Neck and oral cavity Flashcards
How is the oral cavity divided?
Outer oral vestibule and inner oral cavity
What is the oral vestibule?
Lips and cheeks
What composes the roof of the mouth?
Hard palate and soft palate
List the muscles of the soft palate
Palatoglossal arch
Palatopharyngeal arch - uvula
What is the floor of the oral cavity composed of?
Mylohyoid muscle, geniohyoid muscle, submandibular
glands, sublingual glands and tongue
How is the tongue divided?
Anterior two thirds (oral)
Posterior third (pharyngeal)
Demarked by a v shaped sulcus (terminal sulcus)
What covers the tongue?
Papillae cover the tongue and all except filiform have taste buds on the surface
The undersurface contains what?
Medial folds which internally separates the right and left sides of the tongue
What are the intrinsic muscles of the tongue?
Longitudinal, transverse and vertical create precision movements for speech, eating and swallowing
What are the extrinsic muscles?
Genioglossus - depresses and protrudes tongue
Hypoglossus - depresses tongue
Styloglossus - retracts the tongue
Palatoglossus - elevates the tongue and depresses soft palate
What is the blood supply of the tongue?
Lingual artery
lingual veins
Describe the innervation to the anterior 2/3 of the tongue
Taste - special afferent (taste), facial CN7 via chorda tympani via lingual nerve (V3)
Sensation - lingual nerve (V3)
Describe the innervation to the posterior 1/3 of the tongue
Taste - Special afferent (taste) glossopharyngeal (CN9)
Sensation - General sensation glossopharyngeal (CN9)
Motor to whole tongue. Hypoglossal nerve (CN12) except palatoglossus CN10
What type of nerve is cranial nerve 9 Glossopharyngeal?
Type: Sensory (somatic), special sensory (taste), motor and visceral
Where does cranial nerve 9 exit?
Jugular foramen
What is the innervation of cranial nerve 9?
- Sensory- posterior 1/3 tongue, oropharynx
- Taste- posterior 1/3 tongue
- Motor- stylopharyngeus
- Visceral to the parotid gland to stimulate secretion to aid digestion. Note: other salivary glands innervated via facial nerve (CN7)
What type of nerve is cranial nerve 12 hypoglossal?
Type: Motor to intrinsic and extrinsic muscles of the tongue.
Where does cranial nerve 12 exit?
Hypoglossal canal
What is the larynx?
Specialised organ that provides a protective sphincter for the air passages and produces phonation.
What does the larynx contain?
Contains ligaments, the two most important are the vestibular and the vocal ligament.
What makes up the framework of the larynx?
The framework of the larynx is made up of cartilages: Thyroid, cricoid, arytenoid, cuneiform, corniculate and epiglottis.
Describe the nerve supply to the layrnx
Nerve supply: sensory and motor from the vagus, via the superior laryngeal branch and recurrent laryngeal branch.
What is the blood supply of the larynx?
Blood supply: upper half by the superior thyroid artery and lower half by inferior thyroid artery.
What is the pharynx?
Pharynx is the most posterior part of the neck, situated behind the nasal cavity and the larynx.
Name the three sections of the pharynx
Nasopharynx
Laryngopharynx
Oropharynx
What muscles are found in the pharynx?
consist of three constrictors (Superior, middle and inferior)
What is the nerve supply of the pharynx?
Motor via vagus, EXCEPT- stylopharyngeus- CN9
Sensory via V2, CN 9, CN10
What type of nerve is cranial nerve 10 vagus nerve?
Type: Sensory, taste, visceral sensory, motor and visceral motor
Describe the path of the vagus nerve
rootlets from medulla, through jugular foramen continues in carotid sheath, branches into head and thorax
Where does the vagus nerve exit?
Jugular foramen
Describe the innervation of the vagus nerve
Sensory- from larynx, dura mater
Taste- 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 parasympathetic to smooth muscle in glands in pharynx, larynx, thoracic viscera, foregut and midgut.
Which bone does the neck contain?
Mobile hyoid bone
How many cervical vertebrae are there?
7
What are the 3 layers of deep fascia to the neck?
Pretracheal fascia
Prevertebral fascia
Investing fascia
What is the purpose of the fascia in the neck?
Stops spreading of infection
Enables structures to move past each other in movement and swallowing etc.
What is the carotid sheath?
Carotid sheath blends with the pretracheal and prevertebral fascia. It contains: Common and internal carotid arteries. Internal jugular vein. Vagus nerve (CN 10). Some deep cervical lymph nodes. Carotid sinus nerve.
What divides the neck into the anterior and lateral/posterior compartment?
Sternocleidomastoid muscle
What is the anterior compartment divided into?
three paired triangles and one unpaired; the unpaired submental triangle, the paired submandibular, carotid and muscular triangle.
What is the posterior compartment divided into?
bounded posteriorly by the trapezius muscle and is divided into two triangles by the presence of the posterior belly of omohyoid into: the large occipital triangle and the smaller omoclavicular triangle.
Descrbe the submandibular triangle
Submandibular triangle bounded by: anterior and posterior bellies of digastric. Contains: submandibular gland, facial artery and vein.
Describe the submental triangle
Submental triangle bounded by: digastric. Contains lymph nodes.
Describe the muscular triangle
Muscular triangle bounded by: omohyoid, SCM. Contains supra and infra hyoid muscles
Describe the carotid triangle
Carotid triangle bounded by: omohyoid, stylohyoid, digastric, SCM. Contains: common carotid artery, IJV, hypoglossal nerve, vagus nerve, accessory nerve.
Describe the suprahyoid muscles
Stylohyoid, digastric, mylohyoid and geniohyoid
Innervation: Facial nerve for stylohyoid and posterior belly of digastric. Mylohyoid by CN 5 and geniohyoid by CN 12
Describe the infrahyoid muscles
Omohyoid, sternohyoid, thyrohyoid, and sternothyroid
Innervation: C1-C3 of ansa cervicalis
Describe the posterior triangle
Posterior triangle contains: subclavian artery, EJV, brachial plexus, CN 11, cervical plexus
Describe the occipital triangle
Occipital triangle bounded by: SCM, trapezius and omohyoid.
Describe the supraclavicular triangle
Supraclavicular triangle bounded by: clavicular head of SCM, clavicle and omohyoid
Where is the cervical plexus?
Roots of cervical plexus C1-C4 lies anterior to Levator scapulae.
What is the function of cervical plexus?
The cervical plexus provides cutaneous branches and deep motor branches (ansa cervicalis and phrenic nerve)
Describe the arterial supply of the neck
A number of major vessels travel in the neck to supply the viscera, upper limb and head.
Brachiocephalic÷
common carotid÷
Internal and external carotids
External carotid ÷ 6 branches to supply the neck and head
Superior thyroid, ascending pharyngeal, lingual, facial, maxillary, superficial temporal
Subclavian arteries- inferior thyroid
Internal carotid- no branches until inside skull
Describe the venous drainage of the neck
The Internal jugular vein (IJV) drains the brain, face, cervical viscera and neck muscles.
External jugular vein
Anterior jugular vein
What type of nerve is cranial nerve 11 accessory?
Type: Motor to Sternocleidomastoid and Trapezius.
Where does cranial nerve 11 accessory exit?
Jugular foramen
What type of nerve is cranial nerve 8 vestibulocochlear nerve?
Type: Sensory, special somatic afferent for hearing, equilibrium and motion.
Describe the path of cranial nerve 8
Divides into Vestibular and Cochlear Nerves.
Where does the vestibulocochlear nerve exit?
Internal acoustic meatus
