Urinary system, kidney and nephron structure Flashcards
urinary system [8]
kidneys supplied with blood through renal artery1 straight from the aorta at high pressure2. blood filtered3 in the kidneys, and ‘clean’ blood passes out through renal vein4. ureters bring urine to be stored in the bladder5. bladder has a tube leading outside called the urethra6. sphincter7 muscles contract to close urethra to hold back urine. upper sphincter involuntary lower sphincter voluntary8
cortex
contains hundreds of thousands of nephrons
nephrons
filtering units
medulla and pyramids
nephrons in the medulla join up and lead to tips of the pyramids that lead to the pelvis
pelvis
funnel like structure takes urine from collecting ducts from the nephrons and connects to the ureter
ureter
connects to the bladder.
glomerulus and bowman’s capsule process
ultrafiltration. the glomerulus has a high pressure of blood flowing through them. small substances such as urea, glucose, ions, and water can pass through the capillary walls, wall of the capsule, and the basement membrane. the basement membrane is a semi-permeable
proximal convoluted tubule process
selective reabsorption. glucose is reabsorbed in the proximal convoluted tubule through active transport. what is reabsorbed is necessary for the body everything else is waste and is passed out as urine
substances present in blood entering the glomerulus
protein, glucose, urea, ions
substances present in glomerular filtrate beginning of bowman’s capsule
glucose, urea, ions, no protein
substances present at the end of the proximal convoluted tubule
slower flow rate 20%
only urea and ions (more urea than before) glucose has already been reabsorbed through active transport
substances in collection duct
flow rate 1%
a lot of urea more ions than before
what does flow rate rely on in the nephron
percentage water
Loop of Henle on concentration of urine
longer the loop the more concentrated the urine as more water can be absorbed back into the blood
