Stebocleidomastoid . Also known as sternocleidooccipitomastoid muscle, it is a long and robust muscle located in the anterior and lateral area of the neck. It is innervated by the third cervical nerve and the spinal accessory. It acts in the flexion, inclination and rotation of the head and is made up of two bundles or heads in its thoracic section: the sternal, cylindrical, and the clavicular, flattened.
Summary
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- 1 Features
- 1 Inserts and description
- 1.1 Sternomastoideooccipital head or sternal head
- 1.2 Cleidooccipital head
- 1.3 Cleidomastoid head
- 2 Sources
- 1 Inserts and description
characteristics
It is located in the anterolateral part of the neck outside the muscles of the infrahyoid group and the middle fascia and vascular nerve fascia of the neck. It is quadrilateral in shape and runs from the temporal and occipital mastoid processes to the clavicle and sternum.
Inserts and description
It presents four beams according to their insertion:
- Sternomastoid
- Sterno-occipital
These are described as three heads:
Sternomastoideooccipital head or sternal head
It is inserted into the anterior aspect of the sternum handle by a tendon that passes in front of the sternoclavicular joint .
It is directed upwards, backwards and outwards in front of the cleidooccipital head and out of the cleidomastoid head and ends:
On the anterior edge and external face of the mastoid process in front of the splenic insertion of the neck .
On the outside of the upper occipital line.
Cleidooccipital head
It is inserted in the internal third part of the superior aspect of the clavicle.
It ascends behind the sternal head, and outside the cleidomastoid head .
It ends in the superior occipital line inside the insertion of the sternal head.
Cleidomastoid head
It is inserted on the superior aspect of the clavicle behind the insertion of the cleidooccipital head.
It is directed vertically upwards, behind the cleidooccipital and sternal heads. It is crossed by the external branch of the spinal nerve.
It ends at the anterior edge and external face of the mastoid process behind the sternomastoid bundle.
