Lecture 30

Question 1

What are the functions of the kidney?

Answer 1

regulate ECF volume, blood pressure
regulate osmolarity
maintain ion balance
homeostatic regulation of pH
produce hormones (ex. erythropoietin)
excrete wastes (creatinine, urea, etc.)

Question 2

What are the two types of nephrons?

Answer 2

cortical or juxtamedullary

Question 3

Describe the blood vessel sequence as well as the nephron composition

Answer 3

afferent arteriole to glomerulus to efferent arteriole to peritubular capillary (vasa recta = peritubular capillaries stretching into the medulla)

bowman’s capsule (renal corpuscle) to proximal tubule to ascending/descending limbs of Loop of Henle to distal tubule to collecting duct

Question 4

What is the filtration fraction?

Answer 4

percentage of total plasma volume that gets filtered (usually 20%)

Question 5

What are the 3 barriers filtration occurs through?

Answer 5

fenestrations in the glomerular capillary epithelium
lamina of the Bowman’s capsule
epithelium of the bowman’s capsule surrounding the glomerulus (made of podocytes)

Question 6

What determines the glomerular filtration rate

Answer 6

hydrostatic pressure (pressure of blood in glomerulus)
fluid pressure (pressure of fluid in Bowman's capusle)
colloid osmotic gradient (due to proteins remaining in the capillaries and not being filtered)