Topic 5.10 -5.12: Kidneys Flashcards
Where is urea made
in the liver
What are the 2 purposes of the kidneys
- to filter the blood and seperate any waste products
- To regulate the levels of ions and water
How do we loose ions
through sweat
through the kidneys
How do we lose water
sweat
through lungs
through kidneys
Why is water regulation important in humans
Water moves in and out of cells by osmosis
to much water can cause cells to swell and burst
to little water can cause cells to shrink
What is a tubule
a small tube inside the kidney that absorbs most small substances from the blood
What does a tubule absorb and what doesnt it absorb
Absorbs: glucose, water, amino acids and urea
DOES NOT absorb: Cells, Protiens
What is the process where substances are absorbed into the tubules
FILTRATION
Explain SELECTIVE REABSORBTION
some substances are REABSORBED back into the bloodstream from the tubule
ALL glucose is reabsorbed
SOME water is reabsorbed
NO urea is reasborbed
What does the body do if water levels are too low
- The HYPATHALOMOUS detects the low levels and sends a message to the pituitary gland (just below it)
- The pituatry gland release the hormone ADH into the blood stream
- When it reaches the kidney the tubules detect the ADH and allow more water to be reabsorbed into the bloodstream
- meaning less urine is produced
What does the body do if water levels are too high
- The hypathalomous detects the high levels and STOPS sending signals to the pituitary gland
- less ADH is released and reaches the kidneys
- The tubules reabsorb less water into the blood
- more urine is produced
Describe the procsess of Deamination
- if theres to many amino acids they can be converted and stored as carbohydrates or lipids
- but it produces urea which needs to be excreted by the kidney
How does blood enter and exit the kidneys
In through the renal arteries
Out through the renal veins
Where does the urine travel once produced
- down the ureters
- stored in the bladder
- urinated out through the urethra
What are the two teatments for kiney failure
Dialysis
kidney transplant
What do dialysis machines do
filter a persons blood externally to make sure the right substances are being reabsorbed and the waste products are being removed
What happens when blood enters a dialysis machine
it enters the dialysis fluid but is seperated by a partially permeable membrane so only small substances can cross it not cells and potiens
What is the dialysis fluid made of and why is this important
It is made of high levels of glucose and water meaning the glucose and water is less likely to cross the membrane.
However is their is to much of any substance it will cross as there is a higher concentration in the blood
There is no urea in the dialysis fluid so most urea exits the blood
What will happen if we dont replace the dialysis fluid
the substances will reach an equillibrium so it constantly needs to be replaced
What are the disadvantages of dialysis
- time consuming, patients visit hospital 3-4 times a week
- Expensive to run
- can cause blood clots or infection
- will have to have it for their whole life
What are the disdvantages of kidney transpants
- organ may be rejected
- requires surgery
- not enough available organs
What are the advantages of a kidney transplant
- cheaper than dialysis
