Movement of Blood in a Nephron Flashcards
What are the three processes/stages that occur in a nephron?
- FIltration
- Reabsorption
- Secretion
What percentage of blood plasma is filtered at the renal corpuscle?
20%, excluding red blood cells, white blood cells and plasma proteins.
What are 3 benefits of the structure of the nephron?
- A large volume of blood moves through which maintains the concentration gradient.
- There is a large surface area due to a large number of nephrons.
- Efferent arteriole has a small diameter than afferent to increase pressure.
What is the overall function of a nephron?
Filters blood and removes wastes via excretion.
Where does filtration occur?
Renal corpuscle (glomerulus and bowman’s capsule)
Where does reabsorption occur
- Proximal convolute tubule
- Loop of Henle
- Distal convule tubule
- Common collecting duct
Where does secretion occur?
Distal convolute tubule.
Describe filtration.
Blood from the afferent arteriole will enter the glomerulus due to high blood pressure. The arteriole and glomerular capsule are one cell thick and so the high blood pressure forces water and dissolved molecules out of the blood and into the capsule. This is known as filtrate.
What is filtrate?
All material in blood besides blood cells.
Describe reabsorption.
The filtrate passes through the proximal convoluted tubule, loop of Henle, distal convoluted tubule and the collecting duct where substances are reabsorbed actively and passively. Water and other useful substances are reabsorbed into the peritubular capillaries.
Describe secretion.
Materials that need to be removed from the body are secreted into the kidney tubule from the peritubular capillaries.
What is facultative reabsorption?
Refers to the permeability of the cell membrane to change meaning the amount of water absorbed can be changed.
What is tubular secretion?
Are materials removed by reabsorption and put into filtrate through active or passive transport.
