Heart and Blood Vessels

Question 1

what does the circulatory system consist of ?

Answer 1

blood
heart
vessels

Question 2

do all organisms need a circulatory system?

Answer 2

Small organisms, such as amoeba, do not need a circulatory system.
In these organisms, diffusion is adequate to allow for exchange of materials.

Question 3

why do large organisms need a circulatory system?

Answer 3

Large organisms require a circulatory system because diffusion is too slow to meet their needs.

Question 4

what is an open circulatory system?

Answer 4

heart pumps blood into open ended vessels and into the body cavity where cells are submerged in blood. The blood then passes back into blood vessels and to the heart
eg spiders

Question 5

what is a closed circulatory system?

Answer 5

blood remains the in the blood vessels. The exchange of materials is possible. All cells submerged in a fluid called tissue fluid

eg humans

Question 6

what are the advantages of a closed circulatory system

Answer 6

Blood can flow faster around the body.
Blood flow to specific body parts is easier to regulate

Question 7

do humans have a double circulatory system?

Answer 7

yes- the pulmonary and systemic

Question 8

what is the pulmonary circuit in humans?

Answer 8

Pumps blood to the lungs for oxygenation.
Blood exits the pulmonary artery and returns oxygen-rich via the pulmonary vein.

Question 9

what is the systemic circuit?

Answer 9

Pumps oxygenated blood around the rest of the body.
Blood exits the aorta and returns deoxygenated via the vena cava.

Question 10

what are the advantages of the double circulation system?

Answer 10

Oxygen rich and oxygen poor blood are kept separate.
High-pressure pumping: Allows blood to reach all parts of the body quickly

Question 11

wat does the hepatic portal vein do?

Answer 11

The ‘Hepatic Portal Vein’ connects the stomach and intestines with the liver.
It transports glucose and amino acids.

Question 12

what side of the heart is the systemic

Answer 12

left as this has oxygenated blood going to body

Question 13

what side of the heart is the pulmonary

Answer 13

right as this has deoxygenated blood going t lungs

Question 14

what are characteristics of arteries

Answer 14

carry blood away from the heart at high pressure
thick walls
small lumen

Question 15

what are characteristics of veins

Answer 15

carry blood to the heart
have valves
larger lumen
thinner walls than arteries
less pressure

Question 16

what are characteristics of capillaries

Answer 16

thin walls only one cell thick
allow gas exchagne

Question 17

what are branching networks found between
arteries and capillaries and veins and capillaries

Answer 17

arteries and capillaries - arterioles
veins and capillaries- venules

Question 18

what is the function of valves in veins?

Answer 18

Valves prevent the backflow of blood.

As blood in veins is under low pressure, valves are needed to prevent the blood from flowing backwards. These valves ensure that blood flows in the correct direction towards the heart.

Question 19

LORD- acronym for what?

Answer 19

left- oxygenated
right- deoxygenated

Question 20

how does deoxygenated blood flow through the heart
.

Answer 20

Deoxygenated blood enters the right atrium of the heart (from all over the body) through the vena cava.

The right atrium pumps the blood down to the right ventricle through the tricuspid valve.

The right ventricle pumps the blood out through the pulmonary artery to the lungs.

Question 21

how does oxygenated blood flow through the heart

Answer 21

Oxygenated blood enters the left atrium of the heart (blood coming from the lungs) through the pulmonary vein.

The left atrium pumps the blood through the bicuspid valve to the left ventricle.

The left ventricle pumps the blood out to the rest of the body through the aorta.

Question 22

where does the portal system begin and end

Answer 22

in the capillaries

Question 23

what supplies the heart with nutrients?

Answer 23

coronary arteries- bring nutrients to cardiac tissue from the aorta

coronary veins drains blood from the heart wall (the heart muscle) into the right atrium. This allows waste products and CO₂ to be removed from the heart tissue.

Question 24

systole means

Answer 24

Systole: the heart muscle is contracting

cardiac chambers discharge blood

Question 25

diastole means

Answer 25

Diastole: the heart muscle is relaxed. cardiac chambers fill with blood

Question 26

what controls the heratbeat?

Answer 26

Pacemaker (SA Node): Located in the right atrium. It controls heartbeat by sending out electrical impulses which cause the atria to contract.

Question 27

what happens when the sa node sends an electrical impulse to the av node?

Answer 27

AV Node: Found in the septum between the right atrium and right ventricle. When the electrical impulse reaches the AV node, which then sends a electircal impulse to the venricles causing them to contract

Question 28

what is a pulse

Answer 28

Pulse is the alternate expansion and contraction of arteries. It is caused by the left ventricles contracting and forcing blood through the aorta and into arteries causing them to expand rhythmically

Question 29

where can you feel a pulse?

Answer 29

wrist and neck

Question 30

what is blood pressure?

Answer 30

Blood pressure is the force that blood exerts on the walls of blood vessels.

Question 31

what sounds does a heartbeat make and why it is making a sound?

Answer 31

lub-dub opening and closing of valves

Question 32

what is the fraction expressing blood pressure

Answer 32

systolic over diastolic usually 120 over 80

Question 33

what is hypertension

Answer 33

abnormally high blood pressure

Question 34

what is hypotension

Answer 34

abnormally low blood pressure

Question 35

what is the average bpm

Answer 35

72

Question 36

how does exercise affect the heart?

Answer 36

Regular exercise strengthens the heart, leading to improved circulation. Exercise enhances the body's ability to transport oxygen, increasing energy levels.

Question 37

how does smoking affect the heart?

Answer 37

Carbon monoxide (CO) reduces the amount of oxygen (O₂) carried by the blood, lowering energy levels. Nicotine raises the heart rate and blood pressure, increasing the heart’s workload. Chemicals in tobacco increase the risk of blood clots.

Question 38

how does poor diet affect the heart?

Answer 38

A high-fat diet causes a build-up of cholesterol. Cholesterol can block arterioles and increase the risk of stroke or heart attack. High salt intake raises blood pressure, increasing the risk of a heart attack.

Question 39

What are the layers of the vein structure

Answer 39

Collagen Muscle and elastic fibres Endothelium Lumen