REPASO DE MÚSCULOS DEL CUELLO

Summary

In this educational video, the speaker provides a comprehensive overview of the anatomy of the head and neck, focusing on the muscles and bones. The session begins by discussing the superficial and deep muscular layers of the neck, including key muscles like the platysma, sternocleidomastoid, and various infra- and supra-hyoid muscles. Detailed explanations are given for the muscle functions, their origins, insertions, and nerve innervations. The speaker also covers the anatomical planes and offers tips for memorizing the different structures, ensuring students understand the intricacies of neck anatomy for their exams.

Takeaways

• 😀 The video provides a general review of the anatomy of the head and neck, focusing on muscular structures.
• 😀 It is important to start studying muscles from the superficial to the deep layers, starting with the platysma muscle in the neck.
• 😀 The sternocleidomastoid muscle is crucial in head flexion and lateral movement, with attachments at the sternum, clavicle, and mastoid process.
• 😀 The video explains the muscle actions, particularly how the sternocleidomastoid allows flexion and lateral movement of the head.
• 😀 The infra-hyoid and supra-hyoid muscle groups are examined, with specific attention to their positioning below or above the hyoid bone.
• 😀 The digastric muscle, a 'two-bellied' muscle, is highlighted as part of the superior muscular plane, originating from the scapula and inserting at the hyoid bone.
• 😀 The mylohyoid muscle forms the floor of the oral cavity, with its insertion at the internal oblique line of the mandible and hyoid bone.
• 😀 The geniohyoid muscle is located deeper and plays a role in the floor of the mouth, inserting from the genoid process of the mandible to the hyoid bone.
• 😀 The scalene muscles (anterior, middle, and posterior) are part of the deep lateral muscle group and are important for their attachment points along the cervical vertebrae and first rib.
• 😀 The video emphasizes the importance of knowing both the anatomical structures and the innervation of muscles, noting that most of the neck muscles are innervated by the cervical nerve loop, except for the thyrohyoid, which is innervated by the hypoglossal nerve.

Q & A

What is the first muscle discussed in the video, and what is its function?

The first muscle discussed is the platysma, a superficial muscle of the neck. Its main function is to tighten the skin of the neck and help with movements like lowering the jaw.

What is the sternocleidomastoid muscle, and where does it insert?

The sternocleidomastoid muscle is a major muscle of the neck that inserts at the mastoid process of the temporal bone and the clavicle. It is responsible for flexing the head and aiding in lateral movements of the neck.

What are the primary functions of the sternocleidomastoid muscle?

The sternocleidomastoid muscle primarily allows for flexion of the head (bringing the chin toward the chest) and lateral movement of the head.

Which muscle lies beneath the sternocleidomastoid and plays a key role in the infra hyoid region?

The omohyoid muscle lies beneath the sternocleidomastoid. It is divided into superior and inferior bellies and plays an important role in the infra hyoid region.

How are the muscles of the supra hyoid and infra hyoid regions different?

The muscles of the supra hyoid region are located above the hyoid bone and help in swallowing and mouth opening. The infra hyoid muscles, located below the hyoid bone, assist with neck stability and are involved in lowering the larynx.

What is the function of the digastric muscle, and what is its structure?

The digastric muscle has two bellies—an anterior and posterior belly. It is involved in opening the jaw and lowering the hyoid bone during swallowing.

What muscles make up the deep plane of the neck, and where do they insert?

The deep plane of the neck includes muscles such as the thyrohyoid and omohyoid. The thyrohyoid inserts into the thyroid cartilage, while the omohyoid inserts into the scapula and hyoid bone.

What are the key functions of the scalene muscles in the neck?

The scalene muscles (anterior, middle, and posterior) help with lateral flexion of the neck, aid in breathing by elevating the first and second ribs, and contribute to neck stability.

Which muscles are included in the prevertebral group, and what is their primary function?

The prevertebral group includes muscles like the longus colli and rectus capitis anterior. These muscles primarily assist with flexing the neck and stabilizing the cervical spine.

What is the innervation of the muscles in the neck, and which muscle is an exception?

Most muscles in the neck are innervated by the cervical plexus, specifically the hypoglossal nerve. The exception is the thyrohyoid muscle, which is innervated by the cervical nerve roots, not the plexus.