excretion Flashcards
(39 cards)
What is excretion?
Removal of the wastes of metabolism; cells produce wastes and are most likely toxic.
Which organs are involved in excretion?
Kidneys, liver, skin/sweat glands, alimentary canal (bile pigments), and lungs (CO2).
Where are the kidneys located?
Back of the abdomen.
What vessels enter and leave the kidneys?
Renal artery and vein; section is the renal hilum.
Where does the ureter lead to?
Urinary bladder, then urethra.
What encloses the kidney?
Renal capsule.
What lies beneath the renal capsule?
Renal cortex.
What lies beneath the renal cortex?
Renal medulla.
What does the renal medulla consist of?
Many renal pyramids between which many blood vessels lie.
What is the renal pelvis?
The part inside the kidney where urine collects.
What are the main functions of the internal kidney structure?
Remove waste and regulate blood composition.
How many nephrons are in each kidney?
1.2 million.
What are the two parts of the renal corpuscle?
Glomerulus and glomerulus capsule.
What is the glomerulus?
A knot of arterial capillaries.
What is the renal tubule?
5 cm long tubule including PCT, Loop of Henle, DCT.
What is the path from DCT to the ureter?
DCT → collecting ducts → renal pelvis → ureter.
How does blood enter a nephron?
Through the renal arteries.
What is the afferent arteriole?
The wide arteriole that supplies each renal corpuscle.
What is the efferent arteriole?
The thinner arteriole that blood passes out through.
What are peritubular capillaries?
Secondary capillary network formed from efferent arteriole.
What is the first step of urine formation?
Glomerular filtration.
Where does glomerular filtration occur?
Renal corpuscle.
What enhances glomerular filtration?
High pressure caused by glomerulus knots and arteriole size difference.
What passes into the glomerulus capsule?
Water, amino acids, glucose (filtrate).
