Muscles-of-the-Neck.-pptx -from- Anatomy

Muscles-of-the-Neck.pptx -from- Anatomy

1. Muscles of the Neck presented by Shafiya N. Patel

2. Superficial Neck Muscles 1 Platysma A thin, sheet-like muscle that extends from the chest to the lower jaw. It helps with facial expressions, particularly in the lower jaw and neck region. 2 Sternocleidomastoid A large, prominent muscle on each side of the neck, extending from the sternum and clavicle to the mastoid process of the skull. It's crucial for head movement, allowing flexion, extension, rotation, and lateral bending. 3 Trapezius A broad, flat muscle that covers the upper back and neck. It's involved in shoulder movement, head extension, and scapular stabilization. While it's not strictly a neck muscle, its upper portion contributes to neck movements.

3. Origin and Insertion of Key Neck Muscles The neck contains several important muscles that facilitate movement and stability. Three key muscles are the platysma, sternocleidomastoid, and trapezius. Platysma: This broad, thin muscle originates from the fascia over the upper chest and clavicle, and inserts into the skin and fascia of the lower jaw and cheek. Sternocleidomastoid: This muscle has two origins - the sternum and the clavicle. It inserts on the mastoid process of the temporal bone. This muscle is responsible for turning the head and tilting the head to the same side. Trapezius: The trapezius has a wide origin along the occipital bone, ligamentum nuchae, and spinous processes of the thoracic vertebrae. It inserts on the lateral third of the clavicle, acromion, and spine of the scapula. This muscle aids in shoulder blade movement and neck extension.

4. Deep Neck Muscles Anterior The anterior deep neck muscles include the infrahyoid and suprahyoid muscles. The infrahyoid muscles, located below the hyoid bone, act on the larynx and assist in swallowing. The suprahyoid muscles, above the hyoid bone, aid in elevating the hyoid bone during swallowing and speech. Lateral The lateral deep neck muscles are responsible for head movement and stabilization. These include the scalenes, which elevate the first rib and assist in respiration, and the levator scapulae, which elevates the scapula. Posterior The posterior deep neck muscles are situated at the back of the neck and primarily contribute to head extension and rotation. They include the splenius capitis and splenius cervicis, which extend and rotate the head.

5. Infrahyoid and Suprahyoid Muscles: Origin, Insertion, and Action Infrahyoid Muscles: These muscles are located below the hyoid bone and include the sternohyoid, thyrohyoid, omohyoid, and sternothyroid. They originate from the sternum, clavicle, and thyroid cartilage, and insert on the hyoid bone. They act to depress the hyoid bone during swallowing and speech. Suprahyoid Muscles: These muscles are situated above the hyoid bone and include the geniohyoid, mylohyoid, digastric, and stylohyoid. They originate from the mandible, temporal bone, and hyoid bone, and insert on the hyoid bone. They elevate the hyoid bone during swallowing, helping to open the airway. Muscle Actions: The infrahyoid muscles depress the hyoid bone and larynx, while the suprahyoid muscles elevate the hyoid bone. Together, they coordinate swallowing and speech by controlling the position of the hyoid bone and larynx.

6. Scalenes and Levator Scapulae Muscles Scalenes The scalene muscles (anterior, middle, and posterior) originate from the transverse processes of the cervical vertebrae and insert on the first and second ribs. They function to elevate the first and second ribs, assisting with respiration, and laterally flex and rotate the neck. Levator Scapulae The levator scapulae muscle originates from the transverse processes of the upper cervical vertebrae and inserts on the medial border of the scapula. It acts to elevate the scapula, aiding in shoulder blade movement and stabilization.

7. The Splenius Muscles of the Neck The splenius capitis and splenius cervicis are two powerful muscles located at the posterior aspect of the neck. The splenius capitis originates from the lower half of the ligamentum nuchae and the spinous processes of the upper thoracic and lower cervical vertebrae, inserting on the mastoid process of the temporal bone. The splenius cervicis originates from the spinous processes of the upper thoracic vertebrae and inserts on the posterior tubercles of the transverse processes of the upper cervical vertebrae. These muscles work together to extend and rotate the head and neck. The splenius capitis primarily rotates the head, while the splenius cervicis contributes more to neck extension. They play a crucial role in maintaining proper head and neck posture and enabling smooth, controlled movements.