Supracristal plane (Planum supracristale) (or supracrestal plane) is an anatomical transverse plane lying at the upper most part of the pelvis, the iliac crest. This is usually at the level of the L4 vertebrae. [1] It passes through the umbilical region and the left and right lumbar regions.
The supracristal plane can be used as a landmark for several nerve branches, [2] as well as an approximate marker for the umbilicus (belly button). It is also used as the divider between the lower (left and right) and upper (left and right) quadrants of the abdomen (where the vertical midline divides left from right).
It is also the level where the abdominal aorta bifurcates into the left and right common iliac artery and just superior to the union of the common iliac veins.
It can help in the identification of the level of L4/L5 where a lumbar puncture can be done.
The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.
The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process and by the absence of facets on the sides of the body. They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement.
In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.
The periaortic lymph nodes are a group of lymph nodes that lie in front of the lumbar vertebrae near the aorta. These lymph nodes receive drainage from the gastrointestinal tract and the abdominal organs.
In human anatomy, the common iliac veins are formed by the external iliac veins and internal iliac veins. The left and right common iliac veins come together in the abdomen at the level of the fifth lumbar vertebra, forming the inferior vena cava. They drain blood from the pelvis and lower limbs.
The external iliac arteries are two major arteries which bifurcate off the common iliac arteries anterior to the sacroiliac joint of the pelvis.
The common iliac artery is a large artery of the abdomen paired on each side. It originates from the aortic bifurcation at the level of the 4th lumbar vertebra. It ends in front of the sacroiliac joint, one on either side, and each bifurcates into the external and internal iliac arteries.
The psoas major is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In animals, this muscle is equivalent to the tenderloin.
The quadratus lumborum muscle, informally called the QL, is a paired muscle of the left and right posterior abdominal wall. It is the deepest abdominal muscle, and commonly referred to as a back muscle. Each is irregular and quadrilateral in shape.
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 torso. 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.
The internal iliac artery is the main artery of the pelvis.
The iliohypogastric nerve is a nerve that originates from the lumbar plexus that supplies sensation to skin over the lateral gluteal and hypogastric regions and motor to the internal oblique muscles and transverse abdominal muscles.
The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus; the branch from the third is the largest, while that from the second is often very small.
The transpyloric plane, also known as Addison's plane, is an imaginary horizontal plane, located halfway between the suprasternal notch of the manubrium and the upper border of the symphysis pubis at the level of the first lumbar vertebrae, L1. It lies roughly a hand's breadth beneath the xiphisternum or midway between the xiphisternum and the umbilicus. The plane in most cases cuts through the pylorus of the stomach, the tips of the ninth costal cartilages and the lower border of the first lumbar vertebra.
The crest of the ilium is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
The hypogastric nerves are the continuation of the superior hypogastric plexus that descend into the pelvis anterior the sacrum and become the inferior hypogastric plexuses on either side of pelvic organs. The hypogastric nerves serve as a pathway for autonomic fibers to communicate between the lower abdomen and pelvis.
The aortic bifurcation is the point at which the abdominal aorta bifurcates (forks) into the left and right common iliac arteries. The aortic bifurcation is usually seen at the level of L4, just above the junction of the left and right common iliac veins.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors, physicians, and pharmacists.
The human abdomen is divided into quadrants and regions by anatomists and physicians for the purposes of study, diagnosis, and treatment. The division into four quadrants allows the localisation of pain and tenderness, scars, lumps, and other items of interest, narrowing in on which organs and tissues may be involved. The quadrants are referred to as the left lower quadrant, left upper quadrant, right upper quadrant and right lower quadrant. These terms are not used in comparative anatomy, since most other animals do not stand erect.