Chapter 9 Flashcards
Heart
A pump which circulates blood throughout the body
Arteries
A blood vessel that takes blood away from the heart to different organs in the body.
Capillaries
Small blood vessels that are attached to both arteries and veins.
One-Way Flow of Blood
A flow of blood that goes into one specific direction throughout the body in blood vessels.
Semi-lunar Valves
Present in veins and heart chambers that prevent the back flow of blood.
Deoxygenated Blood
Blood that contains only a little bit of oxygen.
Oxygenated Blood
Blood that contains a lot of oxygen.
Purpose of the Circulatory System
To transport waste and glucose throughout the body.
How do Valves Open and Close?
When the pressure of the blood presses against them they open and when the blood flows back to fill the pockets they close.
Single Circulation
When blood flows only once through the heart.
Why is it easier for blood to be transmitted to the lungs?
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.
Name and identify the structures of the mammalian heart
the muscular wall, the septum, the left and right ventricles and atria, one-way valves and coronary arteries
Where is blood pumped away from the heart?
arteries
Where is blood pumped in to the heart?
veins
How can the activity of the heart be monitored?
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.
Investigate and state the effect of physical activity on the pulse rate
Describe coronary heart disease
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.
State the possible risk factors of coronary heart disease
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)
Name and identify the atrioventricular and semilunar valves in the mammalian heart
atrioventricular valves are under the right atrium and the semilunar valves are at the base the pulmonary artery and aorta.
Explain the relative thickness of the muscle wall of the left and right ventricles
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.
Explain the relative thickness of the muscle wall of the atria compared to that of the ventricles
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.
Explain the importance of the septum
it separates oxygenated blood and deoxygenated blood
Describe the functioning of the heart
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.
Discuss the roles of diet and exercise in the prevention of coronary heart disease
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.
Describe ways in which coronary heart disease may be treated
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.
Describe the structure and functions of arteries, veins and capillaries
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.
Name the main blood vessels to and from the heart
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.
Name the main blood vessels to and from the lungs
the pulmonary artery to and pulmonary veins from
Name the main blood vessels to and from the kidneys
the renal artery to and renal vein from
Explain how the structures of arteries, veins and capillaries are adapted for their functions
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
State the function of arterioles, venules and shunt vessels
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.
Outline the lymphatic system in terms of lymphatic vessels and lymph nodes
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.
Describe the function of the lymphatic system
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.
List the components of blood
The blood contains red blood cells, white blood cells, platelets and plasma
Identify red and white blood cells, as seen under the light microscope, on prepared slides and in diagrams and photomicrographs
Red blood cells are discs without nuclei and white blood cells are globs with nuclei.
State the functions of the red blood cells
it is responsible for transporting oxygen in the body using haemoglobin which bond with oxygen to form oxyhemoglobin to allow it to be carried.
State the functions of the white blood cells
It is responsible for phagocytosis (taking pathogens into vacuoles to be digested) and antibody production
State the functions of the platelets
It is responsible for clotting in the blood to prevent you from free bleeding.
State the functions of the plasma
It is responsible for the transport of blood cells, ions, soluble nutrients like glucose or amino acids, hormones and carbon dioxide
Identify lymphocyte and phagocyte white blood cells, as seen under the light microscope, on prepared slides and in diagrams and photomicrographs
Lymphocytes have a more rounded nucleus and phagocytes are a more free nucleus and shape.
State the functions of lymphocytes
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)
State the function of phagocytes
it is responsible for phagocytosis. They ingest pathogens and take them into food vacuoles, then digest them using enzymes which kill them.
Describe the process of clotting
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.
State the roles of blood clotting
It is responsible for preventing blood loss and preventing the entry of pathogens into your blood vessels.
Describe the transfer of materials between capillaries and tissue fluid
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.
tissue fluid inside lymph vessels are called?
lymph
