Axle gap

An axillary gap is a split in two parts between muscles in the back of the shoulder .

Axillary gaps in humans

Axillary gaps in humans

The axillary gaps in humans lie between the teres major and minor muscles and are divided into their two departments by the long head ( caput longum ) of the triceps brachii muscle . The upper arm bone (humerus) also delimits the lateral gap.

The axillary nerve , the posterior circumflex artery and the posterior circumflex humerus pass through the quadrangular lateral axillary gap .

The circumflex scapular artery and the scapular circumflex vein pass through the triangular medial axillary gap .

Axial gaps in pets

In the case of domestic mammals , the situation is significantly different from that of humans. Here the two axillary gaps are divided by the teres major muscle.

The upper axillary gap ( Spatium axillare proximale ) is bounded behind by the long head of the musculus triceps brachii, in front by the muscle coracobrachialis , above by the muscle subscapularis and below by the muscle teres major. The axillary nerve and the caudal circumflex artery pass through it . It corresponds to the lateral axillary gap in humans.

The muscle gap corresponding to the medial axillary gap is not designated in animal anatomy. Instead, a lower axillary gap ( Spatium axillare distale ) is defined, which is delimited at the top by the teres major muscle, behind by the long head of the triceps brachii muscle and in front by the medial head of the triceps brachii muscle. The radial nerve passes through it . The sharp trailing edge of the tendon of the teres major muscle can damage the nerve in this area and lead to radial paralysis .