Pyramidalis muscle | |
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Muscles at the front of the abdomen, showing the pyramidalis at the bottom centre. | |
Details | |
Origin | pubic symphysis and pubic crest |
Insertion | linea alba |
Artery | Inferior and superior epigastric arteries |
Nerve | Subcostal nerve (T12) |
Actions | tensing the linea alba |
Identifiers | |
Latin | musculus pyramidalis |
TA98 | A04.5.01.007 |
TA2 | 2363 |
FMA | 15568 |
Anatomical terms of muscle |
The pyramidalis muscle is a small triangular muscle, anterior to the rectus abdominis muscle, and contained in the rectus sheath.
The pyramidalis muscle is part of the anterior abdominal wall. [1] Inferiorly, the pyramidalis muscle attaches to the pelvis in two places: the pubic symphysis and pubic crest, arising by tendinous fibers from the anterior part of the pubis and the anterior pubic ligament.
Superiorly, the fleshy portion of the pyramidalis muscle passes upward, diminishing in size as it ascends, and ends by a pointed extremity which is inserted into the linea alba, midway between the umbilicus and pubis.[ citation needed ]
The pyramidalis muscle is innervated by the ventral portion of T12.
The inferior and superior epigastric arteries supply blood to the pyramidalis muscle.[ citation needed ]
The pyramidalis muscle is present in 80% of human population. [2] [ unreliable source? ] It may be absent on one or both sides; the lower end of the rectus then becomes proportionately increased in size.
Occasionally, it is doubled on one side, and the muscles of the two sides are sometimes of unequal size.[ citation needed ] It may also extend higher than the usual level.[ citation needed ]
The pyramidalis muscle tenses the linea alba when contracting.[ citation needed ]
While making the longitudinal incision for a classical caesarean section, the pyramidalis muscle is used to determine midline and location of the linea alba.[ citation needed ]
The pubic symphysis is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is located in front of and below the urinary bladder. In males, the suspensory ligament of the penis attaches to the pubic symphysis. In females, the pubic symphysis is close to the clitoris. In normal adults it can be moved roughly 2 mm and with 1 degree rotation. This increases for women at the time of childbirth.
The white line is a fibrous structure that runs down the midline of the abdomen in humans and other vertebrates.
The rectus abdominis muscle, also known as the "abdominal muscle", is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly. The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.
The inguinal ligament, also known as Poupart's ligament or groin ligament, is a band running from the pubic tubercle to the anterior superior iliac spine. It forms the base of the inguinal canal through which an indirect inguinal hernia may develop.
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle. It is thought by most fitness instructors to be a significant component of the core.
The abdominal internal oblique muscle, also internal oblique muscle or interior oblique, is an abdominal muscle in the abdominal wall that lies below the external oblique muscle and just above the transverse abdominal muscle.
The abdominal external oblique muscle is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
The abdomen is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the trunk. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax.
In human anatomy, inferior epigastric artery refers to the artery that arises from the external iliac artery. It anastomoses with the superior epigastric artery. Along its course, it is accompanied by a similarly named vein, the inferior epigastric vein. These epigastric vessels form the lateral border of Hesselbach's triangle, which outlines the area through which direct inguinal hernias protrude.
In vertebrates, the pubic bone is the most forward-facing of the three main bones making up the pelvis. The left and right pubic bones are each made up of three sections, a superior ramus, inferior ramus, and a body.
The transversalis fascia is a thin aponeurotic membrane which lies between the inner surface of the transverse abdominal muscle and the parietal peritoneum.
The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet. Its lower boundary is the pelvic floor.
The pubic tubercle is a prominent tubercle on the superior ramus of the pubis bone of the pelvis.
The arcuate line of rectus sheath, linea semicircularis, arcuate line, or Douglas' line is a horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath. It is also where the inferior epigastric vessels perforate the rectus abdominis.
The rectus abdominis muscle is crossed by three fibrous bands called the tendinous intersections or tendinous inscriptions. One is usually situated at the level of the umbilicus, one at the extremity of the xiphoid process, and the third about midway between the two.
The aponeurosis of the abdominal external oblique muscle is a thin but strong membranous structure, the fibers of which are directed downward and medially.
The superficial inguinal ring is bounded below by the crest of the pubis; on either side by the margins of the opening in the aponeurosis, which are called the crura of the ring; and above, by a series of curved intercrural fibers.
The hip bone is a large irregular bone, constricted in the center and expanded above and below. In some vertebrates it is composed of three parts: the ilium, ischium, and the pubis.
In surgery, a surgical incision is a cut made through the skin and soft tissue to facilitate an operation or procedure. Often, multiple incisions are possible for an operation. In general, a surgical incision is made as small and unobtrusive as possible to facilitate safe and timely operating conditions.
The pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs or the skeleton embedded in it.