Urinary System
o Henle s Loop:
Henle s is a U-shaped structure consisting of thick and thin limb, the thick segment lined by low simple cuboidal epithelium, but thin segment lined with the simple squamous epithelium. This structure of nephrone abundant in medulla of kidneys.
o Collecting tubules & duct:
Urine passes from the distal to the collecting, the papillary ducts of Bellini, the smaller collecting tubules are lined with cuboidal epithelium, but the duct lined with high simple columnar epithelium.
o Juxtaglomerular apparatus:
Adjacent to the renal corpuscle, the tunica media of the afferent arteriole has modified smooth muscle cells, these cells called juxtaglomerular (JG) cells, have ellipsoid nuclei, cytoplasm full of secretory granules that stain with (PAS), secretion of (JG) cells play a role in the maintenance of blood pressure.
o Macula densa:
The cells lines of distal convoluted tubules when near, The (JG) cells where modified from the cuboidal to the high columnar cells.
· Bladder & Urinary Passages:
The mucosa of bladder consists of transitional epithelium and lamina properia of loose connective tissue surrounding the lamina properia of these organs is a dense woven sheath of smooth muscle.
The transitional epithelium of bladder in the undistended state 5-6 cells in thickness; the superficial cells are rounded & bulge into the lumen. The cells are polyploid or binuclate. When epithelium 3-4 cell in thickness and the superficial cell become squamous.
The muscular layer run in every direction (without distinct layers).
o Urethra:
The urethra is a tube that carries the urine from the bladder to the exterior. In men, sperm also pass through it during ejaculation. In women, the urethra is exclusively a urinary organ.
A- Male urethra: The male urethra consist of 4 parts, prostatic, membranous, bulbous & pendulous, the membranous lined stratified or psuedostratified columnar, surrounding this part by striated muscle and found involuntary sphincter muscle in the internal muscle of bladder.
Bulbous & pendulous are located in the corpus spongiosum of penis mostly the epithelium pseudostratified columnar.
Litter s gland are mucous glands found along the entire length of urethra.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .