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Flashcards in the heart Deck (66)
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1

what is single circulation

blood pressure reduced as blood passes through the gill capillaries. slows down flow to the rest of the body. limits the rate of delivery of O2 and nutrients to cells and removal of waste
efficient for level of activity of fish and don't need to maintain body temp - respire relatively less than mammals
only goes to the heart once

2

what is double circulation

heart is composed of two separate pumps
right side pumps blood to the lungs to pick up oxygen left side pumps blood at high pressure to body
necessary because of higher level of activity to maintain body temp
need to deliver and remove materials to and from cells

3

what is a mammals heart made almost entirely of

cardiac muscle which contracts without resting and doesnt need nerve muscles

4

what are the four chambers of the heart

right ventricle and right atrium
left ventricle and left atrium

5

do atria have thin or thick walls and why

thin
don't need to generate huge force

6

do ventricles have thin or think walls and why

thick
need a huge force to pump blood around the whole body

7

what separates the left and right side of the heart

septum

8

what are the purpose of valves

to prevent backflow

9

what valve is in-between the left atrium and ventricle

left atrioventricular valve
bicuspid valve

10

what valve is in between the right atrium and ventricle

right atrioventricular valve
tricuspid valve

11

what is the valve between the aorta and pulmonary arteries

semi lunar valves

12

how are valves attached to the cardiac muscle

via tendons
tendinous chordae

13

what are the major vessels of the heart

coronary vessels
pulmonary veins
pulmonary arteries
aorta artery
vena cava

14

what is the coronary vessel for

responsive for gas/nutrients/waste exchange in the cardiac muscle

15

what is the pulmonary vein for

one from each lung (oxygenated) converging into left atrium

16

what is the pulmonary artery for

from the right ventricle to the lungs (deoxygenated)

17

what is the aorta artery for

left ventricle to body (high pressure)

18

what is the vena cava for

one from upper body one from lower body to right atrium

19

in what direction does blood flow in veins

to the heart

20

in what direction does blood flow in arteries

away from the heart

21

what is an artery

large vessels which carry blood from the heart

22

what is an arterioles

small arteries which deliver blood to capillaries

23

what is a capillary

tiny tubes which deliver/collect blood as close as possible to cells. they link arterioles and venues

24

what are venules

small veins which collect blood from capillaries

25

what are veins

carry blood towards the heart

26

what is structure of blood vessels

- tough outer layer (collagen) to resist pressure
- muscle layer can contract and control the flow of blood
- elastic layer can stretch and recoil to maintain blood pressure
- endothelium smooth layer to prevent friction
- lumen not a layer but a cavity

27

describe the structure of veins

- wide lumen due to a low pressure in veins
- thins walls, less elastic and less muscular
- valves (semi lunar) to prevent back flow
- deoxygenated blood to heart from tissues
except pulmonary veins from lungs
- non pulsatile - smooth flow of blood

28

describe the structure of arteries

- narrow lumen so high pressure
- highly elastic to expand and recoil
- thick muscular wall to withstand force
- more elastic fibres (recoil)
- no valves (except aortic and pulmonary artery semi lunar at start)
- oxygenated blood from heart
except pulmonary artery to lungs
- pulsatile blood flow (expansion and recoil)
- pulse can be felt

29

describe the structure of capillaries

- no muscle
- no elasticity
- no valves
- only one cell thick

30

what does endothelium mean

thin layer of cells that lines the interior surface of blood vessels