The rectus sheath contains within it the superior and inferior epigastric
What arteries are in the rectus sheath?
The arterial supply to the rectus sheath is derived from the superior and inferior epigastric arteries. The inferior epigastric artery originates from the external iliac artery. It rises from the inguinal ligament to enter the posterior rectus sheath inferiorly.
What is the nerve supply to the rectus abdominis?
Innervation. The rectus abdominis muscle is innervated by the thoracoabdominal nerves, which enter the rectus sheath by piercing its anterior surface. They pass between the transversus abdominis and internal oblique muscle layers, and pierce the sheath of the rectus abdominis muscle.
Which vessels run in the rectus sheath deep to rectus abdominis muscle?
Besides the rectus abdominis and pyramidalis muscles, the rectus sheath contains the superior and inferior epigastric arteries and veins, lymphatic vessels, termination parts of lower five intercostal nerves (T7-T11), and the termination of the 12th thoracic nerve (T12).
What direction do the fibers in the rectus abdominis run?
The rectus abdominis muscle runs on both sides of the midline from the rib cage to the pubis. Notice how the muscle fibers run from superior to inferior. Note that the midline is not covered by muscle.
What is arcuate line of rectus sheath?
16919. Anatomical terminology. The arcuate line of rectus sheath, the linea semicircularis, the arcuate line, or the semicircular line of Douglas, is a horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath. It is commonly known simply as the arcuate line.
What is the rectus sheath?
The rectus sheath is the durable, resilient, fibrous compartment that contains both the rectus abdominis muscle and the pyramidalis muscle. The fascial coverings of the external oblique, internal oblique, and transversus abdominis muscles comprise the rectus sheath.
What forms the arcuate line?
The arcuate line is the inferior margin of the posterior leaflet of the rectus sheath within the abdomen. The posterior leaflet of the sheath is formed, superficial to deep, from the: posterior part of the internal oblique aponeurosis. transversus abdominis aponeurosis.
Where is the rectus sheath muscle?
Gross anatomy The rectus sheath is composed of the aponeuroses of transversus abdominis, external oblique and internal oblique muscles, which form anterior and posterior layers of the sheath that fuse laterally at the linea semilunaris and in the midline at the linea alba.
Is rectus abdominis deep or superficial?
Muscles of the anterior abdominal wall consists of two vertical muscles located on the midline and bisected by linea alba; Rectus abdominis and pyramidalis and three flat muscles on the anterolateral side arranged from superficial to deep; external abdominal oblique, internal abdominal oblique, transversus abdominis.
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How rectus sheath is formed?
The rectus sheath, also called the rectus fascia, is formed by the aponeuroses of the transverse abdominal and the internal and external oblique muscles. It contains the rectus abdominis and pyramidalis muscles.
What vein drains the rectus abdominis?
The venous drainage of the transverse rectus abdominis musculocutaneous flap when used for breast reconstruction occurs from the cutaneous part of the flap to the inferior deep epigastric veins through vertical perforators that are mainly periumbilical.
What is the blood supply to the rectus abdominis muscle?
The inferior epigastric artery is the main artery supplying the rectus abdominis muscle. There are sometimes contributions from the lower intercostal and subcostal arteries, posterior lumbar, and deep circumflex iliac arteries.
Which way do fibers run in the external oblique muscles?
The external obliques get their name from their position in the abdomen external to the internal abdominal obliques and from the direction of their fibers, which run obliquely (diagonally) across the sides of the abdomen.
What exercise works the rectus abdominis?
1. Forearm Plank. The forearm plank is a staple in core workouts. Not only does it target the entire rectus abdominis, but it also challenges your entire core and several muscles in your upper body.
What muscles have fibers running in the same direction as the whole muscle?
Parallel muscles have fascicles that are arranged in the same direction as the long axis of the muscle (Figure 11.2. 1). The majority of skeletal muscles in the body have this type of organization.
Where is rectus sheath hematoma?
Rectus sheath hematoma usually occurs in the lower abdominal wall. Firm attachment of the branches of inferior epigastric artery while piercing the rectus abdominis and movement of the body creates shearing forces at arterial branch attachments.
Where is rectus sheath deficient?
The inferior quarter of the posterior wall of the rectus sheath is deficient; the arcuate line forms the inferior border of the posterior wall of the rectus sheath. The arcuate line is midway between the umbilicus and the pubic crest.
Where does the inferior epigastric artery enter the rectus sheath?
Below the arcuate line, the inferior epigastric vessels pierce the transversalis fascia on each side of the rectus sheath and enter the rectus abdominis muscle. The artery then runs within the rectus sheath, between the transversalis fascia and the posterior wall of the rectus abdominis.
What is the posterior rectus sheath made up of above the arcuate line?
The posterior layer is made up of the posterior lamina of the internal oblique aponeurosis and the transversus abdominis aponeurosis. Inferior to the arcuate line, all three muscle aponeuroses make up the rectus sheath, that is now only anterior to the rectus abdominis and not posterior to it at all.
Where is the arcuate line?
The arcuate line or semicircular line of Douglas is located at roughly one-third of the distance from the pubic crest to the umbilicus.
What is muscle sheath?
a fibrous membrane, usually quite thin and devoid of fat, surrounding a single muscle, separating it from adjacent muscles and allowing movements between them; related to contraction. Synonym(s): fascia propria musculi [TA], muscle sheath.
Which muscle has fibers running in a horizontal direction?
The transversus abdominis muscle is the deepest of the abdominal muscles, lying internally to the internal abdominal obliques and is named for the direction of its fibers. It is a thin sheet of muscle whose fibers run horizontally anteriorly.
Why is rectus abdominis segmented?
The anterior fascia of the rectus abdominis muscle separates both of these regions, hence its automatic segmentation facilitates the use of computer based routines to automatically retrieve the required measures.
What is the V called on a man?
Blame it on Mark Walhberg in those Calvin Klein adds or Brad Pitt in Fight Club: Ever since celebrities have showed off that v-shaped line below their abs, there’s been a furor over how to get that love line, moneymaker, or, as it’s officially called, inguinal crease.
Why do stomach muscles run in different directions?
The muscle layers in the human stomach are each striated in different directions. Because smooth muscle can only contract in one direction, it is functionally adaptive for the stomach, which must contract as an organ overall, to contract in three directions.
Which structure forms the medial border of the rectus sheath?
At the lateral margin of the Rectus, the aponeurosis of the Obliquus internus divides into two lamellae, one of which passes in front of the Rectus, blending with the aponeurosis of the Obliquus externus, the other, behind it, blending with the aponeurosis of the Transversus, and these, joining again at the medial …
What forms the anterior wall of the rectus sheath?
Rectus Sheath The anterior wall is formed by the aponeuroses of the external oblique and half of the internal oblique. The posterior wall is formed by the aponeuroses of half of the internal oblique and transversus abdominis.
What vein drains the small intestine?
The mesenteric veins parallel their corresponding arteries. The SMV drains the small intestine, cecum, and ascending and transverse colon via the jejunal, ileal, ileocolic, right colic, and middle colic veins.
Where does superior epigastric vein drain?
Superior epigastric veins drain to the internal thoracic vein, inferior epigastric vein to external iliac vein, and superficial epigastric vein to femoral vein distal to the femoral ring.
What veins drain into the portal vein?
The venous blood from the GI tract drains into the superior and inferior mesenteric veins; these two vessels are then joined by the splenic vein just posterior to the neck of the pancreas to form the portal vein. This then splits to form the right and left branches, each supplying about half of the liver.
