Anatomy of Urinary Tract

Kelompok 6

ANATOMY

THE KIDNEYS

The kidneys serve a number of important functions required to maintain normal human physiologic function. maintaining fluid and electrolyte balance, maintaining acid-base balance. produce renincontrolling blood pressure, produce erythropoietinaffecting red blood cell

production. calcium metabolism, (converting a precursor of

vitamin D 1,25-dihydroxyvitamin D)

Grossly, the kidneys are bilaterally paired reddish brown organs

weighs 150 g each in the male and 135 g in the female.

10 to 12 cm vertically, 5 to 7 cm transversely, and 3 cm in the anteroposterior dimension

Because of compression by the liver, the right kidney tends to be somewhat shorter and wider.

Anatomic Relationships

The position of the kidney within the retroperitoneum varies greatly by side, degree of inspiration, body position, and presence of anatomic anomalies

The right kidney sits 1 to 2 cm lower than the left in most individuals owing to displacement by the liver.

The right kidney 1st lumbar vertebra to the bottom of the 3rd lumbar vertebra.

The left kidney 12th thoracic vertebra to the 3rd lumbar vertebra.

Both kidneys have similar muscular surroundings.

Posteriorly, the diaphragm covers the upper third of each kidney.

Medially the lower two thirds of the kidney lie against the psoas muscle,

laterally the quadratus lumborum and aponeurosis of the transversus abdominis.

Structures related to the posterior surface of the kidney

Anteriorly, the right kidney is bordered by a number of structures.

Cranially, the upper pole lies against the liverAlso at the upper pole, the right adrenal

gland is encountered. On the medial aspect, the descending

duodenum is intimately related to the medial aspect of the kidney and hilar structures.

On the anterior aspect of the lower pole lies the hepatic flexure of the colon.

The left kidney is bordered superiorly by the tail of the pancreas with the splenic vessels adjacent to the hilum and upper pole of the left kidney.

Also cranial to the upper pole is the left adrenal gland and further superolaterally, the spleen.

The splenorenal ligament attaches the left kidney to the spleen.

Superior to the pancreatic tail, the posterior gastric wall can overlie the kidney.

Caudally, the kidney is covered by the splenic flexure of the colon.

Structures related to the anterior surfaces of each kidney

Gerota's Fascia

This fascial layer encompasses the perirenal fat and kidney and encloses the kidney on three sides: superiorly, medially, and laterally.

Superiorly and laterally Gerota's fascia is closed, but medially it extends across the midline to fuse with the contralateral side.

Inferiorly, Gerota's fascia is not closed and remains an open potential space.

Serves as an anatomic barrier to the spread of malignancy as well as a means of containing perinephric fluid collections.

Renal Vasculature

The renal pediclesingle artery and vein that enter the kidney via the renal hilum .

branch from the aorta and inferior vena cava (2nd lumbar vertebra)

The vein is anterior to the artery. The renal pelvis and ureter are located

further posterior to these vascular structures

Renal Artery

the right renal artery leaves the aorta and progresses with a caudal slope under the IVC toward the right kidney.

The left renal artery courses almost directly laterally to the left kidney.

Both renal arteries move posteriorly as they enter the kidney.

Also, both arteries have branches to the respective adrenal gland, renal pelvis, and ureter

Segmental branches of the right renal artery demonstrated by renal angiogram

Once in the renal sinus: the segmental arterieslobar arteriesinterlobar arteries (in the cortical columns of Bertin) arcuate arteries (base of pyramids)Interlobular arteries move radially afferent arteries glomeruli efferent arteriole vasa recta

Renal Veins

post glomerular capillariesThe interlobular veins arcuate interlobarlobarsegmental branches renal vein

The renal vein is located directly anterior to the renal artery

The right renal vein<The left renal veinAdditionally, the left renal vein receives the

left adrenal vein superiorly, lumbar vein posteriorly, and left gonadal vein inferiorly.

The right renal vein typically does not receive any branches.

Renal Lymphatics

On the left, primary lymphatic drainage is into the left lateral para-aortic lymph nodes including nodes anterior and posterior to the aorta between the inferior mesenteric artery and the diaphragm.

On the right, drainage is into the right interaortalcaval and right paracaval lymph nodes, including nodes located anterior and posterior to the vena cava, from the common iliac vessels to the diaphragm.

Renal Collecting System

Microscopically, the renal collecting system originates in the renal cortex at the glomerulus as filtrate enters into Bowman's capsule.

Together the glomerular capillary network and Bowman's capsule form the renal corpuscle (malpighian corpuscle).

The glomerular capillary network is covered by specialized epithelial cells called podocytes that, along with the capillary epithelium, form a selective barrier across which the urinary filtrate must pass.

The filtrate is initially collected in Bowman's capsule and then moves to the proximal convoluted tubule.

The proximal tubule is composed of a thick cuboidal epithelium covered by dense microvilli.

PCTloop of HenleDCTCTrenal papilla

Renal Papillae, Calyces, and Pelvis

Typically, there are 7 to 9 papillae per kidneyEach of these papillae is cupped by a minor calyx After cupping an individual papillae, each minor calyx

narrows to an infundibulum.Infundibuli combine to form two or three major calyceal

branches. These are frequently termed the upper, middle, and lower pole calyces, and these calyces in turn combine to form the renal pelvis.

The renal pelvis itself can vary greatly in size, ranging from a small intrarenal pelvis to a large predominantly extrarenal pelvis.

Eventually the pelvis narrows to form the ureteropelvic junction, marking the beginning of the ureter.

Renal Innervation

Sympathetic8th thoracic – 1st lumbar spinal segments and then travel to the celiac and aorticorenal gangliapostganglionic fibers travel to the kidney via the autonomic plexus surrounding the renal artery.

Parasympathetic vagus nerve and travel with the sympathetic fibers to the autonomic plexus along the renal artery.

The primary function of the renal autonomic innervation is vasomotor, with the sympathetics inducing vasoconstriction and the parasympathetics causing vasodilation.

THE URETERS

bilateral tubular structures 22 to 30 cm in length wall composed of multiple layers

transitional epithelium. lamina propria smooth muscle (inner longitudinal and an outer

circular layer) adventitia (blood vessels and lymphatics)

Anatomic Relationships

The ureter begins at the ureteropelvic junction, which lies posterior to the renal artery and vein.

It then progresses inferiorly along the anterior edge of the psoas muscle.

Anteriorly, the right ureter is related to the ascending colon, caecum, colonic mesentery, and appendix.

The left ureter is closely related to the descending and sigmoid colon and their accompanying mesenteries.

three distinct narrowings: the ureteropelvic junction, crossing of the iliac vessels, and the ureterovesical junction

Ureteral Segmentation and Nomenclature

upper ureter extends from the renal pelvis to the upper border of the sacrum.

The middle ureter comprises the segment from the upper to the lower border of the sacrum.

The lower (distal or pelvic) ureter extends from the lower border of the sacrum to the bladder

Blood Supply and Lymphatic Drainage

upper ureter renal artery, gonadal artery, abdominal aorta, and common iliac artery.

distal ureter internal iliac artery or its branches, especially the vesical and uterine arteries, also from the middle rectal and vaginal arteries.

After reaching the ureter, the arterial vessels course longitudinally within the periureteral adventitia in an extensive anastomosing plexus.

The venous and lymphatic drainage of the ureter parallels the arterial supply

In the pelvisinternal, external, and common iliac nodes

In the abdomen, the left para-aortic lymph nodes are the primary drainage site for the left ureter whereas the abdominal portion of the right ureter is drained primarily to right paracaval and interaortocaval lymph nodes

The upper ureter and renal pelvis join the renal lymphatics and is identical to that of the ipsilateral kidney

Ureteral Innervation

Normal ureteral peristalsis does not require outside autonomic input but, rather, originates and is propagated from intrinsic smooth muscle pacemaker sites located in the minor calyces of the renal collecting system.

The autonomic nervous system may exert some modulating effect on this process, but the exact role is unclear.

Sympathetic input10th thoracic through 2nd lumbar spinal segments.

Parasympathetic input2nd through 4th sacral spinal segments.

Pain Perception and Somatic Referral

Paintension (distention) in the renal capsule, renal collecting system, or ureter.

Direct mucosal irritationalso stimulate nociceptors.

Visceral-type pain referred to the sympathetic distribution of the kidney and ureter (eighth thoracic through second lumbar).

Bladder

When filled, the bladder has a capacity of approximately 500 mL and assumes an ovoid shape.

The empty bladder is tetrahedral and is described as having a superior surface with an apex at the urachus, two inferolateral surfaces, and a posteroinferior surface or base with the bladder neck at the lowest point

The superior surfacecovered by peritoneumAnteriorly, the peritoneum sweeps gently

onto the anterior abdominal wall Posteriorly, the peritoneum passes to the

level of the seminal vesicles and meets the peritoneum on the anterior rectum to form the rectovesical space.

Structure

The internal surface of the bladder is lined with transitional epithelium,

This urothelium is usually six cells thick and rests on a thin basement membrane.

Deep to this, the lamina propria forms a relatively thick layer of fibroelastic connective tissue that allows considerable distention.

This layer is traversed by numerous blood vessels and contains smooth muscle fibers collected into a poorly defined muscularis mucosa.

Beneath this layer lies the smooth muscle of the bladder wall inner longitudinal, middle circular, and outer longitudinal layers

Near the bladder neck, the detrusor muscle is clearly separable into the three layers

Trigone

The triangle of smooth urothelium between the two ureteral orifices and the internal urethral meatustrigone of the bladder

The edges of this muscular sheet are thickened between the ureteral orifices (the interureteric crest or Mercier's bar) and between the ureters and the internal urethral meatus (Bell's muscle).

Bladder Circulation

The main arteries supplying the bladder are branches of the internal iliac arteries.

The superior vesical arteries supply anterosuperior parts of the bladder.

In males, inferior vesical arteries supply the fundus and neck of the bladder.

In females, the vaginal arteries replace the inferior vesical arteries and send small branches to posteroinferior parts of the bladder.

The obturator and inferior gluteal arteries also supply small branches to the bladder

The veins of the bladder coalesce into the vesicle plexus and drain into the internal iliac vein.

the lymphatic drainage passes to the external iliac lymph nodes

Some anterior and lateral drainage may go through the obturator and internal iliac nodes, whereas portions of the bladder base and trigone may drain into the internal and common iliac groups.

Bladder Innervation

The bladder wall is richly supplied with parasympathetic cholinergic

the male bladder neck receives abundant sympathetic innervation and expresses α-adrenergic receptors.

The female bladder neck has little adrenergic innervation.

Prostate

weighs 18 g 3 cm in length, 4 cm in width, and 2 cm in

depth; and is traversed by the prostatic urethraIt is enclosed by a capsule composed of

collagen, elastin, and abundant smooth muscle. PosteriorDenonvilliers' fascia On the anterior endopelvic fascia. Toward the apex, the puboprostatic ligaments

extend anteriorly to fix the prostate to the pubic bone

Structure

70% glandular elements and 30% fibromuscular stroma.

The stroma is continuous with capsule and is composed of collagen and abundant smooth muscle.

It encircles and invests the glands of the prostate and contracts during ejaculation to express prostatic secretions into the urethra

The urethra runs the length of the prostate and is usually closest to its anterior surface.

It is lined by transitional epithelium, which may extend into the prostatic ducts.

Vascular Supply

arises from the inferior vesical artery. inferior vesical arteries but also the internal

pudendal and middle rectal arteries2 branch:

Urethral branch Capsular branch

Nerve Supply

Sympathetic and parasympathetic innervation from the pelvic plexus travels to the prostate through the cavernous nerves.

Parasympathetic nerves end at the acini and promote secretion;

sympathetic fibers cause contraction of the smooth muscle of the capsule and stroma.

Male UrethraMerupakan saluran fibromusculer untuk jalan

urine dari Vesica Urinaria, dan pada pria juga merupakan jalan sekret dari Vesicula Seminalis, Prostat, dan Glandula Bulbourethralis.

Panjangnya ± 20 cm. Dimulai dari Collum Vesicae, menembus kelenjar Prostat, Diafragma Urogenitalis, kemudian melalui Corpus Spongiosum Penis, yang berakhir di Glans Penis.

Urethra dibagi menjadi 3 bagian yaitu Pars Prostatica, Pars Membranacea, dan Pars Cavernosa / Pars Spongiosa.

Sedangkan bagian Urethra yang lumennya melebar adalah Pars Prostatica, Fossa Intrabulbaris ( pada Bulbus Urethrae ), dan Pada Fossa Navicularis.

Female Urethra

Panjangnya ± 4 cm, berjalan ke ventrocaudal, mulai dari Orificium Urethrae Internum ( pada Collum Vesicae ) sampai pada Orificium Urethrae Externum pada Vestibulum Vaginae ( antara Introitus Vaginae dan Clitoris ).

Urethrae melekat pada dinding ventral Vagina dan difiksasi pada Os Pubis oleh beberapa serabut dari Ligamentum Pubovesicalis dan oleh penebalan dari Fascia Diafragma Urogenitalis Superior.

Female Urethra : StructureBagian dalam adalah mucosa dimana terdapat

lubang – lubang Glandula Urethralis ( Lacunae Urethralis ), yang dibagian caudalnya terdapat Ductus Glandula Paraurethralis Scene ( Homolog dengan Prostat ), yang bermuara pada sisi kanan dan kiri Orificium Urethrae Externum.

Bagian tengah terdiri dari jaringan otot polos dan bergaris yang berasal dari Musculus Pubovaginalis. Bagian distalnya tidak ada jaringan ototnya.

Female Urethra

Vascularisasinya oleh : Bagian cranial dari Arteri Vesicalis Inferior Bagian media dari Arteri Vesicalis Inferior dan

Arteri Uterina Bagian caudal dari Arteri Pudendalis Interna Venanya dialirkan menuju Plexus Venosus

Vesicalis dan Vena Pudendalis Interna.Aliran limfenya mengikuti Arteri Pudendalis

Interna, menuju ke Lnn. Iliaca Interna dan Lnn. Iliaca Externa.

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