Kidney Flashcards
Examples of what substances can be filtered from the blood.
5
- Water
- Ions
- Glucose
- Urea
- Amino acids
______ capsule
-Bowman’s
What is the tubule before the collecting duct?
-Distal convoluted duct
How many nephrons are in a kidney?
-1 million
What is the tubule after the bowman’s capsule?
-Proximal convoluted tubule
What is the arteriole before the Glomerulus?
What is the arteriole after the Glomerulus?
- Afferent
- Efferent
What happens when you are dehydrated?
- Low water potential in blood
- Detected by Hypothalamus
- ADH is released from the Pituitary gland
- ADH travels in blood to collecting duct
- ADH binds with receptors on membrane
- Aquaporins (channels) are inserted to membrane
- Increases permeability of c.duct
- More water leaves the c.duct through osmosis so more is reabsorbed into the blood.
What does the renal vein do?
-Blood leaves the kidneys and is transported to the inferior vena cava back to the heart
What does the renal artery do?
-Delivers oxygenated blood supply to the kidneys
What is the ureter?
- A muscular tube, made of smooth muscle fibres.
- Transport urine from kidney to bladder
What is the bladder?
-Hollow muscular organ. That collects urine, urine enters and exits through the urethra
What is the kidney?
- Filters water products from the blood and turns it into urine
- 3 regions- cortex, medulla and in the centre the renal pelvis
What are nephrons?
-Microscopic structure that makes up most of the kidney.. These are where the substances are processed and filtered.
The process of Ultrafiltration
- Blood enters the glomerulus via the afferent arteriole
- This creates high pressure, forcing the substances into the Bowman’s capsule creating Glomerular filtrate.
What are the three layers to pass through between the Glomerulus and the Bowman’s capsule?
- Endothelium of the blood capillaries~ small gaps between the cells that allow substances to pass through
- Basement membrane of the Bowman’s capsule~ thin layer, acts as filter to prevent larger substances passing through
- Epithelial cells of the Bowman’s capsule- Cells called podocytes have foot processes that allow substances through
What is the process of selective reabsorption?
- Fluid moves along the nephron- substances such as glucose, amino acids, some ions and water are reabsorbed.
- Glucose moves in from the P.C.T to capillary through facilitated diffusion using protein channels
- After this it uses co-transport
Process of co-transport
- Na+ pump, pumps Na+ ions out of the lining of the P.C.T. This causes a higher conc of Na+ ions in the P.C.T lumen
- Na+ ion diffuse from the lumen of the P.C.T into the lining of the P.C.T, taking with them the glucose
- There is now a high conc of glucose in the lining of the P.C.T so glucose will move into the capillary through facilitated diffusion
What % is reabsorbed?
-85% of the filtrate is reabsorbed in the proximal convoluted tubule.
What is a diuretic?
Increased urination
what is an Anti-diuretic?
Decreases urination
Osmoregulation~
What happens when you are hydrated?
- High water potential in blood
- Detected by Hypothalamus
- More ADH is released from Pituitary gland
- ADH travels in the blood to collecting duct
- ADH binds to receptors
- Aquaporins are inserted
- Increase in permeability
- More water leaves c.duct through osmosis so more is absorbed.
- Urine-dilute
- Frequent urination
Osmoregulation~
What happens when you are dehydrated?
-Low water potential
-Detected by Hypothalamus
Less ADH is released from Pituitary gland
-ADH travels in the blood to collecting duct
-Fewer ADH binds to receptors
-Fewer aquaporins inserted
-Decrease in permeability
-Less water leaves c.duct through osmosis so less is reabsorbed.
-Urine-concentrated
-Less frequent urination
High water levels =
= low salt levels
Low water levels =
= high salt levels
Where is ADH made and stored?
Adh is made in the hypothalamus and stored in the pituitary gland.
Dilute=
Area of high water potential
Concentrated=
Area of low water potential
Permeability of the descending limb
- Impermeable to ions
- Permeable to water
Permeability of the ascending limb
- Impermeable to water
- Permeable to ions
