The Kidney Flashcards
Structure of the kidney: what does each part do?
Cross section of inside of a kidney
What’s the cortex of the kidney e.g. what it contains, function
- contains glomerulus, bowman’s capsule, proximal convoluted tubule, distal convoluted tubule
- brown colour
- ultrafiltration & selective reabsorption occurs here
What’s the function & what’s in the medullas of the kidney
- red colour
- contains loop of Henle & collecting ducts
- contains pyramids, from tissue of medulla: cone shaped structures
- osmoregulation occurs here
Whats the renal pelvis & what does it do
A large chamber where the ureter joins the kidney
Collects urine from the kidney tubules & funnels it into the ureter
White colour
What’s a nephron and what does it do
The functional unit of a kidney
Produces urine
Renal artery -> efferent arteriole journey and what the stuff does
Renal artery -> afferent arteriole -> ball of capillaries (glomerulus) -> efferent arteriole
The afferent arteriole supplies blood from the renal artery to the glomerulus
Efferent arteriole returns blood from the glomerulus to the renal vein
The bowman’s capsule contains the glomerulus
After the efferent arteriole where does the filtrate go
- intertwines with the rest of the nephron
- > bowman’s capsule -> proximal convoluted tube -> loop of Henley (desc & asc limb) -> distal convoluted tubule -> collecting duct -> URINE!
Where does ultrafiltration occur
In the bowman’s capsule & glomerukus
How does ultrafiltration occur in the bowman’s capsule
What allows the blood plasma & dissolved substances for pass out of the capillary basement membrane
The fenestrations in the endothelium of capillary walls of the glomerulus
What is the capillary basement membrane & its significance
It’s a mesh network of collagen & glycoproteins
Small molecules are forced out of the glomerulus into the bowman’s capsules through the basement membranes e..g glucose, water, urea, vitamins, salts, ions
(Large molecules are prevented from entering the bowman’s capsule e.g. blood cells, platelets etc)
How do podocytes assist in ultrafiltration (podocytes are epithelial cells of the Bowman’s capsule)
- have finger like projections called major processes / PEDICELS
- projections ensure gaps between cells to allow the passage of substances
What is selective reabsorption
Where does selective reabsorption occur
Proximal convoluted tube
- most water, glucose & amino acids reabsorbed
Describe the process of selective reabsorption in the PCT using this image
PCT adaptations for selective reabsorption
- microvilli lining the epithelium & made from folds of the CSM: provide a large SA for uptake during reabsorption
- many mitochondria in pct epithelial cells: provides energy for uptake in reabsorption
- cotransporter proteins in CSM: to cotransport glucose / amino acids, with sodium ions from PCT into epithelial cells of PCT cells lining the PCT
Loop of henle structure & ion movement
What happens in the descending limb of the LOH towards the medulla
What happens in the ascending limb of the LOH (moving towards the cortex)
How does selective reabsorption occur in the distal convoluted tubule
How does selective reabsorption occur in the collecting duct
What does osmoregulation do
Control water & salt levels in the blood, therefore control body W.P.
Therefore an example of negative feedback
How does osmoregulation work in regards to the mechanism of ADH
Osmoreceptors in hypothalamus monitor the water potential of blood
ADH regulates the permeability of walls of the collecting duct
More ADH = more aquaporins fuse with the CSM of the cells of the collecting duct
= more aquaporins on tubule walls
-> = Inc permeability of walls of collecting duct = more water reabsorbed
