Kidneys, thermoregulation, blood glucose, endocrine system Flashcards
dialysis vs kidney transplant
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
Kidney Transplant (what is it)
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
Kidney Dialysis ( process)
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
Someone who has a kidney failure
When someone has a kidney failure, their blood will contain a higher concentration of water, ions and urea than it should.
Kidney Dialysis
Filtration from the blood to dilalysis fluid of water, ions and urea through a semi permeable membrane using a machine
urea
waste product of metabolic breakdown of proteins
Water levels - sweating/ too much salt on a hot day
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
Water level - drink too much
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
Concentration Gradient
The difference in concentrations of a substance between two areas
normal human temperature?
37 degrees celcius
thermoregulatory centre + skin (receptors)
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.
What happens when the body gets TOO HOT
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
What happens when the body gets TOO COLD
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
Homeostasis
The maintenance of a constant internal environment
hormones
chemical messengers that control certain functions in the body
they are produced in various organs that make up the endocrine system
Thyroid Gland (endocrine system)
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
Pituitary Gland (endocrine system)
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
Adrenal glands (endocrine system)
Produces adrenaline which is produced in times of fear or stress
- blood flow increases
- fight/flight
- senses heightened
Pancreas (endocrine system)
Produces insulin which controls the concentration of glucose in blood.
Testes (endocrine system)
Produces testosterone which is involved in puberty and reproduction
Ovaries (endocrine system)
Produces oestrogen which is involved in puberty and reproduction.
Female endocrine system
pancreas -> insulin thyroid gland -> thyroxine pituitary gland -> acts on other glands adrenal glad -> adrenaline ovaries -> oestrogen
Male endocrine system
pancreas -> insulin thyroid gland -> thyroxine adrenal gland -> adrenaline pituitary gland -> acts on other glands testes -> testosterone
The endocrine system
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
Differences between Nervous System and Endocrine System
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
Blood glucose control after a rich meal of carbs
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
Glucose levels rise
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.
Glucose levels fall
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.
glycogen
what glucose is stored as in the liver
glucagon
produced when all glucose is gone
Which 2 factors affect blood sugar levels?
eating -> increase blood sugar levels
exercise -> decreases blood sugar levels, increases respiration
Type 1 diabetes
- 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
Kidney Transplant pros and cons
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
Why are the kidneys important?
- 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
How is blood filtered in the kidneys - urine to bladder
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
What damages kidneys (lead to failure)
Diabetes
High blood pressure
Drugs
Kidney stones
function of the kidneys
to keep the water content of the body relatively constant (homeostasis)
ADH
Anti-diuretic Hormones
- controls the permeability of kidney tubules
- controls how much water is reabsorbed in the nephrons
- secreted by pituitary gland
Ureter
connects kidney to bladder
Type 2 diabetes
- 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
deamination
Liver breaking down amino acids to produce urea
how is urea made/where is is made and stored
By excess amino acids which cannot be stored as it is toxic, so we pee them out.
= made in kidneys
= stored in bladder
what is a gland
an organ in the human or animal body which secretes particular chemical substances for use in the body or for discharge into the surroundings.
