Urinary Alterations

Costovertebral Angle: The angle formed by attachment of 12th rib to spinal column. This is there you have pain and discomfort with kidney conditions.

Kidneys maintain health via homeostasis

  • Form urine, regulate body water volume, composition of extracellular fluid and blood pressure.

  • Eliminates wastes from blood, regulates electrolytes, and acid base balance (blood pH)

  • Maintain fluid balance by regulating amount and makeup of intracellular and extracellular fluids

    • Continuously exchanging water and electrolytes.

  • Regulates RBC production and secretion of erythropoietin

    • Regulates red blood cell production through the creation of erythropoietin which is released in response to hypoxia (low oxygen level) and reduced renal blood flow.

  • Synthesis of vitamin D to active form, which is important in absorbing calcium and promoting bone growth.

  • Help regulate blood pressure - Renin-Angiotensin System and aldosterone.

    • Renin acts on angiotensin I and converts it to angiotensin II, which is a powerful vasoconstrictor. Peripheral resistance is increased and blood pressure is increased.

      Aldosterone production is stimulated by the increase in angiotensin I; therefore sodium and water are retained to increase circulating volume and increase blood pressure.

Renal capsule: the fibrous connective tissue, blood vessels and lymphatics surround each kidney membrane

Hilum: serves as the entry site for the renal artery and nerves and the exit site for the renal vein and ureter. The hilum opens to a cavity called the renal sinus.

Parenchyma: actual tissue of the kidneys, two layers

  • Cortex- the outer layer of the parenchyma located beneath the renal capsule

  • Medulla- the inner layer of the kidneys, contains the loops of Henle, vasa recta, and the collecting ducts of the juxtamedullary nephrons.

Urine travels via the collecting ducts of the cortex & medulla then connect to the papillae (top) of the pyramids. Urine passes to enter the minor calyces which widen and form the major calyces which drains urine into to the renal pelvis. The renal pelvis drains urine into the ureter and can store 3 to 5 mL of urine (~teaspoonful)

Renal Excretion - Kidneys

  • Kidneys excrete substances from body into urinary track to get rid of things we have too much of.

    • Primary route of potassium elimination

    • Major route of elimination of medications and their metabolites

    • Remove excess nitrogen from body

Kidneys and Metabolic Waste

  • Nitrogen waste products

    • Ammonia (NH3) quickly converted to Urea in healthy person

    • Urea - measured by blood urea nitrogen test (BUN)

    • Uric acid

    • Creatinine

Renal Reabsorption - Kidneys

  • Re-absorb fluid and electrolytes that we need from tubular fluid or pre urine.

  • Fluid and electrolytes were filtered out of bloodstream, but kidney can reabsorb them to maintain homeostasis

  • Process allows glucose and amino acids, salts, and water that has passed through Bowman’s capsule to return to body or be excreted into urinary track for disposal.

Functions of the kidney

  1. Removes nitrogenous wastes

  • Urea

  • Uric acid

  • Creatinine

  • Ammonia

  1. Maintains homeostasis

  • Fluid balance

  • Electrolyte balance

  • Acid-base balance

  1. Excretory Organ

  • Via blood filtration & formation of urine

  1. Regulation of Blood Pressure

  • Juxtaglomerular apparatus

  • RAA system

    • Renin

    • Angiotensin

    • Aldosterone 

Urine formation

  1. Filtration

  • Occurs in renal corpuscle

  1. Reabsorption

  • Occurs in proximal convoluted tubule

  • Also occurs in distal convoluted tubule

  • It takes things back into blood

  1. Secretion

  • Occurs in distal convoluted tubule

  • Blood gives things up to the urine

  1. Concentration

  • Occurs in collecting tubules

Blood Flow to Kidneys