Excretion Flashcards
(17 cards)
What is the waste product for respiration?
Carbon dioxide
What waste product is made in the liver cells?
Urea
How is urea made?
Via the breakdown of amino acids
Where is carbon dioxide removed?
Lungs via blood plasma
Where is urea removed?
Kidneys and skin
How does blood enter the liver?
Through the hepatic artery and hepatic portal vein
How does blood exit the liver?
Through the hepatic vein
What are amino acids converted to before being turned to urea?
Carbohydrates -> Ammonia -> Urea
What does the kidney do?
Filters blood and removes excess materials and passes them to the bladder to be excreted
What are the main section of the kidney?
Cortex surrounds medulla, medulla (triangle shaped), pelvis (yellowish part)
What are the stages of the nephron?
Ultrafiltration
Selective reabsorption
Water reabsorption
Where does ultrafiltration take place?
Glomelerus
Where does selective reabsorption take place?
Proximal convulated tubule
Where does water reabsorption take place?
Loop of henle
How does ultrafiltration work?
Small molecules are forced out of the capillaries due to high preasure because of the smaller exit capillary (efferent arteriole) and the larger entrance capillary (afferent arteriole)
Large molecules remain in the blood stream through the exit capillary
How does Selective reabsorption work?
Filtrate from glomelerus contains useful materials which can still be used in the blood such as glucose
Substances are moved back into the blood stream using diffusion and active transport, there are specialised cells in the PCT wall
How does water reabsorption work?
There is still some water left after selective reabsorption, so it needs to be reabsorped again
Loop of henle concentrates urine by transporting salt into the blood by active transport, which causes water to diffuse into the blood by osmosis
