Kidney Function Flashcards
What is ultrafiltration?
The non-specific filtration of the blood under high pressure
Where does ultrafiltration occur?
In the Bowman’s capsule of the nephron
Where does the blood move into the kidneys through?
The afferent arterioles
What is the Bowman’s capsule comprised of?
An inner surface of cells called podocytes
What are pedicels?
Cellular extensions of podocytes that wrap around the blood vessels;s of the glomerulus
What is between podocytes and the glomerulus that filters the blood?
A glycoprotein matrix called the basement membrane
What is the sole filtration barrier within the nephron?
Basement membrane
What does the filtrate not contain?
Blood cells, platelets, and plasma proteins
What is selective reabsorption?
the reuptake of useful substances from the filtrate
Where does selective reabsorption occur?
occurs in the convoluted tubules
Where does The majority of selective reabsorption occur in?
Proximal convoluted tubule
What are some reabsorbed substances?
Water, salts, glucose, and amino acids
What are the several adaptive features of the proximal convoluted tubule?
Microvilli, co-transporter proteins, many mitochondria, tight junctions
How are Na+ ions transported from the proximal convoluted tubule into the surrounding tissues?
Active transport
What does the electrical gradient caused by t6he positively charged sodium ions cause?
Chloride ions to follow by diffusion
What happens in selective reabsorption after chloride ions are diffused?
Sugars and amino acids are transported into the surrounding tissues by co-transporter proteins
What does the movement of ions, sugars, and amino acids into the surrounding tissues cause?
An increase in the osmolarity of the tissues
What does an increase of osmolarity in the tissue cause?
Water leaves the proximal convoluted tubule by osmosis
Where does osmoregulation occur?
Occurs in the medulla
What is the function of the loop of Henle?
establishes a salt gradient (hypertonicity) in the medulla
What does the anti diuretic hormone regulate?
The level of water reabsorption in the collecting duct?
How does the loop of henle ensure that the production of urine that is more concentrated than the blood
countercurrent multiplier system
What increases as the descending limb moves down into the medulla
The osmolarity of the filtrate
Why is the descending limb low-permeable to ions?
Has few transport proteins in the membrane of its cells
What is unable to permeate the ascending limb of the loop of Henle?
Water
What is the capillary that flows directly alongside the loop of Henle
Vasa recta
What is the role of the vasa recta?
supplies oxygen to and removes carbon dioxide from the respiring cells of the loop of Henle
