Renal Physiology I Flashcards
What are the two components of the kidney?
Vascular and a tubular component
How does the kidney contribute to acid base balance?
controls the concentration of H+ and HCO3- ions
How does the kidney balance water?
stabilises the volume of extracellular fluid
What are two ways the kidney can balance water?
either by direct reabsorption or by inserting aquaporin channels
What are some examples of toxins that the kidney may remove?
Urea, Antibiotics, Toxins or Food additives
What is the system that the kidney uses to maintain blood pressure?
Renin Aldosterone Angiotensions system
When would the kidney produce erythropoietin?
In cases of hypoxia
What are the three main processes of the kidney?
Filtration of plasma, Reabsorption of solutes and water, and secretion of substances
What are the two main reasons a kidney may use autoregulation?
to prevent large changes in GFR and urine output
to protect fragile glomerular capillaries
Where is the juxtaglomerular complex?
between the distal convoluted tubule/ ascending loop and the afferent/efferent arterioles
What is the name of the enzyme that converts angiotensin I to angiotensin II and where is it produced?
Angiotensin converting enzyme, and it is produced in pulmonary capillaries
What are macula densa?
groups of cells at the juxta glomerular apparatus that assist with the juxta glomerular complex
Where are kidneys usually found in the abdomen?
Cranio-dorsally
What makes up the renal corpuscle?
The glomerulus and bowmans capsule
What makes up the tubular system?
Fluid filled tubes made from a single epithelial layer and associated vascular supply
What usually stimulates renin release?
A decrease in renal perfusion pressure
What does angiotensin II do?
Increases systemic blood pressure
Where in the kidney is Erythropoietin produced?
within the interstitium of the cortex
What are the three layers of the glomerulus?
Endothelium of the glomerular capillaries, Basement membrane, epithelial cells of bowmans capsule- these serve as a sieve/filtration barrier
What can pass through the endothelium of the bowmans capsule?
Solutes, plasma proteins and fluid
What cant pass through the basement membrane of the glomerulus?
It restricts plasma proteins from flowing out
What are the two forces that effect GFR?
Difference in hydrostatic pressure and difference in protein-osmotic pressure
What does constriction of the afferent arteriole do?
decreases blood flow and therefore decreases hydrostatic pressure and redcues GFR
What does constriction of the efferent arterioles do?
decreases blood flow but increases hydrostatic pressure therefore GFR is unchanged
What is autoregulation
kidneys ability to change resistance so that blood flow is maintained despite changes in pressure
What is the vasa recta?
Veins that supply blood to the medulla of the kidney
What does the kidney produce erythropoietin in response to?
Produced in response to hypoxia, it is produced in the interstitium of the cortex of the kidney
How does the myogenic response to blood pressure work?
Increased blood pressure causes increased stretch in the walls of the capillaries
This increased stretch is detected by VSMC cells
Mechanotransduction leads to depolaristaion of the membrane
this activates voltage gated Ca2+ channels
The influc of Ca2+ leads to contraction
therefore blood flow decreases
What cells produce calcitriol?
Cells in the PCT
What may be the cause of frothy urine?
Proteins in the urine- kidney failure
