The mammalian kidney

?
After the filtration in the kidneys, where does the urine go?
It passes out of the kidneys through the ureters into the bladder, once the bladder is full the sphincter at the end of the bladder opens and the urine passes out of the body through the urethra
1 of 18
When a kidney is sliced open, what are the 3 main areas to it?
The cortex (Dark outer layer, dense capillary network), the medulla (lighter area, contains the tubules that for the pyramids and collecting ducts) and the pelvis (a central chamber where the urine collects before passing out)
2 of 18
Bowmans capsule
A cup-shaped tubule that contains the glomerulus
3 of 18
Glomerulus
A tangled network of capillaries with the afferent arteriole entering (wider) and the efferent arteriole leaving (narrower), this causes a relatively high pressure
4 of 18
Proximal convoluted tubule
The first coiled region of the tubule in the cortex of the kidney
5 of 18
Loop of Henle
Long loop of tubule that creates a very high solute concentration, in the medulla
6 of 18
Distal convoluted tubule
The second coiled region of tubule also in the cortex
7 of 18
Collecting duct
The tube urine passes down into the pelvis
8 of 18
Describe ultrafiltration
Afferent arteriole wider than efferent build up pressure, plasma and all small molecules in blood are forced out into the bowman's capsule, forming glomerular filtrate, cells and plasma proteins stay in capillaries because they are too large
9 of 18
What is the basement membrane
A membrane made up of collagen fibres which acts as a second sieve for the glomerulus filtrate to pass through
10 of 18
What are podocytes?
Special cells that wrap around the capillaries with little slits in to make sure any cells, platelets or large plasma proteins that have manages to pass through the epithelial cells and the basement membrane, don't get into the bowman's capsule
11 of 18
Describe selective reabsorption
This occurs on the proximal convoluted tubule, glucose, vitamins and amino acids are reabsorbed, some of it is by diffusion but most is by active transport with the use of co-transporters, most water is reabsorbed here via osmosis as well
12 of 18
How is the water potential adjusted in the loop of Henle?
In the ascending limb, chloride and sodium ions are pumped out, the ascending limb is impermeable to water so the water cant move out by osmosis, in the descending limb, water moves out via osmosis. more Na&Cl diffuse in
13 of 18
Why do we need the Na and Cl ions to move out of the ascending limb?
To create a high water potential in the tubule by the time it reaches the distal convoluted tubule, also the low water potential in medulla means water can move out of the descending limb by osmosis into the capillaries
14 of 18
What i a countercurrent multiplier system?
A system that uses active transport to create a gradient which then results in the movement of other systems (the process in the loop of Henle is an example of this)
15 of 18
Describe the process by which water is reabsorbed via the distal CT and the collecting duct
Water moves from high water potential in the tubule to lower water potential of capillaries via osmosis, the volume of water reabsorbed depends on the amount of ADH in the blood affecting the permeability of the distal CT and the collecting duct
16 of 18
How does ADH effect the permeability of the collecting duct walls?
ADH stimulates aquaporins to be inserted into the collecting duct, the more ADH in the blood by binding to receptors on the wall, depolarising the membrane, opening Ca channels which causes exocytosis of aquaporins, the more aquaporins inserted
17 of 18
What are aquaporins?
Water channels in a membrane which allows water to pass through
18 of 18

Other cards in this set

Card 2

Front

When a kidney is sliced open, what are the 3 main areas to it?

Back

The cortex (Dark outer layer, dense capillary network), the medulla (lighter area, contains the tubules that for the pyramids and collecting ducts) and the pelvis (a central chamber where the urine collects before passing out)

Card 3

Front

Bowmans capsule

Back

Preview of the front of card 3

Card 4

Front

Glomerulus

Back

Preview of the front of card 4

Card 5

Front

Proximal convoluted tubule

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Homeostasis resources »