homeostatis

Question 1

define homeostasis

Answer 1

the maintenance of a constant internal environment

Question 2

6 things homeostasis controls

Answer 2

temp
water
ions
co2 
urea
blood sugar

Question 3

how is temp regulated

Answer 3

thermoregulatory system in brain containing receptors sensitive to body temp
if too hot
-hairs lie flat
-sweat evaporates, loss of heat
-blood vessels dilate, come close to surface to give off heat
if too cold
-hairs stand up to trap insulating layer of air
-no sweat
-blood vessels close off
-shivering releases energy from respiration, warming body

Question 4

how is water regulated

Answer 4

kidneys take in water through food and drink, lose it through urine, sweat, breathing out
if too much water, more concentrated urine, more sweat

Question 5

how do kidneys regulate ions

Answer 5

taken in by food and water, absorbed into blood, excess are removed my kidneys or sweat

Question 6

how is blood sugar levels regulated

Answer 6

if too little glucose
pancreas releases glucagon into blood stream which increases the level and is stored in liver as glycogen
if too much
pancreas releases insulin into bloodstream to balance level, when balanced insulin is removed by liver

Question 7

causes of type 1 diabetes

Answer 7

pancreas releases little or no insulin, controlled by diet, exercise and injection with insulin
could have pancreas transplant, wouldn’t have to inject but could be rejected

Question 8

how is co2 regulated

Answer 8

removed by lungs from blood when you breathe out

Question 9

regulation of urea

Answer 9

waste product from reactions in liver, release into blood until kidney filters it out so it’s stored in bladder till excreted

Question 10

function of kidneys

Answer 10

keep the right level of water, ions and getting rid of waste products like co2 and urea

Question 11

nephron function in kidneys

Answer 11

filters
ultrafiltration - water urea ions sugar into bowmans capsule because of the high pressure and there small enough whereas red blood cells and proteins too big
reabsorption - useful substances reabsorped into blood, all glucose and sufficient ions and water through active transport
release of wastes - urea continues out of nephron into bladder as urine

Question 12

solutions to kidney failure

Answer 12

dialysis machine - gets rid of waste, runs the patients blood against a partially permeable membrane where waste substances diffuse out but good substances stay as the dialysis liquid has same amount of substance so diffusion doesn’t occur (3-4 times a week 3 hour)
kidney transplant - does the function of a healthy kidney, donor has to have similar tissue, could be rejected