Lut anatomy

Anatomy of the Lower Urinary Tract and Male Genitalia

By

Hassaan Ali GadAssistant lecturer of urology

Aswan University, Egypt

Agenda

• BONY PELVIS

• ANTERIOR ABDOMINAL WALL

• SOFT TISSUES OF THE PELVIS

• PELVIC CIRCULATION

• PELVIC INNERVATION

• PELVIC VISCERA

• PERINEUM

Aswan Urology Depatment [email protected]

• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


BONY PELVIS

• The pelvic bones are

the sacrum (the termination of the axial skeleton)

two innominate bones.

• innominate bones are formed by the fusion of the iliac, ischial, and pubic ossification centers at the acetabulum

• Two joints

sacroiliac (SI) joints and Symphysial joints


Sacrotuberouss


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


ANTERIOR ABDOMINAL WALL

•Skin

•Superficial fascia

•Anterolateral muscles

•Transverse fascia

•Extraperitoneal fascia

•Parietal peritoneum

Layers from superficial to deep


Skin and Subcutaneous Fasciae

• Scarpa fascia forms a distinct layer deep to Camper fascia, although Superiorly and laterally, it blends with Camper fascia. Inferiorly, it fuses with the deep fascia of the thigh 1 cm below the inguinal ligament along a line from the anterior superior iliac spine to the pubic tubercle.

• Medially, it is continuous with Colles fascia of the perineum• Colles fascia attaches to the posterior edge of the urogenital diaphragm

and the inferior ischiopubic rami. It is continuous with the dartos fascia of the penis and scrotum.

• These fasciae can limit both the spread of infection in and the extent of urinary extravasation in an anterior urethral injury. For therefore butterflyshaped.

• Because of these fasciae, bleeding, infection, or urinary extravasation will not extend down the leg or into the buttock but can freely travel up the anterior abdominal wall deep to Scarpa fascia to the clavicles and around the flank to the back


Inguinal Canal• The inguinal canal transmits the spermatic cord in the male, the round ligament

in the female, and the ilioinguinal nerve in both sexes

• Its anterior wall and floor are formed by the external oblique muscle, which folds over at its inferior edge as the inguinal ligament. Above the pubic tubercle, the fibers of the external oblique aponeurosis split to form the lateral edges (crura) of the external inguinal ring. Transverse (intercrural) fibers bridge the crura toformthe superior edge of the external ring. By dividing the intracrural fibers,

• The posterior wall of the canal is formed by the transversalis fascia, which lines the inner surface of the abdominal wall. The cord structures pierce this fascia lateral to the inferior epigastric vessels at the internal inguinal ring.

• Fibers of the internal oblique and transversus abdominis arise from the iliopsoasfascia and inguinal ligament lateral to the internal ring and arch over the canal to form its roof. They fuse as the conjoint. The conjoint tendon reinforces the posterior wall of the inguinal canal at the external ring.

• With contraction of the internal oblique and transversus muscles, the roof of the canal closes


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


Pelvic floor muscles

-Pelvic Diaphragm (levator ani)

Pubococcygeus

Iliococcygeus

Coccygeus

Puborectalis

- Piriformis

- Obturator Internus


(levator ani)

• Consists of three parts the pubococcygeus, the puborectalis and the iliococcygeus.

• they run from the body of the pubis, the tendinous arch of the obturator fascia and the ischial spine

• to the perineal body, the coccyx, the anococcygeal ligament, the walls of the prostate or vagina, the rectum and the anal canal

• Coccygeus Muscle O: ischial spine, I: inferior end of the sacrum,


Pelvic Fascia

. Pelvic wall

• Pelvic fascia is a strong membrane over the piriformis and obturator internus fuses with the periosteum at their margins

2. Pelvic floor

• Fascia is covered with loose areolar tissue lies in the extraperitoneal space between peritoneum and the viscera forming a dead space

3.The perineal body• represents the point of fusion between the free posterior edge of

the urogenital diaphragm and the posterior apex of the urogenitalhiatus. This pyramid-shaped structure forms the pelvic support.


Perineal body


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


Arterial Supply

• The middle sacral artery arises posteriorly

and travels on the pelvic surface of the sacrum

• The common iliac arteries arise at the level of the fourth lumbar vertebra, run anterior

and lateral to their accompanying veins, and bifurcate into the external and internal iliac arteries at the SI joint.


• Middle sacral Aorta Sacral nerves and sacrum

• External Iliac Branches

• Inferior epigastric Rectus abdominis muscle and overlying skin and fascia

• (Inferior epigastric)

• Deep circumflex iliac inguinal ligament and surrounding structures laterally

• PubicI nguinal ligament and surrounding structures medially

• Cremasteric Vas deferens and testis


• Internal Iliac Branches• Posterior trunk• Superior gluteal Gluteus muscles and overlying skin• Ascending lumbar Psoas and quadratus lumborum muscles

and adjacent structures• Lateral sacral Sacral nerves and sacrum

• Anterior trunk• Superior vesical Bladder, ureter, vas deferens, and seminal

vesicle• Middle rectal Rectum, ureter, and bladder• Inferior vesical Bladder, seminal vesicle, prostate, ureter,

and the neurovascular bundle• Uterine Uterus, bladder, and ureter• Internal pudendal Rectum, perineum, and external

genitalia• Obturator Adductor muscles of the leg and

overlying skin• Inferior gluteal Gluteus muscles and overlying


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


sacral plexus

• The lumbosacral trunk (L4, L5) passes into the true pelvis behind the psoas and unites with the ventral rami of the sacral segmentanerves to form the sacral plexus.

• This plexus lies on the pelvic surface of the piriformis deep to the endopelvic fascia and posterior to the internal iliac vessels


• Iliohypogastric L1 Motor supply to internal oblique, transversus muscles, sensation over lower anterior abdominal wall

• Ilioinguinal L1 Sensation over anterior pubis (mons) and anterior scrotum or labia

• Genitofemoral L1, L2

Genital branch: motor supply to cremaster muscle sensation to anterior scrotum

Femoral branch: sensation to anterior thigh

• Femoral L2, L3, L4 Motor supply to extensors of the knee sensory to anterior thigh

• Obturator L2, L3, L4 Motor supply to adductors of the thigh, sensation to medial thigh

• Lumbosacral trunk L4, L5 Joins the sacral nerves to form the lumbosacral plexus that supplies motor and sensory innervation to the lower extremities

• Posterior femoral cutaneous S2, S3 Sensation to perineum, posterior scrotum, and posterior thigh

• Pudendal S2, S3, S4 Motor to levator ani, muscles of the urogenital diaphragm, anal and striated urethral sphincter, sensation to the perineum, scrotum, penis

• Pelvic somatic efferents S2, S3, S4 Motor supply to levator ani and striated urethral sphincter

• Nervi erigentes S2, S3, S4 Parasympathetic fibers from the sacral cord supply the pelvic viscera Aswan Urology Depatment

[email protected]

Pelvic Lymphatic's

Three major lymph node groups are associated with the pelvic vessels

• the internal iliac nodes and their tributaries: the presacral, obturator, and internal pudendal nodes.

• The externaliliac nodes lie lateral, anterior, and medial to the vessels and drain the anterior abdominal wall, urachus, bladder, and, in part, internal genitalia.

• The external genitalia and perineum drain into the superficial and deep inguinal nodes

• The inguinal nodes communicate directly with the internal and external

iliac chains.

The common iliac nodes receive efferent vessels from the external and internal iliac nodes and the pelvic ureter and drain into the lateral aortic nodes.


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


PELVIC VISCERA

• Rectum

• Pelvic Ureter

• Bladder

• Prostate

• Membranous Urethra

• Vas Deferens and Seminal Vesicle


BladderSHAPE:

• It has the shape of three-sided pyramid placed on one of its angles, with the apex of pyramid is directed forward & its base is directed backward

SITE:

It lies behind the body of pubis & is separated from it by the retropubic space

LIGAMENTS:

1. Median umbilical ligament

2. Puboprostatic (pubovesical) ligament: Forms the floor of retropubic space

• In male: is called “puboprostatic” & extends from body of pubis to prostatic fascia & neck of bladder

• In female: is called “pubovesical” & extends from body of pubis to neck of bladderAswan Urology Depatment

[email protected]

Relationships


Bladder Circulation

• Superior and inferior vesicales artery branches of Anterior trunk of Internal Iliac artery.

• In addition to the vesical branches, the bladder may be supplied by any adjacent artery arising from the internal iliac artery.

• For convenience, surgeons refer to the vesical blood supply as the lateral and posterior pedicles, which, when the bladder is approached from the rectovesical space, are lateral and posteromedial to the ureters, respectively.

• These pedicles are the lateral and posterior vesical ligaments in the male and part of cardinal and uterosacral ligaments in the female

• The veins of the bladder coalesce into thev esicle plexus and drain into the internal iliac vein.


• Bladder Innervation• Autonomic efferent fibers from the anterior portion of

the pelvic plexus (the vesical plexus) pass up the lateral and posterior ligaments to innervate the bladder.

• The bladder wall is richly supplied with parasympathetic cholinergic nerve endings

• LymphaticsThe bulk of 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.


Prostate

• The normal prostate weighs 18 g; measures 3 cm in length, 4 cmin width, and 2 cm in depth; and is traversed by the prostatic urethra. Although ovoid, the prostate is referred to as having anterior, posterior, and latera surfaces, with a narrowed apex inferiorly and a broad base superiorly.

• StructureThe prostate is composed of approximately 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


Vascular Supply• THE ARTERIAL SUPPLY TO the prostate arises from the inferior vesical

artery. divides into two main branches

• The urethral arteries penetrate the prostatovesical junction posterolaterally and travel inward, perpendicular to the urethra. They approach the bladder neck in the 1- to 5-o’clock and 7- to 11-o’clock positions, with the largest branches located posteriorly. They then turn caudally, parallel to the urethra, to supply it, the periurethral glands, and the transition zone.

• The capsular artery is the second main branch of the prostatic artery. This artery gives off a few small branches that pass anteriorly to ramify on the prostatic capsule. The bulk of this artery runs postero lateral to the prostate with the cavernous nerves (neurovascular bundles) and ends at the pelvic diaphragm.

• Venous drainage of the prostate is abundant through the periprostaticplexus

• Lymphatic drainage is primarily to the obturator and internal iliac nodes (A small portion of drainage may initially pass through the presacral group or, less commonly, the external iliac nodes.Aswan Urology Depatment

[email protected]

Urethral group

Capsular group


Nerve Supply

• Sympathetic and parasympathetic innervationfrom the pelvic plexus travels to the prostate through the cavernous nerves. Nerves follow branches of the capsular artery to ramify in the glandular and stromal elements.

• Parasympathetic nerves end at the acini and promote secretion;

• Sympathetic fibers cause contraction of the smooth muscle of the capsule and stroma. a


Vas Deferens

• It arises from the tail of the epididymis, the vas deferens is somewhat tortuous for 2 to 3cm.

• It runs posterior to the vessels of the cord and through the inguinal canal and emerges in the pelvis lateral to the inferior epigastric vessels ,At the internal ring, it diverges from the testicular vessels and passes medial to all structures of the pelvic side wall to reach the base of the prostate posteriorly


The seminal vesicle

• is a lateral outpouching of the vas, approximately 5 cm long, with a capacity of 3 to 4 mL contributes the largest portion of fluid to the ejaculate.

• The seminal vesicle comprises a single coiled tube with several outpouchings.

• The seminal vesicle and ampulla of the vas lie posterior to the• bladder. The ureter enters the bladder medial to the tip of the• seminal vesicle.• As the seminal vesicle and vas join to form the ejaculatory

duct, their smooth muscle coats fuse with the prostatic capsule at its base.


The blood supply for the seminal vesicles and vasa

• The vesiculodeferential artery, a branch of the superior vesical artery. This artery supplies the vas throughout its length and then passes onto the anterior surface of the seminal vesicle.

• Additional arterial supply may come from the inferior vesical artery.

• The pelvic vas and seminal vesicle drain into the pelvic venous plexus.


• Lymphatic drainage passes to the external and internal iliac nodes

• Innervation arises from the pelvic plexus, with major excitatory efferents contributed

• by the (sympathetic) hypogastric nerves


• BONY PELVIS





• PELVIC VISCERA

• PERINEUM


The perineum

• The perineum lies among the pubis, thighs, and buttocksand is limited superiorly by the levator ani.

• Viewed from below, the symphysis pubis, ischialtuberosities, and coccyx

• outline the diamond shape of the perineum; the inferior ischiopubic rami and sacrotuberousligaments form its bony and ligamentous walls

• A line drawn through the ischial tuberositiesdivides the perineum into an anal and a urogenital triangle.


Anal Triangle

• At the apex of the prostate, the rectum turns approximately 90 degrees posteriorly and inferiorly to become the anus It traverses 4 cm to reach the skin near the center of the anal triangle.

• The subcutaneous fat that surrounds the anus is continuous with that of the urogenital triangle, buttocks, and medial thigh. Laterally, the fat fills the ischiorectal fossa, a space bounded by the levator ani medially, and

• obturator internus, and the sacrotuberous ligament laterally • Anteriorly, this space extends into a recess above the urogenita diaphragm; • posteriorly, it is continuous with the intermediate stratum of the pelvis through

the sciatic foramina.• Through this continuity, infections may travel between the• perineum and the pelvic cavity.• The anal sphincter is divided into internal and external components.• The internal sphincter represents a thickening• of the inner circular smooth muscle layer of the rectum.


Lut anatomy

Health & Medicine

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