The heart (8)

Question 1

What muscle is the heart made of

Answer 1

Cardiac muscle

Question 2

what is the septums role

Answer 2

it separates the left side from the right side of the heart

Question 3

What produces the pumping movement of the heart

Answer 3

The regular contraction and relaxation of the cardiac muscles

Question 4

What are the atrio ventricular valves for

Answer 4

They separate the ventricles from the atrium

Question 5

Which valve is on the left

Answer 5

The biscupid valve

Question 6

Which valve is on the right

Answer 6

The tricuspid valve

Question 7

When do the valves shut and why

Answer 7

When the ventricles contract, so blood cant flow back into the atria

Question 8

What blood vessels can be seen on the outside of the heart and what do they do

Answer 8

The coronary arteries, they deliver oxygenated blood to the heart walls.

Question 9

Why are there coronary arteries on the outside of the heart

Answer 9

the heart is so thick (especially around the left ventricle) the muscle on the outside of the heart is too far away from the blood inside the ventricles to obtain o2 from it.

Question 10

What is a myocardial infection also known as

Answer 10

A heart attack

Question 11

Why are the atria walls very thin

Answer 11

Theres no need to generate high pressure blood as the blood doesnt need to be pumped far.

Question 12

Why do the left ventricle walls need to be thicker than the right ventricle wall

Answer 12

The left ventricle needs to pump blood around the body against greater resistance so high pressure blood needed

Question 13

Why must the blood from the left side of the heart be separate from the blood on the right side of the heart

Answer 13

To not mix the oxygenated blood (left) with the deoxygenated blood (right). If they were to mix the transport of o2 would be less efficient.

Question 14

Why must the blood pressure be highest in the heart compared to anywhere else in the circulatory system.

Answer 14

To ensure mass flow. Blood will flow from high pressure to low pressure

Question 15

What is a hole in the heart

Answer 15

a gap in the septum. Before birth the septum isn’t fully developed. After birth it closes, sometimes they dont fully close.the bigger holes = severe health problems.

Question 16

What is the foremen ovale

Answer 16

a gap in the septum of the heart

Question 17

With a large hole in the heart what happens

Answer 17

The deoxygenated and oxygenated blood mix, so blood does not carry enough o2 to tissues

Question 18

What is the role of the tendinous cords in the ventricles

Answer 18

They prevent the AV valves from being turned inside out.

Question 19

The 3 parts to the cardiac cycle

Answer 19

Diastole,
Atrial Systole, Ventricular Systole

Question 20

What is diastole

Answer 20

relaxation

Question 21

What happens in atrial systole

Answer 21

the pressure in the atria rises higher than that in the ventricles, so the valves are pushed downwards by the higher pressure of the blood in the atria.

Question 22

What happens in ventricular systole

Answer 22

the pressure in the ventricles rose above that of the atria, so the valves are being pushed upwards. they cant flap past their opening as they are anchored by the heart tendons holding them to the heart wall. (pressure in the ventricles rise much higher than in the atria as it has much thicker walls)

Question 23

Where are the semilunar valves

Answer 23

In the pulmonary artery and aorta

Question 24

Where are the AV valves

Answer 24

Between the atrium and ventricle

Question 25

What is a double circulatory system

Answer 25

Blood passes through the heart twice per circuit. The right side pumps deoxygenated blood to the lungs where it becomes oxygenated and then goes back to the heart. The left side pumps newly oxygenated blood around the body.

Question 26

How does the mammalian double circulatory system work

Question 27

What is the advantage to mammals having the double circulatory system

Answer 27

It keeps the oxygenated and deoxygenated blood separate, this allows for higher metabolic rates to be maintained as the blood isn't mixing.

Question 28

give a detailed explanation of the pressure changes during the cardiac cycle

Answer 28

answer separately in detail on word/paper

Question 29

give a detailed explanation of the cardiac cycle

Answer 29

answer separately

Question 30

why is aortic blood pressure always high

Answer 30

thick walls, and elastic

Question 31

which ventricle has a thinner wall

Answer 31

the right ventricle

Question 32

what creates the lub-dup sound

Answer 32

the lub is the sound of the 2 AV valves shutting at the same time. and the dup sound is the semilunar valves shutting

Question 33

when do the semilunar valves shut

Answer 33

when the pressure in the aorta is higher than in the ventricle (when the ventricle relaxes)

Question 34

why is it important that the atria contract before the ventricles contract

Answer 34

it ensures that the ventricles are filled with blood before they contract.

Question 35

what individual cells make up cardiac muscle

Answer 35

cardiomyocytes

Question 36

what are intercalated discs

Answer 36

cardiomyocytes group together to make fibres with the cell to cell boundary

Question 37

what are 2 adaptations to the heart and why are there adaptations

Answer 37

the cardiac muscle fibres branch, and there's cross fibres between the fibres. the cardiomyocytes group together to make fibres with the cell to cell boundary having an intercalated disc. these adaptations ensure efficient transmission of the contraction through the heart.

Question 38

why is cardiac muscle special

Answer 38

it never tires - it will continuously contract/relax. it is myogenic - it doesn't need any stimulation from a nerve for it to contract cardiac muscle will contract independently of the nervous system

Question 39

what are the walls of the right atrium called

Answer 39

the Sino atrial node

Question 40

what is the Sino atrial node

Answer 40

a group of specialised cardiac cells, which generate electrical impulses that pass rapidly across the walls of the atria from cell to cell making the atrial walls contract - atrial systole. so they create atrial contraction. as muscle in SAN contracts the, it produces an electrical impulse which makes the atrial walls contract (showing up on an ECG as the p wave)

Question 41

why cant electrical impulses pass from the atria to the ventricle walls

Answer 41

cos there's a ring of fibrous tissue preventing this

Question 42

how can electrical impulses pass from atria to ventricles

Answer 42

by a group of specialised muscle cells- the atrio ventricular node (AVN)(which acts as a relay point).

Question 43

what is the atrio ventricular node

Answer 43

a group of specialised muscle cells

Question 44

what happens with the impulses after reaching the AVN

Answer 44

they travel down the heart muscle fibres (the bundle of His) that spread down the septum between the ventricles. the impulses then reach the apex of the heart. the fibres then spread throughout the muscular walls in Purkyne tissue. the impulse causes the ventricular systole.

Question 45

what is the bottom of the heart called

Answer 45

the apex

Question 46

what is the advantage of impulses passing down from the bundle of His and then up through the Purkyne tissue

Answer 46

the ventricles can contract from the apex. its effective, efficient. it pushes the blood up to the arteries ensuring they are completely empty.

Question 47

in the correct order which blood vessels will an erythrocyte travel through when it leaves the heart

Answer 47

arteries, arterioles, capillaries, venules

Question 48

what acts as the pacemaker

Answer 48

the Sino atrial node (it automatically relaxes and contracts, it is myogenic)

Question 49

what does an ECG do and what does it stand for.

Answer 49

an electrocardiogram measures electrical activity in the heart as it beats.

Question 50

when do the ups and downs occur on an ECG

Answer 50

before contractions occur as these electrical impulses are what create the contractions of the muscle in the heart walls.

Question 51

what does a p wave and a t wave on an ECG represent

Answer 51

p wave - the wave of electrical activity spreading through atria walls, which is then followed by the rise in the atria as they contract. t wave - relaxed state

Question 52

cause and effect of ventricular fibrillation

Answer 52

ECG shows no patter. the muscle in the ventricle walls flutters, cause - person has suffered myocardial infection (heart attack). effect - no blood circulation, death.

Question 53

cause and effect of bradychardia

Answer 53

ECG - slower heart rate. cause - SAN not working properly, or ur really fit. effect - tired.

Question 53

cause and effect or atrial fibrillation

Answer 53

ECG - abnormal heart rate (arrythmia). cause - they don't contract properly and some are passed onto ventricles which don't contract often enough

Question 53

cause and effect of tachycardia

Answer 53

ECG - faster heart rate. cause - fright, anger, exercise.

Question 54

which side of the heart pumps deoxygenated blood

Answer 54

the right?