5.6 Functions of the kidney Flashcards
Where are neurones found in the kidney?
Medulla and Cortex
What is each renal pyramid made up of?
A network of multiple nephrons- around a million microscopic nephrons in each kidney
What is the first step of ultrafiltration and reabsorption?
Blood enters the nephron through the renal artery, and enters the renal corpuscle. Inside the corpuscle there is the glomerulus, surrounded by a layer of cells (Bowman’s capsule)
What is the second step of ultrafiltration and reabsorption?
Blood is entering at high pressure, so most of the plasma is forced out of the walls. Small molecules in the plasma and water from the blood pass out of the blood and into the glomerulus and into the Bowman’s capsule. Blood cells and proteins are too large so they stay in the blood.
What is the third step of ultrafiltration and reabsorption?
All of the products that have passed out of the blood are now known as filtrate.
What is the fourth step of ultrafiltration and reabsorption?
Filtrate is sent along convoluted tube, due to it being twisted there is more surface area for reabsorption, so no useful products are wasted and are taken back to the blood via capillaries. Urea, water, and some salts are left and become urine.
What is the final step of ultrafiltration and reabsorption?
By the time the filtrate has reached the end of the tube- everything that can be reused by the body has been reabsorbed- leaving behind urine which is a waste product. This is sent to the collecting duct before heading to the calyx via the renal pelvis, then passing down the ureter and into the bladder.
What is osmoregulation?
An essential process for managing water balance in body.
What is step one to osmoregulation?
Levels of water are measured by the hypothalamus- if water is too low it signals the pituitary gland to release the hormone ADH in the blood.
What is step two to osmoregulation?
Cells in the nephron have receptors which detect ADH- so greater amount of salts are added to the supply of blood passing through the medulla- creating a salt gradient.
What is step three to osmoregulation?
As more filtrate passes through the loop of Henle, water is drawn out the filtrate via osmosis and back into the blood, to balance the salt gradient.
What is the final step to osmoregulation?
When the hypothalamus has detected that the water levels are back to normal, it signals the pituitary gland to stop producing ADH, reducing the salt content and less water id drawn out of the filtrate.
