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AQA A-Level Biology Year 1 > Mass Transport in Animals > Flashcards

Flashcards in Mass Transport in Animals Deck (46)
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1

What are the two components of blood?

liquid plasma and cells

2

What is plasma?

transports dissolved glucose, amino acids, urea, ions and hormones

3

What are the majority of the cells in the blood?

red blood cells

4

What are the other type of cells in the blood?

white blood cells- invloved in the immune response

5

Why are the porportions of the comonents of the blood important?

there has to be enough plasma for the blood to flow, a small decrease and the blood becomes viscous and the heart has to pump harder.

6

What is the human heart?

The double pump of the double circulatory system (blood passes throught the heart twice)

7

What are arteries?
And what are their properties?

Take blood away from the heart.

Thick, flexible walls

inside wall- flattened cells to reduce friction

Middle wall- muscle cells and elastic fibres

outside- layer of tough protein fibres.

8

What are veins and their properties?

Take blood to the heart.

Thinner walls

Lower blood pressure

valves

wider lumen

9

What are capillaries?

8 micrometres in diameter

larger SA

Short diffusion distance

10

Which vessels enter the heart?

vena cava

pulmonary vein

11

Which vessels leave the heart?

pulmonary artery

aorta

12

Which vessels enter the kidney and which leaves?

enters- renal artery

leaves- renal vein

13

What are the location and function of the coronary arteries?

wrap around the outside of the heart.

sends blood flow to the heart.

14

What is cardiac muscle consisted of?

branced myofibrils separated by intercalated discs

15

What is heart rate?

the number of cardiac cycles per minute

16

What is stroke volume?

the volume of blood pumped out of the left ventricle during one cardiac cycle.

17

What is cardiac output?

the volume of blood the left ventricle pumps out to the body per minute.

18

What is coronary heart disease?

any condition that interferes with the coronary arteries that supply blood to the heart muscle

occurs when they become blocked by fatty diposits.

19

What is the cardiac cycle?

the sequence of stages that happen during one heartbeat

20

What is systole?

the stage in the cardiac cycle when the muscles of the heart chambers are contracting

21

What is diastole?

the relaxation of the muscles

22

What are the three stages of the cardiac cycle?

Atrial systole

Ventricular systole

Diastole

23

What happens during the artial systole stage?

atrial msucle contracts

blood forced through the atrioventricular valves into ventricles

24

What happens during the ventricular systole stage?

ventricle muscles contract

blood forced throuhh valves into arteries

25

What happens during the diastole stage?

muscles of the ventricle relax

26

What does contraction of the muscles cause?

walls of ventricles create pressure, higher of that in the aorta and pulmonary artery, forcing open the valves.

27

What does relaxation of the ventricle muscles cause?

walls recoil, increases volume, reduces pressure and semi-lunar valves shut

28

How does blood flow back to the atria?

At a much lower pressure, walls relaxed, as atria fill, some blood passes through the valves, as they fill more, the walls contract and forces valves fully open

29

What is the vena cava?

superior and inferior

Brings blood back from the body

30

What is the aorta?

carriers blood from heart to around the body

31

What is the pulmonary artery?

carries blood from the heart to the lungs

32

What are the pulmonary veins?

returns blood from the lungs

33

What are the semi-lunar valves?

Prevent backflow into the ventricles as blood leaves the heart, e.g. the aortic valve

34

What are the atrioventricular valves?

Tricuspid on right side of heart

Bicuspid on left side of heart

-Prevent backflow into atria.

35

What are the coronary arteries?

Wrap around the outside of the heart.

Sends blood to the heart muscle

36

How to calculate cardiac output?

stroke volume x heart rate

37

What does myogenic mean?

myogenic muscle can generate its own contraction and does not need to be stiumlated by a nerve.

Caused by the atrioventricular and sinoatrial node

38

What does an ECG measure?

electrical change

39

what does an ECG look like

first small bump- atria depolarising, then av node delyaed, then the sharp rise is the ventricles depolarising, then the next bump is the ventricles repolarising.

40

How is blood adapted to transport oxygen?

small size - 7 micrometres, reduces diffusion distance

flattened disc shape- increases SA:V ratio and short diffusion pathway

Thin central part of disc- flexible, edges scrape on walls of cappilairy

absence of organelles- maximum space for haemoglobin

haemoglobin - increases the oxygen carrying capacity of blood

41

What is the structure of haemoglobin?

4 polypeptides (globins) with a haem group

Haem contains iron ion (Fe2+)

42

What is oxyhaemoglobin?

When each haemoglobin combines with a maximum of four molecules of oxygen - 100% saturated if all have combined.

43

What is the oxyhaemoglobin dissociation curve?

s - shaped

shows how much oxygen is combined at different partial pressures of oxygen

44

What is partial pressure?

How much oxygen is available to haemoglobin

45

What is cooperative binding?

where haemoglobin molecules change shape and load with oxygen more easily once the first oxygen has combined.

makes the s shape

46

What is the Bohr effect?

change in position of the dissocaition curve due to an increased concentartion of CO2

occurs in active muscles