Anatomy & Physiology: The Kidneys

Flashcards about kidney anatomy and physiology for vet tech students.

Kidney functions

Regulates water and electrolyte balance, maintains acid-base homeostasis, retains protein and glucose, excretes wastes and toxins, and secretes hormones.

"Renal"

Refers to the kidneys.

Acid

A substance that releases hydrogen ions in solution (pH <7).

Base

A substance that accepts hydrogen ions in solution (pH >7).

Nephron

Functional unit of the kidney.

Renin

Secreted by the kidney, mediates extracellular volume and arterial vasoconstriction (regulates blood pressure) via the renin-angiotensin system.

Aldosterone

Stimulates active sodium resorption.

Antidiuretic hormone (ADH)

Stimulates passive water reabsorption.

Nephron structure

Made up of the glomerulus (surrounded by Bowman’s capsule) and its tubule, which includes the proximal tubule, the medullary loop of Henle, and the distal tubule that empties into the collecting duct.

Filtration through glomerular capillaries

Driven by hydrostatic pressure as a direct result of arterial pressure.

Glomerular Filtration Rate (GFR)

The rate at which filtration occurs.

Loop of Henle

Part of the kidney responsible for concentrating the urine; sodium and chloride are resorbed here.

Proximal tubule

Resorbs all glucose and amino acids, and most bicarbonate, phosphate, and water.

Angiotensin II production

Causes aldosterone release from the adrenal cortex, increased release of ADH from the posterior pituitary, increased thirst, and constriction of the efferent arteriole to maintain GFR.

Aldosterone function

Causes sodium and water resorption in the distal tubule and collecting duct, where sodium is exchanged for potassium and hydrogen.

Antidiuretic hormone function

Makes the distal tubule and collecting duct more permeable to water, increasing urine concentration.

Vitamin D (calcitriol)

Produced by the kidney to help promote calcium absorption from the intestine.

Erythropoietin

Stimulates production of red blood cells.

"Kidney values" on a blood panel

The BUN and creatinine.

GFR

Best indicator of true kidney function.