Chapter 7 - Blood And Circulation Flashcards
What are five functions of the circulatory system?
- Transport oxygen and nutrients to all cells of the body.
- Transport carbon dioxide and other wastes from all cells of the body.
- Maintaining the pH of body fluids.
- Maintaining body temperature.
- Regulating hormones around the body.
Identify, label and name blood as a transport medium
PLASMA - the matrix of blood. Makes up 55% of the blood volume. Made up of water, dissolved substances, nutrients, hormones and wastes.
Erythrocytes (red blood cells) - have no nucleus to allow more room for haemoglobin, which combines with oxygen. Live for roughly 120 days
Leucocytes - larger but fewer that erythrocytes. Defence against the dark arts. During an infection, can live for a couple of minutes. If there is no infection, can survive for many years.
Thrombocytes - small cell fragments with no nucleus. Important for normal blood clotting. Last for about 7 days.
Describe the transport of oxygen
- oxygen is not soluble in water, so only 3% of it is transported in the plasma. The other 97% is carried in combination with haemoglobin molecules to make oxy-haemoglobin.
- the presence of haemoglobin in red blood cells increases the oxygen carrying capacity by about 60 to 70 times.
- erythrocytes are well suited to their function because they contain haemoglobin, which is able to combine with oxygen. Have no nucleus to allow for more room and are shaped as biconcave discs.
Label and explain each component of the heart
Superior vena cava - major vein bring deoxygenated blood to the heart form the upper body (brain and arms)
Inferior vena cava - “ “ from the lower body (stomach and legs)
Right atrium - the receiving chamber for the deoxygenated blood.
Atrioventricular valves - prevents the back flow of blood from the ventricles to the atrium.
Right ventricle - pumps blood to the lungs
Semi lunar valves - stop blood from flowing back into the heart.
Pulmonary arteries/trunk - divides into two arteries that carry blood to each lung.
Pulmonary veins - brings oxygenated blood to the heart from the lungs.
Left atrium - (same as right atrium)
Left ventricle - (same as right ventricle)
Aorta - the main artery that pumps blood to all parts of the body except for the lungs
Septum - heart muscles that seperate the left and right sides of the heart.
Describe the three different types of blood vessels
Arteries - carry blood AWAY from the heart. They have a high pressure. Thick walls of smooth muscle that surround a small lumen (chloe grace mortez)
Veins - carry blood TO the heart. They have a low pressure and have valves that prevent the back flow of blood (Hilary Clinton).
Capillaries - carry blood between cells and around the alveoli. Very fine and have permeable membranes. Have a medium pressure.
Explain the different types of valves
Atrioventricular valves - found between the atrium and ventricle. When the ventricles contract, the flaps of tissue billow out and seal the valves between the atrium and the ventricle.
Semi Lunar valves - where the arteries leave the heart, the semilunar valves stop blood from flowing back into the heart. Each semi lunar valve has three cusps.
What happens to prevent blood loss in a damaged blood vessel?
When an injury occurs that involves damage to blood vessels, its the body’s job to minimise blood loss and prevent the entry of infecting microorganisms.
- the walls of the small arteries constrict immediately to reduce blood flow.
- the internal walls of blood vessels are usually smooth, but when damaged the surface becomes rough and causes platelets to stick and provide a plug.
What is blood clotting?
Also know as coagulation, blood clotting is a complex series of reactions that result in a formation of threads of insoluble protein called fibrin. The fibrin forms a mesh and traps materials in a clot. The thread stick to the damaged blood vessel and hold the clot in position. After the clot is formed, clot retraction occurs in which the network of fibrin contract and become denser and stronger pulling the damaged blood vessel opening together. The clot then dries and forms a scar over the wound.
What are the components of the lymphatic system?
The main functions of the lymphatic system is 1. to collect some of the fluid that escapes from the blood capillaries and return it to the circulatory system 2. Defence against the dark arts and their microorganisms.
It is a one way system.
Lymph vessels - fluid that is returned to the capillaries is called a lymph. These lymph capillaries are generally slightly larger than blood vessels and are more permeable. The lymph vessels join up to form two lymphatic ducts that empty the lymph into large veins in the upper chest.
Lymph nodes (or glands) - most numerous is the neck, armpit, groin and around the alimentary canal. Masses of lymphoid tissue that contain lymphocytes, macrophages and plasma cells. The lymph passes through several nodes before entering the circulatory system.
What is the role of the lymphatic system in defence against disease?
Some lymphs that enter nodes contain cell debris, foreign particles and micro-organisms that may cause infection and therefore need to be destroyed.
Larger particles such as bacteria, are trapped in a mesh work of fibres as the lymph flows into the nodes. The bacteria is then destroyed by large phagotic cells called macrophages.
When infections occur, the formation of lymphocytes increase and the lymph nodes become swollen and sore.
What are antigens and antibodies?
An antigen is a substance that is capable of stimulating the formation of a specific protein called an antibody. Antibodies are produced in response to an antigen and are able to combine with the antigen that initiated the response.
What are ABO blood groups?
There are two antigens involved in the ABO classification of blood groups ; antigen A and antigen B. There are four possibilities of having these antigens : group A, group B, group AB and group O.
A person with antigen A can only produce antibodies against B and fuse versa.
What are Rh blood groups?
A person with Rh antigens is said to be Rh positive. (Sames as ABO blood groups)
What is vasoconstriction and vasodilation?
Vasoconstriction - a decrease in the diameter of blood vessels, restricting the flow of blood through them.
Vasodilation - an increase in the diameter of blood vessels, allowing for an increase in the flow of blood. A vasodilator is a substance that produces a local widening or dilation of blood vessels.
