The Kidney Flashcards
(17 cards)
What organ is responsible for removing urea produced by the liver?
Kidney
The kidney filters the blood and removes excess materials.
What are the three main sections of the kidney?
- Cortex
- Medulla
- Pelvis
The cortex is around the outside, the medulla is triangular shaped in the middle, and the pelvis is in the center.
What tiny structures in the kidney are responsible for filtering the blood?
Nephrons
Nephrons are the functional units of the kidney.
What is the first stage of urine formation in the nephron?
Ultrafiltration
This stage involves the filtration of blood in the glomerulus.
What creates the build-up of pressure in the glomerulus during ultrafiltration?
The diameter of the efferent arteriole is smaller than the afferent arteriole
This pressure forces small molecules out of the capillaries.
What molecules are forced out of the capillaries into the Bowman’s Capsule during ultrafiltration?
- Urea
- Glucose
- Amino acids
- Salts
This forms the glomerular filtrate.
What happens to larger molecules like proteins during ultrafiltration?
They stay in the blood
Larger molecules cannot fit across the capillary walls.
What is the second stage of urine formation in the nephron?
Selective Reabsorption
This stage recovers useful materials from the filtrate.
What specialized structures in the proximal convoluted tubule (PCT) help in selective reabsorption?
Cells with a folded membrane and many mitochondria
The folded membrane increases surface area and mitochondria provide ATP for active transport.
How are glucose and amino acids reabsorbed back into the bloodstream?
By diffusion and active transport
Active transport uses ATP to move substances against a concentration gradient.
What percentage of water is reabsorbed in the proximal convoluted tubule?
80%
This is part of the selective reabsorption process.
What is the role of the Loop of Henle in urine concentration?
It transports salt into the blood by active transport
This causes water to diffuse into the blood by osmosis.
What hormone regulates water reabsorption in the collecting duct?
ADH (Antidiuretic Hormone)
ADH helps the kidneys manage water balance.
What is osmoregulation?
The process of regulating water reabsorption in the kidneys
Osmoregulation helps maintain fluid balance in the body.
Fill in the blank: The nephron contains structures essential in the __________ of the blood.
filtration
The filtration process begins with ultrafiltration.
True or False: The collecting duct does not respond to any hormones.
False
The collecting duct responds to ADH to vary water reabsorption.
What volume of urine is typically produced by the kidneys per day?
1.5L
The kidneys filter 180L of fluid daily but only produce a fraction as urine.
