Anatomy

The first dorsal vertebra is marked at each side by a complete articular surface for the first rib, and on its inferior border by a slight excavation, which receives half the head of the second : the upper articular processes are oblique, and the spinous more nearly horizontal than those below it. 

Muscles are characterized by their shapes, insertions and relationships. These characteristics are sometimes subject to variation.

Amongst the lumbar vertebrae, the fifth only is distinguishable by any peculiarity deserving of notice, its body being thicker anteriorly than posteriorly, and its transverse process short, thick, and rounded. 

 

This is a flat, thin, digastric muscle, extended from the occiput to the forehead (from which circumstance its name is derived), and placed immediately beneath the cranial integument, to which it closely adheres, at the same time that it rests upon the arch of the skull, over which it slides. It consists of two broad but short fleshy bellies, united by an intervening aponeurosis. 

We include under this heading of appendices: 1° the aponeuroses, which cover the muscles or even envelop them entirely

On the nose develop four muscles, knowledge in top, the pyramidal one; in bottom, the myrtiforme; on the sides, the transverse and the dilator one of the nostrils.

Muscle in humans has an average density of 1055.

 

All around the oral opening  eleven muscles are laid out: one initially, of annular form, the labial or orbicular one of the lips, which governs its occlusion then a series of ten others which from the various areas of the face, come to fit on its circumference like so many convergent rays. They are, from top to bottom: the common elevator of the wing of the nose and the upper lip; the very elevator of the upper lip; the canine one; the minor zygomatic muscle; the big zygomatic; the buccinator; the risorius; the triangular one of the lips; the square of the chin; the muscle of the bunch of the chin.

The tendon, whether long or short, cylindrical or flattened, joins by one of its extremities with the corresponding muscular body; by the other, it is inserted into various formations which, depending on the case, are a piece of bone, cartilage, fascia, etc., and is then inserted into the muscular body.

The biceps flexor cubiti (French: muscle biceps-brachial) - named from its two heads and its action - is a thick, somewhat flattened fusiform muscle with a bifid upper extremity.

The striated muscles each consist of two distinct parts: 1° a red, soft, contractile part, constituting the muscle proper; 2° a whitish, firm, non-contractile part, forming the tendon.

The subscapularis muscle (French: muscle sous-scapulaire)- named from its position beneath the scapula - is a thick triangular and somewhat multipenniform sheet.

Forum Anatomy

No Entries available yet

This website puts documents at your disposal only and solely for information purposes. They can not in any way replace the consultation of a physician or the care provided by a qualified practitioner and should therefore never be interpreted as being able to do so.