Urology: Diseases and Disorders of the Genitourinary Tract

1. بسم الله الرحمن الرحيم

2. Urology Urology is the science deals with diseases and disorders of the male genitourinary tract and the female urinary tract. Surgical diseases of the adrenal gland are also included.

3. Anatomy

4. The retroperitonial space Lies on the posterior abdominal wall behind the parietal peritoneum. The floor of the space is formed by psoas, quadratus lumborum & origin of transversus abdominis muscle .

5. Each of these muscle is covered by definite layer of fascia & in front of the fascial layer variable amount of fatty connective tissue that forms the bed of the suprarenal gland ,the kidneys , the ascending & descending parts of colon & the duodenum. also contain the ureters &the renal &gonadal blood vessel

6. Kidneys The kidneys are reddish brown &lie behind the peritoneum high up in the posterior abdominal wall on the either side of the vertebral column. The Rt. Kidney lie slightly lower than the Lt. because of the large size of the liver. On the medial concave part of the kidney lies the hilum which transmit the renal veins, arteries &the ureters. With lymph vessel &sympathetic fibers .

7. The kidneys have the following covers . Fibrous capsule ,closely applied to the kidneys. Perirenal fat ,covers the fibrous capsule. Renal fascia ,condensation of connective tissue lies outside the perirenal fat & encloses the kidneys &the suprarenal gland . Pararenal fat, lies external to the renal fascia &is often large in quantity

8. Renal structure Each kidney has dark brown outer cortex & light brown inner medulla The medulla is composed of about a dozen renal pyramids ,each having its base oriented toward the cortex & its apex , the renal papilla projecting medially .

9. the cortex extend into the medulla between adjacent Pyramids as the renal columns. The renal sinus is the space within the hilum contain upper expand end of the ureter ,the renal pelvis ,this divides into 2 or 3 major calyces Each of which divides into 2 or 3 minor calyces each minor calyces indented by the apex of renal pyramid , the renal papilla .

10. Histology The functioning unit of the kidney is the nephron, which is composed of a tubule that has both secretory and excretory functions. The secretory portion is contained largely within the cortex and consists of a renal corpuscle and the secretory part of the renal tubule

11. The excretory portion of this duct lies in the medulla. The renal corpuscle is composed of the vascular glomerulus, which projects into Bowman’s capsule, which, in turn, is continuous with the epithelium of the proximal convoluted tubule.

12. The secretory portion is made up of the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule The excretory portion is the collecting tubule, which is continuous with the distal end of the ascending limb of the convoluted tubule. It empties its contents through the tip (papilla) of a pyramid into a minor calyx.

13. Important relations of the Rt. Kidney Anteriorly ;-the suprarenal gland ,the liver , the 2nd part of the doudenum & the Rt colic flexure. Posteriorly;-the diaphragm ,the 12th rib, & the psoas, quadratus lumborum & the transversus abdominis muscle .

14. important relations of the Lt. Kidney Anteriorly ;- the suprarenal gland, the spleen, the stomach ,the pancreas, the Lt. Colic flexure ,the coils of the jejunum. posteriorly;- the diaphragm, the costodiaphragmatic recessof the pleura,the eleventh &12th rib, the psoas ,quadratus lumborum ,& transversus abdominis muscles. The subcostal iliohtpogastric &ilioinguinal nerves run downward &laterally

15. Blood supply Arteries The renal artery arise from the aorta at the level of the 2nd lumber vertebra .each renal artery usually divides into 5 segmental arteries That enter the hilum of the kidney between the renal pelvis (posteriorly) & the renal vein. they are distributed to different segments or areas of the kidney.

16. Lobar arteries arise from each segmental artery ,one for each renal pyramid. each lobar artery gives off 2 or 3 interlobar arteries . at the junction of the cortex & medulla the interlobar arteries give off the Arcuate arteries ,which arch over the bases of the pyramids . the arcuate arteries give off several interlobular arteries that ascend in the cortex .the afferent glomerular arterioles arise as branches of the Interlobular arteries .

17. Veins The renal vein emerge from the hilum in front of the renal artery &drains into the I.V.C The left renal vein is about 3 times longer than the right one Lymph drainage Lateral aortic lymph nodes around the origin of the renal artery Nerve supply Renal sympathetic plexus .the afferent enter the spinal cord in the 10th ,11th ,&12th thoracic nerves .

18. Ureter The two ureters are muscular tubes that extend from the kidneys to the posterior surface of the bladder , The urine is propelled along the ureter by peristaltic contraction of the muscle coat .assisted by the filtration pressure of the glomeruli . Each ureter measures about 10 in.(25 cm) long & resembles the esophagus in having 3 constrictions along its course . where the renal Pelvis join the uerter, where its kinked as it cross the pelvic brim & where it pierces the bladder wall .

19. The renal pelvis is the funnel shaped expanded upper end of the ureter It lies within the hilum of the kidney & receive the major calyces . The ureter emerges from the hilum of the kidney & run vertically downward behind the parietal peritoneum (adherent to it ) on the psoas muscle. It enters the pelvis by crossing the bifurcation of the common iliac artery, Then runs down the lateral wall of the pelvis,to the ischial spine turn forward to enter the lateral angle of the bladder

20. Relations of the Rt. Ureter. Anteriorly ;- the duodenum,the terminal part of the ileum ,the Rt. Colic &ileocolic vessels ,the Rt.testicular or ovarian vessels ,&the root of the Mesentery of the intestine . Posteriorly;- The Rt, psoas muscle which separates it from the lumbar Transverse process ,&the bifurcation of the Rt. common iliac artery . Relations of the Lt. Ureter Anteriorly;- the sigmoid colon &sigmoid mesocolon ,the Lt. Colic vessels ,&the Lt. Testicular or ovarian vessels . Posteriorly ;- the Lt. Psoas muscle ,which separates it form the lumbar Transverse process ,& the bifurcation of the Lt. common iliac artery.

21. Blood supply Arteries ;- the arterial supply to the ureter is as follow . Upper end The renal artery Middle portion The testicular or ovarian artery In the pelvis The superior vesical artery Veins Venous blood drains into the veins that correspond to the arteries . Lymph drainage ;- to the lateral aortic &iliac nodes . Nerve supply ;- renal, testicular (or ovarian), & hypogastric plexus (in the pelvis). Afferent fibers travel with the sympathetic nerves &enter the spinal cord in the 1st. &2nd. Spinal segments .

22. The urinary bladder The urinary bladder situated immediately behind the pubic bones within the pelvis . It is receptacle for the storage of urine & in the adult has a maximum capacity of about 500 ml. The bladder has a strong muscular wall its shape & relations vary according to the amount of urine that it contains. The empty bladder in the adult lies entirely within the pelvis ;as the bladder fills, its superior wall rises up into the hypogastric region. .

23. The empty bladder is pyramidal having an apex ,a base, & superior & 2 inferolateral surfaces ;it also has a neck. The apex of the bladder points anteriorly & lies behind the upper margin of the symphysis pubis. Its connected to the umbilicus by the median umbilical ligament The base, or posterior surface of the bladder ,faces posteriorly & is triangular. the superolateral angles are joined by the ureters ,& the inferior angle give rise to the urethra.

24. the 2 vasa deferentia lie side by side on the posterior surface of the bladder & separate the seminal vesicle from each other. the upper part of the posterior surface of the bladder is covered by peritoneum, which forms the anterior wall of the rectovesical pouch. The lower part of the posterior surface is separated from the rectum by the vasa deferentia, the seminal vesicles,and the rectovesical fascia.

25. As the bladder fills ,the superior surface bulges upward into the abdominal Cavity. The peritoneal covering is peeled off the lower part of anterior abdominal wall ,so that the bladder comes into direct contact with the anterior abdominal wall.

26. The inferolateral surface are related in front to the retropubic pad of fat & the pubic bones. More posteriorly, they lie in contact with the obturator internus muscle above & the levator ani muscle below

27. . THE NECK OF THE BLADDER lies inferiorly & rests on the upper surface of the prostate ,here the smooth muscle fibers of the bladder wall are continuous with those of the prostate. The neck of the bladder is held in position by the PUBOPROSTATIC LIGAMENTS in the male & PUBOVESICAL LIGAMENTS in the female. These ligaments are thickening of the pelvic fascia.

28. The mucous membrane of the greater part of the empty bladder is thrown into folds that disappear when the bladder is full. The area of the mucous membrane covering the internal surface of the base of the bladder is referred to as the TRIGONE. Here, the mucous membrane is always smooth ,even when the viscus is empty ,because the mucous membrane over the trigone is firmly adherent to the underlying muscular coat.

29. The superior angles of the of the trigone correspond to the openings of the ureters , & the inferior angle to the internal urethral orifice. The ureters pierce the bladder wall obliquely,& this provide valvelike action , which prevent reverse flow of urine toward the kidneys as the bladder fills.

30. the trigone is limited above by muscular ridge, which runs from the opening of one ureter to that of the other & is known as the interureteric ridge . The muscular coat of the bladder is composed of smooth muscle & is arranged in 3 layers of interlacing bundles known as the detrusor muscle. At the neck of the bladder ,the circular component of the muscle coat is thickened to form the sphincter vesicae.

31. Blood supply Arteries ;- the superior & inferior vesical arteries ,branches of internal iliac arteries ,supply the bladder . Veins ;- The veins form the vesical venous plexus, which communicates below with the prostatic plexus ; its drained into the internal iliac vein. Lymph drainage The lymph vessels drain into the internal& external iliac nodes.

32. Nerve supply From the inferior hypogastric plexuses The sympathetic postganglionic fibers originate in the 1st &2nd lumber ganglia & descend to the bladder via the hypogastric plexuses. The parasympathetic preganglionic fibers arise as the pelvic splanchnic nerves from the 2nd 3rd &4th sacral nerves ,they pass through the inferior hypogastric plexus to reach the bladder wall.

33. where they synapse with postganglionic neurons. Most afferent sensory fibers arising in the bladder reach the central nervous system via the pelvic splanchnic nerves .some afferent fibers travel with the sympathetic nerves via the hypogastric nerves & enter the 1st & 2nd lumber segments of the spinal cord . The sympathetic nerves inhibit contraction of the detrusor muscle of the bladder wall & stimulate closure of the sphincter vesicae . The parasympathetic nerves stimulate contraction of the detrusor muscle of the bladder wall & inhibit action of the sphincter vesicae.

34. Micturition Micturition is a reflex action that is controlled by higher centers in the brain. The reflex is initiated when the volume of urine reaches about 300 ml. Stretch receptors in the bladder wall are stimulated & transmit impulses to the c.n.s.& individual has a conscious desire to micturate. Most afferent impulses pass up the pelvic splanchnic nerves & enter the 2nd ,3rd &4th sacral segment of the spinal cord.

35. Some afferent impulses travel with the sympathetic nerves via the hypogastric plexus & enter the 1st &2nd lumber segment of the spinal cord. Efferent parasympathetic impulses leave the cord from the 2nd ,3rd &4th sacral segment & pass via the parasympathetic preganglionic nerve fibers through the pelvic splanchnic nerves & the inferior hypogastric plexus to the bladder wall where they synapse with the postganglionic neurons.

36. By means of this nervous pathway ,the smooth muscle of the bladder wall (the detrusor muscle ) is made to contract ,& the sphincter vesicae is made to relax. Efferent impulses also pass to the urethral sphincter via the pudendal nerve (S2,3&4), & is undergoes relaxation. Micturition can be assisted by contraction of the abdominal muscles to raise the intra-abdominal & pelvic pressure & exert external pressure on the bladder .

37. In young children ,micturition is a simple reflex act & takes place whenever the bladder become distended. In adult this reflex is inhibited by the activity of the cerebral cortex until the time & place for micturition are favorable . Voluntary control of micturition is accomplished by contracting the Sphincter urethrae , assisted by the sphincter vesicae. Control reflex normally developed during the 2nd or 3rd year of life .

38. Suprarenal glands The 2 suprarenal glands are yellowish retroperitoneal organs that lie on the upper pole of the kidneys. They are surrounded by the renal fascia. Separated from the kidneys by the perirenal fat. Each gland has yellow cortex & dark brown medulla

39. The cortex ;- secretes hormones that include 1-mineralocorticoids, which Concerned with the control of fluid & electrolyte balance. 2-glucocorticoids, which concerned with the control of the metabolism of carbohydrates. 3-sex hormones, which may play role in the prepubertal development of the sex organ. The medulla ;- secretes the catecholamines epinephrine & norepinephrine

40. . The Rt. Suprarenal g Is pyramid shaped &caps the upper pole of the Rt. kidney. It lies behind the Rt. lobe of the liver & extend medially behind the I.v.c. it rests posteriorly on the diaphragm.

41. The Lt. Suprarenal g. Is crescentic in shape & extends along the medial border of the Lt. kidney from the upper pole to the hilus. It lies behind the pancreas and the lesser sac, & the stomach & rests posteriorly on the diaphragm nerve supply preganglionic sympathetic derived from the splanchnic nerve & supply most of the nerves end in the medulla of the gland.

42. Blood supply Arteries are 3 in no. inferior phrenic , aorta, & renal arteries . Veins single vein emerge from each gland & drain into the I.V.C. on the Rt. & into the renal vein on the Lt. Lymph drainage ;- to lateral oartic nodes .