The Urinary System PDF

KIDNEYS, URETERS, ADRENAL Presented by Assistant professor Dr. Ali Al-najjar General Surgeon Organs of the Urina system  Kidneys (2)  Ureters (2)  Urina bladder (1)  Urethra (1)  Organs of the Urina System Kidneys – excreto organs that separate waste substa...

KIDNEYS, URETERS, ADRENAL Presented by Assistant professor Dr. Ali Al-najjar General Surgeon Organs of the Urina system  Kidneys (2)  Ureters (2)  Urina bladder (1)  Urethra (1)  Organs of the Urina System Kidneys – excreto organs that separate waste substances from the blood and discharge them. Ureters – a pair of thick-walled tubes that car urine from the kidney to the urina bladder. Urina bladder – a membranous sac for tempora retention of urine. Urethra – a duct through which urine is discharged and which se es as the male genital duct.  Diagram of renal system Copyright © 2014 John Wiley & Sons, Inc. All rights rese ed.  Location of the Kidneys  Attached to ureters, renal blood vessels, and ne es at renal hilus (medial indention)  On the top of each kidney is an adrenal gland Dimensions Reddish-brown, bean shaped 12cm long, 6cm wide, 3cm thick e kidneys are located behind the peritoneum, and so are called retroperitoneal organs. ey sit in the back of the abdomen between the levels of the T12 and L3 ve ebrae. e right kidney is slightly lower than the left kidney to accommodate the liver. Both kidneys are bean- shaped and about the size of an adult st. Ptosis-kidneys drop to a lower position due to rapid fat loss, creating problems with the ureters. Ptosis can lead to hydronephrosis, a condition where urine backs up the ureters and exe s pressure on the kidney tissue. Coverings of the Kidneys  Adipose capsule  Surrounds the kidney  Provides protection to the kidney  Helps keep the kidney in its correct location against muscles of posterior trunk wall  Renal capsule  Surrounds each kidney Regions of the Kidney  ree regions of kidneys  Renal co ex – outer region, forms an outer shell  Renal columns – extensions of co ex- material inward  Renal medulla – inside the co ex, contains medulla (renal) pyramids  Medulla pyramids – triangular regions of tissue in the medulla, appear striated  Renal pelvis – inner collecting tube, divides into major and minor calyces  Calyces – cup-shaped structures enclosing the tips of the pyramids that collect and funnel urine towards the renal pelvis  Internal Renal Anatomy Copyright © 2014 John Wiley & Sons, Inc. All rights rese ed.  Internal Renal Anatomy 10 Functions of the Urina System  Elimination of waste products  ltering gallons of uid from the bloodstream eve day creating “ ltrate”  “ ltrate” includes: metabolic wastes, ionic salts, toxins, drugs  Maintenance of blood  Red blood cell production- by producing hormone e thropoietin to stimulate RBC production in bone marrow  Blood pressure (vessel size)- by producing renin which causes vasoconstriction  Blood volume (water balance)- ADH released from Anterior Pituita targets the kidney to limit water loss when blood pressure decreases or changes in blood composition  Blood composition (electrolyte balance)- water follows salt; aldosterone reclaims sodium to the blood  Blood pH- regulates H+ ions and HCO3- ions Nnnnnnnnn mmn nnnn Nnnnnnnnn nnnn12 Nephrons  e structural and functional units of the kidneys  Over 1 million in each kidney  Responsible for forming urine  Consist of renal corpuscle and renal tubule  Renal corpuscle composed of a knot of capillaries called the Glomerulus (a.k.a. Bowman’s Capsule)  Renal tubule- enlarged, closed, cup-shaped end giving rise to the PCT, dLOH, aLOH, DCT, and CD.  Ureters  Slender tubes attaching the kidney to the bladder 10-12” long & ¼” diameter  Superior end is continuous with the renal pelvis of the kidney  Mucosal lining is continuous with that lining the renal pelvis and the bladder below.  Enter the posterior aspect of the bladder at a slight angle  Runs behind the peritoneum  Peristalsis aids gravity in urine transpo from the kidneys to the bladder.  Smooth muscle layers in the ureter walls contract to propel urine.  ere is a valve-like fold of bladder mucosa that ap over  Urina Bladder  Smooth, collapsible, muscular sac  Temporarily stores urine  Located retroperitoneally in the pelvis posterior to the pubic symphysis. Urina Bladder  Trigone – three openings  Two from the ureters (ureteral ori ces)  One to the urethra (internal urethral ori ce) which drains the bladder.  In males, prostate gland surrounds the neck of the bladder where it empties into the urethra. Urine produced in the kidneys travels down the ureters into the urina bladder. e bladder expands like an elastic sac to hold more urine. Involunta muscle movements send signals to the ne ous system, putting the decision to urinate under conscious control.  e internal urethral sphincter and the external urethral sphincter both provide muscle control for the ow of urine. e internal sphincter is involunta. e external sphincter is volunta.  Urethra  in-walled tube that carries urine from the bladder to the outside of the body by peristalsis  Release of urine is controlled by two sphincters  Internal urethral sphincter (involunta ) – a thickening of smooth muscle at the bladder- urethra jxn. keeps urethra closed when urine is not being passed.  External urethral sphincter (volunta ) -- skeletal muscle that controls urine as the urethra passes Urethra Gender Di erences  Length  Females – 3–4 cm (1-1.5 inches)  Males – 20 cm (7-8 inches)  Location  Females – along wall of the vagina  Males – through the prostate and penis  Function  Females – only carries urine  Males – carries urine and is a passageway for sperm cells ank You