Renal - 16

Question 1

Bile from liver will normally enter the gallbladder for storage when..

Answer 1

the sphincter of oddi is closed

Question 2

Posis

Answer 2

-posis = kidney droop when lose weight too quick (kidneys can fail)

Question 3

Urine Pathway

Answer 3

-blood comes in renal artery and into nephrons
-urine made in nephron
-urine flows out of nephron into collecting duct, papilla, calyx, renal pelvis, ureter

Question 4

The Nephron

Answer 4

-veryyyy small
-renal cortex (top) has the renal corpuscle (made of glomerular capsule and glomerulus)
-has an afferent and efferent arteriole
-has a proximal convulated tubule
-juxtaglomerular apparatus (hass macula dense and JG cells) tastes urine to alter flow to glomerulus based on concentration is distal tubule

Question 5

Renal Medulla

Answer 5

-has loop of henle, but goes back up into renal cortex has the distal convoluted tubule
-distal convoluted tubule talks to afferent arteriole
-after detail convoluted tubule, urine enters collecting duct

Question 6

Kidneys take a lot of blood

Answer 6

-about 20-25% of circulation goes to kidney but kidney only weights about .5% of body
-from 20-25% of blood flow, 180L is made into filtrate (no protein or blood elements)
-out of the 180L, 1L of urine is made in a day - about 99% is reabsorbed

Question 7

The Big Picture of Renal Function - The nephron

Answer 7

practice this slide

Question 8

Podocyte

Answer 8

-surrounds all capillaries in glomerulus
-a pedicel comes off each podocyte and pedicels have filtrations slits between them

Question 9

The glomerular capillaries are involved in ___ while the peritubular capillaries are involved in ___

Answer 9

The glomerular capillaries are involved in FILTRATION while the peritubular capillaries are involved in SECRETION

Question 10

Kidney + CV = BFFS

Answer 10

-kidneys work in partnership with the cardiovascular system
-the CV generates pressure necessary for glomerular filtration and drives the high flow needed to maintain a stable cortical interstitial solute composition
-hypertension = drug to get you peeing (diuretic)
-hypotension = antidiuretic?
-kidneys maintain blood volume, regulate plasma osmolality and secrete things

Question 11

Net Filtration Pressure

Answer 11

pressure pushing fluid out of glomerular capillaries (+VE): blood, hydrostatic pressure in capillaries (pressure of blood in glomerular capillaries)

pressure holding fluid in glomerular capillaries (-ve): capsular hydrostatic pressure
(pressure of fluid already in capsule) and blood osmotic pressure (attraction of dissolved materials in blood for water)

Question 12

GFR Glomerular Filtration Rate

Answer 12

-net positive pressure of 10mm of Hg
-this is the pressure that pushes filtrate into capsular space

Question 13

Changing glomerulus pressure

Answer 13

1. myogenic mechanism
   -smooth muscle of afferent arteriole is stretched by increase in blood pressure and afferent arteriole response with contraction which decreases GFR
   OR
2. tubuloglomerular feedback
   -macula dense of juxtaglomerular apparatus decreases high amounts of filtrate (water and Na, and Cl) and increases adenosine release which causes Ca release that constricts the afferent arteriole, decreasing GFR

Question 13

Renal Autoregulation of GFR

Answer 13

-kidney itself can act to alter GFR bay changing blood pressure in glomerulus and leakiness of glomerulus capillaries

Question 14

Hormone regulation of GFR

Answer 14

-ANP atrial natriuretic peptide and angiotensin 2 (sympathetic)

Question 15

ANP

Answer 15

atrium, pee, sodium
-distention of the atrium of heart leads to release of ANP
-anp causes relaxation of mesangial cells between glomerular capillaries
-once mesangial cells relax the glomerular cappilaries are more spread out and relaxed so filtration can occur
-anp also relaxes afferent arteriole of glomerulus and increases sodium loss

Question 16

Neural Regulation of GFR

Answer 16

sympathetic ANS has input of musuclar walls of afferent arterioles
-receptors are a1-adrenoceptors like most arteriols in body
-with low blood flow, glomerular hydrostatic pressure goes down and filtration decreases