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22 Cards in this Set
- Front
- Back
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What are the four main components of blood? |
Plasma White blood cells Red blood cells Platelets |
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What is the function of plasma? |
Carries everything that needs transporting around the body |
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What is the function of red blood cells? |
Transport oxygen from the lungs to all the cells in the body |
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How are red blood cells adapted? |
1. Bioconcave shape - large surface area for absorbing/releasing oxygen 2. Haemoglobin - carry oxygen 3. No nucleus - more space for haemoglobin |
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What are the two types od white blood cell? |
Phagocytes and lymphocytes |
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What do phagocytes do? |
Detect anything foreign to the body (e.g. pathogens) Engulf the pathogens and digest them |
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What do lymphocytes do when a foreign antigen is detected? |
Produce antibodies Which attach to invading pathogens with foreign antigens This marks them for destruction by other white blood cells Antibodies are then produced rapidly |
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What are memory cells? |
When some lymphocytes stay in the body after the infection is fought ofd This means they can produce antibodies very fast if the same antigen is detected This makes you immune to diseases you've already had |
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What are the three types of blood vessel and what do they do? |
Arteries - carry blood away from the heart Capillaries - for exchange of materials at the tissues Veins - carry blood to the heart |
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How are arteries adapted? |
Heart pumps out blood at high pressure, so walls are strong and elastic |
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How are capillaries adapted? |
Permeable walls - so substances can diffuse in and out Walls only one cell thick - increasing the rate of diffusion by decreasing the distance |
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How are veins adapted? |
Big lumen to help blood flow despite lower pressure Have valves to keep the blood flowing in the right direction |
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In what order does deoxygenated blood travel? |
Body Vena cava Right atrium Right ventricle Pulmoany artery Lungs |
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In what order does oxygenated blood travel? |
Lungs Pulmonary vein Left atrium Left ventricle Aorta Body |
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What do kidneys excrete? |
Urine (urea, excess water, excess salt) |
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What are the three stages of filtration in the kidneys? |
Ultrafiltration Selective reabsorption Release of wastes |
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What happens in ultrafiltration? |
Blood from the capillaries flow through the glomerulus A high pressure is built up which squeezes water, urea, salts and glucose out of the blood into the Bowmans capsule |
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Why don't big molecules get squeezed out during ultrafiltration? |
The membranes between the blood vessels in the glomerulus and the Bowmans capsule act like filters |
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What happens in selective reabsorption? |
Useful substances are selectively reabsorbed bacl into the blood: All glucose is reabsorbed from the proximal convoluted tubule Sufficient salt is reabsorbed Sufficient water is reabsorbed from the collecting duct |
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What happens to the wastes of filtration? |
They form urine This continues out of the nephron, through the ureter, stored in the bladder and released via the urethra |
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What is adh and what does it do? |
Anti-diuretic hormone (hormone) Makes the nephrons more permeable so more water is reabsorbed into the blood |
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Which organ adjusts the body's water content? |
The kidneys |
