The Circulatory System Flashcards
Red blood cells
🌈carry oxygen around the body.
🌈specialised cell
🌈contain haemoglobin which is rich in iron.
🌈biconcave shape increases surface area for diffusion of oxygen
🌈absence of a nucleus allows for more haemoglobin to be carried in each cell.
White blood cells
Defence aginest disease
Platelets
Convert fibrinogen to fibrin, causing blood clotting and scab formation
Plasma
Transport cell, food molecules, carbon dioxide, hormones and urea.
Two functions of white blood cell
🌈lymphocytes - produce antibodies
🌈phagocytes- engulf and digest microorganism - phagocytosis
Cell lysis
🌈salts and other chemicals in the plasma keep its concentration stable at a concentration similar to the blood cells.
🌈If red blood cells are placed in water they will take in water by osmosis and burst.
🌈Red blood cells have no cell wall, nothing stoping them swelling and bursting.
Artery structure
🌈flow away from heart 🌈thick wall 🌈no valves 🌈muscle layer and elastic fibres 🌈small Lumen
Vein structure
🌈flows back to heart 🌈relatively thick wall 🌈valves 🌈less muscle fibres and few/no elastic fibres 🌈large lumen
Capillary structure
🌈links veins and arteries
🌈one cell thick and permeable allows diffusion, Oxygen and glucose in, carbon dioxide and urea out
🌈no valves
🌈no muscle layer or elastic fibres
Why do Arteries contain muscle and elastic fibres?
🌈They expand as the blood is pulsed through (elastic fibres give strength to prevent bursting.)
🌈After the high pressure pulse, the elastic fibres recoil and muscles contract returning the wall to its original size while maintaining some pressure in the blood.
🌈overall effect is smoothing out the blood flow.
What is the point large lumen?
Reduces friction and further aids the movement of blood
Arteries spec
Carry blood under high pressure away from heart (usually oxygenated blood)
Veins spec
Carry (usually deoxygenated) blood under low pressure towards the heart
Valves
Maintain the direction of blood flow
Capillaries spec
Allow the exchange of material with tissues through permeable walls
Flow of blood round the body
Double circulation
Benefits of regular exercise
🌈strengthens heart muscle
🌈increased cardiac output when at rest
Pulmonary vein def
Carries oxygenated blood from lungs to the heart
Aorta
Carries oxygenated blood from heart all around the body
Vena cava
Carries deoxygenated blood from the body back to the heart
Pulmonary artery
Carries deoxygenated blood from the heart to the lungs
Hepatic artery
Carries oxygen and glucose to the liver
Hepatic portal vein
Carries digested food eg glucose and amino acid from s intestine to liver
Hepatic vein
Carries glucose and amino acid from the liver around the body
C02 from respiration back to heart and lungs
Rental artery
Carries blood rich in urea to kidney for excretion
Renal vein
Carries purified blood from kidneys to vena cava and CO2 from respiration back to heart and lungs
Why does a fit person have a lower pulse rate
Stronger heart and will therefore be able pump more blood with each contraction therefore does not have to pump as often to pump same volume of blood
Why does a fit person gave shorter recovery time
Can pump more O2 to their muscles during exercise may not need to respire anaerobically therefore less lactic acid made. Recovery time quicker not need O2 to break down lactic acid
