Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

urinary system(urinary tract)

108 visualizaciones

Publicado el

urinary system

Publicado en: Educación
  • Sé el primero en comentar

urinary system(urinary tract)

  1. 1. urinary system
  2. 2.  The urinary system, also known as the renal system, consists of the kidneys, ureters, bladder, and the urethra. Each kidney consists of millions of functional units called nephrons
  3. 3. Kidneys
  4. 4. Definition  The kidneys are two bean- shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine  The kidneys remove waste products from the blood and produce urine. As blood flows through the kidneys, the kidneys filter waste products, chemicals, and unneeded water from the blood Figure of kidney
  5. 5.  Kidneys are bean shaped organ  11 cm long, 6 cm wide, 3 cm thick Renal fascia 3cm 11cm 6cm
  6. 6. Approximately the position of both kidney
  7. 7. Organ associated with kidney Right kidney  Superiorly right adrenal gland  Anteriorly Right lobe of liver, duodenum and the hepatic flexure of colon  Posteriorly Diaphragm, muscle of posterior abdominal wall
  8. 8. Organ associated with kidney Left kidney  Superior left adrenal gland  Anteriorly Spleen ,stomach ,pancreas ,jejunum and spleenic flexure of the colon  Posteriorly Diaphragm and muscle of posterior abdominal wall
  9. 9. Gross structure of kidney The internal structure of the kidney is divided into two main areas  renal cortex Light outer area called the renal cortex  Renal medulla darker Inner area called the renal medulla  Renal pyramids Within the medulla there are eight (8) or more cone-shaped sections known as renal pyramids
  10. 10.  renal papilla The renal papilla is located at the smaller end of the cone- shaped renal pyramids  renal columns The areas between the pyramids are called renal columns  minor calyx Each renal papilla is attached to a cup, or a small tube, called the minor calyx  major calyx. Two or three of these minor calices (plural of minor calyx) merge into what is called a major calyx.
  11. 11. Anatomy of kidney
  12. 12. Microscopic Anatomy of the Kidney The renal structures that conduct the essential work of the kidney cannot be seen by the naked eye. Only a light or electron microscope can reveal these structures  Nephrons: Functional Unit The nephron is the structural and functional unit of the kidney. Each nephron functions as an independent unit and produces a miniscule quantity of urine. The nephron can be differentiated into the following regions 1. Malpighian Corpuscle 2. Renal tubule 3. Collecting tubule
  13. 13. Malpighian Corpuscle  Bowman's Capsule This is a cup - shaped structure which is double walled in the hollow of which is a net work of capillaries called the glomerulus  Glomerulus This is a knotted mass of blood capillaries formed by the afferent arteriole (incoming) and the efferent arteriole (outgoing).
  14. 14. Renal Tubule This is the remaining part of the nephron, continuous with the Bowman's capsule. It is lined with ciliated epithelium and differentiated into the following regions  Proximal Convoluted Tubule (PCT) This is the region behind the Bowman's capsule and consists of a coiled tube that descends to form the Henle's loop. The proximal convoluted tubule is present in the cortex region.  Henle's loop This is continuous with the proximal convoluted tubule and is U-shaped having a narrow descending limb and a thick ascending limb. This part of the nephron descends from the cortex into the medulla region.
  15. 15.  Distal Convoluted Tubule (DCT) This is another coiled and twisted tubule that continues from the ascending limb of loop of Henle found in the renal cortex.
  16. 16. Collecting Tubule The distal convoluted tubule continues to form the collecting tubule. Collecting Ducts Several collecting tubules fuse to form large collecting ducts which pass downwards from the cortex to the medulla region. Ducts of Bellini Several collecting ducts join to form the larger ducts of Bellini in the medulla region. Running through the pyramids they finally open in the renal pelvis draining all the urine collected from the various nephrons. The renal pelvis is an expanded region which opens into the ureter. 
  17. 17.  Vasa Rectae The efferent arteriole that exits from the glomerulus does not merge into a vein but breaks up into a system of capillaries called vasa rectae or peritubular capillaries which envelop the proximal convoluted tubule, the Henle's loop and distal convoluted tubule. These capillaries rejoin and drain into the venule. Venules join together to form the renal vein which drain blood from the kidneys.
  18. 18. Ureters The ureters are paired muscular ducts with narrow lumina that carry urine from the kidneys to the bladder.  The ureteric walls are comprised of smooth muscle, which contracts to produce peristaltic waves. This propels the urine towards the bladder. 
  19. 19. Relation,abdomin ureter  posteriorly: psoas muscle; genitofemoral nerve; common iliac vessels; tips of L2-L5 transverse processes  anteriorly  right ureter: descending duodenum (D2); gonadal vessels; right colic vessels; ileocolicvessels  left ureter: gonadal artery; left colic artery; loops of jejunum; sigmoid mesentery and colon  medially  right ureter: IVC  left ureter: abdominal aorta, inferior mesenteric vein
  20. 20. Relation, pelvic ureter  posteriorly: sacroiliac joint, internal iliac artery  inferiorly  male: seminal vesicle  female: lateral fornix of the vagina  anteriorly  male: ductus deferens  female: uterine artery (in the broad ligament)  medially  female: cervix  It should be noted that the only structures to anteriorly pass over the pelvic ureter is the ductus deferens in males and the uterine artery in females.
  21. 21. Blood supply  arterial supply: from branches of the renal artery, abdominal aorta, superior and inferior vesical arteries  some texts also include supply from the gonadal, middle rectal and uterine arteries 1-2  venous drainage: via similarly named veins but is highly variable 1-2
  22. 22. Histology The ureteric wall is composed of three layers (from outside to inside): 1) adventitia 2) smooth muscle 3) transitional cell epithelium
  23. 23. Urinary bladder  The urinary bladder (more commonly just called the bladder) is a distal part of the urinary tract and is an extra- peritoneal structure located in the true pelvis. 
  24. 24. Gross anatomy  The bladder has a triangular shape with a posterior base, an anterior apex and an inferior neck with two inferolateral surfaces. It is lined with a rough, trabeculated transitional cell epithelium except at the trigone.  The trigone is a triangular area of smooth mucosa found on the internal surface of the base. The superolateral angles are formed by the ureteric orifices and the inferior angle is formed by the internal urethral orifice.  The urethra arises from the neck of the bladder and is surrounded by the internal urethral sphincter.  As the bladder fills with urine it becomes ovoid in shape and extends superiorly into the abdominal cavity.
  25. 25. Blood supply  Arterial supply superior and inferior vesical arteries (from anterior division of internal iliac artery)  Venous drainage male: vesical and prostatic venous plexus via similarly named veins to the internal iliac veins and internal vertebral veins female: vesical and uterovaginal plexuses draining into the internal iliac vein
  26. 26. Urethra  The urethra is the terminal segment of the genitourinary system. Because of vastly different anatomy between the sexes, male and female urethras are discussed separately: 1. female urethra 2. male urethra
  27. 27. Female urethra  The female urethra is a simple tube that extends from the internal urethral orifice of the bladderto the external urethral orifice in the vestibule of the vagina
  28. 28. Gross anatomy  The female urethra measures approximately 4 cm in length. It is embedded in the anterior vaginal wall and runs with the vagina through the urogenital hiatus.  The female urethra begins at the internal urethral meatus at the bladder neck and opens in the vestibule of the vagina, 2.5 cm below the clitoris. Paraurethral glands line the urethra at the external urethral meatus
  29. 29.  Relations  anteriorly: pubic symphysis  posteriorly: vagina  laterally: puborectalis muscle  Blood supply  arterial supply: internal pudendal and vaginal arteries  venous drainage: similarly named veins
  30. 30. Male urethra  The male urethra is a fibromuscular tube that drains urine from the bladder. It has a longer, more complicated, course than the female urethra and is also more prone to pathology.
  31. 31. Gross anatomy  The male urethra measures, on average, 18- 20 cm in length. It commences at the internal urethral orifice in the trigone of the bladder and opens in the navicular fossa of the glans penis at the external urethral meatus, which is the narrowest part of the urethra.  The male urethra can be divided into anterior and posterior portions. The anterior urethra is composed of the penile and bulbar urethra to the level of the urogenital diaphragm. The posterior urethra is composed of the membranous and prostatic urethra
  32. 32. Anterior urethra  penile (spongy, pendulous) urethra (~16 cm long): encased by corpus spongiosum of the penis  the longest portion  the 'fossa navicularis' is a small normal dilatation of the distal penile urethra  bulbar (bulbous) urethra: traverses the root of the penis  it receives the ducts from the bulbourethral glands and the glands of Littré  The anterior urethra is lined by pseudostratified columnar epithelium. The very distal portion (at approximately the level of the fossa navicularis) is lined by squamous epithelium.
  33. 33. Posterior urethra  membranous urethra (1 cm long): passes through the urogenital diaphragm, surrounded by sphincter urethrae  the shortest and narrowest portion  prostatic urethra (3 cm long): surrounded by the prostate gland; on its posterior wall lies the smooth muscle verumontanum  it receives the ejaculatory ducts and numerous small prostatic ducts  The posterior urethra is lined by transtional columnar epithelium

×