B3.3.4 Flashcards
What is a capsule
A capsule is the outer membrane of the kidney which helps it to maintain its shape and protect it from damage.
What is a cortex
The outer part of the kidney
What is the medulla
Inner part of the kidney
Where is urine produced
Urine is produced in tubules called nephrons in kidneys.
where does blood enter the kidney from and under what pressure
Blood enters the kidney under high pressure from the renal artery.
Where does the blood then go
Contains many branches which leads to the glomerulus. Each glomerulus has a knot of capillaries.
What happens at the exit of the glomerulus
Blood vessels narrow at the exit of the glomerulus leading to increased blood pressure. This forces small molecules like water, glucose, salts and urea out of the capillary wall, into the Bowman’s capsule. Large molecules are too large to fit through and stay in the blood stream.
What is the next stage
Selective reabsorption takes place. As the filtrate moves through the nephron tubule all of the glucose is reabsorbed, as well as some of the water and any salts needed by the body. Filtrate passes through the loop of Henlé and into the collecting duct.
What does reabsorption do
Regulates how much salt and water is in the body by reabsorption
How does the body control how much water is produced
Hypothalamus detects water potential of blood as it passes through the brain. Responds by secreting ADH from pituitary glands. This goes to the kidney where it makes the walls of the collecting duct more permeable meaning more water is reabsorbed.
What happens when there is a low water potential
More ADH is produced. More water reabsorbed from nephron into the blood stream. Less water is lost from body, so a small volume of concentrated urine produced.
What happens when there is a high water potential
Less ADH is produced, less water is being reabsorbed by the nephron into blood stream. So a large volume of dilute urine is produced.
What is the flowchart of water through the kidney
In kidney liquid travels through Bowman’s capsule –> proximal convoluted tubule –> loop of Henlé –> distile convulated tubule –> collecting duct
