b5 d-f

b5 d-f

d
1. when inhaling the intercostal contract causing the ribs to move up and out. at the same time the diaphragm contracts causing a decrease in pressure in the lungs which means that air flows into the lungs so the volume of air increases. When exhaling the intercostal muscles relax causing the lungs to move in and down as the diaphragm relaxes causing pressure to increase and air is forced out of the lungs which decreases the volume of air in the lungs.
2. tidal volume – the volume of air breathed in or out in one normal breath
3. vital capacity – the maximum volume of air that can be breathed out after breathing in as much as you can
4. residual volume – the volume of air left in the lungs after breathing out as hard as you can
5. mucus - dust sticks to it
6. ciliated calls have cilia which waft the muscus out of respiration system
7. polliution, dust particles, etc pass through it. once it's in there is way out. the cells are thin and delecate
8. Methods of gaseous exchange of amphibians and fish restrict them to their habitats i.e. amphibians need moist habitats, fish gills only work in water.
9. The permeable skin of amphibians makes them susceptible to excessive water loss
10. Fish gills work by forcing water across the filaments.
11. Gaseous exchange occurs within alveoli by diffusion between air and blood.
12. Gaseous exchange surfaces are adapted for efficient gaseous exchange in the following ways: permeable, moist surface, large surface area, good blood supply and thin lining (one cell thick).
13. There are lung diseases with industrial causes (such as asbestosis); with genetic causes (such as cystic fibrosis); caused by life style (such as lung cancer).
14. Asbestosis results in inflammation and scarring which limits gas exchange
15. Cystic fibrosis results in too much mucus in the bronchioles
16. Lung cancer is when cells grow rapidly reducing surface area in lungs.
17. The symptoms of asthma are: difficulty breathing, wheezing, tight chest and can be treated with inhalers.
18. During an asthma attack: lining of airways becomes inflamed, fluid builds up in airways, and muscles around bronchioles contract constricting airways.
e
1. bile is stored in the gall bladder. it neutralises material in the stomatch to an optimum ph. it helps break down fat particles into ssmaller dorplets by emulsifying.
2. smaller molecules have a larger surface area than large molecules. this means that there is a faster rate of reaction between the molecules and the enzymes
3. small intestine is adapted because...
  1. large surface area due to ridges called villi
  2. walls are only one cell thick so food molecules can easily diffuse
  3. good blood supply so food molecules are carried away and the diffusion gradient increases
  4. fat is separates from other food molecules to avoid blockages as it is carried off by the liphatic system
4. the ph of the stomach is very low. this is because it maintains an optimum level for protease enzymes to function. other enzymes work at a different ph such as in the mouth and the small intestine which have a ph close to neutral
5. The importance of physical digestion is so food can pass more easily through the digestive system and to provide a larger surface area.
6. Carbohydrates, proteins and fats are digested by specialised enzymes in the mouth, stomach and small intestine respectively: carbohydrase breaks down starch to sugar, protease breaks down protein to amino acids, and lipase breaks down fat to fatty acids and glycerol.
7. Stomach acid aids protease function.
8. Breakdown of starch is a two step process involving the breakdown of starch into maltose and maltose into glucose.
9. Small digested food molecules are absorbed into the blood plasma or lymph in the small intestine by diffusion.
f
1. if water concentration in blood plasma is too high then the blood cells absorbe the water through osmosis and will explode (lysis) blood wouldn't be able to flow and it would agglutinate
2. low water consumption - more urine less water - high consentration
3. heat/excersize - less water, more urine - high concentration
4. dialysis
  1. ‘Dirty’ blood (high in urea) is taken from a blood vessel in the arm, mixed with blood thinners to prevent clotting, and pumped into the machine. Inside the machine - separated by a partially permeable membrane the blood flows in the opposite direction to dialysis fluid, allowing exchange to occur between the two where a concentration gradient exists.
  2. Kidney failure has serious consequences as it means that the water and ion balance cannot be regulated, and the levels of toxic urea build up in the body. This would ultimately be fatal if not treated.
5. carbon dioxide is removed from the body through respiration. when CO2 reacts with water in blood plasma it created carbolic acid. carbolic acid lowers the ph of the blood. the carotid arteries in the neck detect levels of CO2 in the body. the carotid arteries send messages to the brain. then the brain send messages to muscles such as the intercostal muscles, heart muscles and muscles in small arteries telling them to contract.
6. The gross structure of a kidney and associated blood vessels includes cortex, medulla, ureter, renal artery and renal vein.
7. Kidneys work by filtering blood at high pressure, and re-absorbing water and useful substances.
8. Urea, is produced in the liver (from excess amino acids), and is removed from the blood by the kidneys.
9. The structure of the kidney tubule (nephron) is related to filtration of the blood and formation of urine. It consists of: a filter unit of glomerulus and capsule, a region for selective re-absorption, and a region for salt and water regulation.
10. The concentration of urine is controlled by the anti-diuretic hormone (ADH), released by the pituitary gland.
11. ADH increases permeability of kidney tubules so more water is reabsorbed back into the blood.
12. ADH production is controlled by a negative feedback mechanism.
13. Increased carbon dioxide levels in the blood are detected by the brain and the body responds by increasing the rate of breathing.

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