Unit 1: Section 5 - Circulatory System Flashcards Preview

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Flashcards in Unit 1: Section 5 - Circulatory System Deck (52)
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1

The right side of the heart pumps what blood to were?

Deoxygenated to the lungs

2

The left side of the heart pumps what blood to were?

Oxygenated to the body

3

Where does deoxygenated blood enter the heart?

Vena cava

4

Where does deoxygenated blood leave the heart?

Pulmonary artery

5

Where dos oxygenated blood enter the heart?

Pulmonary vein

6

Where does oxygenated blood leave the heart?

Aorta

7

Are the atriums or ventricle at the bottom of the heart?

Ventricles

8

What valves control what blood enter the ventricles?

Atrioventricular valves

9

What valves control what blood leaves the ventricles?

Semi-lunar valves

10

On the drawing what side will the right atrium be on?

The left hand side

11

Where are cords attached in the heart and what is their purpose?

They attach the atrioventricular valve to the ventricles to stop them being forced up into the atria when the ventricles contract

12

Why does the left ventricle have a thicker more muscular wall?

Because it needs to contract powerfully to pump blood all the way around the body

13

Why do the ventricles have thicker walls than the atria?

Because they need to pump blood out of the heart where as the atria just need to pump it a small distance

14

Why are there valves in the heart?

To stop blood from flowing backwards

15

What happens when there is higher pressure behind a valve and when there is higher pressure in front of the valve?

Forced open
Forced shut

16

What does the cardiac muscle is myogenic mean?

It can contract and relax without receiving signals from nerves

17

What is the pace maker of the heart called

Sino atrial node (SAN)

18

How does the SAN make the left and right atria contract at the same time?

It sends out regular electrical waves to both atrial walls, which causes them to both contract

19

Why are the electrical impulses passed from the SAN to the AVN?

There is non conducting tissue preventing the electrical waves reaching the ventricles, so to get these to contract the waves have to be passed to the AVN.

20

What does AVN stand for?

atrioventricular node

21

How does the AVN make the ventricles contract?

It passes the electrical waves down the bundle of His, which passes it onto the finer muscle fibres called the Purkyne fibres. The purkyne fibres carry the electricl impulse tot the left and right ventricular walls and causes them to contract

22

Why is there a delay before the AVN reacts?

To make sure the ventricle contract after the atria are emptied

23

What is cardiac output?

The volume of blood pumped by the heart per minute

24

What is the formula for cardiac output?

Cardiac output = stroke volume x heart rate

25

What is heart rate?

The number of heart beats per minute

26

What is stroke volume?

The volume of blood pumped during each heartbeat

27

What three stages can the cardiac cycle be simplified into?

1.) ventricles relax, atria contract
2.) ventricles contract, atria relax
3.) ventricles relax, atria relax

28

Why is blood forced into the ventricles when the atria contract?

It decreases the volume of the chamber, increasing the pressure pushing the blood through the valves into the ventricles

29

What happens when the ventricles contract?

It decreases the volume of the chamber, increasing the pressure, forcing the atrioventricular valves shut, forcing the semi lunar valves opening, forcing the blood out of the arties?

30

Is it vein or arties that take blood to the heart?

Veins - to the heart
Arteries - away