Transverse abdominal muscle: Difference between revisions

Latest revision as of 05:06, 18 February 2025

Muscle layer of the anterior and lateral abdominal wall

Transverse section through the middle of the first lumbar vertebra, showing the relations of the pancreas. (Transversus abdominis labeled at bottom left.)

Diagram of a transverse section through the anterior abdomino-thoracic wall, showing the transversus abdominis.

The transversus abdominis is shown in this diagram of the muscles of the trunk.

The transversus abdominis is visible in this diagram of the muscles of the trunk.

The transverse abdominal muscle (musculus transversus abdominis), also known as the transversus abdominis, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle. It is a major component of the core muscles and plays a crucial role in maintaining abdominal tension and stability.

Structure[edit]

The transverse abdominal muscle is the innermost of the flat muscles of the abdomen. It arises from the lateral third of the inguinal ligament, the anterior two-thirds of the inner lip of the iliac crest, the thoracolumbar fascia, and the inner surfaces of the lower six costal cartilages. The fibers run horizontally and insert into the linea alba, the pubic crest, and the pectineal line of the pubis.

Function[edit]

The primary function of the transversus abdominis is to compress the abdominal contents. This action is crucial for maintaining intra-abdominal pressure, which is important for stabilizing the spine and pelvis during movement. It also plays a role in forced expiration and acts as a stabilizer for the lumbar spine during lifting and other activities.

Innervation[edit]

The transversus abdominis is innervated by the lower six thoracoabdominal nerves (T7-T11) and the first lumbar nerve (L1). The iliohypogastric and ilioinguinal nerves, which are branches of the lumbar plexus, also contribute to its innervation.

Clinical significance[edit]

Weakness or dysfunction of the transversus abdominis can lead to lower back pain and instability. Strengthening this muscle is often a focus in rehabilitation programs for individuals with back pain or core instability. Techniques such as the "drawing-in maneuver" are used to activate the transversus abdominis during exercises.

Related pages[edit]

References[edit]

Illustration of trunk muscles
Transversus abdominis muscle
Transverse section through the middle of the first lumbar vertebra
Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia
Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia
The relations of the viscera and large vessels of the abdomen

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-'''Transverse Abdominal Muscle'''
+{{Short description|Muscle layer of the anterior and lateral abdominal wall}}
+{{Use dmy dates|date=October 2023}}
-The '''Transverse Abdominal Muscle''' (TAM) is a muscle layer of the [[Anterior and lateral abdominal wall]] and is also known as the transversalis muscle. It is the deepest of the [[abdominal muscles]], located beneath the [[internal oblique muscle]].
+[[File:Illu trunk muscles.jpg|thumb|Illustration of trunk muscles, including the transverse abdominal muscle]]
+[[File:Transversus abdominis.png|thumb|Transversus abdominis muscle]]
+[[File:Gray388.png|thumb|Transverse section through the middle of the first lumbar vertebra, showing the relations of the pancreas. (Transversus abdominis labeled at bottom left.)]]
+[[File:Gray390.png|thumb|Diagram of a transverse section through the anterior abdomino-thoracic wall, showing the transversus abdominis.]]
+[[File:Gray398.png|thumb|The transversus abdominis is shown in this diagram of the muscles of the trunk.]]
+[[File:Gray399.svg|thumb|The transversus abdominis is visible in this diagram of the muscles of the trunk.]]
+[[File:Gray400.png|thumb|The transversus abdominis is shown in this diagram of the muscles of the trunk.]]
+[[File:Gray401.png|thumb|The transversus abdominis is shown in this diagram of the muscles of the trunk.]]
+[[File:Gray531.png|thumb|The transversus abdominis is shown in this diagram of the muscles of the trunk.]]
-== Anatomy ==
+The '''transverse abdominal muscle''' (''musculus transversus abdominis''), also known as the '''transversus abdominis''', is a muscle layer of the anterior and lateral [[abdominal wall]] which is deep to the internal oblique muscle. It is a major component of the core muscles and plays a crucial role in maintaining abdominal tension and stability.
-The transverse abdominal muscle is a thin sheet of muscle whose fibers run horizontally. It originates from the [[iliac crest]], the [[inguinal ligament]], the [[thoracolumbar fascia]], and the inner surface of the lower six [[ribs]]. It inserts into the [[linea alba (abdomen)|linea alba]], the [[pubic crest]], and the [[pecten pubis]] via the [[conjoint tendon]].
+==Structure==
+The transverse abdominal muscle is the innermost of the flat muscles of the abdomen. It arises from the lateral third of the [[inguinal ligament]], the anterior two-thirds of the inner lip of the [[iliac crest]], the thoracolumbar fascia, and the inner surfaces of the lower six costal cartilages. The fibers run horizontally and insert into the linea alba, the pubic crest, and the pectineal line of the pubis.
-== Function ==
+==Function==
+The primary function of the transversus abdominis is to compress the abdominal contents. This action is crucial for maintaining intra-abdominal pressure, which is important for stabilizing the [[spine]] and [[pelvis]] during movement. It also plays a role in forced expiration and acts as a stabilizer for the [[lumbar spine]] during lifting and other activities.
-The transverse abdominal muscle helps in the process of [[respiration]] by assisting in [[exhalation]] and compressing the internal organs. However, its main function is to activate the core and stabilize the [[pelvis]] and lower back prior to movement of the body.
+==Innervation==
+The transversus abdominis is innervated by the lower six thoracoabdominal nerves (T7-T11) and the first lumbar nerve (L1). The iliohypogastric and ilioinguinal nerves, which are branches of the lumbar plexus, also contribute to its innervation.
-== Clinical significance ==
+==Clinical significance==
+Weakness or dysfunction of the transversus abdominis can lead to lower back pain and instability. Strengthening this muscle is often a focus in rehabilitation programs for individuals with back pain or core instability. Techniques such as the "drawing-in maneuver" are used to activate the transversus abdominis during exercises.
-A weak transverse abdominal muscle can lead to a poor [[posture]] and increase the risk of having [[lower back pain]]. It is also one of the muscles that can be trained to help reduce the waistline.
+==Related pages==
-== See also ==
-* [[Abdominal exercise]]
 * [[Rectus abdominis muscle]]
 * [[Internal oblique muscle]]
 * [[External oblique muscle]]
+* [[Abdominal muscles]]
-== References ==
+==References==
+{{Reflist}}
-<references />
 [[Category:Muscles of the torso]]
-[[Category:Human anatomy]]
+<gallery>
-{{stub}}
+File:Illu_trunk_muscles.jpg|Illustration of trunk muscles
+File:Transversus_abdominis.png|Transversus abdominis muscle
-This article is a stub. You can help Wikipedia by expanding it.
+File:Gray388.png|Transverse section through the middle of the first lumbar vertebra
+File:Gray390.png|Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia
+File:Gray398.png|Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia
+File:Gray531.png|The relations of the viscera and large vessels of the abdomen
+</gallery>