Ultrafiltration and Selective Reabsorption in the Kidneys

Flashcards covering key concepts related to renal biology, specifically focusing on the processes of ultrafiltration and selective reabsorption in kidney function.

Glomerular Filtrate

The fluid that is filtered from the blood in the kidneys, containing water, glucose, amino acids, and ions.

Ultrafiltration

The process by which the blood is filtered in the glomerulus to form urine.

Selective Reabsorption

The process of reabsorbing certain substances from the filtrate back into the blood while leaving others behind.

Proximal Convoluted Tubule

The part of the nephron where most of the reabsorption of nutrients like glucose and amino acids occurs.

Loop of Henle

The section of the nephron responsible for the reabsorption of water; it consists of descending and ascending limbs.

Distal Convoluted Tubule

A segment of the nephron where further processing of the filtrate occurs, although less is required compared to the proximal tubule.

Collecting Duct

The part of the nephron that collects urine from multiple nephrons and delivers it to the ureter, its permeability influences water reabsorption.

Aquaporins

Channel proteins in cell membranes that facilitate the transport of water, influenced by the hormone ADH.

ADH (Antidiuretic Hormone)

A hormone released from the pituitary gland that regulates water retention in the kidneys, influencing the permeability of the collecting duct.

Osmosis

The movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.

Cortex

The outer region of the kidney where the renal corpuscles and convoluted tubules are located.

Medulla

The inner region of the kidney, containing the loop of Henle and collecting ducts.

Tight Junctions

Connections between epithelial cells that prevent the passage of molecules through the space between cells, ensuring substances pass through the cells.

Sodium-Potassium Pump

A membrane protein that uses ATP to transport sodium out of cells and potassium into cells, essential for maintaining concentration gradients.

Paracellular Route

The pathway that substances can take to move between epithelial cells rather than through them.

Filtrate

The liquid that passes through the nephron, consisting of water, urea, ions, and other small molecules prior to reabsorption.

Reabsorption

The process of taking substances back into the bloodstream after they have been filtered out in the kidneys.