W5 Muscles of tongue Flashcards
The muscle of the tongue can be divided into 2 components, name them
The bulk of tongue is made up of striated muscle, which can be divided into:
Intrinsic muscle: Origin within the tongue. Responsible for altering it’s shape.
Extrinsic muscle: has origins outside of the tongue, but all fibres insert into it; acts principally
Name the instrinsic muscles of the tongues direction of fibres, actions, innervations, blood supply
Direction of Fibres:
Superior longitudinal group
Inferior longitudinal group
Transverse group
Verticle group
Actions; Alters the shape of tongue in all planes.
Innervates CNXII - hypoglossal n.
Blood supply: Lingual artery and veins
Name the (4) intrinsic muscles of the tongue
- Superior Longitudinal
- Inferior Longitudinal
- Transverse Longitudinal
- Vertical Longitudinal
What is the origin, insertion and action of the Superior longitudinal instrinsic muscle?
Origin: Median Fibrous Septum Submucosa near epiglottis. Inserts: Submucosa along edges of the tongue
Action: Shortens Located immediately deep to mucous membrane dorsal of tongue.
What is the origin, insertion and action of the inferior longitudinal instrinsic muscle?
Origin: Root of tongue
Insertion: Submucosa at the apex of the tongue
Actions: Shortens Runs along width of tongue
What is the origin, insertion and action of the transverse longitudinal instrinsic muscle?
Origin Median fibrous septum,
Insertion: Fibrous tissue in submucosa of the sides of the tongue
Action: Narrows Runs along width of tongue
What is the origin, insertion and action of the vertical longitudinal instrinsic muscle?
Origin: submucosa of the upper layer of the tongue.
Insertion: submucosa of lower layer of the tongue
Action: broadens and flattens. Runs superior to inferior aspect of tongue
What innervates the extrinsic muscles of the tongue?
Hypoglossal nerve (CNXII 12) except for palataglossis which is innervated by the pharyngeal plexus (pharyngeal part of vagus nerve and cranial part of accessory nerve).
What are the (4) extrinsic muscles of the tongue?
Genioglossus
Hyoglossus
Styloglossis
Palatoglossus
What is the origin, insertion and action of the Genioglossus extrinsic muscle?
Origin: Superior Genial Tubercles of mandible.
Insertion: Ventral surface of the tongue & body of hyoid
Actions:
- Protrusion of tongue
- Depresses tongue
What is the origin, insertion and action of the Hyoglossis extrinsic muscle?
Origin Hyoid Bone (greater cornu and portion of body)
Insertion: lateral border of the tongue.
Action: depresses tongue
Lingual n, hypoglossal n and submandibular duct is located lateral to this muscle
What is the origin, insertion and action of the Styloglossus extrinsic muscle?
Origin: Styloid process
Insertion: Lateral border of the tongue its apex and the border of the body and base.
Actions: retracts tongue and slightly elevates (↑↓) Smallest of the extrinsic tongue muscles
What is the origin, insertion and action of the Palatoglossis extrinsic muscle?
Origin: Anterior soft palate
Insertion: lateral border of the tongue.
Action: elevates tongue and narrows.
Can be grouped as exstrinsic or soft palate muscle
What are the function of the hyoid muscles?
They are considered an accessory muscle to the muscles of mastication as they have involvement in speech and chewing.
Instrinsic and Extrinsic are active in
- Helping to stabilize the hyoid bone
- Helping to depress the mandible
- Movement of the voice box
- Assist in movement of the tongue
Name the (2) groups of the hyoid muscles and functions
Suprahyoid group: located superior to the hyoid bone, form the bulk of the floor of mouth. Connects the hyoid bone to the skull. All elevate the hyoid bone as apart of their actions.
Infrahyoid group: located inferior to the hyoid bone, called the strap muscles due to their appearance 4 pars of muscles and anchors the hyoid bone
What is the origin, insertion, action and innervation of the Geniogyoid? -(suprahyoid group)
Origin: Inferior Genial tubercles
Insertion: Hyoid bone
Actions: Elevated hyoid bone, Depresses mandible
Innervation: C1 via hypoglossa CNXII (12)
What is the origin, insertion, action and innervation of the Mylohyoid? (suprahyoid group)
Origin: Mylohyoid ridge/line
Insertion: Hyoid bone
Actions: Elevates hyoid bone, depresses mandible
Innervation: Trigeminal nerve CNVIII - mylohyoid branch
What is the origin, insertion, action and innervation of the Stylohyoid? (suprahyoid group)
Origin: Styloid process
Insertion: Hyoid bone
Actions: Elevates hyoid bone
Innervation: CNVII (7) Facial nerve - diagastric branch (stylohyoid nerve)
What is the origin, insertion, action and innervation of the Digastric suprahyoid group?
Origin:
Anterior belly; diagastric fossa.
Posterior belly: mastoid process
Insertion: Hyoid bone
Actions: Elevates hyoid bone, retrudes mandible - lifts larynx Innervation:
Anterior belly: trigeminal CNV3 - mylohyoid branch.
Posterior belly: facial nerve diagastric branch