Neck and oral cavity Flashcards
Oral cavity
Located inferior to the nasal cavities and is continuous with both nasa cavities superiorly and pharynx inferiorly
Outer oral vesitbule
Includes lips and cheeks
Inner oral cavity
Enclosed by teeth
Roof of oral cavity
Hard and soft palate
Arches of oral cavity
Created by muscles of soft palate
Palatoglossal arch
Palaropharyngeal arach- ulva
Floor of oral cavity
Formed by muscles (mylohyoid and geniohyoid) and tongue
Contains submandibular and sublingual galnds
Tongue
Divided into anterior two thirds (oral) and posterior third (pharyngeal)
Papillae cover tongue
Undersurface contains medial fold
Muscles of the tongue
Divided into left and right halves
All muscles are paired
Intrinsic and extrinsic
Intrinsic tongue muscles
Longitudinal, transverse and ventricle create precision movements for speech, eating and swallowing
Extrinsic tongue muscles
Genioglossus- depresses and protrudes tongue
Hyoglossus- depresses tongue
Styloglossus- retract tongue
Palatoglossus- elevates back of tongue and depresses soft palate
Blood supply of tongue
Lingual arteries and drained to lingual veins
Tongue innervation: anterior 2/3
Taste
- special affereent facial CN7 via chorda tympani via lingual nerve (V3)
Sensation
- general sensation lingual nerve (V3)
Tongue innervation: posterior 1/3
Taste
- special afferent glossopharyngeal (CN9)
Sensation
- general sensation glossopharyngeal (CN9)
Motor innervation to whole tongue
Hypoglossal nerve (CN12) except platoglossus CN10
Cranial nerve 9
Glossopharyngeal
Type: sensory, special sensory, motor and visceral
Exit: jugular forament
Cranial nerve 9 innervation
Sensory: posterior 1/3 tongue, oropharynx
Taste: posterior 1/3 tongue
Motor: stylopharyngeus
Visceral to parotid gland to stimulate secretion to aid digestion
Cranial nerve 12
Hypoglossal
Type: motor to intrinsic and extrinsic muscles of the tongue
Exit: hypoglossal canal
Larynx function
Provides protective sphincter for air passage and produces phonation
Framework of larynx
Cartilages: thyroid, cricoid, arytenoid, cuneiform, corniculate and epiglottis
Contains ligaments
Nerve supply to larynx
Sensory and motor from the vagus via superior laryngeal branch and recurrent laryngeal branch
Blood supply to larynx
Upper half by superior thyroid artery and lower half by inferior thyroid artery
Pharynx
Most posterior part of neck
Funnel shaped tube with three sections
- nasopharynx
- laryngopharynx
- oropharynx
Muscles of pharynx
Consist of three constrictors (superior, middle and inferior)
Nerve supply to pharynx
Motor via vagus, except stylopharynx is CN9
Sensory via V2, CN9, CN10
Cranial nerve 10
Vagus
Type: sensory, taste, visceral sensory, motor and visceral motor
Path: rootlets from medulla, through jugular foramen continues in carotid sheath, branches into head and thorax
Exit: jugular foramen
Cranial nerve 10 innervation
Sensory: from larynx, dura mater
Tase: epiglottis and pharynx
Visceral sensory: aortic bodies, aortic arch chemoreceptors, bronchi, heart, lungs, midgut and foregut
Motor: palatoglossus, muscles of pharynx and larynx
Visceral motor: as part of PS to smooth muscle in glands in pharynx, larynx, thoracic viscera, foregut and midgut
Neck
Transition area between base of cranium superiorly and thoracic cage inferiorly
Major conduit for structures passing between the head and thorax
Supported posteriorly by 7 cervical vertebrae
Contains mobile hyoid bone
Fascia
Three important layers
- pretracheal fascia
- prevertebral fascia
- onvesting fascia
Important as reduces spread of infection
Submandibular triangle bound by
Anterior and posterior bellies of digastric
Contains: submandibular gland, facial artery and vein
Submental triangle bounded by
Digastric
Contains lymph nodes
Muscular triangle bounded by
Omohyoid, SCM
Contains supra and infra hyoid muscles
Carotid triangle bounded by
Omohyoid, stylohyoid, digastric, SCM
Contains: common carotid artery, IJV, hypoglossal nerve, vagus nerve, accessory nerve
Suprahyoid muscles
Stylohyoid, digastric, mylohyoid and geniohyoid
Innervation: facial nerve for stylohyoid and posterior belly of digastric, mylohyoid by CN 5 and geniohyoid by CN12
Infrahyoid muscles
Omohyoid, sternohyoid, thyrohyoid and sternothyroid
Innervation: C1 and C3 of ansa cervicallis
Posterior triangle contains
Subclavian artery
EJV
Branchial plexus
CN 11
Cervical plexus
Occipital triangle bounded by
SCM
Trapezius
Omohyoid
Supraclavicular triangle bounded by
Clavicular head of SCM
Clavicle
Omohyoid
Arterial supply
Brachiocephalic
Common carotid
Internal and external carotids
External carotid and 6 branches to supply the neck and head
Superior thyroid, ascending pharyngeal, lingual, facial, maxillary, superficial
Subclavian arteries- inferior thyroid
Internal carotid- no branches until inside skull
Venous drainage
The IJV drains the brain, face, cervical viscera and neck muscles
External jugular vein
Anterior jugular vein
Cranial nerve 11
Accessory nerve
Type: motor to sternocleidomastoid and trapezius
Exit: jugular foramen
Cranial nerve 8
Vestibulocochlear nerve
Type: sensory, special somatic afferent for hearing, equilibrium adn motion
Path: divides into vestibular and cochlear nerves
Exit: internal acoustic meatus