The intercostobrachial nerves are
cutaneous
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different de ...
branches of the
intercostal nerve
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum, and diffe ...
s.
Second intercostal nerve
The
lateral cutaneous branch of the
second intercostal nerve does not divide, like the others, into an anterior and a posterior branch; it is named the intercostobrachial nerve. It pierces the
Intercostalis externus and the
Serratus anterior
The serratus anterior is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. The serratus anterior acts to pull the scapula fo ...
, crosses the
axilla
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded super ...
to the medial side of the arm, and joins with a filament from the
medial brachial cutaneous nerve. It then pierces the fascia, and supplies the skin of the upper half of the medial and posterior part of the arm, communicating with the
posterior brachial cutaneous branch of the
radial nerve
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compa ...
. It is often the source of referred cardiac pain.
The intercostobrachial nerve is also sometimes divided in axillary node clearance (ANC), such as that done for breast cancer surgery which requires the removal of the axillary nodes. Sensation to the cutaneous region supplied by the nerve is affected.
The size of the intercostobrachial nerve is in inverse relationship to that of the
medial brachial cutaneous nerve.
Third intercostal nerve
A second intercostobrachial nerve is frequently given off from the
lateral cutaneous branch of the
third intercostal; it supplies filaments to the
axilla
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded super ...
and medial side of the arm.
See also
*
Cutaneous innervation of the upper limbs
Additional images
File:Gray811and813.PNG, Cutaneous nerves of right upper extremity.
File:Gray812and814.PNG, Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.
File:Innervation oberarm.gif, Innervation
References
External links
* - "Axillary Region: Nerves"
*
{{Authority control
Spinal nerves