The Urinary System

1. The Urinary System By: everybody

2. Kidneys • Structure • Lie in the retroperitoneal space • 2 Kidneys • Subdivided into branches • Nephron • Vessels • Renal Vein • Inferior Vena Cava • Heart • Right Atrium Right Ventricle • Etc.

3. Function • Regulates fluid of the body • Sorts chemicals from the blood • Filtration • Tubular Reabsorption • Tubular Secretion • Filtration Pressure • Filtration Membrane

4. Hilus • The Hilus is the notch where the renal artery, renal vein, and ureters connect with the kidney. • It is an indented surface that acts as a point where nerves and vessels enter or leave • The renal artery and nerves enter the hilus and the renal vein and ureter exit. • It opens into the renal sinus. • Problems that can occur: • If you get hit in the kidney, the hilus can become detached, which would result in internal bleeding. • The bleeding may involve blood that contains toxins and waste • Internal bleeding may lead to blood poisoning.

6. Kidney Disorders • Glomerulonephritis - Inflammation of the filtration membrane within the renal corpuscle, releasing an increase in the filtration membrane’s permeability; plasma proteins and blood cells enter the filtrate which increases urine volume due to increased osmotic concentration of the filtrate • Acute Glomerulonephritis - Often occurs1-3 weeks after a severe bacterial infection, such as strep throat; normally subsides after several days • Chronic Glomerulonephritis - Long-term, progressive process whereby the filtration membrane thickens and is eventually replaced by connective tissue; the kidneys become non-functional • Pyelonephritis - Often begins as a bacterial, usually E.Coli, infection of the renal pelvis, which spread to the rest of the kidney; the infection can destroy nephrons, corpuscles, and Loops of Henle, dramatically reducing the kidney’s ability to concentrate urine • Renal Failure - Can result from any condition that interferes with the kidney failure

7. Continued…. • Acute Renal Failure - Occurs when damage to the kidney is rapid and extensive; leads to accumulation of wastes in the blood; if renal failure is complete, death can occur in 1-2 weeks • Chronic Renal Failure - Caused by permanent damage to so many nephrons that the remaining nephrons are inadequate for normal kidney function; can result from chronic glomerulonephritis, trauma to the kidneys, tumors, or kidney stones

8. Glomerular Filtration • Function • The glomerulus fills the Bowman’s capsule and filters fluid into it • This fluid then flows into the proximal convulted tubule and is carried from the Bowman’s capsule • Materials are pushed out of the blood and into Bowman’s capsule of hepron

9. Disease and regulation • Glomerular nephritis = disease • Autoregulation – maintaining GFR • Glomerular Filtration Rate (GFR) • Amount of plasma that enters the Bowman capsule per minute • Renal plasma flow x the % of plasma entering the renal canal

10. Tubular Secretion • 1 of 3 major processes of urine formation • Occurs when the nephron cells transport solutes from the blood into the filtrate • Urine filters consists of substances filtered directly from the blood • Secreted directly from the blood and the nephrons • These solutes are secreted from the peritubular capillaries across the wall of the nephron into the filtrate • Converts to urine expelled from the body

11. Atomic makeup • Major solutes include • Water • Organic molecules • Protein • Glucose • Urine • Uric acid • Creatinine

12. Ionic makeup • Major Ionic compounds include • Sodium • Potassium • Chlorine • Bicarbonate • Hydrogen • Ammonium • Creatine • Urea

14. Urine concentration • When a person drinks enough liquids, the body must eliminate the excess without losing substances essential for maintaining homeostasis. • When this process is finished, the product of this is called diluted urine. • When a person doesn’t drink enough fluid, the amount of diluted urine produced would lead to dehydration. • This person produces concentrated urine that conserves water.

15. Countercurrent Mechanism- method for concentrating urine based on movement of ions out of the nephron • It consists of parallel tubes and works so that the fluid in both sets of tubes has the same composition. • Movement of Urine- Urine moves from the cortex toward the medulla and the interstitial fluid becomes progressively more concentrated until it achieves a maximum concentration of 1200 mOsm/kg at the tip of the renal pyramid.

16. Countercurrent Mechanism

17. Ureters • Tubes that urine flows through • From the kidney to the urinary bladder • One from each kidney • Structure • Outside: connective tissue • Middle: Layer of smooth muscle • Inner: more connective tissue

18. How urine travels: • Pushed through the ureters by peristaltic contractions. • These contractions will last between 1-2 seconds and 1-2 minutes. • The urine travels at 3 cm / second • The pressure from the urinary bladder compresses at the entry way of the urinary bladder to prevent backflow into the ureters

19. The Urinary Bladder • A hollow, muscular container • Different locations for males and females

20. Trigone • Triangular shape flap • Prevents backflow of urine • Located in…

21. Urethra • Function is urination/ expelling of urine from the urinary bladder • Tube extending from the bladder to the outside of the body • In both males and females it drains the bladder, but in males it also conveys sex cells • Voluntarily and involuntarily with the aid of external urethral sphincters, and internal urethral sphincters • 8 in. long in males and 1.5 in long in females

22. Urinary Disorders of Everything Else • Bladder • Cancer • Grows rapidly, blood in urine • 50% of cases caused by cigarette smoking • Cystitis • Inflammation of the bladder • 10x more likely in females • Abdominal pain • Can hurt to urinate • Urethra • Polyuria- increased urine volume • Symptom of Diabetes • Nocturia-urination at night • Incontence- inability to control bladder • Usually affects the elderly • Blood Urea Nitrogen Increase- increases chance of infection of urethra

23. Ureters • Strictures • Abnormally narrow parts of ureters • Stones- calcium deposits in ureters that can block urine flow to bladder • Kidneys stones must travel through the ureters

24. DONE