B12.1 - 12.5 - Homeostasis In Action✔️

Question 1

How is urea removed from the body?

Answer 1

Urea is removed by travelling to the kidneys through the bloodstream where it is then filtered allong with salts and water to form urine

Question 2

What is ammonia?

Answer 2

Ammonia is the waste product when amino acids are broken down in the liver - highly toxic and is converted into urea - less toxic

Question 3

What is deamination?

Answer 3

The process in which amino acids are broken down into ammonia a highly toxic waste product

Question 4

What is urea?

Answer 4

Nitrogenous wate product produced when amino acids are broken down and is less toxic then ammonia which it is converted from removed via sweating or as urine - uread is produced when you eat more protein than you need

Question 5

What can excess urea cause?

Answer 5

Urea is highly toxic and can cause damage to cells

Question 6

Ways in which water be removed from the body?

Answer 6

-skin
-urine
-faeces
-lungs

Question 7

Two ways urea can be removed and how?

Answer 7

-removed through sweating along with salts,minreal ions and water

-removed along witch excess water as urine

Question 8

What waste products does the lungs remove?

Answer 8

-removes carbon dioxide - waste product of aerobic respiration

-removes water

Question 9

What waste products does the skin remove?

Answer 9

removes minreal ions,salts,water and urea

Question 10

What waste products are removed with urine?

Answer 10

Excess water,minreal ions and urea

Question 11

Controlled way of removing excess minreal ions from the body?

Answer 11

Urinating

Question 12

Uncontrolled way of removing excess minreal ions from the body?

Answer 12

Sweating

Question 13

What chemical process produced carbon dioxide as a waste product?

Answer 13

Aerobic respiration

Question 14

Describe how carbon dioxide is transported out the body from where it is produced?

Answer 14

Carbon dioxide transported from tissues like muscles into the bloodstream and then diffuses into the air in the alveoli of your lungs out of the bloodstream - where it is then released when we exhale

Question 15

Name the organs where urea is made?

Answer 15

Liver - produced by the breakdown of excess amino acids

Question 16

Why is it important to maintain a water balance?

Answer 16

So cells do not gain or loos water through osmosis which can cause cell damage

Question 17

How does the body achieve water ballance?

Answer 17

If we are dehydrated kidneys produce less urine - which becomes more concentrated - we also get thirsty - if overhydrated the kidneys will produce large amounts of dilute urine

Question 18

Which organs removes water and carbon dioxide from the body?

Answer 18

Lungs

Question 19

Average body temperature?

Answer 19

37 degrees - temperature at which enzymes work best

Question 20

What does control of core body temperature relie on?

Answer 20

Core body temperature relies on the thermoregulatory centre in the hypothalamus of your brain

Question 21

How is the thermoregulatory centre in the hypothalamus of your brain adapted for its job?

Answer 21

Contains receptors that are sensitive to temperature changes in the blood flowing through the brain - extra information comes from temperature receptors in the skin

Question 22

What happens when core body temperature begins to rise?

Answer 22

When core body temperature begins to rise impulses are sent from the thermoregulatroy centre to the body so more energy is transferred to the surroudings to cool you down

Question 23

What is vasodilation?

Answer 23

When the blood vessels dilate (widen) as a result of the blood vessels muscular walls relaxing - helps to enhance blood flow to areas that are lacking oxygen or other nutrients

Question 24

How does vasodilation help with temperature control?

Answer 24

Blood vessles widen so skin flushes as there is more blood and more energy is transfered from your skin to the surroundings - cooling you down

Question 25

Why does the body produce more sweat to cool down?

Answer 25

More sweat from the sweat glands in your skin this extra sweat cools your body down as water evaporates from your skin - transfering more energy from your skin to the surroundings

Question 26

How does the body keep warm?

Answer 26

-vasoconstrictionin of the blood vessels - they close up which reduces energy transfered by radiation through the surface of the skin

-sweat production is reduced or stopped - less water from sweat evaporates

-skeletal muscles contract and relax rapidly causing you to shiver - muscle contratins require respiration and the energy transfered raises your body temperature

Question 27

How does the blood vessels vasconstrcting keep you warm?

Answer 27

The blood vessels constrict (close up) reducing the energy transfered by radiation through the surface of the skin

Question 28

Why are the kidneys important?

Answer 28

Important for homeostasis in the water balance of your body - kidneys conserve water if your short of it (urine little and very concentrated) if you have to much water (lot of urine and will be dilute) - kidneys also control concentration of minreal ions in your body by removing excess minreal ions by excreting them in your urine

Question 29

How do the kidneys filter the blood?

Answer 29

Glucose,minreal ion,urea and water all move out of the blood into the kidney but the red blood cells and proteins are to big and do not go into the kidney tissues - urine trickles into the bladder to be stored and the glucose is reabsorbed back into the blood by diffusion and active transport - water and dissolved minreal ion are reabsorbed depending on the bodies need for them (selective reabsorption)

Question 30

What is selective reabsortpion?

Answer 30

The body deciding the amount of water and dissolved minreal ions that are needed to be reabsorbed back into the blood - amount of water reabsorbed into blood is controlled by a sensetie feeback mechanism that makes sure the water balance of your bodily fluids and cells is always kept whithin a narrow range

Question 31

What hormone is involved in maintaining water balance?

Answer 31

ADH secreted by the pituratary gland when the receptor cells in the brain detect the concentration of solutes in the blood plasma

Question 32

What are the kidneys made up of?

Answer 32

Millions of tiny tubules - along these tubules that selective reabsorption of water and minreal ions takes place

Question 33

What happens when the concentration of solutes in the blood becomes to concentrated?

Answer 33

if the concentraion of solutes in the blood becomes to concentrated lots of ADH is released which causes the kidneys tubules to reabsorb more water returning concentration of solutes in the blood to normal

Question 34

What happens when the concentration of solutes in the blood becomes to dilute?

Answer 34

If the solute concentration in the blood becomes too dilute, less ADH is released into the blood and less water is reabsorbed in the kidneys tubules so you produce a large volume of dilute urine and the blood solute concentration returns back to normal

Question 35

Two ways of treating kidney failure?

Answer 35

-dialysis - function of kidney is carried out artificialy
-kidney transplant - failed kidney replaced with a healthy one

Question 36

How does a dialysis machine work?

Answer 36

Carries out the function of the kidneys (cleans the blood) - persons blood leaves their body and flows between partially permeable membranes (on the other side of the partially permeable membranes is the dialysis fluid which contains the same concentration of useful substance as the blood of a healthy persons)treatment of dialysis restores the concentration of these dissolved substances to that of a normal person

Question 37

Issues with dialysis tratement?

Answer 37

-takes a long time - 8 hours and may have to go to hospital if you dont have a machine at home

-have to recieve treatment severeal times a week - due to the build up of waste substance in the blood

-have to manage diet carefully - have to manage protein intake to keep urea levels low

Question 38

How is the loss of useful substances prevented during dialysis?

Answer 38

Careful control of the dialysis fluid which contains the same concentration of glucose and minreal ions as the blood of a healthy person which ensures there is no net movment of glucose out of the blood as the dialysis fluid contains normal plasma levels of minreal ions (so any excess minreal ions are removed from the blood by diffusion down a concentration gradient returning levels to normal)

Question 39

Why does the dialysid fluid contain no urea?

Answer 39

Ensures there is a steep gradient from the blood down to the fluid - ensues most of the urea leaves the blood

Question 40

What type of transport does dialysis depend on?

Answer 40

Diffusion down concentraion gradient which has to be maintained there is no active transport

Question 41

What is a problem with kidney transplants?

Answer 41

-risk of rejection - the antigens on the donor organ are different to those of the recipient and the patients immune system starts to attack the donor organ which can result in its destruction

Question 42

How to reduce risk of rejection with kidney transplants?

Answer 42

-match the antigens of the donor and the recipents - so the “tissue type” is very similar

-take immunosuppressant drugs to supress the immune system which prevents the rejection of the new organ - have to be taken your whole life

Question 43

Issues with taking immunosuppressant drugs?

Answer 43

-immunosuppressant drugs - prevent the pateient from dealing effectivley with infectious diseases - have to be carefull if they beccome ill

-transplanted organs dont last forever once it fails patient has to return to dialysis machine until another match is found - however scientists grew functioning embryonic kidney tissue from stem cell so there is perhaps a possibility of growing them without antigens

Question 44

Factors of dialysis?

Answer 44

much more expensive then a transplant and eventually dialysis causes serious damage to the body however it is more widley available and alows people with kidney failure to live an almsot normal life

Question 45

Factors of a kidney transplant?

Answer 45

You can eat and drink what you want and have an almost normal life however the disadvantages of kidney transplants are the risk of rejection and you have to take immunosuppressant drugs every day for your life an you need frequent check ups