Chapter 9

Question 1

Heart

Answer 1

A pump which circulates blood throughout the body

Question 2

Arteries

Answer 2

A blood vessel that takes blood away from the heart to different organs in the body.

Question 3

Capillaries

Answer 3

Small blood vessels that are attached to both arteries and veins.

Question 4

One-Way Flow of Blood

Answer 4

A flow of blood that goes into one specific direction throughout the body in blood vessels.

Question 5

Semi-lunar Valves

Answer 5

Present in veins and heart chambers that prevent the back flow of blood.

Question 6

Deoxygenated Blood

Answer 6

Blood that contains only a little bit of oxygen.

Question 7

Oxygenated Blood

Answer 7

Blood that contains a lot of oxygen.

Question 8

Purpose of the Circulatory System

Answer 8

To transport waste and glucose throughout the body.

Question 9

How do Valves Open and Close?

Answer 9

When the pressure of the blood presses against them they open and when the blood flows back to fill the pockets they close.

Question 10

Single Circulation

Answer 10

When blood flows only once through the heart.

Question 11

Why is it easier for blood to be transmitted to the lungs?

Answer 11

It is because the heart is near the lungs making the distance shorter for blood to reach the lungs. This also means there is a low blood pressure.

Question 12

Name and identify the structures of the mammalian heart

Answer 12

the muscular wall, the septum, the left and right ventricles and atria, one-way valves and coronary arteries

Question 13

Where is blood pumped away from the heart?

Answer 13

arteries

Question 14

Where is blood pumped in to the heart?

Answer 14

veins

Question 15

How can the activity of the heart be monitored?

Answer 15

by ECG, pulse rate and listening to sounds of valves closing.
ECG - It detects the heart by looking at its electrical activity. The small bump shows the atria contracting, the spike shows the contraction of the ventricles and the larger bump shows the ventricles relaxing.

Pulse rate - you can detect blood flow as a pulse as each time your ventricles beat, a wave passes along the arteries which you can feel. The pulse rate is the same as the heart rate.

Sounds - You can hear your heart sometimes; during the contraction phase the muscular walls contract to force blood out of the pulmonary artery. This causes the atrioventricular valves to shut making the first sound. Then during the relaxation phase, the ventricles relax. The blood under high pressure in the arteries causes the semi-lunar valves to shut, making the second sound.

Question 16

Investigate and state the effect of physical activity on the pulse rate

Question 17

Describe coronary heart disease

Answer 17

Healthy arteries have a smooth lining, however cholesterol made from the live can stick to their walls making them thinner. This is called coronary heart disease when this happens in your coronary arteries.

Question 18

State the possible risk factors of coronary heart disease

Answer 18

If you eat too much saturated fats, it can increase the amount of cholesterol in the blood. This can be improved by eating less saturated fats and eating more fruits and vegetables.
Other factors include too much stress, smoking, genetic predisposition (inheritance from parents), age (the chances of getting CHD increases with age) and gender ( men are more likely than women)

Question 19

Name and identify the atrioventricular and semilunar valves in the mammalian heart

Answer 19

atrioventricular valves are under the right atrium and the semilunar valves are at the base the pulmonary artery and aorta.

Question 20

Explain the relative thickness of the muscle wall of the left and right ventricles

Answer 20

The left ventricle is thicker than the right because it has to pump the blood further around the body, and against more resistance, compared with the right ventricle. The right ventricle only needs to pump to the lungs, close by.

Question 21

Explain the relative thickness of the muscle wall of the atria compared to that of the ventricles

Answer 21

The ventricles have a thicker muscle wall than that of the atriums because they need to be able to pump the blood much further to other parts of the body.

Question 22

Explain the importance of the septum

Answer 22

it separates oxygenated blood and deoxygenated blood

Question 23

Describe the functioning of the heart

Answer 23

During the relaxation phase, blood flows from the veins into the atria.

During the contraction phase in the heart:

• the atria contract and force blood into the ventricles
• the valves between the atria and ventricles open due to pressure of blood against them
• the ventricles contract to force blood out into the arteries
• valves close to prevent that blood from coming back into the atria.

Question 24

Discuss the roles of diet and exercise in the prevention of coronary heart disease

Answer 24

Exercising helps for blood flow and to train your heart to beat more at once than a lot. Diet is also important as you need to eat less saturated fats, red meats and more fruits, vegetables and poultry. These helps to reduce the risk for coronary heart disease.

Question 25

Describe ways in which coronary heart disease may be treated

Answer 25

One can go through a coronary artery bypass which helps to relieve symptoms. A blood vessel is taken from another part of the body (arm or leg) and attached below or above the the narrowed or blocked area. Coronary angioplasty involves inflating a small balloon inside the artery to widen it. A stent is then added to keep the artery open. Anti platelet medicine like aspirin prevent blood clots from forming in the artery. It helps for blood flow in the artery.

Question 26

Describe the structure and functions of arteries, veins and capillaries

Answer 26

Arteries (blood is forced in them at high pressure): - thick walls of muscle and elastic fibre to withstand pressure - narrow space for blood flow Veins: - wider space for blood flow than arteries - thinner - less muscular and have less elastic walls - the pressure inside veins is lower than arteries so no need for thick walls - semi lunar valves in veins to make sure blood flows in one direction Capillaries: - small arteries - very narrow (one red blood cell thick) - wall made up of single layer of very thin cells so it is easy for blood to pass to and from the blood.

Question 27

Name the main blood vessels to and from the heart

Answer 27

vena cava from the body to the right atrium, aorta from the left ventricle to the rest of the body, pulmonary artery from the right ventricle to the left lung and pulmonary vein from lungs to the left atrium.

Question 28

Name the main blood vessels to and from the lungs

Answer 28

the pulmonary artery to and pulmonary veins from

Question 29

Name the main blood vessels to and from the kidneys

Answer 29

the renal artery to and renal vein from

Question 30

Explain how the structures of arteries, veins and capillaries are adapted for their functions

Answer 30

arteries: - the recoil of the elastic fibres helps to push blood along so maintaining the pressure. Capillaries - large surface area to make sure a lot of a substance is transported at one time - they are one cell thick to allow the substances to easily pass into the blood vessel - pressure is low to make the flow of the blood slow to give more time for every substance molecule to pass through. High blood pressure can break the capillaries as well. Veins: - the surrounding body parts help to push the blood despite the low pressure

Question 31

State the function of arterioles, venules and shunt vessels

Answer 31

Arterioles small subdivisions of arteries that carry blood into the capillaries. They are important for regulating blood pressure They receive nerve impulses and responsible to hormones to control their diameter, helping to regulate blood flow in capillaries. Venules small blood vessels whose function is to collect blood from the capillary beds. These are thin walled which eventually unite to form a vein. Shunt links an artery directly to a vein, which allows blood to bypass the capillaries in some areas. They control blood flow via constriction and dilation. They constrict in response to the cold, cutting off blood flow to extremities and reducing heat loss.

Question 32

Outline the lymphatic system in terms of lymphatic vessels and lymph nodes

Answer 32

lymphatic vessels are joined lymph capillaries that are thin walled and contain semi-lunar valves. These lymph vessels join up to form 2 large lymph vessels which empty into the subclavian veins. At intervals along the length of lymph vessels are lymph nodes which hold lymphocytes responsible for making antibodies in the bodies immune system.

Question 33

Describe the function of the lymphatic system

Answer 33

The lymphatic system helps to get rid of waste present in tissue fluids which help substances to pass in and out of the cell and give a suitable environment by bringing them into the blood vessels. Also, the lymph nodes hold lymphocytes which are responsible for making antibodies for the bodies immune system.

Question 34

List the components of blood

Answer 34

The blood contains red blood cells, white blood cells, platelets and plasma

Question 35

Identify red and white blood cells, as seen under the light microscope, on prepared slides and in diagrams and photomicrographs

Answer 35

Red blood cells are discs without nuclei and white blood cells are globs with nuclei.

Question 36

State the functions of the red blood cells

Answer 36

it is responsible for transporting oxygen in the body using haemoglobin which bond with oxygen to form oxyhemoglobin to allow it to be carried.

Question 37

State the functions of the white blood cells

Answer 37

It is responsible for phagocytosis (taking pathogens into vacuoles to be digested) and antibody production

Question 38

State the functions of the platelets

Answer 38

It is responsible for clotting in the blood to prevent you from free bleeding.

Question 39

State the functions of the plasma

Answer 39

It is responsible for the transport of blood cells, ions, soluble nutrients like glucose or amino acids, hormones and carbon dioxide

Question 40

Identify lymphocyte and phagocyte white blood cells, as seen under the light microscope, on prepared slides and in diagrams and photomicrographs

Answer 40

Lymphocytes have a more rounded nucleus and phagocytes are a more free nucleus and shape.

Question 41

State the functions of lymphocytes

Answer 41

it is responsible for antibody production (antibodies get rid of pathogens by sticking them together, dissolving their cell membranes and neutralising toxins that some pathogens produce)

Question 42

State the function of phagocytes

Answer 42

it is responsible for phagocytosis. They ingest pathogens and take them into food vacuoles, then digest them using enzymes which kill them.

Question 43

Describe the process of clotting

Answer 43

Platelets release substances when a blood vessel is damaged to cause the conversion of the soluble protein fibrinogen to the insoluble protein fibrin to form a mesh. Red blood cells get caught under these threads and them form a clot. The clot then hardens to form a scab.

Question 44

State the roles of blood clotting

Answer 44

It is responsible for preventing blood loss and preventing the entry of pathogens into your blood vessels.

Question 45

Describe the transfer of materials between capillaries and tissue fluid

Answer 45

Substances (like glucose and oxygen) passes through the capillaries into the tissue fluid and then into the cells, waste substances (like urea and carbon dioxides) pass through into the tissue fluid and then into the capillaries. Fluid is constantly flowing from the plasma and back into the plasma.

Question 46

tissue fluid inside lymph vessels are called?

Answer 46

lymph