Final Review Flashcards
What are the roles of the kidneys in the body?
- Cleansing the blood
- regulation of pH
- Regulation of blood pressure
- Regulating concentration of solutes
- Helps determine the concentration of red blood cells
- Vital step in vitamin D activation
What is another way to think of the kidneys other than a urine producer
As a regulator of plasma
How much of resting CO do the kidneys receive?
20-25%
Where does aldosterone come from?
Adrenal cortex
Where do catecholamines come from?
Adrenal medulla
What are the regions of the kidneys called?
Renal cortex
Renal medulla: renal columns and renal pyramids
What is a renal pyramid?
Bundles of collecting ducts that transports urine to the calyces for excretion
What do renal columns and pyramids make up?
Kidney lobes
What is the renal corpsicle made up of?
The glomerulus capillaries and the bowmans capsule
What is found in the renal cortex?
Proximal and distal convoluted tubules
What is a nephron know as if it has a short loop of henle?
Cortical nephron
What is a nephron know as if it has a long loop of henle that extends deep into the medulla?
Juxtamedullary nephron
What is the principal task of a nephron?
Balance the plasma and excrete toxins
What are the secondary functions of the nephron?
Produce renin, secrete EPO and help make calcitrol
What are the three layers over the glomerulus capillaries?
Inner: fenestration (pore) of glomerular endothelial cell
Mid: Basement membrane of glomerulus (prevents large proteins)
Outer: Slit membrane between pedicals (prevents medium sized particles)
What do fenestrations not allow through?
Prevents blood cells from passing through or large proteins
There is also a charge associated with the pores, so negatively charged proteins are repelled
What substances does filtrate contain and not contain after going through the glomerulus?
Does not contain cells (RBC) or large proteins (albumin)
Does contain positively charged molecules and is therefore slightlty positively charged
What lines the proximal convoluted tubule?
A brush border to create lots of surface area
What is reabsorbed and secreted in the proximal convoluted tubule?
Na+, Cl-, glucose
What cells are in the thick portion of the loop of Henle?
Simple cuboidal epithelium
What cells are in the thin portion of the loop of Henle?
Simple squamous epithelium
What does the juxtaglomerular appartus contain and where is it located?
Located outside where the afferent and efferent arterioles enter and exit the bowmans capsule
Contains the macula densa and juxtaglomerular cells
What does the macula densa do based on how fast the fluid is flowing and the contration of Na+ inthe fluid?
It releases paracrine signals, consisting of ATP asnd adenosine
What is the juxtaglomerular cell?
A lining in the afferent arteriole that reacts to adenosine
What happens if the osmolarity in the solute is too high?
The juxtaglomerular cells contract to decrease GFR and decrease water loss
What happens if the osmolarity in the solute is too low?
The juxtaglomerular cells relax to increase GFR and enhance water loss
What is a second function of the macula densa?
Regulate renin release from the juxtaglomerular cells
How many terminal ducts do the collecting ducts form
30
What are the collecting ducts lined with and what do they have receptors for?
Lined with simple squamous epithelium and has receptors for ADH
What will happen when receptors in the collecting duct are stimulated?
Cells will insert aquaporin channel and allow water to readily pass and then get recovered by the vasa recta
What is glomerular filtration rate?
The volume formed by both kidneys per minute
How many litres of urine is produced in a day?
Only 1-2 litres
How many litres of filtrate is produced in men and women?
180 litres/day for men
150 litres/day women
What are the two pressure that influence glomerular filtration?
Hydrostatic pressure and colloid osmotic pressure
What is hydrostatic pressure?
Pressure produced by a fluid against a surface, net fluid movement will be to the area of lower pressure
Glomerular filtration occurs when…
Glomerular hydrostatic pressure exceeds the capsular (luminal) hydrostatic pressure of the bowman’s capsule
