Unit 1- Section 5 the circulatory system

Question 0

Is the left side of the heart deoxygenated or oxygenated?

Answer 0

Oxygenated

Question 1

Is the right side of the heart oxygenated or deoxygenated?

Answer 1

Deoxygenated

Question 2

Where does the blood flow into and out of for the right side of the heart?

Answer 2

Flows in from the vena cava, then into the right atrium through the atrioventricular valve into the right ventricle. It then goes through the semi lunar valve in to the pulmonary artery

Question 3

Where does the blood flow into and out of for the left side of the heart?

Answer 3

Into the pulmonary vein, into the left atrium then through the atrioventricular valve. It then goes into the left ventricle through the semi lunar valve and into the aorta

Question 4

How is the left ventricle adapted to its job?

Answer 4

It has thicker, more muscular walls than the right ventricle because it needs to contract more powerfully to pump blood all around the body. The right side only needs to pump to the lungs which is near by

Question 5

How are the ventricles adapted to their function?

Answer 5

Thicker walls than the atria because they need to pump blood out of the heart whereas the atria only need to push blood into the ventricles

Question 6

How are the atrioventricular and semi-lunar valves adapted to their function?

Answer 6

Prevent a back flow of blood

Question 7

How are the cords adapted for their function?

Answer 7

They attach the antigen trickle valves to the ventricles to stop them being forced up into the atria when the ventricles contract

Question 8

Do the valves open one way or two?

Answer 8

One

Question 9

If there is a higher pressure behind the valve then which way is the valve forced?

Answer 9

It is forced open

Question 10

If they pressure is higher in front of the valve is the valve forced open or shut?

Answer 10

Shut

Question 11

How do you control the heart beat?

Answer 11

SAN initiates the heart beat
This sends electrical impulses to the AVN, this then delays the impulses to allow the atria to empty and ventricles to fill up.
The AVN then sends electrical impulses down the bundle of his causing the heart to contract from the base up

Question 12

How do you calculate cardiac output?

Answer 12

Cardiac output= stroke volume x heart rate

Question 13

What is a heart rate?

Answer 13

The number of heart beats per minute, you can measure this by feeling your pulse

Question 14

What is the stroke volume?

Answer 14

The volume of blood pumped during each heart beat, is measured in cm3

Question 15

What is the cardiac cycle?

Answer 15

It’s an ongoing sequence of contraction and relaxation of the atria and ventricles that keeps blood continuously circulating around the body. The volume of the atria and ventricles changes as they contract and relax. Pressure changes also occur, due to the changes in chamber volume.

Question 16

Describe the cardiac cycle

Answer 16

1. The ventricles are relaxed and the atria contract, decreasing the volume of the chamber and increasing the pressure inside the chamber. This pushes the blood into the ventricles. There is a slight increase in ventricular pressure and chamber volume as the ventricles receive the ejected blood from the contracting area
2. The atria relax, the ventricles contract decreasing their volume and increasing their pressure. The pressure becomes higher in the ventricles than in the atria which forces the AV valves shut to prevent back flow. The pressure in the ventricles is also higher than in the aorta and pulmonary artery, which forces open the SL calves and blood is forced into these arteries
3. The ventricles and atria both relax. The higher pressure in the pulmonary artery and aorta classes the SL valves to prevent back flow into the ventricles. Blood returns to the heart and the atria fill again due to the higher pressure in the vena cave and pulmonary vein. This then increases the pressure in the atria as the ventricles begin to relax, their pressure falls below the atria and so the AV valve opens this allows blood to flow freely. Then the atria contract and the process begins again

Question 17

What is the cardiovascular disease?

Answer 17

It is a general term used to describe the diseases associated with the heart and blood vessels. Cardiovascular diseases include aneurysms, thrombosis and myocardial infarction. Most cardio diseases start with atheroma formation

Question 18

What is an atheroma formation?

Answer 18

The wall of the artery is made up of several layers. The endothelium is usually smooth and unbroken. If damage occurs to the endothelium (from high blood pressure) white blood cells and lipids from the blood clump together under the lining to form fatty streaks
Over time more white blood cells, lipids and connective tissue build up and harden to form a fibrous plaque called an atheroma. The plaque partially blocks the lumen of the artery and restricts blood flow, which causes blood pressure to increase

Question 19

What is an aneurysm?

Answer 19

It is a balloon like swelling of the artery, it starts with the formation if an atheroma. Atheroma plaque damages and weakens arteries, they also narrow arteries thus increasing the blood pressure. When blood travels through a weakened artery at high pressure it may push the inner layers of the artery through the outer elastic layer to form an aneurysm, they then may burst and cause a haemorrhage

Question 20

What is thrombosis?

Answer 20

It is the formation of a blood clot. It also starts with the formation of atheromas, an atheroma plaque can rupture the endothelium of an artery. This damages the artery wall and leaves a rough surface, platelets and proteins accumulate at the site of damage and form a blood clot, this blood clot can cause a complete blockage of the artery or it may become dislodged and block a blood vessel somewhere sales in the body. Debris from the rupture can cause another blood clot to form further down the artery

Question 21

What is a myocardial infarction and how does it happen?

Answer 21

The heart muscle is supplied with blood by the coronary arteries, this blood contains the oxygen needed by heart muscle cells to carry out respiration. If a coronary artery becomes completely blocked then a complete area of the heart muscle will be totally cut off from its blood supply, receiving no oxygen. This causes a myocardial infarction (heart attack)

Question 22

What are the symptoms of a myocardial infarction?

Answer 22

Pain in the chest and upper body, shortness of breath, sweating, heart failure. A heart attack can cause damage or even death of a heart muscle

Question 23

What is coronary heart disease?

Answer 23

It is when the coronary arteries have lots of atheromas in them which restrict blood flow to the heart, they can then cause blood clots which could block flow of blood to the heart muscle, possibly resulting in a myocardial infarction

Question 24

Why is high blood pressure a common risk factor for coronary heart disease?

Answer 24

High blood pressure can cause an atheroma formation that leads to blood clots and therefore a myocardial infarction

Question 25

How can high cholesterol/poor diet increase the risk of coronary heart disease?

Answer 25

Diet high in saturated fat can lead to high blood cholesterol that leads to atheroma formation. Blood clots can then form then this increases the risk of myocardial infarction.

Diet high in salt can lead to high blood pressure that leads to atheroma formation. Blood clots can then form then this increases the risk of myocardial infarction

Question 26

How can cigarette smoking increase the risk of coronary heart disease?

Answer 26

Carbon monoxide combines the haemoglobin and reduces the amount of oxygen transported in the blood, and so reduces the amount of oxygen available to tissues. If heart muscle doesn’t revive enough oxygen it can lead to a heart attack

Question 27

What are the two gasses/effects from smoking that increase the risk of a heart attack?

Answer 27

Smoking—–carbon monoxide—–less oxygen in blood—–less oxygen to tissues—- myocardial infarction

Smoking—–fewer antioxidants—–damage of coronary artery walls—–atheroma formation—–myocardial infarction

Question 28

How can you reduce the risk of having a heart attack?

Answer 28

Stop smoking, eating fatty foods, high blood pressure may not be controlled if it is a genetic factor

reduce the risk factors as much as possible