It is the area of the human body that is below the junction between the shoulder and the arm , differentiating itself from the groin , between the leg and the hip .
Description
The armpit is defined as the cavity below the shoulder , between the chest and the upper medial end of the arm . The axilla region is made up of all the soft tissues located between the costal wall medially, the shoulder joint laterally, and the scapula posteriorly. It has a truncated quadrangular pyramid shape, which is why the following are described:
Four walls (anterior, posterior, medial and lateral)
One base
A vertex
A cavity, called the axillary fossa , between the walls of the pyramid.
Axilla Anatomy
The armpit is a more or less pyramidal space that is located at the junction of the arm and the thorax . It is a pathway through which vessels and nerves pass to the upper limb.
In the armpit there are 6 parts:
A vertex
One base
4 walls
Vertex of the armpit
It is directed towards the root of the neck and is located in the medial portion of the root of the coracoid process of the shoulder blade . It is formed by the convergence of the following bones in the three main walls of the armpit:
The clavicle on the anterior wall.
The scapula on the posterior wall.
The first rib on the medial wall.
The space between these three bones is considered the entrance of the armpit through which all the vessels and nerves pass to the upper limb.
Base of armpit
This looks downwards, it is formed by the fascia and the skin of the axillary concavity. The skin of the armpit concavity is normally covered by hair after puberty . In a cross section the limits of the armpit can be distinguished much better :.
Anterior wall of armpits
It is made up of the clavicle and the pectoral muscles . The lateral border of the pectoralis major muscle forms what is called the anterior axillary crease. In the deep layer of this anterior wall are the pectoralis minor and subclavian muscles that are located behind the pectoralis major muscle.
Back wall of the armpit
It is formed by the clavicle and the subscapularis muscle , below this muscle is the teres major muscle which, joining the latissimo muscle of the back, form what is called the posterior axillary fold. The tendon of the latissimus muscle of the dorsum wraps the lateral part of the teres major muscle forming the part of the posterior wall of the armpit.
Medial wall of the armpit
It is made up of the ribs and the intercostal muscles , which are covered by the serratus anterior muscle, the main component of this wall.
Side wall of the armpit
It is a thin wall formed by the floor of the intertubercular groove of the humerus , where the tendon of the long head of the biceps brachii is located .