Glomerular Filtration and Mechanisms

These flashcards cover key concepts related to glomerular filtration rate, control mechanisms, and kidney function.

GFR

Glomerular Filtration Rate - the rate at which blood is filtered in the glomerulus.

Net Filtration Pressure

The pressure driving the formation of filtrate in the kidney; directly related to blood pressure.

Auto-regulation

Intrinsic control mechanisms that regulate GFR at the nephron level.

Extrinsic control mechanisms

Regulatory systems involving neural and hormonal signals affecting systemic blood pressure and indirectly GFR.

Afferent arteriole

The blood vessel that supplies blood to the glomerulus; constriction reduces blood flow and lowers GFR.

Macula Densa

Cells that monitor salt concentration in the distal convoluted tubule and help regulate GFR.

Renin

An enzyme released by granular cells in response to low blood pressure; initiates the renin-angiotensin mechanism.

Angiotensin II

A potent vasoconstrictor hormone that increases blood pressure and affects GFR.

Atrial Natriuretic Peptide (ANP)

A hormone released by the heart in response to high blood pressure; promotes diuresis and reduces blood volume.

Transport maximum

The maximum rate at which a substance can be reabsorbed or secreted by the renal tubules.

Renal threshold

The plasma concentration at which a substance begins to appear in the urine due to saturation of transport mechanisms.

Concentration gradient

The difference in concentration of solutes across a membrane, essential for the reabsorption of water in the kidneys.

Antidiuretic Hormone (ADH)

A hormone that promotes water retention in the kidneys by increasing the permeability of collecting ducts.

Urine concentration

The process of removing water from the filtrate to concentrate waste products for excretion.

Myogenic response

A mechanism where afferent arterioles constrict or dilate in response to changes in blood pressure.

Physiological changes

Changes in the body that result from variations in GFR and blood filtration rates.