The inferior rectal artery (inferior hemorrhoidal artery) is an

artery An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...

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 s ...

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 ...

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 posterior bony protuberance on the superior ramus of the ischium. It ...

. Piercing the wall of the pudendal canal, it divides into two or three branches which cross the ischioanal fossa, and are distributed to the muscles and integument of the anal region, and send offshoots around the lower edge of the

gluteus maximus The gluteus maximus is the main extensor muscle of the hip in humans. 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 ...

to the skin of the

buttock The buttocks (: 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 of a laye ...

. They

anastomose An anastomosis (, : 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 (su ...

with the corresponding vessels of the opposite side, with the superior and middle rectal arteries, 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 interspa ...

. These anastomoses can be seen during

angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfo ...

performed for hemorrhoidal artery embolization.

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 Cell (biology), cells, and transports Metabolic waste, metabolic waste products away from th ...

to the anal sphincter and the lower third of the

below the pectinate line.

Additional images

File:Gray405.png, The perineum. The integument and superficial layer of superficial fascia reflected.

References

External links

* - "Inferior view of female perineum, branches of the internal pudendal artery." * - "Branches of internal pudendal artery in the male perineum." * * * () * * Arteries of the abdomen {{circulatory-stub

Structure

Function

Additional images

See also

References

External links