Excretory System Flashcards
How is ammonia produced in the liver
An amino group is removed from proteins
Called deamination
_____ produces nitrogenous waste that must be discarded from the body
Proteins
What does ammonia get converted to in the liver
Urea 1 million times less toxic
Ammonia + co2= urea + water
The kidneys do what 3 things
Forms urine by removing waste from blood
Balances blood ph
Maintains water balance
Cortex of a kidney
Outer layer
Madula of a kidney
Inner layer
Renal pelvis
Where urine exits kidney and into ureter
What do the nephrons do
Form urine and reabsorb essential nutrients to maintain homeostasis
Describe Filtration in the nephron
Afferent arteriole carries blood to glomerulus Small substances pass into glomerulus (like a sieve) and diffuse into Bowmans capsule Large substances (proteins, WBC, RBC) are not filtered and continue through efferent arteriole.
Describe reabsorption
Movement of substances from the nephron back into the bloodstream. Water gets reabsorbed at proximal tubule, the descending loop of henly and the distal tubule via osmosis
Dissolved substances (glucose, amino acids, ions) get reabsorbed at the proximal tubule via active transport
Describe secretion
Movement of substances from the blood into the nephron from the peritubular capillaries.
H+, K+, toxins, ammonia secreted at the proximal and distal tubules.
What are the 3 steps in urine formation?
Filtration
Reabsorption
Secretion
Describe the importance of the loop of henle
The descending loop of henle reabsorbs water due to the increasing salt concentration as the filtrate moves down.
The ascending loop reabsorbs salts through passive and active transport to set up this gradient and ensure the reabsorption of water is possible.
Draw and label the key components of the nephron
See your notes for accuracy!
