Ch 25 Urinary System

Ch 25 Urinary System - Ch. 25: The Urinary System The...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch. 25: The Urinary System The urinary system is one the excretory mechanisms of the body. Excretion of carbon dioxide occurs through the lungs, undigestible food wastes through the large intestine and some salts in sweat from the skin. The urinary system produces urine by filtering blood. Its major homeostatic roles are the maintenance of osmotic balance and the excretion of nitrogenous wastes derived from protein metabolism. Osmoregulation 1. Fluid balance a. Fluid volume of urine is directly proportional to fluid volume of blood b. Blood pressure is directly proportional to blood volume 2. Electrolyte balance = solute concentration bodily fluids a. Solute concentrations determine tonicity b. Tonicity affects water movement =>electrolyte balance related to fluid balance 3. Regulation of blood pH is also regulated during urine production Excretion of nitrogenous waste 1. Ammonia (water-soluble, toxic) is converted to urea (water-soluble, non-toxic) in liver 2. Major nitrogenous wastes are a. Urea from amino acid metabolism b. Creatine from the breakdown of creatine phosphate in skeletal/cardiac muscle c. Uric acid from RNA metabolism 3. Main excretory route is in urine Hormone production 1. Renin 2. Erythropoietin 3. Calcitriol Organs of the Urinary System Kidneys Coverings of the kidney (in--->out) 1. Renal capsule 2. Adipose capsule 3. Renal fascia 4. Internal anatomy => 3 regions (out--->in) 5. Renal cortex 6. Renal medulla a. Medullary pyramids b. Renal columns 7. Renal pelvis (continuous w/ureter) a. Major calyx(ces) b. Minor calyx(ces) Blood supply Renal arteries (1/4 total CO/min to kidneys) --->Segmental arteries--->Lobar arteries--->Interlobar arteries (btwn pyramids to cortex) At cortical-medullary border: --->Arcuate arteries--->Interlobular arteries--->afferent arteriole--->glomerulus--- >efferent arteriole--->peritubular capillaries/vasa recta--->venules --->Interlobular veins--->Arcuate veins--->Interlobar veins--->Segmental veins---> Renal vein Nerve Supply Innervation from renal plexus Autonomic fibers, ganglia=>mainly sympathetic
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
=>regulation blood flow by altering vasoconstriction Ureters(1/kidney) Drain urine from renal pelvis of kidney to urinary bladder Urinary Bladder Stores urine prior to excretion Urethra Excretion of urine from urinary bladder Urine formation Functional anatomic subunit= NEPHRON 3 processes involved in urine formation; each localized to a specific region of the nephron Process Site Selectivity Energy req. Filtration
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/23/2009 for the course BIOL 1141 taught by Professor Loripaul during the Summer '09 term at UMSL.

Page1 / 6

Ch 25 Urinary System - Ch. 25: The Urinary System The...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online