Tendinous Intersections Of Rectus Abdominis

Tendinous intersection
Rectus abdominis
Details
Identifiers
Latin	Intersectiones tendineae musculi recti abdominis
Anatomical terminology [edit on Wikidata]

The rectus abdominis muscle is crossed by 3 gristly bands called the tendinous intersections or tendinous inscriptions. Ane is usually situated at the level of the umbilicus, ane at the extremity of the xiphoid process, and the third about midway between the two.

These intersections pass transversely or obliquely across the muscle; they rarely extend completely through its substance and may pass but halfway beyond it; they are intimately adherent in front end to the sheath of the musculus.

Sometimes one or ii additional intersections, more often than not incomplete, are present below the navel.

Vernacular reference [edit]

If well-defined, the rectus abdominis is colloquially chosen a "six-pack". This is due to tendinous intersections within the muscle, usually at the level of the belly button (belly-push), the xiphisternum, and about halfway between.

An extremely well divers abdominal department can appear to be an "eight pack", as all eight sections of the abdominal muscle go defined. This definition is prominent amidst athletes with low torso fatty percentages, such as bodybuilders, boxers, mixed martial artists, rock climbers, and track and field athletes.

Physiological function [edit]

The tendinous intersections, in conjunction with the rectus abdominis, role to provide varying degrees of forrard flexion to the lumbar region of the vertebral cavalcade, producing forward bending at the waist. Forrard flexion results in a decreased angle betwixt the trunk and lower torso.

The anatomical segmentation of the rectus abdominis into three pairs of muscles^{[ citation needed ]} and the positioning of these iii pairs of muscles at different levels along the lumbar region (which are created by the tendinous intersections) are responsible for the forward flexion of the vertebral column:

As the superior (or proximal) pair of rectus abdominis muscles contract, the vertebral column is able to slightly flex frontwards.^{[ commendation needed ]}
If more forward flexion is needed, the eye pair of rectus abdominis muscles tin contract forth with the distal pair to allow the vertebral cavalcade to flex forrard fifty-fifty farther.^{[ commendation needed ]}
Lastly, as the inferior (or distal) pair of muscles contract in conjunction with the other two muscle groups, the vertebral cavalcade is able to produce the nearly frontwards flexion and the smallest bending between the trunk and lower body.^{[ citation needed ]}

The tendinous intersections ascertain the anatomy of the rectus abdominis and assist with physiological movement. If the rectus abdominis did not accept tendinous intersections, there would be ane big musculus group on each side of the linea alba. This big muscle grouping would permit the vertebral cavalcade to flex forward, but would non permit^{[ citation needed ]} a large extent of forward flexion.

The forrard flexion provided by tendinous intersections makes daily activities like stretching or angle over to pick upward an object possible.^{[ citation needed ]}

Additional images [edit]

The Obliquus externus abdominis.

References [edit]

This article incorporates text in the public domain from the 20th edition of Greyness's Anatomy (1918)

External links [edit]

Anatomy photograph:35:10-0104 at the SUNY Downstate Medical Middle - "Anterior Abdominal Wall: The Rectus Abdominis Musculus"
Anatomy image:7554 at the SUNY Downstate Medical Center
Atlas image: abdo_wall60 at the University of Michigan Wellness System - "The Rectus Sheath, Anterior View & Transverse Section"