The Circulatory System Flashcards
What are the 3 major functions of the blood?
Transport substances around body.
Defend against disease.
Help distribute heat throughout body.
What are the 4 major components of the blood.
Red blood cells.
White blood cells.
Platelets.
Plasma.
Where are blood cells made in the body?
Marrow of your bones.
Liver.
Kidneys.
What cells transport oxygen in the blood to the body cells?
Red blood cells.
How is carbon dioxide transported from body cells into the blood and carried away?
Diffusion into blood and then transported in red blood cells or dissolved in plasma.
Where does the blood gets its oxygen from?
Alveoli in lungs.
Where does blood get its red colour?
Haemoglobin which contains protein.
What is the function of haemoglobin?
Attach to oxygen so it can be carried to all parts of body in red blood cells.
What do the body cells use the oxygen for?
Cellular respiration.
How is the blood able to circulate in the body?
Heart pumping blood constantly around body.
What are the three types of blood vessels involved in transporting blood around the body?
Veins, capillaries and arteries.
Which blood vessel takes blood away from the heart?
Artery.
(Except pulmonary artery)
Which blood vessel is involved in the exchange of materials between blood and cells of the body?
Capillary.
Why do the capillaries have low blood pressure?
So blood moves slowly enough to allow for gas exchange of oxygen and carbon dioxide and diffusion of glucose between the cells and the blood.
What component of the blood helps stop bleeding and forms blood clots?
Platelets.
Which cell type is more numerous in your blood?
Red blood cells.
Which blood cell is largest in your blood?
White blood cells.
Which component of the blood transports blood cells through your body?
Plasma.
What is plasma?
Straw-coloured liquid.
What is plasma mostly made up of?
Water.
What the some examples of the dissolved substances that the plasma transports around the body?
Glucose.
Amino acids.
Fatty acids and glycerol.
Vitamins.
Minerals.
Hormones.
Carbon dioxide.
Urea.
What do white blood cells do in your blood?
Destroy germs and bacteria and help prevent disease.
What is the study of the blood called?
Haematology.
What is the function of the red blood cells?
Transport oxygen from lungs to body tissues and carbon dioxide from tissues to lungs.
What is the structure of red blood cells?
Biconcave shape.
No nucleus.
Contains haemoglobin.
What are the two types of white blood cells?
Phagocytes and lymphocytes.
What is the function of phagocytes?
Engulf and digest pathogens and debris (phagocytosis).
What is the structure of phagocytes?
Irregular shape.
Large nucleus.
Contains lysosomes.
What is the function of lymphocytes?
Produce antibodies to fight infections.
What is the structure of lymphocytes?
Large.
Round nucleus.
Small amount of cytoplasm.
What is the function of platelets?
Help in blood clotting to prevent bleeding.
How do platelets prevent bleeding?
Convert protein fibrinogen to fibrin. Fibrin forms mesh network that traps other blood components, clotting blood.
What is the structure of platelets?
Small.
Cell fragments.
No nucleus.
What is the function of plasma?
Transport nutrients, hormones and proteins throughout body.
What is the structure of plasma?
Liquid component of blood.
Mostly water.
Contains dissolved substances.
How thick is the wall of each blood vessel?
Artery - thick
Veins - thick
Capillaries - 1 cell thick
Do each blood vessel contain elastic and muscle fibres?
Artery - yes
Veins - very few
Capillaries - none
Do each blood vessel contain endothelium lining?
Artery - yes
Veins - yes
Capillaries - yes (outer wall is endothelium)
What is the size of the lumen in each blood vessel?
Artery - small
Veins - large
Capillaries - very small (however compared to artery is big)
How high is the blood pressure in each blood vessel?
Artery - high
Veins - low
Capillaries - low (allows diffusion)
Where do each blood vessel carry blood to in the body?
Artery - away from heart
Veins - back to heart
Capillaries - from arteries to veins
Do each blood vessel contain valves?
Artery - none
Veins - yes
Capillaries - none
What type of blood is carried by each blood vessel?
Artery - oxygenated blood (except for pulmonary artery to lungs)
Veins - deoxygenated blood (except for pulmonary vein)
Capillaries - both
What is the role of the elastic fibres in the artery walls?
Stretch as blood pulsed through.
Give strength to prevent bursting.
Recoil after high pressure.
What is the role of the smooth muscle in the artery walls?
Relax to allow increase in size of artery lumen as pulse of blood passes through.
Contract as elastic fibres recoil, returning wall to its original size, while maintaining some pressure in blood.
What is the overall effect of the elastic fibres and smooth muscle in the artery walls?
Smoothing out of blood flow.
Why is there little need for elastic fibres of muscle in the veins?
Blood in under low pressure and there is no pulse as blood does not need to be pumped very far around the body.
What is the role of valves in veins?
Prevent back flow of blood. (Blood kept flowing towards learn by muscles of limbs contracting).
What does the pulmonary vein do?
Carries oxygenated blood from lungs to heart.
What does the aorta do?
Carries oxygenated blood from heart around body.
What does the hepatic artery do?
Carries oxygen and glucose to liver.
What does the hepatic portal vein do?
Carries digested food (e.g. glucose and amino acids) from small intestines to liver.
What does the renal artery do?
Carries blood rich in urea to kidneys for excretion.
What does the renal vein do?
Carries purified (low in urea) blood from kidney to veins cava; also carbon dioxide (from respiration) back to heart and lungs.
What does the hepatic vein do?
Carries glucose and amino acids from liver around body; also carbon dioxide (from respiration) back to heart and lungs.
What does the vena cava do?
Carries deoxygenated blood from body back to heart.
What does the pulmonary artery do?
Carries deoxygenated blood from heart to lungs.
How does regular exercise benefit the circulatory system?
Strength heart muscle.
Increase cardiac output (pump more blood per minute) even when not exercising.
What is cardiac output?
Volume (amount) of blood pumped by heart per minute.
What is the heart rate?
How often heart beats.
What is the pulse rate?
How often a pulse or surge of blood passes round body.
What is the recovery time?
Length of time it takes for someone’s pulse rate to return to normal after exercise.
What is a double circulation system?
System where blood passes through heart twice for every complete circuit of body.
What is anaemia?
Blood disorder caused by lack of iron in diet so person has lack of red blood cells.
How is a person affected by anaemia?
Less oxygen able to reach body cells in muscle tissue, causing less energy to be produced and person being more tired and weaker.
How can anaemia be treated?
Iron supplements
Eating red meat
Blood transfusions
What is the artery that enters the small intestines?
Mesenteric artery.
Which structures stop blood flowing back into the heart when the heart pumps blood to the organs?
Semilunar valves.
What is the valve in the left side of the heart?
Bicuspid valve.
What is the valve in the right side of the heart?
Tricuspid valve.
