Anatomy of the Kidney Flashcards
U4L3a (8 cards)
How does the urinary system work?
Wastes in the blood are filtered by the kidneys and ultimately disposed of in the bladder.
Renal arteries pass blood to the kidneys and the ureters pass urine to the bladder.
The bladder has a renal sphincter which is voluntarily used to determine when to urinate.
The urethra is the tube that is used to empty the bladder.
What typically happens as the bladder fills with urine?
At 200mL, the bladder begins to expand which put pressure on stretch receptors. These receptors send signals to the b rain telling the person they gotta go.
At 400mL, the urge to urinate will become more reoccurring and more obnoxious.
At 600mL, you’re kinda cooked. The body takes over at this point.
What’s urinalysis?
Urinalysis is a diagnostic tool that is used to test for any abnormalities present in the urine (glucose prescence).
Colour, odour, pH, ketones, glucose, protein, blood, and many more substances are tested
What is the structure of the kidney?
You got the renal artery and renal vein that brings blood in and out of the kidney. You have tissues inside of the kidney called ‘Medulla’ and tissues outside called the ‘cortex’.
There is a center that connects the kidney with the ureter which is called the renal pelvis.
There is roughly 1 million nephrons inside each kidney (small functional units).
What’s a nephron?
A nephron spans the area between the medulla and the cortex (like a bridge).
It is comprised of special blood vessels and tubes that wrap around eachother for filtering waste from the blood, which produces urine.
How does blood flow through a nephron?
Afferent arterioles supply blood from the kidney to the renal artery. They end up in a capillary network called the glomerulus.
Blood then exits the glomerulus through the efferent arterioles which leads to a network of peritubular capillaries (surrounds nephron tubules).
They collect into renal venules (tiny veins) and blood exits the kidneys via renal vein.
What is in the cortex of the kidney?
The glomerulus is surrounded by the bowman’s capsule. It along with efferent and afferent arterioles make up the cortex.
Fluids that need to be processed into urine enter the bowman’s capsule from the blood in the glomerulus (its like the center).
How does fluid flow in the nephron?
the bowman’s capsule leads to a thin tubule called the proximal tubule.
urine goes from the proximal tubule, around the loop of Henle (like a ‘U’), which descends into the medulla of the kidney. Urine then moves through the distal tubule and into the collecting ducts, which collects urine from many nephrons and leads into the renal pelvis of the kidney.
Upon meeting the renal pelvis, the waste gets sent down the ureter and gets deposited into the bladder.
