Keef Overview of Renal physiology Flashcards
(blank) percent of nephrons are cortical while (blank) are juxtamedullary
85%, 15%
What is the distal tubule right next to?
the glomerular capillary (glomerulus)
The more resistance you have the less (blank)
permeable
The expression pattern of (blank) along the nephron determines the relative ability of water and particles to move via a paracellular route.
tight junction proteins
What part of the nephron has the most resistance?
The collecting duct
(blank) are key integral membrane proteins that provide the barrier function and permit selective paracellular transport in the nephron.
Claudins
With injury to the nephron, multiple signaling pathways are activated, resulting in phosphorylation of (blank) and disruption of the complex.
Tight junction proteins
resistance goes up from what end to what end of the nephron and is dependent on the properties of the what?.
It gets more resistance from beginning (glomerulus) all the way to the end (collecting duct).
Dependent on properties of in between cells
The permeability of tight junctions between epithelial cells (blank) throughout the nephron
differs
The permeability of tight junctions between epithelial cells differs throughout the nephron. It is determined by the expression levels of (blank) that project into the paracellular space between cells. Disruption of these proteins through injury, disease or mutation can lead to serious disruption of normal renal function.
various proteins
Arginine vasopression is another name for what?
antidiuretic hormone
Antidiuretic hormone (ADH) aka arginine vasopressin (AVP) greatly increases water permeability in the collecting duct by recruiting (blank)
water channels (aquaporins).
Antidiuretic hormone (ADH) aka arginine vasopressin (AVP) greatly increases water permeability in the (blank) by recruiting water channels (aquaporins).
collecting duct
Different parts of the nephron express different (blank)
aquaporins (AQP).
Are ALL aquaporins recruited by ADH?
Which ones are recruited by ADH?
No
AQP2,3,4
What aquaporins are found in the proximal tubule?
AQP1, 7
(blank) surround all parts of the nephron and a subset of these supplying the Juxtamedullary nephrons are referred to as the “vasa recta”
Peritubular capillaries
Peritubular capillaries surround all parts of the nephron and a subset of these supplying the Juxtamedullary nephrons are referred to as the (blank)
“vasa recta”
Which have longer loops of henley, juxtamedullary or cortical nephrons?
juxtamedullary
How many layers of epithelium does bowmens capsule have?
one layer
Which creates the osmotic gradient, juxtamedullary or cortical nephrons?
the juxtamedullary
Where are vasa recta found? Is it high or low pressure?
in the juxtamedullary nephrons
Low pressure
Explain the blood flow of the cortical nephron
renal artery->afferent arteriole(resistance)->glomeruls (high pressure)->efferent arteriole (resistance)-> peritubular capillaries (low pressure) ->renal vein
Explain the blood flow of the juxtamedullary nephron
renal artery->afferent arteriole(resistance)->glomeruls (high pressure)->efferent arteriole (resistance)-> Blood flow splits between Peritubular capillaries(low pressure) and Vasa Recta (most blood flows here, low pressure)-> renal vein
Where is the majority of blood flow and how much RBF goes here?
90% to cortex
10% to medulla
What is the first point of resistance?
afferent arteriole
What is the juxtaglomeruluar apparatus?
it is the point where the distal convuluted tubule is in close proximity to the glomerulus
What are the specialized granular cells of the afferent arterioles? What do they secrete?
juxtaglomerular cells
renin
What are part of the juxtaglomerular apparatus and sense the level of flow?
macula densa cells
(blank) cells are used as feedback mechanisms to regulate flow via renin release
macula densa cells
(blank) is a mechanism that serves to maintain a relatively constant Glomerular filtration rate by sensing NaCl levels in the distal nephron and releasing substances that feed back onto the glomerulus to modify arteriolar resistance.
tubuloglomerular feedback (TGF)
If you have low amount of salt what is your GFR like? (low tubular flow)
you have low GFR, salt levels and GFR is directly proportional
If you have decreased arterial pressure in the nephron due to blood loss or something, what will happen?
you will have decreased glomerular hydrostatic pressure which will then decrease your GFR, which the macula densa will sense via the low levels of salt, the macula densa will then increase renin secretion to case EFFERENT constriction and AFFERENT dialation to increase glomerular filtration rate.
If you have decreased arterial pressure in the nephron due to blood loss or something, what will happen?
you will have decreased glomerular hydrostatic pressure which will then decrease your GFR, which the macula densa will sense via the low levels of salt, the macula densa will then increase renin secretion to case EFFERENT constriction and AFFERENT dialation to increase glomerular filtration rate.
What are the two cell types laying outside of the epithelium of the affarent and efferent arteriole?
smooth muscl cells that are granular cells (juxtaglomerular cells) and outside of the SMC cells are extraglomerular mesangeal cells
What happens when you have increase in arterial pressure (tubular flow and increase in salt delivery) from the distal convoluted tubule?
Na+-K+-2Cl-cotransporter (NKCC2) sense the extra salt and bring it into the macula densa. The macula densa senses this amount of salt and WITH ATP creates adenosine. Adenosine then binds to adenosine receptors on the mesangeal cells of the arterioles. The mesangeal cells then increases amount of Ca, the Ca2+ propogates a signal via gap junctions to the granular cells and afferent arterioles. The signal tells afferent arterioles to vasoconstrict and it inhibits renin release.