URINARY SYSTEM
The organs of the urinary system (kidneys, ureters, bladder, and urethra) all play a role in urine
formation, storage, or expulsion. However, the function of the urinary system cannot be simply defined
...
URINARY SYSTEM
The organs of the urinary system (kidneys, ureters, bladder, and urethra) all play a role in urine
formation, storage, or expulsion. However, the function of the urinary system cannot be simply defined
as “urine production” or “waste removal.”
Kidney
• Function: adjust solute and water concentration (Excretion and Regulation)
Ureter
• Muscular tube leading from renal pelvis to bladder (Elimination)
• Conduit for formed urine
• Differ in length
Bladder
• Muscular sac on pelvic floor (Elimination)
• Distensible and expands
• Opening of two ureters and the urethra mark the triangular area (trigone)
Urethra
• Discharge of waste to external environment
The primary functions of the urinary system include:
• Regulating blood volume.
• Regulating the chemical makeup of blood. (filtration, reabsorption, secretion)
• Acid base balance
• detoxification
Secondary functions include:
• Metabolism of vitamin D (calcitriol)
• Production of renin.
• Production of Erythropoietin.
• Gluconeogenesis (glucose production from noncarbohydrate precursors (e.g., amino acids, fatty
acids).
RENAL ANATOMY
Location and External Anatomy of the Kidneys
• Kidneys lie retroperitoneally in the superior lumbar region.
• Each kidney is about the size of a large bar of soap.
• The right kidney lies lower than the left b/c it’s crowded by the liver.
• The lateral surface is convex and medial surface is concave. Medial surface has a cleft, the renal
hilus, which opens into a space called the renal sinus.
• The space within the renal sinus is filled with the ureter, blood vessels, lymphatics, and nerves.
• Sitting on top of each kidney is an adrenal gland – an endocrine organ that produces epinephrine,
norepinephrine, aldosterone, cortisol, and other hormones.
• 3 layers of supportive tissue surround each kidney:
• Renal capsule – fibrous transparent structure directly adherent to the kidney surface.
• Adipose capsule – fatty mass that attaches the kidney to the posterior body wall and provides
cushioning.
• Renal fascia – outer layer of dense fibrous CT that anchors the kidney and adrenal gland to
surrounding structures.
Internal Anatomy of the Kidney
• Frontal section reveals 3 distinct regions: cortex, medulla, and pelvis.
• The most superficial region is the renal cortex. Urine formation occurs here.
[Show More]
.png)
.png)
