Renal Physiology Lecture 1: Nephron - The Functional Unit of the Kidneys Flashcards
What are the types of kidney nephrons?
Cortical & Juxtamedullary nephrons
- ~1 million nephrons in each kidney
- 80% are cortical nephrons
- 20% are juxtamedullary nephrons
Where are the nephrons found?
- Corticial → in the cortex
- juxtamedullary → Begin at border of cortex and medulla and project into medulla
What surrounds the nephrons?
Peritubular capillaries surround the renal tubules
What are peritubular capillaries around juxtamedullary nephrons called?
vasa recta
What is Bowmans capsule?
a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine.
- surrounds the glomerular capillary tuft
Bowman’s capsule + glomerulus = ??
Bowman’s capsule + glomerulus = renal corpuscle
Renal tubule successive segments
- Proximal tubule → filtered fluid
- Loop of Henle → ascending (thick and thin) and descending segments
- Dips down toward or within the medulla
- Distal tubule → from adjacent nephrons
- Collecting duct
- Renal pelvis → final urine
- Ureter, bladder, urethra
What forms the juxtaglomerular apparatus?
Ascending limb of loop of Henle passes between afferent & efferent arterioles
- a specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It is located near the vascular pole of the glomerulus
Main function of the juxtaglomerular apparatus
regulate blood pressure and the filtration rate of the glomerulus.
Tubular wall
Tubular wall is a layer of tubular epithelial cells → Mostly connected by tight junctions
- Apical surface faces the tubular lumen
-
Basolateral surface rests on a basement membrane
- Faces the renal interstitium
What is the renal interstium?
the intertubular, extraglomerular, extravascular space of the kidney. It is bounded on all sides by tubular and vascular basement membranes and is filled with cells, extracellular matrix, and interstitial fluid
