Median sacral artery
Encyclopedia
The median sacral artery (or middle sacral artery) is a small vessel, which arises from the back of the aorta
, a little above its bifurcation.
It descends in the middle line in front of the fourth and fifth lumbar vertebræ, the sacrum
and coccyx
, and ends in the glomus coccygeum (coccygeal gland).
From it, minute branches are said to pass to the posterior surface of the rectum
.
On the last lumbar vertebra it anastomoses with the lumbar branch of the iliolumbar artery
; in front of the sacrum it anastomoses with the lateral sacral arteries, and sends offsets into the anterior sacral foramina
.
It is crossed by the left common iliac vein
, and is accompanied by a pair of venæ comitantes; these unite to form a single vessel, which opens into the left common iliac vein
.
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
, a little above its bifurcation.
It descends in the middle line in front of the fourth and fifth lumbar vertebræ, the sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
and coccyx
Coccyx
The coccyx , commonly referred to as the tailbone, is the final segment of the vertebral column. Comprising three to five separate or fused vertebrae below the sacrum, it is attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between...
, and ends in the glomus coccygeum (coccygeal gland).
From it, minute branches are said to pass to the posterior surface of the rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
.
On the last lumbar vertebra it anastomoses with the lumbar branch of the iliolumbar artery
Iliolumbar artery
The iliolumbar artery is the first branch of the posterior trunk of the internal iliac artery.-Course:The iliolumbar artery turns upward behind the obturator nerve and the external iliac artery and vein, to the medial border of the psoas major, behind which it divides into:* Lumbar branch of...
; in front of the sacrum it anastomoses with the lateral sacral arteries, and sends offsets into the anterior sacral foramina
Anterior sacral foramina
At the ends of the transverse ridges of the pelvic surface of the sacrum are seen the anterior sacral foramina , four in number on either side, somewhat rounded in form, diminishing in size from above downward, and directed lateralward and forward.They give exit to the anterior divisions of the...
.
It is crossed by the left common iliac vein
Common iliac vein
In human anatomy, the common iliac veins are formed by the external iliac veins and internal iliac veins and together, in the abdomen at the level of the fifth lumbar vertebrae, form the inferior vena cava. They drain blood from the pelvis and lower limbs....
, and is accompanied by a pair of venæ comitantes; these unite to form a single vessel, which opens into the left common iliac vein
Common iliac vein
In human anatomy, the common iliac veins are formed by the external iliac veins and internal iliac veins and together, in the abdomen at the level of the fifth lumbar vertebrae, form the inferior vena cava. They drain blood from the pelvis and lower limbs....
.