Questions and Answers
Which cranial nerve is primarily responsible for the innervation of the muscles mentioned in the content?
What is one of the primary functions of the splenius capitis muscle?
Which structure supplies blood to the splenius muscles?
The splenius cervicis originates from which vertebrae?
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When acting bilaterally, which movement is primarily performed by the muscles described?
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What is the innervation of the splenius capitis muscle?
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Which of the following statements about the muscle function is incorrect?
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Which structure does the accessory nerve innervate?
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The splenius cervicis inserts into which part of the cervical vertebrae?
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Which of the following arteries is NOT involved in the blood supply to the splenius cervicis?
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Study Notes
Neck Muscle Groups
- Neck muscles facilitate head movement in multiple directions.
- Three main groups of neck muscles are: anterior, lateral, and posterior.
Innervation of the Neck
- Cervical Plexus arises from anterior rami of cervical spinal nerve C1 - C4.
- Facial Nerve has eight extra cranial branches, including:
- Posterior Auricular
- Nerve to posterior belly of digastric
- Nerve to stylohyoid
- Five terminal branches: temporal, zygomatic, buccal, marginal mandibular, and cervical branches.
Blood Supply to the Neck
- External Carotid Artery is a branch of the common carotid artery.
- Thyrocervical trunk branches from both right and left subclavian arteries, consisting of four branches:
- Inferior Thyroid artery
- Ascending cervical artery
- Transverse cervical artery
- Suprascapular artery
Superficial Anterior Muscles
Platysma
- Thin muscle located in the anterior neck.
- Originates from skin and fascia of infra and supraclavicular regions.
- Inserts at the lower border of the mandible and several facial regions.
- Innervated by the cervical branch of the facial nerve (CN VII).
- Functions to depress the mandible, angle of mouth, and tense skin of the lower face and neck.
- Blood supply from the submental artery and suprascapular artery.
Sternocleidomastoid
- Origin:
- Sternal Head: manubrium sterni
- Clavicular Head: medial third of clavicle
- Inserts at the lateral surface of the mastoid process and superior nuchal line.
- Innervated by the Accessory Nerve (CN XI) and branches of cervical plexus (C2 - C3).
- Functions in lateral flexion, rotation of the neck, and extension at the atlanto-occipital joints.
- Blood supply from the superior thyroid artery.
Anterior Neck Muscles
-
Suprahyoid Muscles (elevate the hyoid bone):
- Include digastric, mylohyoid, geniohyoid, and stylohyoid.
-
Infrahyoid Muscles (depress the hyoid bone):
- Include sternohyoid, omohyoid, sternothyroid, and thyrohyoid.
Lateral Neck Muscles
Anterior Scalene Muscle
- Origin: transverse processes of C3 - C6.
- Inserts at the scalene tubercle and superior border of rib 1.
- Innervation from anterior rami of spinal nerves C4 - C6.
- Functions include neck flexion, lateral flexion, rotation, and elevating rib 1.
- Blood supply from the ascending cervical branch of the inferior thyroid artery.
Middle Scalene Muscle
- Origin: transverse processes of C3 - C7.
- Inserts at the superior border of rib 1.
- Innervated by anterior rami of spinal nerves C3 - C8.
- Functions mainly in neck lateral flexion and rib elevation.
Posterior Scalene Muscle
- Origin: transverse processes C4 - C6 and C5 - C7.
- Inserts at the external surface of rib 2.
- Innervated by anterior rami of spinal nerves C6 - C8.
- Functions in neck lateral flexion and elevates rib 2.
- Blood supply from ascending cervical and superficial cervical arteries.
Superficial Posterior Muscles
Trapezius
- Origin: superior nuchal line, external occipital protuberance, and nuchal ligament.
- Inserts at the lateral third of the clavicle.
- Innervated by the accessory nerve (CN XI) and anterior rami of spinal nerves C3 - C4.
- Functions in elevation of the scapula and neck extension bilaterally, with lateral flexion and contralateral rotation when acting unilaterally.
- Blood supply from the occipital artery.
Splenius Capitis
- Origin: spinous processes of C7 - T3 and nuchal ligament.
- Inserts at the lateral superior nuchal line and mastoid process.
- Innervated by lateral branches of posterior rami of spinal nerves C2 - C3.
- Functions to rotate the head to the same side.
- Blood supply from muscular branches of the occipital artery.
Splenius Cervicis
- Paired muscle within prevertebral neck space.
- Origin: spinous processes of T3 - T6.
- Inserts at the transverse processes of C1 - C3.
- Innervated by lateral branches of posterior rami of lower cervical spinal nerves.
- Functions in head rotation to the same side.
- Blood supply from vertebral, occipital, superior intercostal, and deep cervical arteries.
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Description
Explore the superficial and lateral neck muscles responsible for head movement. This quiz covers the anatomy, classification, and innervation of neck muscles including the cervical plexus and facial nerve. Test your knowledge on this essential aspect of human anatomy.
