Kidneys, thermoregulation, blood glucose, endocrine system

Question 1

dialysis vs kidney transplant

Answer 1

Dialysis:

• no shortage of machines
• requires frequent treatments (7x a week) and controlled diet so not to produce too much urea
• expensive (longterm)

Transplant:

• shortage of donors
• allow patients to lead a normal life
• only expensive initially
• patients must take anti-rejection drugs for rest of their life

Question 2

Kidney Transplant (what is it)

Answer 2

Failed kidney replaced with a healthy kidney from donor.
Some cases the donor kidney is rejected from patients immune system so they must take anti-rejection drugs for their whole life

Question 3

Kidney Dialysis ( process)

Answer 3

Patients blood passes over a semi permeable membrane (only allows water, ions, blood cells and urea through).
Other side of membrane is the dialysis fluid which contains the normal concentration of water and but NOT any urea.

There is a concentration gradient for urea, so the urea uses osmosis from blood to fluid.
The fluid is refreshed constantly to ensure there is a large concentration gradient of urea.
There is a normal concentration of water and ions so some water and some ions will diffuse past the membrane , this will make th concentrations of the patients blood return back to normal

Question 4

Someone who has a kidney failure

Answer 4

When someone has a kidney failure, their blood will contain a higher concentration of water, ions and urea than it should.

Question 5

Kidney Dialysis

Answer 5

Filtration from the blood to dilalysis fluid of water, ions and urea through a semi permeable membrane using a machine

Question 6

urea

Answer 6

waste product of metabolic breakdown of proteins

Question 7

Water levels - sweating/ too much salt on a hot day

Answer 7

1) water content of blood too low
2) Pituitary gland secretes a lot of ADH
3) kidney becomes more permeable
4) high volume of water reabsorbed by kidney (kidneys conserve the water so that there is more water for the body)
5) small volume of concentrated urine to bladder
6) high volume of water in blood
6) content of water is normal

Question 8

Water level - drink too much

Answer 8

1) water content of blood too high
2) little amounts of ADH released by pituitary gland
3) Kidneys become less permeable
4) low volume of water reabsorbed by kidneys
5) high amounts of dilute urine to bladder
6) low volume of water in blood
7) water content of blood back to normal
6) content back to normal

Question 9

Concentration Gradient

Answer 9

The difference in concentrations of a substance between two areas

Question 10

normal human temperature?

Answer 10

37 degrees celcius

Question 11

thermoregulatory centre + skin (receptors)

Answer 11

How the body’s temperature is controlled by the brain in hypothalamus . It contains receptors which are sensitive to the temperature of the blood.
The skin also contains temperature receptors which send electrical impulses down sensory neurons to thermoregulatory centre.

Question 12

What happens when the body gets TOO HOT

Answer 12

1) sweat glands release sweat onto surface of skin. The sweat evaporates taking energy from the body, cooling it down.
2) flushing : episodes of redness on skin
3) vasodilation: blood vessels dilate (become wider) increasing the blood flow to working muscles. this heat is transferred out of the blood so body temperature returns back to normal

Question 13

What happens when the body gets TOO COLD

Answer 13

1) vasoconstriction : blood vessels constrict (get narrower) to restrict blood flow to working muscles. Less blood means less heat is lost from the body.
2) shivering, our muscles contract. To generate energy for this, muscle cells increase their rate of respiration which releases heat which warms our body.
3) stop sweating
4) hairs stand up to trap insulating air

Question 14

Homeostasis

Answer 14

The maintenance of a constant internal environment

Question 15

hormones

Answer 15

chemical messengers that control certain functions in the body
they are produced in various organs that make up the endocrine system

Question 16

Thyroid Gland (endocrine system)

Answer 16

Produces thyroxine which is involved in growth and regulating the body’s basal metabolic rate (reaction time)

• increases heart rate
• improves oxygen uptake

over production effects : too fast heart rate

Question 17

Pituitary Gland (endocrine system)

Answer 17

The ‘master gland’ in brain.
Releases a number of different hormones in the blood depending on conditions
ACTS ON OTHER GLANDS -> causing other hormones to be released which can trigger different effects on the body

Question 18

Adrenal glands (endocrine system)

Answer 18

Produces adrenaline which is produced in times of fear or stress

• blood flow increases
• fight/flight
• senses heightened

Question 19

Pancreas (endocrine system)

Answer 19

Produces insulin which controls the concentration of glucose in blood.

Question 20

Testes (endocrine system)

Answer 20

Produces testosterone which is involved in puberty and reproduction

Question 21

Ovaries (endocrine system)

Answer 21

Produces oestrogen which is involved in puberty and reproduction.

Question 22

Female endocrine system

Answer 22

pancreas -> insulin 
thyroid gland -> thyroxine 
pituitary gland -> acts on other glands
adrenal glad -> adrenaline 
ovaries -> oestrogen

Question 23

Male endocrine system

Answer 23

pancreas -> insulin 
thyroid gland -> thyroxine 
adrenal gland -> adrenaline 
pituitary gland -> acts on other glands
testes -> testosterone

Question 24

The endocrine system

Answer 24

How the body is controlled via hormones which consists of glands that secrete hormones directly into the bloodstream
(each hormone acts on a specific target organs for an affect)

1) hormones release by endocrine glands into blood system
2) they travel around body to target organs
3) pituitary gland is the master gland and controls a number of other endocrine glands

Question 25

Differences between Nervous System and Endocrine System

Answer 25

n-> uses electrical impulses which travel down neurons , extremely fast but short lasting

e-> uses hormones (chemicals) that are carried in bloodstream, slower effect but long lasting

Question 26

Blood glucose control after a rich meal of carbs

Answer 26

1) concentration of blood glucose levels rises
2) causes the pancreas to produce and release insulin as blood glucose levels are too high
3) triggers livers to concert glucose into glycogen
= blood glucose levels fall
4) pancreas releases and produces the hormone glucagon
5) triggers liver to convert glycogen into glucose to increase the blood glucose concentrations

Question 27

Glucose levels rise

Answer 27

Glucose level rise -> pancreas produces hormone insulin which travels through the bloodstream triggering the liver and muscles to convert glucose into glycogen. Returning glucose levels back to normal.

Question 28

Glucose levels fall

Answer 28

Glucose level falls -> pancreas produces glucagon as there is no glucose, the stored glycogen is then converted into glucose by the liver. Glucose levels return back to normal.

Question 29

glycogen

Answer 29

what glucose is stored as in the liver

Question 30

glucagon

Answer 30

produced when all glucose is gone

Question 31

Which 2 factors affect blood sugar levels?

Answer 31

eating -> increase blood sugar levels

exercise -> decreases blood sugar levels, increases respiration

Question 32

Type 1 diabetes

Answer 32

• Pancreas does NOT produce insulin = not enough sugar
• Effects major organs (heart, blood vessels, eyes, nerves, kidneys)
• treatments: taking insulin by injection
• symptoms: increased thirst, frequent urination, increases hunger, fatigue
• genetic disorder

Question 33

Kidney Transplant pros and cons

Answer 33

pros:

• have a normal lifestyle as no dialysis
• the recipient can have extra life

cons:

• expensive
• shortage of donors
• only lasts around 10 yrs
• risk of infection –>risk that the antibodies of the immune system of recipient will attack the antigens of the donor organ. This results in rejection and destruction of kidney.
• some religions don’t allow it
• a good tissue match is needed for donor kidney to reduce infection

Question 34

Why are the kidneys important?

Answer 34

• Water and ion content in the blood and body is kept constant.
• If not regulated, cells will take up water by osmosis , they will eventually swell up, burst and die

Question 35

How is blood filtered in the kidneys - urine to bladder

Answer 35

1) Blood enters capillaries , causing pressure so fluid enters nephrons in kidney
2) Blood is filtered in kidney in millions of nephrons
3) Reabsorption of useful substances (inc glucose) in blood
4) ureter (connects kidney to bladder) releases urine

Question 36

What damages kidneys (lead to failure)

Answer 36

Diabetes
High blood pressure
Drugs
Kidney stones

Question 37

function of the kidneys

Answer 37

to keep the water content of the body relatively constant (homeostasis)

Question 38

ADH

Answer 38

Anti-diuretic Hormones

• controls the permeability of kidney tubules
• controls how much water is reabsorbed in the nephrons
• secreted by pituitary gland

Question 39

Ureter

Answer 39

connects kidney to bladder

Question 40

Type 2 diabetes

Answer 40

• When the liver doesn’t recognise insulin = too much sugar in bloodstream
• Treatments: healthy eating, regular exercise, weight loss
  -same symptoms as type 1
  = largely diet related

Question 41

deamination

Answer 41

Liver breaking down amino acids to produce urea

Question 42

how is urea made/where is is made and stored

Answer 42

By excess amino acids which cannot be stored as it is toxic, so we pee them out.

= made in kidneys
= stored in bladder

Question 43

what is a gland

Answer 43

an organ in the human or animal body which secretes particular chemical substances for use in the body or for discharge into the surroundings.