Physiology Unit 5 Glomerular Filtration

What is the functional unit of the kidney?

nephron

What is the order of filtration in the nephron?

renal corpuscle, pct, descending limb, ascending limb, dct, collecting duct

What two things make up the renal corpuscle?

glomerulus and glomerular capsule

What part of the nephron collects urine from several different nephrons?

collecting duct

The collecting duct crosses pyramid to drain into what?

minor calyx

What kind of nephron originates in the outer 2/3 of the cortex?

cortical nephrons

What kind of nephron originates in the inner 1/3 of the cortex

juxtamedullary

Which type of nephron has a longer loop which produces more concentrated urine?

juxtamedullary nephron

This type of nephron has a shorter loop but it still must cross into the medulla

cortical nephron

In the renal corpuscle, the glomerulus is surrounded by what?

the glomerular capsule

What do afferent arterioles feed in the renal corpuscle and they’re how many times more permeable than a normal continuous capillary?

fenestrated capillaries, 100-400x

What is forced out of the capillary in the renal corpuscle in order to not be in urine?

plasma and solutes

What are the three layers of filtration in the renal corpuscle?

capillary endothelial cell fenestrae, glomerular basement membrane, slit diaphragm of glomerular capsule inner visceral layer

Of the 3 layers of filtration in the renal corpuscle which is the most restrictive?

glomerular basement membrane

How does the capillary endothelial cell fenestrae in the renal corpuscle prevent proteins from exiting the vessel?

the fenestrae is charged

What is the other name for the glomerular capsule?

bowman’s capsule

Podocytes have thousands of what?

foot processes

What is the last layer of defense against proteinuria?

slit diaphragm

How wide are the slits that form between foot processes?

30-50nm

Filtrate officially gets its name when it enters what?

glomerular capsule

Are plasma and plasma solutes included in filtrate?

yes

What is the volume of filtrate produced by both kidneys per minute in men and women?

115mL/min for women and 125 mL/min for men

Around how much total blood is filtered every 40 minutes?

7.5L

What are the two major functions of the kindeys?

regulating blood composition and blood volume

During renal autoregulation, what senses changes in renal artery blood pressure and adjusts blood flow?

juxtaglomerular apparatus

If someone has high blood pressure would the renal artery be constricted or dilated?

constricted

Does the GFR remain relatively constant despite variabilities in blood pressure?

yes

Will fluid ever be reabsorbed in the glomerulus?

no, never

What kind of starling force forces filtrate out of the blood?

hydrostatic pressure

Are the efferent arterioles significantly smaller or bigger than the afferent arterioles?

significantly smaller

Is there more protein in the plasma or the filtrate?

plasma

What is the total net filtration pressure for glomerular filtration?

10mmHg

How much filtrate does the renal corpuscle produce per day?

180L/day

Is filtrate or urine more dilute?

filtrate

How much urine is excreted per day on average?

1-2L

What is the minimum amount of urine that has to be excreted per day?

400 mL/day

What is the obligatory amount of water loss?

0.3 mL/minute

What is the maximum production rate that water can be filtered?

16mL/min

What percent of filtrate is reabsorbed?

99.2% - 99.8%

At least what percent of filtrate is reabsorbed in an unregulated manner?

85%

What does an unregulated reabsorption manner mean?

the reabsorption happens the same way every time without impact from hormones or anything external

Concentration gradients must be formed between nephron and surrounding capillaries to achieve what?

filtration

Acute renal failure is usually diagnosed by a rise in what?

blood creatinine levels

Acute renal failure may be caused by what which is a result of what?

reduced blood flow to the kidneys caused by atherosclerosis of renal arteries

What is acute renal failure?

ability of kidneys to excrete waste and regulate homeostasis decreasing over a short period of time

What are the 4 things that renal insufficiency is caused by?

nephron destruction, diabetes mellitus, arteriosclerosis, kidney stones

What are symptoms of kidney disease?

hypertension, uremia, acidosis, hyperkalemia

How is kidney disease traditionally treated?

hemodialysis 3x per week

What is a new treatment for kidney disease?

continuous ambulatory peritoneal dialysis (dialysis fluid being injected into the peritoneal cavity)

Using continuous ambulatory peritoneal dialysis what happens to waste?

it accumulates in the peritoneal fluid and then the fluid is removed and discarded a few hours later

What are ureters?

ducts that channel urine from kidneys to urinary bladder

What is the structure of the kidneys?

2 bilateral organs

What is the renal hilum of the kidney?

renal artery supplies blood, renal vein drains blood

Why is the kidney slightly tilted inward?

prevents ureter from kinking

What is the retroperitoneal protected by?

a VERY large fat pad

What is the renal cortex of the kidney?

the outer layer, contains renal corpuscles

How many renal pyramids/medullas are there per kidney

8-15

What does the renal pelvis do?

collects urine from calyces, drains into ureter

What does the renal medulla contain?

renal tubules and collecting ducts, drains into minor calyx then major calyx

What is the capacity of the bladder?

700-800mL

What is the guarding reflex?

initial stretch reflexes inhibit parasympathetic detrusor stimulation, 200-400mL

What does the voiding reflex stimulate?

parasympathetic detrusor contraction, may relax internal sphincter

What are the segmental arteries?

terminal branches of the renal artery

What do the interlobar arteries pass through?

renal columns

What are the arcuate arteries?

arch between the cortex and medulla

What do the interlobular arteries do?

radiate outward into the cortex

What do the peritubular capillaries surround?

renal tubules