less steep

43
Q

what is fetal haemoglobin

A

placenta allows transfer of o2 to foetus
low po2

44
Q

describe and explain the affinity fetal haemoglobin has for oxygen

A

stronger affinity so it gets more saturated at a lower po2, meaning oxygen can dissociate from maternal Hb easily

45
Q

how is co2 transported in blood

A

5% dissolved in plasma
10% associated with Hb to make carbaminohaemoglobin
85% uses carbonic anhydrase and chloride shift to take co2 into an erythrocyte

46
Q

explain the role of carbonic anhydrase

A

co2 diffuses into erythrocyte
co2 + h2o = carbonic acid using the enzyme carbonic anhydrase

47
Q

what happens to carbonic acid in an erythrocyte after being formed

A

a hydrogen carbonate ion and a H+ proton are produced
hydrogen carbonate ion diffuses out
H+ ion is added to Hb which acts as a buffer, making haemoglobinic acid
Cl- diffuses in to counteract negative charge (chloride shift)

48
Q

what is the bohr shift

A

in a co2 rich environment, more o2 dissociates from oxyhaemoglobin
H+ reduces affinity of haemoglobin for o2 so curve goes to the right

OCR A Biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions