Week 20 Flashcards
What are the main roles of the kidney?
Filter blood to make urine
Regulate blood volume and ion concentration
Production of hormones
How much water on average does the human body contain?
42L
What is the tube that connects the kidneys to the bladder called?
ureter
How long is the urethra in males vs females?
Female= 4cm
male=20cm
Describe where the cortex and medulla are in the kidney?
Cortex is outermost part, contains the nephrons
Medulla is more inner, contains renal papilla, and connects to urinary pelvis of the kidney
What percentage of nephrons are cortical vs juxtaglomedullary?
Cortical= 80%
Juxtamedullary= 20%
What’s the difference between cortical and juxtamedullary nephrons?
Cortical= shorter loops of henle, main role is to filter blood
Juxtamedullary= longer loops of henle, as you go down medulla it gets saltier so more resposible for urine concentration
WHat is the renal corpsucle?
the initial filtering component of a nephron in the kidney, consisting of the glomerulus and Bowman’s capsule
What supplies blood to the glomereular capillaries and takes blood away?
Afferent arterioles
efferent arterioles
Where are podocytes located?
Hug around glomerular capillary
What does a substance have to pass thru to get into urine?
- Fenestration in capillary endothelium
- basement membrane (like a fishing net)
- Filtration slit between podocytes
Describe the Juxtaglomereular apparatus
The Glomereulus is supplied with blood and filters into the bowmans capsule which travels thru proximal and distal convoluted tubules via loops of henle then to collecting duct then ureter and bladder.
WHere are macula densa cells and what do they do?
found in the distal convoluted tubule
Monitors sodium chloride (NaCl) concentration in the filtrate
Where are juxtaglomerular cells and what do they do?
Where: Smooth muscle cells in the wall of the afferent arteriole.
release renin when macula densa signals for them to do so
What is the role of vitamin D in the body?
Helps absorb clacium and phosphate from the gut
Where do humans get vitamin D from?
made from cholesterol and sunlight on the skin
WHere does inactive vitamin D become active?
The kidney
What is erythropoietin?
A hormone made by the kidneys that causes bone marrow to make RBCs
Describe how eryhtropoietin functions?
- Kidney detects lo O2 in the renal cortex
2.Hypoxia inducible factor (HIF) is made - More erythropoietin is transcribed
- Stimulates progenitor cells in bone marrow to make eryhtrocytes
How much EPO is the kidney responsible for making?
80%
In a 24hr period, how many times will the kidney filter blood plasma?
60 times
Where does the energy to do glomerular filtration come from?
The hydrostatic pressure of blood from the beat of the heart
What should glomerular filtration not contain?
No Cells
No traces of protein
What do blood plasma and glomerular filtrate have in common?
Same conc of ions and small organic substances
