Kidney Function & Failure
- Created by: Jo Wells
- Created on: 28-04-13 17:53
View mindmap
- Kidney Function
- nephrons are the filtration units in the kidneys
- 1.ultrafiltration
- a high pressure squeezes water, urea, ions & sugar out of the blood into the Bowman's capsule
- membranes between the blood vessels & Bowman's capsule act like filters so big molecules (e.g.proteins) stay in the blood
- a high pressure squeezes water, urea, ions & sugar out of the blood into the Bowman's capsule
- 2.reabsorption
- as the liquid flows along the nephron, useful substances are reabsorbed back into the blood
- all sugar is reabsorbed (via active transport)
- sufficient ions are reabsorbed (AT)
- sufficient water is reabsorbed (osmosis)
- as the liquid flows along the nephron, useful substances are reabsorbed back into the blood
- 3. release of wastes
- remaining substances (not reabsorbed) - urea - continue out the nephron
- into the ureter and down to the bladder as urine
- remaining substances (not reabsorbed) - urea - continue out the nephron
- 1.ultrafiltration
- Kidney Failure
- kidneys remove waste substances from the blood
- if they don't work properly waste substances build up in the blood, causing problems (eventually death)
- dialysis machines filter the blood
- has to be done regularly to keep concentrations of dissolved substances in the blood at normal levels & to remove waste substances
- a persons blood flows alongside a semi-permeable barrier surrounded by dialysis fluid
- is permeable to water, ions and waste substances etc
- but not big molecules (e.g.proteins)
- fluid has the same concentration of dissolved ions and glucose as healthy blood
- means useful dissolved ions & glucose won't be lost from the blood
- only waste substances diffuse across the barrier
- is permeable to water, ions and waste substances etc
- most patients need to have a dialysis session 3 times a week, with each session taking 3-4 hours
- dialysis may cause blood clots or infections
- transplanted organs
- donor kidney can be rejected by the patient's immune system
- the foreign antigens are attacked by the patient's antibodies
- to help prevent this from happening, precautions are taken
- a donor with a tissue type that closely matches the patient is chosen
- tissue type is based on antigens (proteins on surface of most cells)
- patient is treated with drugs that suppress the immune system
- a donor with a tissue type that closely matches the patient is chosen
- donor kidney can be rejected by the patient's immune system
- kidneys remove waste substances from the blood
- nephrons are the filtration units in the kidneys
Comments
No comments have yet been made