Nephrons and Urine Formation

These flashcards cover key vocabulary related to nephron structure and the processes involved in urine formation.

Cortical Nephrons

Nephrons with a short loop of Henle that extends only a little into the medulla.

Juxtamedullary Nephrons

Nephrons characterized by a long loop of Henle that runs deep into the medulla.

Peritubular Capillaries

Capillary network around the renal tubule formed from the efferent atrial emerging from the glomerulus.

Vasa Recta

Long, U-shaped capillaries that run parallel to Henle's loop; absent or reduced in cortical nephrons.

Glomerular Filtration Rate (GFR)

The amount of filtrate formed by the kidneys per minute; approximately 125 ml/min in a healthy individual.

Ultrafiltration

The process where blood is filtered through glomerular membranes, allowing most components except proteins to enter Bowman's capsule.

Juxtaglomerular Apparatus (JGA)

A region formed by modifications of the distal convoluted tubule and afferent arteriole; helps regulate GFR.

Renin

An enzyme released by juxtaglomerular cells when GFR falls; stimulates glomerular blood flow and raises GFR.

Reabsorption

The process by which nearly 99% of the filtrate is absorbed by the renal tubules after filtration.

Tubular Secretion

The process involving the secretion of substances like H+, K+, and ammonia into the filtrate, important for ionic and acid-base balance.