Head, Neck, and Trunk Muscles

Head, Neck, and Trunk Muscles


Welcome to another tutor short provided
by the Educational Support Services Department of Lehigh Carbon Community
College in Schnecksville, Pennsylvania just outside of Allentown. These
videos review key learnings for the science courses provided here at LCCC and please remember that the Education Support Services Department
does provide walk-in tutoring five days a week. Welcome to the anatomy and physiology
1 tutor short muscle part 1: Head, Neck (Anterior and Posterior) and the Posterior
Trunk and Shoulder, given by your tutors Kim Reylander and Laura Heck. This is where we will be focusing on this model. Here is our orbicularis oris. The origin is the various facial muscles, maxilla, mandible and the septum of the nose. The insertion is the lips. The action is to close the lips. Here is our orbicularis oculi. The origin is the nasal portion of the frontal bone, frontal process of the maxilla, and the medial palpebral ligament. The insertion is the eyelids. The action is blinking and squinting. Here is our masseter. The origin is the zygomatic arch. The insertion is the angle and ramus of the mandible. The action is to elevate the jaw and clench teeth. Here we get a better view of the temporalis. The origin is the temporal fossa. The insertion is the coronoid process of the mandible. The action is to elevate the
jaw and retract the mandible. Here we also get a better view of the masseter.
A side view of the orbicularis oculi and orbicularis oris. From this angle we can see the digastric located, here as well as here. In the posterior belly of the digastric, the origin is the mastoid process while the anterior belly of the digastic is the inner surface of the mandible. Both have an insertion at the fiberous loop of the hyoid bone. The action is to raise the hyoid and assist in lowering the mandible. Here we can see the sternocleidomastoid. Its origin is
the manubrium and medial end of the clavicle. The insertion is the mastoid process of the temporal bone. The action is rotation or flexion of the head. Next to the sternocleidomastoid is our sternohyoid. The origin is the manubrium and clavicle located down here. The insertion is the hyoid bone. The action is to pull
down on the hyoid bone. Now we will look at the posterior neck muscles. Here we see the trapezius. The origin is the occipital bone, the ligamentum nuchae, the spinous process of C7 and all thoracic vertebrae. The insertion is the clavicle, the spine of the scapula, and the acromion process of the scapula. The action is to ADduct the scapula and hyper extend the head. On to the back muscles. Here we see the latissimus dorsi. The origin is the lower 6 thoacic vertebrae, lumbar and sacral vertebrae, iliac crest, and lower ribs. The insertion is the greater tubercle of the humerus. The action is to extend, ADduct, and medially rotate the humerus. Here we see the Infraspinatus just underneath the spine of the scapula. The origin is the infraspinous fossa of the scapula. The insertion is the greater tubercle of the humerus. The action is to rotate the humerus laterally. Here we see the supraspinatus
above the spine of the scapula. The origin is the supraspinous fossa. The
insertion is the greater tubercle of the humerus. The action is ABduction of the humerus. Below the infraspinatus is the teres minor located here Teres minor has its origin at the lateral border of the scapula located down here. The insertion is the lower portion of the greater tubercle of the humerus. The action is to rotate the humerus laterally and weakly ADduct it. Below the teres minor is the teres major located here. Teres major has its origin at the inferior angle of the scapula located here. The insertion is at the crest of the lesser tubercle of the humerus. Its action is to ADduct, extend, and rotate the humerus medially. Here we see the rhomboid major and the rhomboid minor. The rhomboid major has its origin at the spinous process of thoracic vertebrae 1-5 And the rhomboid minor has its origin at the 7th cervical and 1st thoracic vertebrae. They both have an insertion at the upper part the medial border of the scapula here. Underneath the scapula we have the subscapularis. Its origin is the subscapular fossa. Its insertion is the lesser tubercle of the humerus and the action is to medially rotate the humerus and hold the head of the humerus in the glenoid cavity. You get a better photo of this in muscle part 3: upper limb. Here we get a better view of the levator scapulae located here. The origin is the 1st through 4th cervical vertebrae. The insertion is the superior angle of the scapula. The action is to extend the head backward and flexes laterally and elevate the
scapula. Next to the levator scapula is the spinous group located here. The origin is the ligamentum nuchae and the 7th cervical and the 1st 3 thoracic
vertebrae. The insertion is the occipital bone and mastoid process. The action is to extend and rotate the head. Thank you for watching! To view any of
the models or if you have any questions please come to the science lab in SH 150
in the educational support services center. Thank you!

Leave a Reply

Your email address will not be published. Required fields are marked *