The Nephron
What are the 3 barriers of the filtration membrane?
1.) Fenestrated Capillaries
2.) Basement Membrane
3.) Filtration Slits
What cells are in the juxtaglomerular apparatus?
1.) Mesangial cells
2.) Granular Cells
3.) Macula densa
1.) ADH
2.) PTH
3.) Aldosterone
4.) Natriuretic peptide
where do the following start digestion
carbs, fats, proteins
carbs --> mouth
protein --> stomach
lipids --> mouth / stomach
What organs are mainly involved with this system for conversion into angiotensin 2?
lungs
medulla - brain
liver
kidney
GFR is controlled by what 3 homeostatic mechanisms?
1.) Renal Autoregulation
2.) Sympathetic Control
3.) Hormonal Control
What is the importance of ATP in the juxtaglomerular apparatus?
ATP is metabolized into adenosine, which stimulates the granular cells to constrict the afferent arterioles
What creates aquaporins on the collecting duct, making H2O to renter tissue?
ADH
what enzymes before the small intestine work on carbs
salivary amylase & pancreatic amylase
What secretes the following:
renin, ACE, Angiotensinogen
Renin --> kidney
ACE --> lungs
Angiotensinogen --> liver
At what part of the nephron does most reabsorption occur?
PCT
______ will release ATP, where ______ metabolizes ATP into _________. This causes ____________ to contract around afferent arterioles, constricting diameters to help lower ________, which ultimately lowers GFR.
Macula densa will release ATP, where mesangial cells metabolizes ATP into Adenosine. This causes granular cells to contract around afferent arterioles, constricting diameters to help lower BP, which ultimately lowers GFR.
What hormone is secreted so that reabsorption is decreased, reducing BV, increasing GFR, and increasing urine volume?
Natriuretic peptide
What are the importance of chief cells and parietal cells
chief cells --> secrete gastric lipase, pepsinogen
parietal cells --> secrete HCL, intrinsic factor, ghrelin
What 2 hormones are released in response to angiotensinogen 2?
ADH & Aldosterone
What are the DCT, nephron loop, and collecting duct responsible for?
DCT --> reabsorbs salts
Nephron loop descending --> reabsorption of water
Nephron loop ascending --> reabsorption of salts
CD --> conserves water
If arterial BP falls, what happens to afferent arterioles during the myogenic mechanism? Why does it need to do this? (Think about what happens to flow rate when BP falls and how that affects GFR)
Afferent arterioles relax to allow more BF more easily into glomerulus, so that flow rates remain similar & filtration remains stable.
List everything about the PTH: why it is secreted, what secretes it, what does it do.
PTH is secreted by parathyroid glands in response to low CA+ in the blood (hypocalcemia). It acts on the PCT to increase phosphate excretion & also acts on DCT (and ascending limb of nephron loop) to increase CA+ reabsorption.
What are the activated & inactivated brush border enzymes for digestion of proteins
trypsinogen --> trypsin
Procarboxypeptidase --> carboxypeptidase
Chymotrypsinogen --> chymotrypsin
List everything that angiotensin 2 does
brain to release ADH & stimulate thirst
makes adrenal gland secrete aldosterone
What part of nephron loop completes process of making urine?
DCT
List all the hormones and why they are secreted.
1.) Aldosterone --> low BP, low salts
2.) ADH --> dehydration, low BV, high osmolarity in blood
3.) Natriuretic peptide --> high BP
4.) PTH --> hypocalcemia, low CA+ in blood
explain the pathway of one of the nutrients from start to finish
...
Can you list the pathway of RAAS
In response to low BP: baroreceptors sense change and send signal to SNS to stimulate following: Renin converts angiotensinogen to angiotensin 1. Angiotensin 1 is then converted to angiotensin 2. Renin comes from granular cells in kidney, angiotensinogen comes from liver. ACE is made in LUNGS and converts angiotensin 1 to angiotensin 2.