The Urinary System Chapter 15 Quick Overview of the Urinary System Urinalysis Lab will be preformed next week

Urinary System Facts or Myths? 1. It is healthy to drink your own urine. Myth. Some believe it’s a good health practice that can help treat cancer, AIDS, and a variety of other conditions. But there’s little evidence to back up these claims. In a survival situation, though, urine can be distilled by using the sun's heat to separate out the water vapors, leaving the salt, potassium, urea, and other components behind.

Urinary System Facts or Myths? 2. Urine can soften your skin. Fact. It's not urine per se, but a synthetic version of urea, a major component of urine, is used in many moisturizers for its skin-softening properties. Urea helps skin retain its natural moisture and can also exfoliate dead skin in higher concentrations. It’s also a common ingredient in athlete’s foot treatments, which may explain why, way back in 1994, Madonna famously told David Letterman that she urinated on her feet in the shower to get rid of athlete’s foot.

Urinary System Facts or Myths? 3. Coffee makes you have to urinate more. Fact. Coffee inhibits antidiuretic hormone (ADH), which works to keep the water levels in your body in balance. When ADH is blocked, the kidneys get a signal to release excess water — which is why you may sprint to the bathroom after downing your AM cup of joe.

Urinary System Facts or Myths? 4. Holding your urine can cause a bladder infection. Fact. The longer one holds their urine the more potential for bacteria to grow and multiply. The average bladder can hold about 8 cups of water. On average a person must go “number 1” 8-10 times a day. Women are more likely to get an infection because the urethra is shorter in women and bacteria can enter the bladder easier.

Urinary System Facts or Myths? 5. Urinating on a jellyfish sting will help alleviate the pain. Myth. A recent paper in Annals of Emergency Medicine reviewed several home remedies, like urine, meat tenderizer, alcohol, and baking soda, for relieving pain of jellyfish stings. The researchers found that none of the home cures were as effective as simply washing the stung area in hot water and applying lidocaine, a local anesthetic designed to numb skin and relieve pain, sold over-the-counter as a gel, liquid, or spray.

Urinary System Facts or Myths? 6. Putting one’s hand in warm water while they sleep makes them pee their pants. Myth. Sorry, regardless of slumber party pranksters everywhere, there no real evidence for this.

Why do we need a Urinary System? - Cells produce waste that can become toxic if it accumulates Three Functions 1. Removes salts and nitrogenous wastes 2. maintains normal concentration of water and electrolytes 3. maintains pH, controls red blood cell production and blood pressure

kidneys ureters bladder urethra Urethral sphincter

Structures and Functions of Urinary System Pair of kidneys, remove substances from the blood Ureters, transport urine from the kidneys to the bladder Urinary bladder, stores urine Urethra conveys urine to the outside of the body

The kidneys represent only 0.5% of the total weight of the body, but receive 20-25% of the total arterial blood pumped by the heart. The rate of filtrate is approximately 125 ml/min or 45 gallons (180 liters) per day. Considering you have 7 to 8 liters of blood in your body, this means that your entire blood volume gets filtered approximately times a day. Random Kidney Factoids

-renal cortex = outer shell around the medulla; the cortex appears granulated due to the presence of nephrons. - Renal Arteries attach to the abdominal aorta -Renal Veins attach to the inferior vena cava

NEPHRONS - functional unit of the urinary system. Microscopic structure that produces urine. -each kidney contains about 1 million nephrons -renal corpuscle: composed of a tangled cluster called a glomerulus which filters fluid

Kidney Facts: The kidneys represent only 0.5% of the total weight of the body, but receive 20-25% of the total arterial blood pumped by the heart. The rate of filtrate is approximately 125 ml/min or 45 gallons (180 liters) per day. Considering you have 7 to 8 liters of blood in your body, this means that your entire blood volume gets filtered approximately times a day. The right kidney is slightly lower than the left. Each kidney weighs about grams and is about 11.4 cm long and 6 cm wide and 2.5 cm thick. The first workable artificial kidney was developed during World War II in 1944 by Dr. William Kolff who was living in Holland. According to the National Kidney Foundation, more than 370,000 Americans are being treated with dialysis or kidney transplantation for kidney failure. Nearly 12 million Americans may be at risk for chronic kidney disease. The use of a dialysis machine is suggested when a patient’s blood urea nitrogen value exceeds 100 mg/dl (the normal value is 30 mg/dl)

Urine Composition - 95% Water, slightly acidic pH=6 - Contains wastes: urea and uric acid (characteristic smell, by products of breakdown of proteins in liver) - contains trace amino acids, sugar and bacteria Urine is yellow from the pigment: urochrome. This molecule results from the body’s destruction of hemoglobin. More solutes = brighter color.

Urine Formation occurs in the neprhon. Has 3 steps: Glomerular Filtration Tubular Reabsorption Tubular Secretion

Glomerular Filtration – Water, plasma and solutes smaller than proteins are filtered out (Glomerulus)

Electron Scanning Microscope view of several glomeruli and collecting ducts. Filtration begins here when. Blood cells and proteins are too large to fit through the filtration membrane. If either are found in the urine, it is a fair bet that there is a problem with the glomerular filters.

Tubular Reabsorption – Necessary substances (water, glucose, amino acids) are taken out of filtrate and returned to blood. (proximal tubule)

Tubular Secretion – Tubular Secretion – H+, K+, creatinine, and drugs are removed from blood and put in urine(distal tubule)

Urine may also contain other chemicals that can be detected. Hormones present in a pregnant woman are detectable in urine

17.4 Urine Elimination After urine forms in the nephrons, the ureters (starting with the renal pelvis) carry the urine away to the bladder Bladder is an expandable structure that stores urine before it is eliminated from the body. Transitional epithelial cells change shape to allow for expansion and contraction. artificial bladder grown in a lab

Micturation = urination; as the bladder fills this reflex occurs though it is also under voluntary control Urethra = tube carries urine to the outside of the body Detrusor Muscle - attach to bladder and sphincter, control urination

Disorders of the Urinary System Many urinary problems can be solved by drinking enough water. So how much fluid does the average, healthy adult living in a temperate climate need? The Institute of Medicine determined that an adequate intake (AI) for men is roughly 3 liters (about 13 cups) of total beverages a day. The AI for women is 2.2 liters (about 9 cups) of total beverages a day.

Kidney Stones - Kidney stones are small "pebbles" of salt and mineral in the urine. Very painful when passed. - Extracorporeal shock wave lithotripsy (ESWL) is a procedure used to shatter simple stones in the kidney or upper urinary tract. Ultrasonic waves are passed through the body until they strike the dense stones, and make them smaller

Cystitis = bacteria enters the bladder or kidneys (kidney infection); more common in women because the urethra is shorter Commonly known as a "bladder infection" UTI = urinary tract infection Frequent need to urinate Pain in the abdomen Burning sensation during urination Cloudy, bad-smelling urine Blood in the urine Leaking urine Low back pain Fever and chills Nausea and poor appetite

Catheters In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. The process of inserting a catheter is catheterization. Catheterization of the bladder is a common medical procedure, often performed by nurses

Overactive Bladder = sudden contractions of the bladder produce sensation of urgency, also more common in women Incontinence - inability to control urination (or defecation)

When Kidneys Fail.... Dialysis may be used to clean the blood (hemodialysis) 4 hours, 3 times a week Patients will eventually need a new kidney

Word Bank for #7 (page 269) Dialysis Evaporation of perspiration Urea Urine output Uric acid Creatinine Afferent Decreases efferent Blood plasma Microvilli Diffusion Secretion Active transport Diet Cellular metabolism Urochrome lungs

Kidney Transplants Modern Family Actress talks about kidney disease Laparoscopic Kidney Removal (surgery) Domino Kidney Transplants or Kidney Exchanges - when you aren't a match for a family member, you can participate in a kidney exchange.