Chapter 7 and 8 Flashcards
What is the circulatory system?
The transporting system of the body, consisting of the heart, blood, blood vessels, lymph and lymph vessels
Functions of the blood:
Transporting oxygen and nutrients to all cells of the body; transporting carbon dioxide and other wastes away from the cells; transporting hormones to cells; maintain pH of body fluids; distributing heat and maintain body temperature; maintain water content of body fluids; protect against disease-causing microorganisms; clot when vessels are damaged.
What is plasma?
The fluid part of the blood in which the cells are suspended. (45% of the blood is plasma).
What are formed elements?
Any cell or cell-like structure in the blood.
What are red blood cells?
(erythrocytes) One of the formed elements of the blood; red blood cells contain haemoglobin.
What are white blood cells?
(leucocytes) One of the blood cells; it contains a nucleus but no haemoglobin.
What are platelets?
(thrombocytes) One of the formed elements of blood; a fragment of cytoplasm enclosed in a membrane but lacking a nucleus.
What is haemoglobin?
The pigment in red blood cells; it is involved in the transport of oxygen and some carbon dioxide throughout the body.
What is oxyhemoglobin?
Oxygen combined with haemoglobin.
Equation for oxyhemoglobin:
Hb (haemoglobin) + O2 (oxygen) = HbO2 (oxyhemoglobin)
The transport of oxygen
Oxygen combines with haemoglobin in capillaries in the lungs. Oxyhemoglobin breaks down to haemoglobin and oxygen when oxygen is low. while flowing through capillaries between body cells, red blood cells give up oxygen which diffuses into tissue fluid and then cells.
What is oxygenated blood?
Blood containing a lot of oxygen. (Bright red).
What is deoxygenated blood?
Blood that contains little oxygen. (Dark red).
Why are red blood cells suited to transport oxygen?
They contain haemoglobin which combines with oxygen:; have no nucleus so there is more room for haemoglobin molecules; shaped like biconcave discs which increases surface area for oxygen exchange.
What is carbaminohaemoglobin?
A molecule resulting from a combination of carbon dioxide and haemoglobin.
Formula for transport of carbon dioxide:
CO2 (carbon dioxide) + H2O (water) –> H2CO3 (carbonic acid) –> H+ (hydrogen ions) + HCO3- (bicarbonate ions)
Transport of carbon dioxide.
As blood flows through capillaries, CO2 diffuses into plasma. Some CO2 dissolves in plasma and some with haemoglobin and forms carbonic acid. in blood in alveoli capillaries, CO2 dissolves in plasma into air in alveolus. hydrogen ions and bicarbonate ions form carbonic acid and breaks down into water and CO2.
What is alveoli?
Air sacs in the lungs; also, the milk-secreting part of the mammary glands; singular, alveolus.
What are wastes?
Substances produced by cells that cannot be used and that would be harmful if allowed to accumulate; also called metabolic wastes.
What is the heart?
A hollow, muscular organ that pumps blood.
What is the pericardium?
A membrane that encloses the heart. Prevents the heart from over-stretching.
What is the cardiac muscle?
The muscle that forms the wall of the heart.
What is circulation?
The movement of blood through the heart and blood vessels.
What are the three blood vessels?
Arteries, capillaries and veins.
What are arteries?
A blood vessel that carries blood away from the heart.
What are capillaries?
A microscopic blood vessel which links arterioles and venules.
What are veins?
A blood vessel that carries blood towards the heart.
What is the function of valves?
Valves ensure that the blood can flow in one direction.
What are atrioventricular valves?
Valves within the heart that ensure that the blood flows through it in one direction only. When ventricles contract, blood catches between flaps, sealing off the opening between the atria and ventricles. Blood then leaves the heart through the arteries.
What are semi-lunar valves?
Valves located where the arteries leave the heart; stops blood from flowing back into the ventricles.