Alyssa Murray, Katja Swartz, Kalista Creighton Ahouse, Antonio Xelhua, Emily O’Brien

Study the different parts of the kidney/urinary tract Understand the process of urine formation Know the content of urine Learn the different possible disorders and problems

Ureter: passageways that are 30 cm long and carry urine from the kidneys to the bladder Bladder: a smooth, collapsible sac made of muscle where urine is stored temporarily Urethra: a thin-wall tube that carries urine by peristalsis from the bladder to the outside of the body

Internal Urethral Sphincter – an involuntary sphincter that keeps the urethra closed when urine is not being passed. External Urethral sphincter – is fashioned by skeletal muscle as the urethra passes through the pelvic floor. (voluntarily) The length and the structure of the urethra are different between a male and a female: Male Urethra – approximately 20 CM long; extends from the urinary bladder to the exterior of the body Female Urethra – about 3 to 4 CM long; extends from the bladder to the exterior opening.

Internal urethral sphincter - keeps the urethra closed when urine is not being passed, involuntary, smooth muscle External urethral sphincter - allows us to choose to keep the urethra closed and postpone bladder emptying temporarily or one can relax the sphincter so urine can leave the body

Kidney: a homeostatic organ that maintains the purity and constancy of our internal fluids and is situated just below the rib cage – Renal Cortex: The outer region of the kidney – Renal Medulla: the inner region of the kidney – Medullary pyramids: mostly triangular regions with a striped appearance

1.Bowman’s Capsule 2. Efferent Arteriole 3. Afferent Arteriole 4. Renal vein 5. Renal artery 6. Proximal tubule 7. Glomerulus 8. Distal tubule 9. Loop of Henle

Nephrons: tiny structures that are the functional units of kidneys; responsible for urine production - Glomerulus: a knot of capillaries - Renal tubule: contains the tubular fluid filtered through the glomerulus - Loop of Henle: increases the surface area of the renal tubule - Bowman’s/Glomerular Capsule: a portion of the renal tubule that surrounds the glomerulus - Afferent arterioles: feed the glomerulus with blood - Efferent arterioles: receives blood that had passed through the glomerulus - Proximal tubule: leads from Bowman’s capsule to the Loop of Henle - Distal tubule: leads from the Loop of Henle to the Collecting Duct

Filtration: As blood courses through the glomeruli fluid soaks out of the blood through the membranes where it is filtered and then flows into the Bowman's capsule. Reabsorption: the movement of substances out of the renal tubules back into the blood. (ex: water, glucose, other nutrients, sodium (Na + ) and other ions) Secretion: secretion moves nitrogen-containing wastes out of the blood and into the tubules where they mix with the water and other wastes and are converted into urine

Filtration: force particles from blood into renal tube Reabsorption: water, glucose, amino acids, ions, pulled into blood Secretion: H+, K+, creatinine, drugs, removed into filtrate generally clear to yellow urochrome: breakdown of hemoglobin odor comes from ammonia pH around 6 -> changes based on metabolism sodium & potassium

glucose blood protein (albumin) red blood cells hemoglobin white blood cells (pus) bile

(voiding) - the act of emptying the bladder 1. The bladder collects 200ml of urine 2. Stretching of the bladder wall activates stretch receptors 3. Impulses transmitted to sacral region of spinal cord and back to bladder via pelvic splanchnic nerves 4. Bladder goes into reflex contractions 5. Stronger contractions forces stored urine past internal sphincter into upper part of urethra 6. Person feels the urge to void

Polyuria: excrete large amounts of urine, lose too much salt and water Anuria: abnormally low urinary output if below 100 ml/day Oliguria: abnormally low urinary output if between 100 and 400 ml/day Diuresis: flow of urine from kidney

Renal calculi - kidney stones, crystals, urine becomes extremely concentrated, solutes (uric acid salts) form crystals that precipitate in renal pelvis, very painful Urinary tract infection - painful urination, urgent and frequent urination, fever, cloudy or blood tinged urine Incontinence - occurs when we are unable to voluntarily control the external sphincter, normal in children under the age of 2; can be a result of emotional problems, pressure, or nervous system problems Urinary retention - a condition in which the bladder is unable to expel its contained urine, occurs in elderly men and after surgery

"Dissected Kidney." Wikimedia.org. Wikipedia, n.d. Web. 2 May Marieb, Elaine Nicpon. Essentials of Human Anatomy and Physiology. San Francisco: Benjamin Cummings, Print. "THE FORMATION OF URINE: FIGURATION, REABSORPTION, AND SECRETION." NSBRI. N.p., n.d. Web. 15 May "EOS, Our ENEMY." : Micturition. N.p., n.d. Web. 15 May