Glomerular Filtration (Chapter 34)

Flashcards covering key concepts and details about glomerular filtration, its mechanisms, and factors affecting it.

What are the main components of the renal corpuscle?

Glomerulus, Bowman’s space, and Bowman’s capsule.

What role do podocytes play in the filtration process?

Podocytes form the visceral layer of Bowman’s capsule and wrap around glomerular capillaries, contributing to the filtration barrier.

What elements make up the glomerular filtration barrier?

Glycocalyx, endothelial cells, glomerular basement membrane, and podocytes.

How does molecular size affect filterability across the glomerular filtration barrier?

The molecular size, weight, and effective radius determine how well a solute is filtered.

What effect does electrical charge have on solute filterability through the glomerular filtration barrier?

Negative charges on the barrier restrict the movement of anions and enhance cation movement.

What is Starling's equation used for in the context of glomerular filtration?

It is used to calculate fluid movement across capillary walls, focusing on hydrostatic and colloid osmotic pressures.

What factors contribute to the higher filtration rate in the glomerulus compared to other capillary beds?

Greater Starling forces and higher capillary permeability due to large fenestrations.

How does renal blood flow (RBF) relate to filtration?

Increased renal plasma flow enhances filtration, with RBF being approximately 1L/min out of a total cardiac output of 5L/min.

What happens when hydrostatic pressure difference exceeds colloid osmotic pressure difference?

Ultrafiltration occurs, allowing movement of water out of the capillary.

What critical components control the glomerular plasma flow?

Resistance at the afferent and efferent arterioles.

What is the role of peritubular capillaries?

They provide nutrients to the renal tubules and retrieve reabsorbed fluid.

How does increased extracellular fluid volume affect the renin-angiotensin system?

It inhibits the system, leading to a greater decrease in efferent resistance than afferent resistance.

What is the net effect of the pressures along the peritubular capillary?

A large net absorptive pressure, favoring absorption across the entire capillary.

What is the significance of the filtration slits formed by podocytes?

They determine the size and charge selectivity of the filtration process.