Quiz 6 Flashcards
The two groups of hyoid muscles
- suprahyoid
- infrahyoid
Assists in the movements during mastication and swallowing
Hyoid muscle
Innervation of the hyoid muscles
- mylohyoid nerve
- posterior digastric nerve
- stylohyoid nerve
- first cervical nerve
Mylohyoid nerve
Branch of the mandibular division of the trigeminal V cranial nerve
1) digastric- anterior belly
2) mylohyoid muscle
Posterior digastric nerve
Branch of the facial nerve VII cranial nerve
1) digastric- posterior belly
Stylohyoid nerve
Branch of the facial nerve VII cranial nerve
1) stylohyoid muscle
First cervical nerve
Conduct by the way of hypoglossal nerve XII cranial nerve
1) geniohyoid muscle
Second and third cervical nerves (infrahyoid)
1) sternothyroid muscle
2) sternohyoid muscle
3) omohyoid muscle
4) thyrohyoid muscle
Suprahyoid
- digastric
- mylohyoid
- geniohyoid
- stylohyoid
Anterior digastric
- intermediate tendon attached to hyoid bone (body and greater horn)
Forms midline of the sub mental triangle
Posterior digastric
Mastoid notch of the temporal bone
- forms submandibular triangle (with the mandible)
Anterior mylohyoid
- mylohyoid line of the mandible
- also forms the floor of the mouth and helps elevate the tongue
Anterior geniohyoid
Genial tubercles of the mandible
- assists in swallowing, depresses mandible
Posterior stylohyoid
Styloid process of the mandible
- assists in swallowing, depresses mandible
Omohyoid muscle
Superior belly- short tendon attached to the inferior belly
** divides inferior portion of the anterior cervical triangle into carotid and muscular triangles
Inferior belly- scapula
*** divides the posterior cervical triangle into occipital and subclavian triangles
Sternohyoid muscle
Posterior and superior surfaces of the sternum
Sternothyroid muscle
Posterior surface of the sternum
- depresses thyroid cartilage an larynx (not hyoid bone)
Thyrohyoid muscle
On the thyroid cartilage
- depresses the hyoid bone and raises the thyroid cartilage and larynx
Two groups of muscles for the tongue
1) intrinsic
2) extrinsic
Intrinsic location
Origin/insertion are inside the tongue
Intrinsic action
Change the shape of the tongue during mastication, speech and swallowing
Intrinsic Innervation
Facial nerve VII cranial and the glossopharyngeal IX cranial nerve
Extrinsic location
All have their origin outside the tongue and all insert inside the tongue
Extrinsic action
Move the tongue and suspend an anchor it to the mandible styloid process and hyoid bone during mastication, speech and swallowing
Extrinsic Innervation
Hypoglossal XII cranial nerve
Midline depression on the dorsal surface
Median lingual sulcus
Deep fibrous structure in the midline of the tongue, corresponds with median lingual sulcus
Median septum
Divisions of the tongue
Apex, body (dorsal, lateral and ventral surfaces), base
Intrinsic muscle group
Superior longitudinal
Inferior longitudinal
Transverse ( horizontal )
Vertical
Extrinsic muscles
- hyoglossus
- styloglossus
- genioglossus
Superior longitudinal
Base- dorsal surface
- alters it’s shape
Inferior longitudinal
Base- ventral surface
*alters it’s shape
Transverse
Median septum, deep to superior longitudinal
- alters it’s shape
Vertical
Dorsal surface- body of the tongue
** alters it’s shape
Hyoglossus
Greater horn and body of the hyoid bone
- depress the tongue
Styloglossus
Styloid process of temporal bone
** retracts the tongue, moving superioppsteriorly
Genioglossus
Genial tubercles
** protrudes and depresses portions of the tongue
Region of the soft palate
Posterior portion of the roof of the mouth and connects laterally with the tongue
Soft palate action
Involved with speaking and swallowing
Total number of muscles in the soft palate
5
Soft palate muscle Innervation: pharyngeal plexus
Pharyngeal plexus: pharyngeal branches of the vagus nerve- x cranial nerve
- palatoglossus
- palatopharyngeus
- musculus uvula
- levator veli palatini (part of uvula)
Soft palate Innervation of the muscles: mandibular division
Mandibular division of the trigeminal nerve- v cranial nerve
*tensor veli palatini
Palatoglossus (palatoglossal fold)
Median palatine raphe
- raises base of tongue, arches tongue, and depresses soft palate
Palatopharyngeus (Palatopharyngeal fold)
Soft palate
- moves palate posteriorinferiorly and posterior pharyngeal wall anterosuperiorly (closes off nasopharynx)
Musculus uvula
Posterior margin of the soft palate
- shortens and broadens uvula, alters contour of palate; allows soft palate to adapt to posterior pharyngeal wall ( closes off nasopharynx)
Levator veli palatini
Medial cartilage of auditory tube and apex if petrous (inferior surface of temporal bone)
- raises the soft palate and helps the palate contact the posterior pharyngeal wall (closes off nasopharynx) and opens the auditory tube orifice
Tensor veli palatini
Lateral cartilage of the auditory tube an scaphoid fossa of the sphenoid bone
- tenses and slightly lowers the palate (closes off the nasopharynx) and opens the auditory canal
Action of the muscles of the pharynx
Movements involved with speaking, swallowing, and middle ear function
Muscles of the pharynx include…
A) stylopharyngeus
B) pharyngeal constrictor muscles: three PAIRED muscles
- superior
- middle
- inferior
Innervation of the soft palate muscles
Glossopharyngeal nerve- IX cranial nerve (not soft palate)
Pharyngeal plexus: pharyngeal branch of the vagus- X cranial nerve (all three pharyngeal constrictors
Stylopharyngeus
Styloid process of temporal bone
* raises and widens the pharynx
Superior pharyngeal constrictor
Pterygoid hamulus, mandible, and pterygomandibular raphe
Middle pharyngeal constrictor
Hyoid bone and stylohyoid ligament
- raises pharynx and larynx and helps push bonus inferiorly into the esophagus
Inferior pharyngeal constrictor
Thyroid & cricoid cartilages
- raises pharynx and larynx and helps push bolus inferiorly into the esophagus
Cervical muscles superficial position
Both are most superficial of the cervical muscles
A) Sternocleidomastoid
B) trapezius
Sternocleidomastoid : anterolateral part of the neck
Palpate: move head down and to the side
Divides the lateral neck region into the anterior and posterior cervical triangles
Trapezius: posterior part of the neck
Covers the lateral and posterior surfaces of the neck and upper back; forms a broad, flat triangle
Sternocleidomastoid origin
Medial portion of clavicle and superior and lateral surfaces of sternum
- one side contracts head turn to one side
- both sides contract; head tilts backwards
Trapezius origin
External surface of the occipital bone and the posterior midline of the cervical and thoracic regions
** helps cervical vertebrae support the head and neck; lifts the clavicle and scapula as to “shrug”
Clinical considerations: extra/intra oral exams
You need to know the muscle anatomy to perform these exams
- these muscles serve as landmarks for other structures; bones, blood vessels, nerves and lymph nodes
Malfunction of the muscles
TMD
Muscles spasms of the muscles of mastication
Occlusal dis function
Caused by disease or trauma to: the teeth, periodontium or the TMJ which in turn effects the muscles I mastication
Nervous system disorders
A) tic douloureux/trigeminal neuralgia: neuralgia of theaxillary division of the trigeminal nerve (v)
B) facial tic: irritation to the facial nerve (VII) causing spasms of the facial muscles
Route of infection
Infection always travels the path of least resistance it will travel in the fascia tissue
Facial paralysis
Bell’s palsy
Stroke
Malignant neoplasm of the parotid gland
Surgery on the parotid gland
Trauma to the parotid gland via facial lacerations
Trauma to the facial nerve from poorly given local anesthesia (inferior alveolar block)
Embryonic structures
1) enamel organ
2) dental papilla
3) dental follicle
4) bony crypt
Enamel organ
Highly specialized epithelial tissue, forms enamel
Dental papilla
Embryonic connective tissue, forms dentin and pulp
Dental follicle/dental sac
Embryonic connective tissue that encapsulates the developing tooth (enamel organ and dental papilla) forms cementum, PDL, alveolar bone
Bony crypt
Space in which the developing tooth forms
Developmental structures
1) lobe
2) grooves
3) depressions
4) pits
Lobe
One primary section of formation in the developing crown
Grooves
Groove or line between primary parts of the crown or root ex. Buccal groove mand 1 st molar
Depressions
Form when lobes fuse
Ex. Labial aspect of maxillary incisors
Root depressions also form to add in function and suppoet
Pits
Form at the termination of a single groove and at the junction of two or more grooves
Developmental tissues and associated structures
1) enamel
2) dentin
Enamel
Highly calcified epithelial tissue (96%) calcified
- ameloblasts
- no viable cells after eruption
Dentin
Calcified connective tissue (65-70%) calcified
- odontoblasts
- viable cells present so long as the pulp is vital
Types of dentin
Primary: all dentin formed before eruption
Secondary: all dentin formed after eruption
Tertiary: dentin formed in response to trauma
