Normal Kidney Flashcards
What are the two types of tubular reabsorption?
Passive transport
Active transport
What is most the kidneys’ energy requirement needed for?
Na+ transport
Where are glucose, amino acids, and proteins reabsorbed?
PCT
Where is most of the Na+ reabsorbed?
PCT
What cell type is in the PCT?
Simple cuboidal epithelium
What filters fluid from the blood into Bowman’s capsule and prevents the passage of blood cells and proteins?
Glomerulus
Where are 2/3 of filtered water and electrolytes and all filtered bicarbonate, glucose, amino acids, and vitamins reabsorbed?
PCT
What reabsorbs water and delivers concentrated filtrate to the ascending loop of Henle?
Descending loof of Henle
What activately reabsorbs Na+, K+, Cl- to produce a hyposmotic filtrate and high interstitial osmolality ?
Ascending loop of Henle
What reabsorbs Na+ and Cl-, water, urea, is responsive to aldosterole and is a site of macula densa regulation of GFR and also secrete H+ and K+
DCT
Where is water reabsorbed under the influence of ADH?
Collecting tubule
Are cells permeable to water in the descending limb of the loop of Henle?
Yes- very
there is passive reabsorption of water in response to osmotic forces
What cell type s found in the descending limb of the loop of henle?
Simple squamous epithelium
Does water leave the lumen in the ascending limb of the loop of henle?
NO! Cells are impereable to water here (tight junctions)
What cell type is found in the ascending limb of the loop of henle?
simple cuboidal epithelium
What happens in the ascending limb of the loop of henle?
Reabsorption (ions go into interstitium)
Active transport of NA+ at basolateral border
Cl- ions follow Na+ out
What is reabsorption of Na in the DCT and collecting duct controlled by?
Aldosterone
What is reabsoprtion of water in the DCT and collecting duct controlled by?
ADH
Where s H+ added into filtrate?
PCT
DCT
collecting ducts
Where is K+ actively reabsorbed?
PCT
Where is K+ actively secreted?
DCT
collecting tubules
What does increased aldosterone promote in Na+ and K+?
Increased Na+ reabsorption
increased K+ secretion
What is the normal amount of excretion of urine per day?
1.5 liters
What is the typical pH of urine?
6
What nerves innervate the kidneys?
Less splanchnic
Where is pain sensed in the kidney?
Capsul and HIlum
What is the functional unit of the kidney?
Nephron
What is the macula densa?
A thickened segment of the ascendign limb that passes b/w afferent and efferent arterioles
What are the 5 parts of the tubular component of the renal system?
Bowman's capsule proximal tubules loop of henle (descending, ascending) Distal tubule Collecting tubule or duct
What 6 things are involved in the vascular component of the renal system?
Renal artery Afferent arterioles Glomerulus Efferent arterioles Peritubular capillaries and vasa recta Renal venous system
What is the most common type of nephron?
Cortical (superficial)
Lie almost completely in the cortex
Short loop of henle
Where are juxtamedullary nephrons founds?
Cortex and medulla
What are the three basic renal processes?
Glomerular filtration
Tubular reabsorption
Tubular secretion
What are the three layers of a glomerular capillary?
Endothelium
Basement membrane
Epithelium
Where are pores or fenestrae found?
Endothelium of glomerular capillary
WHere are negatively charged glycoproteins found?
Basement membrane of glomerular capillary
Where are podocytes found?
Epithelium (attached to basement membrane)
form filtration slits
What do fenestrae, podocytes, and filtration slits in the glomerular capillary facilitate?
Filtration
What do negatively charge glycoproteins do?
Attract cations and repel anions (preveting proteinuria)
Where does most the renal blood flow to?
Cortex
What are the three forces affecting filtration?
Hydrostatic pressure within glomerular capillaries (favors filtration)
hydrostatic pressure within Bowman’s capsule (back pressure)
Osmotic pressure within glomerular capillaries (against filtration)
What is the net filtration pressure
10 mm Hg in favor of filtration
How does decreasing arterial pressure affect net filtration pressure?
decreases it
What does increasing resistance of the afferent arteriole cause
Decreases glomerular hydrostatic pressure
What does decreasing resistance of the efferent arteriole cause?
Decrease in glomerular hydrostatic pressure
What is GFR?
Glomerular filtration rate
quantity of filtrate formed each minute in all nephrons in both kidneys
Does a decrease in arterial pressure affect GFR?
Not really because of the phenomenon of autoregulation (within 80-180 mm Hg)
What is the macula densa sensitive to?
Filtrate osmolarity and/or rate of flow
What are juxtaglomerular cells sensitive to?
blood pressure
what is the extrinsic sympathetic control of GFR mediated by?
sympathetic nervous system; aimed at regulation of arterial BPs
Hat is the chain of events in the kidney of BP drops
increase sympathetic activity afferent arteriolar vasoconstriction decrease GFR decrease urine volume leads to an increase in BP
a High GFR means there is a ____ filtrate flow rate in the tubules?
high
a high filtrate flow rate in tubules means there is a _________ reabsorption of ions in the tubules
decreased
with a decreased reabsorption of ions in the tubules there is ____ osmolarity in the tubules
High
With high osmolarity in the tubules the mascular densa cells _______ vasoconstrictor?
Release
When the afferent arteriole contricts GFR _____
Decreases
If GFR is decreased, filtration flow rate ______
Decreases
With decreased filtration flow rate, there is ____ reabsorption of ions in the tubules
Increased
With increased reabsorption of ions in the tubules, there is _____ osmolarity in the tubules
lower
