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67 Cards in this Set
- Front
- Back
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Describe osmosis |
Diffusion of water from a dilute to more concentrated solution through a partially permeable membrane |
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What do sports drinks contain |
Sugars to replace sugars lost in respiration Water and ions to replace those lost in sweating |
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What is active transport |
Movement of substance against the concentration gradient requires engery from respiration |
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How can you increase the effectiveness of an exchange |
Large surface area Being thin Efficient blood supply Well ventilated Eg alveoli villi |
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What happens during ventilation |
Rib cage moves up and down Diaphragm becomes flatter Decrease pressure in thorax Air goes into lungs |
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How are exchange surfaces adapter to maximise effectiveness |
Thin so substances travel short distance Large suface ares so more diffuses In animals lots of blood vessels move in and out od blood quickly Gas exchanges are ventilated |
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How does carbon dioxide diffuse into a leaf |
Diffuse into air spaces then into cells Diffuses through stomata |
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What is diffused out of stomata |
Oxygen Water vapour |
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What controls the stomata |
Guard cells close if more water is lost than gained/replaced |
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When is evaporation quickest |
Hot dry windy conditions |
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How can a leaf increase surface area |
Flattened shape Air spaces (wall of cell) |
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Explain the parts of the lungs |
Air goes into the trachea Splits into bronchi Bronchi splits into small 4 tubes bronchioles Bronchioles have small bag= avioli gas exchange happens |
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What happens when you breath in |
Intercostal muscle and diaphragm contract Thorax volume increase Decrease pressure draws air in |
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What happens when you breathe out |
Intercostal muscle and diaphragm relax Thorax volume decrease Pressure increase forces air out |
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What was the iron lung |
Giant case Air pumped out of it the pressure dropped draws air in Air pumped in increase pressure forces air out Could interfere with blood flow |
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Explain modern ventilators |
Pumps air into lungs ribcage expands Stops pumping ribcage relaxs pushes air out |
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What is the job of lungs |
Transfer oxygen into the blood and remove waste carbon dioxide |
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How are avioli specialised to maximise diffusion |
Enormous surface area Moist lining to disolve gases Thin walls Good blood supply |
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Where are villie |
Small intestines |
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What is the role of villi |
Increase surface area so food can be absorbed quickly into the blood |
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Explain how root hair cells take in minerals |
Concentration higher in cell then in plant soo active transport Needs energy from respiration |
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Explain how active transport is used in the gut |
High concentration or glucose and amino acids get diffused out into blood When concentration is lower active transport is used for the remains |
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What does phloem do |
Transport food substances made in leaves to growing regions Transport in both directions Made of living cells |
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What does xylem do |
Transport water and minerals from roots to stem and leaves Made of dead cells |
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Explain transpiration |
Cause by evaporation and diffusion Slight shortage of water in leaf Drawn up through rest of plant through xylem Water escapes from leaves through stomata |
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Explain the double circulatory system |
1st one pumps deoxygenated blood to the lungs then comes back 2nd one pumps oxygenated blood to organs to give out oxygen Deoxygenated blood goes back to the heart |
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Name the four chambers in the heart |
Right atrium Right ventricle Left atrium Left ventricle |
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The right side of the heart contains what |
Pulmonary artery Vena cava |
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What is in the left side of the heart |
Pulmonary vein Atora |
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Explain how blood is pumped around the heart |
Blood flows into vena cava and pulmonary vein Atria contracts pushing blood into ventricles Ventricles contract pushing blood into pulmonary artery and aorta out the heart Goes to organs through arteries returns into vein |
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Name 3 types of blood vessels |
Artery Vein Capillaries |
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Explain arteries |
Carries blood away from heart Blood pumped out at high pressure so thick Thick wall compared to lumen |
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Explain capillaries |
Arteries branch into capillaries Tiny used to exchange substances Permeable wall 1 cell thick Supply food and oxygen |
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Explain veins |
Capillaries join up to form veins Bigger lumen Valves= flows in 1 direction Lower pressure |
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Explain red blood cells |
Carry oxygen from lungs to all cells Concave shave=larger surface area No nucleus=more room for oxygen Contains haemoglobin Combines with oxygen=oxyhaemoglobin In tissue reverse oxyhaemoglobin breaks up to release oxygen |
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Explain white blood cells |
Have nucleus Engulf unwanted microorganisms Produces antibodies+antitoxins |
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Explain platelets |
Small fragment of cell no nucleus Clots at wound stops blood pouring out Stops microorganism getting in |
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Explain plasma |
Liquid that carries: Red white blood cells plasma Glucose amino acid Co2 from organs to lungs Urea from liver to kidneys Hormone Antibodies antitoxins |
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What is artificial blood |
Blood substitute salt solutions saline Safe if no air bubbles get into blood Keep people alive if 2/3 red blood cell lost |
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What is an artificial heart |
Mechanical device put in humans to pump blood Temporary fix |
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What are the advantages of an artificial heart |
Not rejected as made metal/plastic |
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Disadvantages of artificial heart |
Surgery leads to bleeding and infection Dont work as well and natural heart Wear out/motor fail Blood dont flow smoothly causes clots leads to strokes |
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Can you replace heart valves with mechanical valves |
Yes |
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What are stents |
Tubes inserted in arteries to keep it open Lower risk of heart attack in coronary heart disease |
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What is coronary heart disease |
When fatty disposits block arteries |
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What is homeostasis |
Maintenance of a constant internal environment |
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What are the 6 things that need to be controlled |
Body temperature Water content Ion content Blood sugar level Carbon dioxide Urea |
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Whats in the brain that acts as a personal thermostat |
Thermoregulatory centre Receptors sensitive to temperature in blood flow Receives impulses from the skin |
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What happens when your hot |
Hair lies flat Sweat produced Blood vessels suppling the skin dilate more blood close to surface easy heat transfer |
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What happens when you're cold |
Hair standa traps air No sweat Bloos vessels supplying skin capillaries constrict close off blood supply to skin Shiver (muscles contract) requires respiration engery released warms the body |
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What do kidneys do |
Remove urea from blood Adjustment of ions in blood Adjustment or water content in blood |
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How do kidneys remove urea |
Protien cant be stored so converted into fat and carbs Occurs in liver urea is a waste product its poison Release into blood stream kidneys filter it out Temporarly stored in bladder in urine and excreted |
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How does the body adjust ion content |
Kidneys remove it Lost in sweat Too much or too little = cell damage Balance maintained by kidneys |
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How is water lost from our bodies |
Sweat Urine Air we breath out |
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How is the water balance controlled |
Liquids consumed Amount of sweat Amount excreted by kidneys Cold day less sweat more urine dilute plae Hot day more sweat less urine concentrated darker |
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What do sports drinks contain |
Water Ions Sugars |
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What are nephrons |
Filtration units in kidneys |
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Explain ultra filtration |
High pressure squeeze water and urea ions and sugar out of blood into bowmans capsule Membrane between blood vessels and bowman capsule like filter stops protien and blood cels as big molecules |
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Explain reabsorption |
All useful substance are reaborbed when flowing through nephron All sugars are reabsorbed Sufficient ions excess are not Sufficient water |
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Explain dialysis machine |
Blood flows along side selectively permeable barrier surrounded by dialysis fluid permeable like membrane in kidneys Dialysis fluid same concentration of ions and glucose as healthy blood=useful disolved ions and glucose wont be lost Can cause blood colts or infection |
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True or false transplant organs can be rejected |
True so donors with similar tissue type are chosen |
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What happens when the blood glucose level is to high |
Insulin is added secreated from pancreas Insulin makes liver convert glucose into glycogen |
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What happens when blood glucose level is to low |
Glucagon is added secreated from pancreas Glucagon makes liver convert glycogen into glucose |
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What is type 1 diabetes |
Condition where the pancreas make little or no insulin so blood glucose level rises |
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How can type 1 diabetes be treated |
Inject insulin before eating this gets rid of glucose as soon as its digested Avoid foods high in carbs |
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How do you get insulin for the injection |
Taken from pigs or cows Now genetically engineered |
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Are there any cures for type 1 diabetes |
Yes pancreas transplant Research in artificial pancreas and stem cell |
