The Urinary System By: everybody

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.

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

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.

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

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

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

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

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

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

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

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.

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.

Countercurrent Mechanism

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

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

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

Trigone Triangular shape flap Prevents backflow of urine Located in…

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

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

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

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