Kidneys and the Urinary System Kidneys and the Urinary System Chapter 16

Overview of Lesson Formation of urine Urinary system Water balance and alcohol Problems of the urinary tract

When protein is broken down in the body, it results in nitrogenous waste that must be eliminated from the body

All 20 amino acids have a nitrogen group (NH 2 ). When broken down for energy, the nitrogen group is converted to ammonia (NH 3 ). which is toxic to the body Examples of Amino Acids Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Ammonia is converted into urea by the liver. Urea is then transported in the blood to the kidneys where the urea is removed from the blood. Circulatory System Based on: Mader, S., Inquiry Into Life

Formation of Urine Amino acids in protein are broken down, resulting in production of ammonia Ammonia is converted to urea in liver Urea travels in blood to kidneys, where removed from blood and incorporated into urine

Overview of Lesson Amino acids, ammonia and urea Urinary system Water balance and alcohol Problems of the urinary tract

Based on: Mader, S., Inquiry Into Life, McGraw-Hill Major organs of the system 1.Kidneys (2) 2.Ureters(2) 3.Bladder (1) 4.Urethra(1)

Kidneys excrete nitrogenous waste, such as urea, uric acid, creatine and ammonium Maintain blood volume by regulating the amount of water excreted Monitor blood composition by regulating electrolyte excretion- sodium the most significant; potassium; bicarbonate and calcium among others Functions of the Urinary System

Monitor blood ph chiefly by regulating the secretion of certain ions such as hydrogen Secretion of the enzyme Renin, which helps maintain blood pressure Secretion of the growth factor erythropoietin which stimulates the production of RBC.

Lie in depressions against deep muscles of the back- behind peritoneum Connective & adipose tissue adhere to each kidney Renal capsule- fibrous connective tissue Hilus- depresssion on concave side where renal blood vessels & ureters exit Renal cortex- outer granulated layer Based on: Mader, S., Inquiry Into Life, McGraw-Hill Kidneys

Urine Formation by Nephron Blood pressure forces water, glucose, amino acids and urea from capillaries into nephron Glucose and amino acids are reabsorbed into blood from nephron Some water is reabsorbed into blood Urine is urea and salt concentrated in water

Nephron Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Urine moves from the collecting ducts through the renal pelvis to the ureter Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Urine moves from the kidneys, through the ureters to the bladder and finally through the urethra Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Overview of Lesson Amino acids, ammonia and urea Urinary system Water balance and alcohol Problems of the urinary tract

Regulation of Water Balance Brain monitors water content of blood If low water content, pituitary releases ADH ADH travels in blood to nephron ADH causes more water to move from urine back into blood

Nephron Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Alcohol consumption suppresses the production of ADH by the pituitary. Why would this result in dehydration and a hangover?

Alcohol Effects Alcohol suppresses ADH production by the pituitary Without ADH, higher amounts of water stay in the urine Urine with high concentrations of water leaves the body

Overview of Lesson Amino acids, ammonia and urea Urinary system Water balance and alcohol Problems of the urinary tract

Incontinence (urine leakage) More than 10 million Americans experience incontinenceMore than 10 million Americans experience incontinence Most do not seek treatmentMost do not seek treatment Treatment can improve or eliminate the problem 90% of the timeTreatment can improve or eliminate the problem 90% of the time

Causes of Incontinence Stress incontinence: leaking small amounts of urine when coughing, lifting, or exercising Urge incontinence: the bladder suddenly and unexpectedly contracts and expels urine Overflow incontinence: bladder cannot completely empty so urine dribbles

Kidney stones form in the kidney pelvis. There are 4 types of stones. Calcium stones (most common) Uric acid stones Bacteria caused stones Cystein stones Based on Mayo Clinic Health Letter

Kidney stones cause pain when they pass down the ureters to the bladder and urethra Based on: Mader, S., Inquiry Into Life, McGraw-Hill

Treatments for Kidney Stones Small stones may pass with no painSmall stones may pass with no pain Larger stones may pass but cause extreme of pain, requiring a lot pain medicationLarger stones may pass but cause extreme of pain, requiring a lot pain medication Stones that are too large to pass may require surgical treatment including:Stones that are too large to pass may require surgical treatment including: – using a ureteroscope to go up and snare the stone – using a nephroscope to crush the stone and retrieve it –using shock wave lithotripsy where a person is submerged in water containing shock waves to pulverize the stones

Urinary Tract Infection (UTI) Second most common infection following respiratory infectionsSecond most common infection following respiratory infections UTI occur when bacteria (E. coli) from the digestive tract get into the opening of the urinary tract and multiplyUTI occur when bacteria (E. coli) from the digestive tract get into the opening of the urinary tract and multiply Bacteria first infect the urethra, then move to the bladder and finally to the kidneysBacteria first infect the urethra, then move to the bladder and finally to the kidneys UTI tend to occur more in women than menUTI tend to occur more in women than men

Women may have more UTIs than men because: 1)they have a shorter urethra, allowing quicker access to the bladder 2)the urethral opening is nearer the anus 3)intercourse may result in UTIs in women Based on: Harvard Medical School Family Health Guide

Symptoms of UTIs Urge to urinate but only small amount of urine producedUrge to urinate but only small amount of urine produced Pain and burning sensation in bladderPain and burning sensation in bladder FeverFever Blood in urineBlood in urine

Diagnosis and Treatment Doctors check urine for white and red blood cells and bacteriaDoctors check urine for white and red blood cells and bacteria Bacteria grown in culture to determine which antibiotic will work the bestBacteria grown in culture to determine which antibiotic will work the best UTIs are treated with antibiotics and are often cured within 1 or 2 daysUTIs are treated with antibiotics and are often cured within 1 or 2 days