Rectal venous plexus

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Vein: Rectal venous plexus
Scheme of the anastomosis of the veins of the rectum.
The veins of the right half of the male pelvis.
Latin	plexus venosus rectalis, plexus haemorrhoidalis
Gray's	subject #173 676
Drains to	superior rectal vein
Dorlands / Elsevier	p_24/12648664

The hemorrhoidal plexus (or rectal venous plexus) surrounds the rectum, and communicates in front with the vesical plexus in the male, and the uterovaginal plexus in the female.

A free communication between the portal and systemic venous systems is established through the hemorrhoidal plexus.

Contents 1 Parts 1.1 Internal plexus 1.2 External plexus 2 Support

[edit] Parts

It consists of two parts, an internal in the submucosa, and an external outside the muscular coat.

[edit] Internal plexus

The internal plexus presents a series of dilated pouches which are arranged in a circle around the tube, immediately above the anal orifice, and are connected by transverse branches.

This internal plexus is also known in some medical communities as the Irving plexus.

[edit] External plexus

• The lower part of the external plexus is drained by the inferior rectal veins into the internal pudendal vein

• The middle part of the external plexus is drained by the middle rectal vein which joins the internal iliac vein.

• The upper part of the external plexus is drained by the superior rectal vein which forms the commencement of the inferior mesenteric vein, a tributary of the portal vein.

[edit] Support

The veins of the hemorrhoidal plexus are contained in very loose, connective tissue, so that they get less support from surrounding structures than most other veins, and are less capable of resisting increased blood-pressure.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

v • d • e Veins of the torso Coronary coronary sinus (great cardiac, left marginal, small cardiac, middle cardiac, posterior of the left ventricle, oblique of the left atrium) • anterior cardiac (right marginal) • pulmonary Thorax/ SVC brachiocephalic: internal thoracic (anterior intercostal, superior epigastric) - left superior intercostal - supreme - vertebral - subclavian (axillary: lateral thoracic, thoracoepigastric, dorsal scapular) - pericardiacophrenic azygos: right superior intercostal - bronchial - intercostal/posterior intercostal 5-11 - accessory hemiazygos/hemiazygos - superior phrenic Vertebral column vertebral venous plexuses (external, internal) • spinal (posterior, anterior) • basivertebral • intervertebral Abdomen/ IVC to IVC (some to renal vein on left): inferior phrenic - hepatic - suprarenal - renal - gonadal (ovarian ♀/testicular ♂, pampiniform plexus ♂) - lumbar - common iliac to azygos system: ascending lumbar (subcostal) Pelvis/common iliac median sacral vein external iliac: inferior epigastric - deep circumflex iliac vein internal iliac - posterior: iliolumbar - superior gluteal - lateral sacral internal iliac - anterior: inferior gluteal - obturator - uterine ♀ (uterine plexus ♀) - vesical (vesical plexus, prostatic plexus ♂, deep of penis ♂/clitoris ♀, posterior scrotal ♂/labial ♀) - vaginal plexus/vein ♀ - middle rectal - internal pudendal (inferior rectal, bulb of penis ♂/vestibule ♀) - rectal plexus Portal system/ portal vein splenic: short gastric - left gastroepiploic - pancreatic - inferior mesenteric (superior rectal, left colic) superior mesenteric: right gastroepiploic - pancreaticoduodenal - jejunal - ileal - middle colic - right colic - ileocolic (appendicular) direct (cystic, left gastric/esophageal, right gastric, paraumbilical) fetal ductus venosus • umbilical