Class 9 - THE MUSCLES OF THE NECK AND THE BACK COPY Flashcards
Landmark of the neck (cervical) region
Sternocleidomastoid (SCM)
Anterior region of the neck is divided into two triangles by the SCM
Anterior triangle
Posterior triangle
Muscles of the anterior of the neck assist in…
Deglutition and speech
Two groups of muscles in relation to the hyoid bone
Suprahyoid muscles
Infrahyoid muscles
Suprahyoid muscles form…
The floor of the mouth
Suprahyoid muscles action
Elevate the hyoid bone, the floor of the mouth and the tongue when swallowing
Four suprahyoid muscles
- Digastric
- Stylohyoid
- Mylohyoid
- Geniohyoid
Suprahyoid muscles actively…the mandible when…
Depress the mandible when we need to open the mouth wider
Digastric origin
Anterior belly from inner side of inferior border of mandible
Posterior belly from temporal bone
Digastric insertion
Body of hyoid via an intermediate tendon
Digastric action
Elevates hyoid bone
RMA: Depresses mandible (opening mouth)
Digastric innervation
Anterior belly: mandibular division of trigeminal (V) nerve
Posterior belly: facial (VII) nerve
Stylohyoid origin
Styloid process of temporal bone
Stylohyoid insertion
Body of hyoid bone
Stylohyoid action
Elevates hyoid bone and draws it posteriorly
Stylohyoid innervation
Facial (VII) nerve
Mylohyoid origin
Inner surface of mandible
Mylohyoid insertion
Body of hyoid bone
Mylohyoid action
Elevates hyoid bone and floor of mouth and depresses mandible
Mylohyoid innervation
Mandibular division of trigeminal (V) nerve
Geniohyoid origin
Inner surface of mandible
Geniohyoid insertion
Body of hyoid bone
Geniohyoid action
Elevates hyoid bone, draws hyoid bone and tongue anteriorly. Depresses mandible
Geniohyoid innervation
First cervical spinal nerve (C1)
Infrahyoid muscles look like
Ribbons or straps inferior to the hyoid bone
Infrahyoid muscles action
Depress the hyoid bone and move the larynx when swallowing and talking
Four infrahyoid muscles
- Omohyoid
- Sternohyoid
- Sternothyroid
- Thyrohyoid
Omohyoid origin
Superior border of scapula and superior transverse ligament
Omohyoid insertion
Body of hyoid
Omohyoid action
Depresses hyoid bone
Omohyoid innervation
Branches of spinal nerves C1-C3
Sternohyoid origin
Medial end of clavicle and manubrium of sternum
Sternohyoid insertion
Body of hyoid bone
Sternohyoid action
Depresses hyoid bone
Sternohyoid innervation
Branches of spinal nerves C1-C3
Sternothyroid origin
Manubrium of sternum
Sternothyroid insertion
Thyroid cartilage of larynx
Sternohyoid action
Depresses thyroid cartilage of larynx
Sternothyroid innervation
Branches of spinal nerves C1-C3
Thyrohyoid origin
Thyroid cartilage of larynx
Thyrohyoid insertion
Greater horn of hyoid bone
Thyrohyoid action
Depresses hyoid bone
RMA: elevates thyroid cartilage
Thyrohyoid innervation
Branches of spinal nerves C1-C2 and descending hypoglossal (XII) nerve
The head is attached to the vertebral column at the…
Atlanta-occipital joint
Suboccipital muscles
Deep muscles in the back of the head attached between the occipital bone and C1-C2
Bilateral contraction of the neck muscles allows for…
Balance
Unilateral contraction of the neck muscles allow for…
Rotation
Flexion
Extension
Lateral flexion
Sternocleidomastoid (SCM) origin
Sternal head: manubrium of sternum
Clavicular head: medial third of clavicle
Sternocleidomastoid (SCM) insertion
Mastoid process of temporal bone and lateral hand of superior nuchal line of occipital bone
Sternocleidomastoid (SCM) bilateral action
Flex cervical portion of vertebral column, extend head at AOJ
Sternocleidomastoid (SCM) unilateral action
Lateral flexion of neck and head to same side
Rotate head opposite to contracting muscle
Lateral flexion to opposite side of contracting muscle
Sternocleidomastoid (SCM) posterior fibre action
Assist in extension of head
Sternocleidomastoid (SCM) RMA
Elevates sternum during forced inhalation
Sternocleidomastoid (SCM) innervation
Accessor (XI) nerve, C2 and C3
Semispinalis capitis origin
Articular process of C4-C6 and transverse processes of C7-T7