What is the action of the sternocleidomastoid?
When acting together it flexes the neck and extends the head. When acting alone it rotates to the opposite side (contralaterally) and slightly (laterally) flexes to the same side. It also acts as an accessory muscle of inspiration.
What is the insertion for the sternocleidomastoid?
Sternocleidomastoid Attachments
| Origin | Insertion |
|---|---|
| Upper part of the anterior surface of manubrium | Lateral surface of mastoid process |
| Superior border/anterior surface of medial third of clavicle | Nuchal line of occipital bone |
Which set of structures make up the origin and insertion of the sternocleidomastoid?
The sternocleidomastoid muscles originate from the sternum and clavicle and insert on the mastoid process. Each one (1) rotates the head to the opposite side of the body, that is, away from the side of the muscle; (2) tilts the head to the same side of the body.
What is the function of the sternocleidomastoid muscle EMT?
Sternocleidomastoid Function When just one SCM muscle contracts, it tilts your head to the same side (called the ipsilateral side) to which the muscle is located. For example, the SCM on the right side of your neck tilts your head to your right. One SCM can also turn, or rotate, your head to the opposite side.
What is the unilateral action of the sternocleidomastoid muscle quizlet?
unilaterally – it draws the head toward the shoulder and rotates it pointing the chin superiorly and to the opposite side.
What is blood supply to Sternocleidomastoid?
The main blood supply of the sternocleidomastoid muscle enters it above from branches of the superior thyroid, posterior auricular and occipital arteries. The lower third is supplied by a branch from the transverse cervical artery and at this level there are few if any musculocutaneous branches.
Can SCM cause dizziness?
In the clavicular head of SCM rest 3 TPs which can give issues with pain in forehead, ear and mastoid zone, nausea, vertigo, ataxia, dizziness. Often, there is a triad of concomitant symptoms like dizziness, frontal headache, and dysmetria (lack of coordination of movement).
What causes pain in the sternocleidomastoid muscle?
Causes of SCM pain can include chronic health conditions, such as asthma, and acute respiratory infections, such as sinusitis, bronchitis, pneumonia, and the flu. Other causes of SCM pain include: injuries such as whiplash or falls. overhead work such as painting, carpentry, or hanging curtains.
Is the sternocleidomastoid named for its origin and insertion?
It is given the name sternocleidomastoid because it originates at the manubrium of the sternum ( sterno-) and the clavicle ( cleido- ), and has an insertion at the mastoid process of the temporal bone of the skull. The sternocleidomastoid muscle originates from two locations: the manubrium of the sternum and the clavicle.
What is the function of a sternocleidomastoid muscle?
Sternocleidomastoid. Two nerves serve the sternocleidomastoid muscle. For motor functions (movement), the muscle uses the accessory nerve. The cervical plexus nerve provides for sensory function, which includes proprioception – the sense we have of our body’s position and movement within the space around us.
Which muscle has its insertion on the sternum?
The chest muscles form a large, triangular mass of muscles collectively called the pectoral group. These muscles originate on the sternum and insert on or near the humerus. The major action of these muscles is adduction of the forelimb (i.e. the front leg is drawn toward the midline).
What does muscle have it insertion at the clavicle?
There are five muscles that make their origin or insertion on the clavicle: pectoralis major and sternocleidomastoid muscles medially; subclavius muscle centrally; and deltoid and trapezius muscles distally ( Gray, 1918; Netter, 1987 ). The pectoralis, trapezius, and deltoid each have long and narrow attachment sites on the clavicle.
