The inferior rectal artery (inferior hemorrhoidal artery) is an
artery
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...
that supplies blood to the lower third of the
anal canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment ...
below the pectinate line.
Structure
The inferior rectal artery arises from the
internal pudendal artery
The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia.
Structure
The internal pudendal artery is the terminal branch of the anterior trunk of t ...
as it passes above the
ischial tuberosity
The ischial tuberosity (or tuberosity of the ischium, tuber ischiadicum), also known colloquially as the sit bones or sitz bones, or as a pair the sitting bones, is a large swelling posteriorly on the superior ramus of the ischium. It marks th ...
.
Piercing the wall of the
pudendal canal
The pudendal canal (also called Alcock's canal) is an anatomical structure in the pelvis through which the internal pudendal artery, internal pudendal veins, and the pudendal nerve pass.
Structure
The pudendal canal is formed by the fascia of the ...
, it divides into two or three branches which cross the
ischioanal fossa
The ischioanal fossa (formerly called ischiorectal fossa) is the fat-filled wedge-shaped space located lateral to the anal canal and inferior to the pelvic diaphragm. It is somewhat prismatic in shape, with its base directed to the surface of the p ...
, and are distributed to the muscles and integument of the
anal
Anal may refer to:
Related to the anus
*Related to the anus of animals:
** Anal fin, in fish anatomy
** Anal vein, in insect anatomy
** Anal scale, in reptile anatomy
*Related to the human anus:
** Anal sex, a type of sexual activity involvin ...
region, and send offshoots around the lower edge of the
gluteus maximus
The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human ...
to the skin of the
buttock
The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed ...
.
They
anastomose
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...
with the corresponding vessels of the opposite side, with the
superior and
middle rectal arteries
The middle rectal artery is an artery in the pelvis that supplies blood to the rectum.
Structure
The middle rectal artery usually arises from the internal iliac artery. It is distributed to the rectum above the pectinate line. It Anastomosis, an ...
, and with the
perineal artery
The perineal artery (superficial perineal artery) arises from the internal pudendal artery, and turns upward, crossing either over or under the superficial transverse perineal muscle, and runs forward, parallel to the pubic arch, in the interspac ...
.
Function
The inferior rectal artery supplies
oxygenated blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the ci ...
to the
anal sphincter and the lower third of the
anal canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment ...
below the pectinate line.
Additional images
File:Gray405.png, The perineum. The integument and superficial layer of superficial fascia reflected.
See also
*
Superior rectal artery
The superior rectal artery (superior hemorrhoidal artery) is an artery that descends into the pelvis to supply blood to the rectum.
Structure
The superior rectal artery is the continuation of the inferior mesenteric artery. It descends into the ...
*
Middle rectal artery
The middle rectal artery is an artery in the pelvis that supplies blood to the rectum.
Structure
The middle rectal artery usually arises from the internal iliac artery. It is distributed to the rectum above the pectinate line. It anastomoses wi ...
*
Inferior rectal nerve
The Inferior rectal nerves (inferior anal nerves, inferior hemorrhoidal nerve) usually branch from the pudendal nerve but occasionally arises directly from the sacral plexus; they cross the ischiorectal fossa along with the inferior rectal artery ...
References
External links
* - "Inferior view of female perineum, branches of the internal pudendal artery."
* - "Branches of internal pudendal artery in the male perineum."
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Arteries of the abdomen
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