Gross II Unit 1 Flashcards
Sensory innervation to the face
Trigeminal nerve (C.N. V)
Motor innervation of face
Facial Nerve (C.N. VII)
Name branches of Trigeminal Nerve.
Where does each distribute?
V1 Ophthalmic Nerve - face and scalp
V2 Maxillary Nerve - cheek and area lateral to orbit
V 3Mandibular Nerve - chin and temporal area
Name branches of Ophthalmic Nerve.
Where does each distribute?
Supraorbital nerve - above eye up toward top of scalp (end of vertex)
Supratrochlear nerve - medial to supraorbital nerve
External nasal nerve - nose
Infratrochlear nerve - bridge of nose/lacrimal area
Lacrimal nerve - along top of upper eyelid
Name branches of Maxillary Nerve.
Where does each distribute?
Zygomaticotemporal nerve - temporal area
Zygomaticofascial nerve - lateral cheeks
Infraorbital nerve - below eye/cheek
Which nerve is most frequently injured due to blows to the face?
Infraorbital nerve
Name branches of the Mandibular Nerve.
Where does each distribute?
Auriculotemporal nerve - along temporal or lateral head region
Buccal nerve - Cheek/lateral to mouth
Mental nerve - Chin
Condition characterized by sudden attacks of severe pain in the area of sensory distribution of trigeminal nerve, mostly seen in maxillary division and not so much in opthalmic.
Trigeminal Neuralgia/Tic Douloureux
Sensory innervations of the posterior aspect of neck and scalp come from what? What its branches and innervations?
Posterior (Dorsal) Primary Rami of C2-C4
- Greater Occipital Nerve (Posterior Primary Ramus of C2): occipital region
- Third Occipital Nerve (Posterior Primary Ramus of C3): upper part of back of neck
- Posterior Primary Ramus of C4: lower part of back of neck
Is C1 motor or sensory?
Motor
What is the sensory innervation of the anterior lateral aspect of the neck? What are its branches and their innervations?
Cervical Plexus (formed by anterior primary rami [C2-C4] of C1-C4)
- Lesser Occipital Nerve (C2): lateral part of occipital region, posterior to ear
- Great Auricular Nerve (C2,C3): angle of mandible, inferior to ear, accompanies external jugular vein
- Transverse Cervical Nerve (C2,C3): supplies anterior surface of neck (throat)
- Supraclavicular Nerve (C3,C4): lateral surface of neck
Where do motor fibers of Cervical Plexus arise?
Ansa Cervicalis
What are the parts of the Ansa Cervicalis? Where does each come from? What muscles do they supply?
- Superior Root - from C1 (or C1 and C2); descends from hypoglossal nerve to inferior root
- Inferior Root - from C2 and C3; descends from cervical nerve branches to superior root
- They supply three of the four infrahyoid muscles: STERNOHYOID, STERNOTHYROID, and OMOHYOID
Where infrahyoid muscle receives innervation exclusively from C1 via hypoglossal nerve?
Thyrohyoid
Discuss the Phrenic Nerve. Origin? Innervations? Location?
- Part of the cervical plexus; from C3, C4, and C5
- Motor function: diaphragm; Sensory function: membranes of thorax and abdomen
- On neck lying on anterior surface of anterior scalene muscle –> thorax
Name superficial muscles of the neck.
Platysma
Sternocleidomastoid
Trapezius
Platysma: origin? insertion? nerve? fxn?
- Superficial fascia over pectoralis major and deltoid muscles
- Lower border of mandible and angle of mouth
- Cervical branch of Facial Nerve (C.N. VII)
- Depresses mandible, draws down corner of mouth
Sternocleoidmastoid muscle: origin? insertion? nerve? fxn?
- Sternal head from FRONT OF THE MANUBRIUM, clavicular head from the medial third of clavicle
- Lateral surface of mastoid process, lateral half of the superior nuchal line
- Accessory nerve (C.N. XI)
- Chief flexor of head
Pathological contraction of SCM where head is tilted toward and face away from affected side
Torticollis (Wryneck)
Forms of Torticollis (w/ description)
Congenital - from fibrous tissue tumor which develops at or near birth
Muscular - due to birth injury
Spasmodic - due to abnormal tonicity (adults)
Trapezius: origin, insertion, nerve, function
O: external occipital protuberance, ligamentum nuchae, spinous process of C7 and all thoracic vertebrae
I: Lateral third of clavicle, spine of scapula, and acromion process
N: Accessory nerve (C.N. XI) and C3 and C4 from cervical plexus
F: Upper portion elevates, middle portion retracts, and lower portion depresses SCAPULA
Coordination between muscles that abduct humerus and those that rotate scapula
Scapulohumeral rhythm
Drains blood from face and scalp and contains a large amount of cerebral blood
External jugular vein
Vein that forms immediately below the parotid gland by union of the retromandibular vein and posterior auricular vein
External jugular vein
External jugular vein forms immediately below parotid gland by union of what veins?
Retromandibular vein
Posterior auricular vein
Only vein to vertically run downward and backward along the lateral surface of the sternocleidomastoid. What vein does it empty into?
External jugular vein
Subclavian vein
Tributaries of external jugular vein and describe location.
Retromandibular vein - behind mandible
Posterior auricular vein - behind ear
Posterior external jugular vein - posterior scalp
Anterior jugular vein - throat/chin
Transverse cervical vein - above suprascapular
Suprascapular - branches off around lower neck
Describe prominent external jugular vein
Normal venous pressure; external jugular invisible topographically
In Congestive heart failure, superior vena cava obstruction creates prominence throughout length
Opera singers/bagpipe players may develop prominent external jugular due to increased intrathoracic pressure during singing/playing
Lymph nodes running along the external jugular vein are superficial to what muscle?
Sternocleidomastoid
Boundaries of posterior triangle
Anterior boundary: posterior border of sternocleidomastoid
Posterior boundary: anterior border of trapezius
Inferior boundary: superior border of middle third of clavicle
Boundaries of anterior triangle
Superior boundary: inferior border of mandible
Anterior boundary: anterior midline
Posterior boundary: anterior border of sternocleidomastoid
What forms the roof of the anterior triangle?
Deep cervical fascia, superficial cervical fascia, and platysma
Subdivisions of the anterior triangle
Submental triangle
Submandibular (diagastric) triangle
Carotid triangle
Muscular triangle
What anterior triangle subdivision is located below the chin?
Submental triangle
Only one of the anterior triangle subdivisions which is unpaired.
Submental triangle
Boundaries, floor, and contents of the submental triangle.
B: Left and right anterior bellies of digastric and body of hyoid bond
F: Mylohyoid muscle
C: Minor veins and lymph nodes (submental nodes)
Boundaries, floor, and contents of submandibular (digastric) triangle.
B: Inferior border of the mandible, anterior belly of digastric, posterior belly of digastric
F: Mylohyoid and hyoglossus muscles
C: Submandibular gland (one of three major salivary glands along parotid and sublingual), internal carotid artery, facial artery, internal jugular vein, glossopharyngeal nerve (C.N. IX) and Vagus nerve (C.N. X)
Why should one be careful when treating a patient for TMJ?
Mandible is close to the submandibular triangle, which contains numerous neurovascular structures
Boundaries, floor, and contents of the carotid triangle (vascular triangle)
B: posterior belly of digastric, superior belly of omohyoid, and anterior border of sternocleidomastoid
F: thyrohyoid, hyoglossus, and inferior and middle constrictor muscles
C: common and internal carotid arteries, external carotid artery (and three of its branches - superior thyroid artery, lingual artery, and facial artery -), and tributaries of internal jugular vein
Boundaries, floor, and contents of muscular triangle
B: Superior belly of omohyoid, anterior midline of neck, anterior border of SCM
F: Posterior layer of pretracheal fascia
C: Sternohyoid and sternothyroid muscles, thyroid gland, trachea, and esophagus
Point of attachment for many muscles between mandible and larynx
Hyoid bone
This bone may be broken due to strangulation
Hyoid bone
Primary function of infrahyoid muscles
Move hyoid bone and larynx
Name the infrahyoid muscles
Omohyoid
Sternohyoid
Sternothyroid
Thyrohyoid
Omohyoid: origin, insertion, nerve, function
O: inferior belly of omohyoid from upper border of scapula; ends in intermediate tendon deep to the sternocleidomastoid muscle; superior belly extends upward from tendon
I: Body of hyoid bone
N: Ansa Cervicalis (C1,C2,C3)
F: Depresses hyoid bone and larynx
Sternohyoid: origin, insertion, nerve, function
O: Posterior surface of manubrium and medial end of clavicle
I: body of hyoid bone
N: Ansa Cervicalis (C1,C2,C3)
F: depresses the hyoid bone and larynx
Sternothyroid: origin, insertion, nerve, function
O: posterior surface of manubrium, inferior to origin of sternohyoid
I: oblique line of lamina of thyroid cartilage
N: Ansa Cervicalis (C1,C2,C3)
F: depresses the larynx
Thyrohyoid: origin, insertion, nerve, function
O: oblique line on the lamina of the thyroid cartilage
I: body of the hyoid bone
N: C1 through hypoglossal nerve
F: depresses the hyoid bone
Infrahyoid muscles depress the hyoid and larynx to accomplish what functions?
Swallowing
Speech
Breathing
If hyoid fixed diastric depresses mandible opening jaw against resistance
Dense, sheet-like layer of connective tissue
Fascia
Surrounds and supports both the superficial and deep structures of the neck
Cervical fascia
What are the two major layers of the cervical fascia?
Superficial cervical fascia
Deep cervical fascia
Thin layer of connective tissue which encloses the platysma muscle, and contains cutaneous nerves, superficial veins and lymph nodes
Superficial cervical fascia
What are the layers of the deep cervical fascia? What is the function of each?
Investing layer of the deep cervical fascia - deep to superficial; encloses the sternocleidomastoid and trapezius
Pretracheal fascia - encloses thyroid gland, trachea, esophagus
Prevertebral fascia - encloses the vertebral column and the deep muscles of the back
Carotid Sheath - cylinder of fascia extending from base of skull to root of neck
What does the carotid sheath of the deep cervical fascia contain?
Common carotid artery, internal carotid artery, internal jugular vein, vagus nerve, and deep cervical lymph nodes
Function and clinical significance of fascial layers
Slippery surface to reduce friction (allows gross movements of head and neck; and swallowing)
Adhesion, which can be reduced with myofascial release
Can serve as a channel for infection: (1) pretracheal fascia can spread from head and neck to mediastinum directly, (2) Dental abscess, strepthroat (fistula)
Cancer involving deep cervical lymph nodes can compress internal jugular veins (can also cause headaches)
Opening through which structures of the neck pass into the thorax
Superior thoracic aperture
What are the boundaries of the superior thoracic aperture? Hint: its kidney-shaped.
First thoracic vertebra
First ribs and their cartilages
Manubrium of sternum
Name all the major arteries and veins that pass through the superior thoracic aperture
Brachiocephalic trunk Left common carotid artery Left subclavian artery Internal thoracic artery Brachiocephalic vein
Name the nerves that pass through the superior thoracic aperture.
Phrenic nerve
Vagus nerve
Recurrent laryngeal nerve
Sympathetic trunk
Name the viscera that can be found in the superior thoracic aperture.
Trachea, esophagus, cervical pleura, apex of lung, and thymus
Explain how the lung may collapse with a neck injury
Cervical pleura and lung apex pass through superior thoracic aperture, posterior to SCM origin
A broken 1st rib on penetrating wound to neck can cause collapse lung
Condition where broken 1st rib due to penetrating wound can cause lung to collapse
Atelectasis
Where is the thymus located? What does the thymus produce? What is the thymus blood supply? What innervates the thymus?
Posterior to the manubrium
It produces T-lymphocytes
Internal thoracic artery
Stellate ganglion of sympathetic trunk and vagus
What muscles lie anterior to the thymus and thyroid gland?
Sternohyoid
Sternothyroid
What does the thyroid gland produce?
Thyroxine
Calcitonin
Parts of the thyroid gland
Left lobe
Right lobe
Isthmus
50% of the time, pyramidal lobe
Muscle which connects the isthmus of the thyroid glad with hyoid bone
Levator glandulae thyroideae muscle
Which arteries supply blood to thyroid gland? Where does each branch from?
Superior Thyroid artery (from the external carotid artery)
Inferior thyroid artery (from the thyrocervical trunk)
(Variation) Thyroid Ima Artery (brachiocephalic trunk)
Which veins run from the thyroid gland? Where does each go?
Superior thyroid vein (to the internal jugular vein)
Middle thyroid vein (to the internal jugular vein)
Inferior thyroid vein (to the brachiocephalic vein)
What does the thyroid gland innervate?
Superior, middle, and inferior cervical sympathetic ganglia
Condition where thyroid gland is abnormally enlarged, seen in anterior neck
Goiter
What is endemic goiter?
Goiter due to dietary deficiency of iodine, which is necessary to produce thyroxine; gland increases to increase output; hormone largely inactive; symptoms include hypothyroidism (moon face and weight gain
What is exothalamic goiter?
Goiter due to autoimmune disease; thyroid stimulating immunoglobulins bind to receptor site cause overactivity of gland hormone and active; symptoms include hyperthyroidism (Granes disease: hunger, skinny, hot) and bulging eyes (fat deposit in center behind eyes)
This nerve branches off the vagus within the thorax and then travels up into the neck to supply motor innervation to all but one of the laryngeal muscles
Recurrent laryngeal nerve
Describe the recurrent laryngeal nerve location, where is runs, and what is controls?
It branches off the vagus within the thorax and then travels up into the neck to supply motor innervation to all but one of the laryngeal muscles: speech and airway
Which endocrine gland is involved with calcium homeostasis?
Parathyroid gland
Small ovoid bodies on posterior surface of the thyroid gland
Parathyroid glands
How many parathyroid glands are usually found in body?
Usually there are four. It can vary between two and six.
What is the blood supply for the parathyroid gland?
Inferior thyroid artery
Superior thyroid artery
What does the parathyroid gland innervate?
Inferior or middle cervical sympathetic ganglia
What are some factors that make performing a thyroid surgery difficult?
Vascularity
Parathyroid glands (essential for life)
Recurrent laryngeal nerve (if damaged, my paralyze half of larynx affecting speech and airway)
“Windpipe”, begins at larynx at the level of cervical vertebra six and will split into left and right bronchi
Trachea
What are cartilaginous rings?
Incomplete supporting rings along the trachea that open posteriorly where the trachealis muscle (smooth) spans
What supplies blood to the trachea?
Inferior thyroid artery
What innervates the trachea?
Recurrent laryngeal nerve
Describe the esophagus.
Muscular tube connecting pharynx to the stomach; begins at cervical vertebra six; lies posterior to trachea
Main arteries of the head and neck
Carotid arteries
Where does the common carotid artery split?
Carotid triangle
What does the common carotid artery split into?
Internal carotid artery
External carotid artery
Which artery is the main source of blood to structures of the neck, face, and scalp (external skull)?
External carotid artery
What are the branches of the external carotid artery?
Superior thyroid artery Ascending pharyngeal artery lingual artery facial artery occipital artery posterior auricular artery superficial temporal artery maxillary artery
Slight dilation of the internal carotid artery where it joins the common carotid. What is this structure’s function? What is it innervated by?
Carotid sinus
Baroreceptor (blood pressure sensor): within increased blood pressure, heart rate decreases
Glossopharyngeal nerve (CN IX)
Small reddish-brown mass located within or deep to the bifurcation of the common carotid artery. What is this structure’s function? What is its innervation?
Carotid body Chemoreceptor: detects changes in the chemical makeup of the blood within carotid Glossopharyngeal nerve (CN IX)
Vein deep to the sternocleidomastoid and never topographically visible
Internal Jugular Vein
Where does the internal jugular vein begin? What is it a continuation of? Where does it drain?
Jugular foramen
Sigmoid sinus
Brachiocephalic vein
Dilation of the internal jugular vein at its origin below the jugular foramen
Superior jugular bulb
Tributaries of the internal jugular vein
Inferior petrosal sinus Pharyngeal veins Facial vein Lingual vein Superior thyroid vein Middle thyroid vein
Structure of the internal jugular vein with dilation near its termination into the brachiocephalic vein
Inferior Jugular bulb
Branches of the glossopharyngeal nerve (CN IX)
Tympanic nerve Branch to the Carotid sinus Pharyngeal branch Branch to the stylopharyngeus Tonsillar Branch Lingual Branch
Nerve that is sensory to the tympanic cavity and secretomotor to the parotid gland; senses pain in otitis media
Tympanic nerve
Branch of CN IX that is sensory to both the carotid sinus and carotid body; changes in blood pressure and blood gases
Branch to the Carotid Sinus
Branch of CN IX that unites with branches from vagus and sympathetic trunk to form the pharyngeal plexus; sensory to pharynx, senses pain in acute pharyngitis, and afferent limb of gag reflex
Pharyngeal branch
Branch of CN IX sensory to the mucous membrane over the tonsil and to the soft palate; only muscle of pharynx not innervated by vagus nerve
Branch to the Stylopharyngeus
Branch of CN IX sensory to the mucous membrane over the tonsil and to the soft palate; senses pain in tonsillitis
Tonsillar branch
Branch of CN IX that supplies taste and general sensation to the posterior third of the tongue
Lingual branch
Longest cranial nerve and has extensive distribution in head, neck, thorax, and abdomen; name means “wanderer”
Vagus nerve
Where does the vagus nerve emerge? Where does it exit the skull? Do any other nerves exit from the same location?
Medulla Oblongata Jugular foramen glossopharyngeal nerve (CN IX) and accessory nerve (CN XI)
Name the two ganglia of the vagus nerve. Are they motor or sensory?
- Superior (jugular) ganglion: located in jugular foramen, generally smaller
- Inferior (nodose) ganglion: generally bigger
Both are sensory
Functions of nasal cavity
Provide airway
olfaction
warming and moistening inspired air
cleansing inspired air
Where does nasal cavity extend?
Nostrils (nares) anteriorly to choanae posteriorly
Posterior apertures of the nasal cavity which open into the nasopharynx
Choanae
External nose consists of:
Tip: free end of nose
Root: connects the nose to the forehead
Nares: (Nostrils)
Alae: bound the nares laterally
What are the boundaries of the nasal cavity? What does each boundary consist of?
Roof: nasal bone, frontal bone, cribriform plate of the ethmoid bone, and body of the sphenoid bone
Floor: Palatine process of the maxilla and the horizontal plate of the palatine bone; both these bones form the HARD PALATE
Medial Wall: septal cartilage, perpendicular plate of the ethmoid bone, and the vomer
Condition where the nasal septum does not lie in the median plane
Deviated Septum
A severely deviated septum may touch what? What symptom might this create?
The lateral wall
Difficulty breathing
What are causes of a deviated septum?
Congenital malformation
Birth injury
Postnatal injury
What makes up the nose’s lateral wall?
Nasal bone Frontal process of the maxilla Lacrimal bone Ethmoid bone Inferior nasal concha perpendicular plate of the palatine bone Medial pterygoid plate of the sphenoid bone
What are the structures within the lateral wall?
Superior nasal concha (of the ethmoid)
Middle nasal concha (of ethmoid)
Inferior nasal concha (separate bone)
Small space located above and behind the superior nasal concha that receives the opening of the sphenoid sinus
Sphenoethmoidal recess
Space below the superior nasal concha that receives the opening of the posterior ethmoidal cells
Superior Meatus
The space below the middle nasal concha that receives the openings of the frontal sinus, the maxillary sinus, the middle ethmoidal cells, and the anterior ethmoidal cells
Middle Meatus
Rounded projection into the middle meatus where the middle ethmoidal cells open onto this structure
Ethmoidal Bulla
A curved slit lying below the ethmoidal bulla within the middle meatus where the frontonasal duct, anterior ethmoidal cells, and maxillary sinus open into this slit
Hiatus Semilunaris
Space below the inferior nasal concha that receives the opening of the nasolacrimal duct
Inferior Meatus
Connects the lacrimal sac of the orbit to the nasal cavity
Nasolacrimal duct
Area just inside each nostril; contains hair, sebaceous glands, and sweat glands
Nasal Vestibule of the Nasal cavity
Lower two-thirds of the nasal cavity
Respiratory Region of the nasal cavity
Superior nasal concha and the upper one-third of the nasal septum; contains the fibers of the olfactory nerve, which pass down through the cribriform plate
Olfactory region of the nasal cavity
Which nerve innervates the special senses of the nasal cavity?
Olfactory nerve (CN 1)
Where does general sensory innervation of the nasal cavity come from?
Branches of the maxillary and ophthalmic divisions of the trigeminal nerve (CN V)
Where does autonomic innervation (sympathetic and parasympathetic) of the nasal cavity come from?
Pterygopalatine ganglion
What provides primary blood supply to the nasal cavity?
Sphenopalatine branch of the maxillary artery
Anterior ethmoidal branch of the ophthalmic artery
Condition of nasal cavity where richness in blood may bleed out
Epitaxis
Where do lymph nodes of the nasal cavity drain?
Deep cervical node
Cavities found within the bones of the face that develop as outgrowths of the nasal cavity
Paranasal Sinuses
What do the paranasal sinuses do?
Facilitates drainage of the sinuses in the face
Sinus that lies in the frontal bone. Where does it open into?
Frontal Sinus
Opens into hiatus semilunaris of the middle meatus via the frontonasal duct
Largest of the paranasal sinuses. Where is it found? Where does it open into?
Maxillary Sinus
Lies within Maxilla on each side, lateral to nasal cavity and inferior to the orbit
Opens into the hiatus semilunaris within the middle meatus.
Which paranasal sinus is present at birth?
Maxillary sinus
Which paranasal sinus is the most prone to infection? Why?
Maxillary Sinus
Poor drainage due to its superior positioning
Sinus that lies within the sphenoid bone. Where does it open into?
Sphenoid Sinus
Opens into the sphenoethmoidal recess
Sinus that consists of several groups of ethmoidal cells lying in the ethmoid bone between the orbit and nasal cavity. List these groups of cells
Ethmoidal Sinus
- Posterior ethmoidal cells - open into the superior meatus
- Middle ethmoidal cells: open into the ethmoidal bulla within the middle meatus
- Anterior ethmoidal cells: open into the hiatus semilunaris within the middle meatus
Where can a nasal cavity infection spread? (Hint: there are six locations)
- Lacrimal apparatus and conjunctiva via nasolacrimal duct –> CONJUNCTIVITIS “pink eye”
- Paranasal sinus –> “Sinusitis”
- Nasopharynx (MC) –> “Acute Pharyngitis”
- Pharyngotympanic tube –> “Otitis Media” (ear infections)
- Anterior cranial fossa via Cribriform plate –> “meningitis” or “Brain abscess”
- Mastoid air cells from inner ear via aditus –> “Mastoiditis”
Amoeba found in stagnant warm water that eats brains
Naegleria fowler
What may CSF dripping from nose indicate?
Damage to the cribriform plate
Halo effect insinuates CSF dripping
What are the branches of the vagus in the head and neck?
Meningeal Branch Auricular Branch Pharyngeal Branch Superior Laryngeal Nerve Recurrent Laryngeal Nerve
Which vagus branches in the head and neck make up the superior ganglia?
Meningeal branch and Auricular branch
Branch of the vagus arising from the superior ganglion that supplies the dura mater with sensory innervation
Meningeal Branch
Branch of the vagus nerve that arises from the superior ganglion and is sensory to the auricle, the floor of the external auditory meatus, and the tympanic membrane
Auricular branch
Which of the vagus nerves of the head and neck make up the inferior ganglion?
Pharyngeal branch
Superior laryngeal nerve
Recurrent laryngeal nerve
Branch of the Vagus that arises from the inferior ganglion and is the chief motor nerve to the pharynx muscles and soft palate; also the efferent limb of the gag reflex
Pharyngeal branch
What is the origin of the pharyngeal branch of the vagus?
Cranial part of the accessory nerve CN XI
How does the pharyngeal plexus form?
Pharyngeal branch of the vagus joints with branches from the glossopharyngeal nerve and sympathetic trunk
What does the pharyngeal plexus innervate?
Motor to all muscles of the pharynx MINUS the stylopharyngeus (innervated by the glossopharyngeal nerve)
Motor to all muscles of the soft palate MINUS the tensor veli palatini (innervated by the Trigeminal nerve)
Innervates all muscles of the pharynx and soft palate minus a couple exceptions. What are the exceptions?
Pharyngeal plexus
- Stylopharyngeus - innervated by the glossopharyngeal nerve
- Tensor Veli Palatini - innervated by the Trigeminal nerve
Nerve of the vagus that arises from the inferior ganglion and splits into two subnerves. What are these two nerves and their functions?
Superior laryngeal nerve
- Internal laryngeal nerve: SENSORY to the mucous membrane of the larynx superior to the true vocal chords
- External Laryngeal nerve: MOTOR to the cricothyroid and inferior constrictor muscles
Nerve that arises from the vagus within the thorax and then ascends, in the groove between the trachea and esophagus, back into the neck. Is it sensory or motor? What structure is it closely applied to?
Recurrent laryngeal nerve
- BOTH sensory and motor
- Thyroid Gland
What are the boundaries of the oral cavity?
Roof: the palate
Floor: the tongue and oral mucosa (supported by the mylohyoid and geniohyoid muscles)
Anterior and lateral boundaries: the lips and cheeks
Posterior boundary: oropharyngeal isthmus, demarcated by the palatoglossal arch
What are the two parts making up the oral cavity?
Oral vestibule
Oral cavity
Portion of the oral cavity which lies between the lips and gums, or cheek and gums, portion of the oral cavity external to the tooth rows
Oral Vestibule
What are the openings into the oral vestibule?
- Labial glands: small salivary glands
2. Parotid duct (largest salivary duct): opens lateral to the maxillary second molar within the vestibule
Portion of the oral cavity which lies internal to the tooth rows
Oral cavity proper
Two mobile musculofibrous folds which bound the opening of the mouth. Each is connected to a gum by what median fold?
Lips
- Frenulum of upper lip
- Frenulum of lower lip
Median groove seen externally which extends from the nose to the vermilion border of the upper lip (hint: cleft lip happens here)
Philtrum
What are the kissing muscles of the lips?
Orbicularis oris muscle and labial glands
What muscle and gland in the cheek are similar to the labial glands in the lips?
Buccinator muscle and buccal glands
This structure forms the roof of the mouth and the floor of the nasal cavity and is arched both transversely and anteroposteriorly
Palate
What are the parts that makeup the palate?
Hard Palate - forms the anterior two thirds of the palate
Soft palate - forms the posterior one third of the palate
Bony partition between the nasal and oral cavities. What does this consist of?
Hard Palate
- Palatine process of the maxilla (anteriorly)
- Horizontal plate of the palatine bone (posteriorly
What foramina does the hard palate contain? How does each function?
Incisive foramen: Transmits the nasopalatine nerves (sensory)
Greater Palatine foramen and lesser palatine foramen: transmits nerves and vessels of the same name
What covers the hard palate?
Mucoperiosteum
Describe the mucoperiosteum
Along the hard palate, presents a palatine raphe extending to the incisive papilla
Mobile fibromuscular fold suspended from the posterior border of the hard palate. What is this structures function? How is its function accomplished?
Soft Palate
- Prevents food and fluid from entering the nose
- The soft palate elevates during swallowing to close the opening between the nasopharynx above and the oropharynx below
The soft palate is continuous with what two lateral arches?
Palatoglossal arch: palatoglossal fold (superficially) + Palatoglossus Muscle (deep to fold)
Palatophargyngeal arch: palatoglossus muscle (deep to the fold)
Median projection of the soft palate
Uvula
Where does the tonsillar fossa lie?
Between the palatoglossal and palatopharyngeal arches on each side and contains the Palatine Tonsil
Musculus Uvulae: O, I, N, F
O: posterior nasal spine
I: mucous membrane of uvula
N: vagus nerve (CN X) via the pharyngeal plexus
F: elevates the uvula
Levator Veli Palatini: O, I, N, F
O: inferior surface of temporal bone
I: Aponeurosis of soft palate
N: Vagus nerve (CN X) via the pharyngeal plexus
F: Elevates the soft palate
Tensor Veli Palatini: O, I, N, F
Origin: Scaphoid fossa of the medial pterygoid plate, pharyngotympanic tube
Insertion: the tendon winds around the pterygoid hamulus and inserts into the aponeurosis of the soft palate
Nerve: Mandibular division of trigeminal (CN V)
Function: Tenses soft palate, opens pharyngotympanic tube
What innervates the hard palate?
Greater palatine and nasopalatine nerves
What innervates the soft palate?
Lesser palatine nerve
What provides blood supply to the hard palate?
Greater palatine artery (from maxillary)
What provides blood supply to soft palate?
Lesser palatine and facial arteries
Diagnosis of nerve damage to vagus
Damage to the left vagus nerve causes the uvula to deviate to the right due to paralysis of the musculus uvulae on the left side, and vice versa
The branch of the vagus is sensory to the mucous membrane of the larynx below the true vocal folds, and to the trachea and motor to all muscles of the larynx except the cricothyroid
Recurrent laryngeal nerve
The recurrent laryngeal nerve innervates all the muscles of the larynx except for which one?
Cricothyroid
Clinical consequences of damage to the recurrent laryngeal nerve
Unilateral damage: respiratory distress, hoarseness (partial aphornea)
Bilateral damage: complete aphornea (mute)
Causes of damage to the recurrent laryngeal nerve
- Trauma during thyroid surgery
- Goiter or thyroid tumor
- Lung tumor (compression)
- Aortic aneurysm (left side only)
What two parts and their origins form the Accessory Nerve (CN XI)?
Cranial part: originates from the medulla oblongata
Spinal part: originates from the sides of the spinal cord
Describe how cranial and spinal parts of the accessory nerve join.
The spinal part ascends through the FORAMEN MAGNUM and joins the the cranial part.
Both exit through the jugular foramen.
Where does the cranial part of the accessory nerve join the vagus? Where do these provided motor fibers travel to?
Inferior vagal ganglion
- Pharyngeal branch of the vagus: to the muscles of the pharynx and the soft palate
- Recurrent laryngeal nerve: to the muscles of the larynx
The spinal part of the accessory provides motor fibers for what?
Sternocleidomastoid and trapezius muscles
Motor nerve for the tongue. Describe the location.
Hypoglossal Nerve (CN XII) - Originates from the MEDULLA OBLONGATA, and exits the skull through the HYPOGLOSSAL CANAL
Name the branches of the hypoglossal nerve. Name the function of each.
Meningeal branches: supply dura matter; contribute to cervicogenic headaches (like meningeal branch of Vagus)
Superior Root (C1 & C2) of the Ansa Cervicalis: sternohyoid, sternothyroid, omohyoid
Nerves to thyrohyoid and geniohyoid: C1 fibers that are motor to thyrohyoid and geniohyoid muscles
Lingual branches: motor to extrinsic and intrinsic muscles of tongue
Describe the preganglionic and postganglionic fibers of the cervical part of the sympathetic trunk.
Preganglionic Fibers supply structures of head and neck originate from T1 and T3, travel up the trunk and synapse with several cervical ganglia
Postganglionic fibers distribute from the ganglia to the blood vessels, smooth muscle and glands of the head and neck
Attachments of tongue
Hyoid bone mandible styloid process palate pharynx
Functions of tongue
Taste
Mastication
Swallowing
Speech
Parts of tongue
Apex: rests against incisor teeth
Margin: rests against teeth and gums on each side
Dorsum: the upper surface of the tongue
Inferior surface: the lower surface of the tongue
Root: the attached base of the tongue
What part of the tongue lies partly in the oral cavity and partly in the oropharynx?
Dorsum of the tongue
V-shaped groove that divides tongue into oral and oropharyngeal parts. Which part is larger?
Sulcus Terminalis
- Oral part is larger
Foramen located at the apex of the V of the sulcus terminalis and is remnant of the embryonic thyroglossal duct
Foramen cecum
This structure along the midline of the neck occurs when embryonic thyroglossal duct does not obliterate; may result in a thyroglossal cyst; this is often mistaken for a thyroid tumor
Foramen cecum
Describe Filiform papillae
Conical projections with sharply pointed tips
Generally sensory only, lacks taste buds
Describe Fungiform Papillae
Mushroom shaped, contain taste buds
Which papillae of the tongue is the largest?
Vallate papillae
Describe Vallate papillae
largest of lingual papillae, arranged in V-shaped row in front of the sulcus terminalis, contains taste buds (bitter taste and gag reflex and survival mechanism to poison)
Describe foliate papillae
Grooves and ridges along the margin of the tongue, poorly developed in humans. Contain taste buds (sour)
Name the lingual papillae
Filiform
Fungiform
Vallate
Foliate
A mass of lymphoid tissue found on the oropharyngeal surface of the tongue.
Lingual Tonsil
What are the two folds of the tongue?
Median glossoepiglottic fold and lateral glossoepiglottic fold
Space on either side of the median glossoepiglottic fold
Vallecula
inferior surface of tongue is connected to the floor of mouth by what?
Frenulum of the tongue
Condition of some infants where frenulum of the tongue is short superior to inferior and long anterior to posterior, extending to near the apex of the tongue; tongue is strapped to the floor of mouth
Ankyloglossia aka “Tongue-Tied”
- This condition may impede speech
Frenulum usually grows when?
The first year of life
Where do nerves, vessels, and extrinsic muscles enter or leave the tongue?
Root of the tongue
Name the extrinsic muscles of the tongue
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
Platoglossus: O, I, N, F
O: Soft palate
I: Sides of tongue
N: Vagus nerve (CN X) via the pharyngeal plexus
F: Elevates back of tongue
Which of the extrinsic muscles is NOT innervated by the hypoglossal nerve?
Palatoglossus
This muscle pulls the tongue forward preventing it from falling backwards blocking the airway
Genioglossus
Why is the genioglossus so important?
Constantly pulls the tongue forward; very important for general anesthesia and seizure disorders (epilepsy)
Describe the sensory innervation of the anterior two-thirds of the tongue.
General sensation through the lingual nerve, a branch of the mandibular division of the trigeminal nerve (CN V).
Taste through the chorda tympani, a branch of the facial nerve (CN VII)
Describe the sensory innervation of the posterior one-third of the tongue
General sensation and taste through the glossopharyngeal nerve (CN IX); includes vallate papillae and taste fibers from CN IX that cross the sulcus terminalis to innervate the vallate papillae allowing the gag reflex in response to bitter tastes
Describe blood flow of the tongue
Lingual artery from external carotid flows in, and lingual vein to internal jugular out
Name the parts of the teeth. Describe each.
Crown: projects above gums, covered by ENAMEL
Neck: jxn btw crown and root
Root: embedded in alveolar processes of the maxilla and mandible, covered in CEMENTUM
This structure lies at cervical levels 1 through 3 and supplies sympathetic innervation to everything in the head
Superior Cervical Ganglion
Name the branches of the superior cervical ganglion
Internal carotid nerve
Superior cervical cardiac nerve
Branches to the pharyngeal plexus
This structure lies at the cervical vertebral level 6 and supplies the thyroid gland with stimulus. What nerve branches off of it?
Middle cervical ganglion
- Middle cervical cardiac nerve (to the cardiac plexus)
This structure lies at cervical vertebra 7, is often fused with either the middle or inferior cervical ganglion, and gives off a branch to the plexus along the vertebral artery
Vertebral Ganglion
This structure lies at cervical vertebra 7 through thoracic vertebra 1 and is formed by the fusion of the inferior cervical ganglion to the first thoracic ganglion
Cervicothoracic (stellate) ganglion
What is a branch of the cervicothoracic (stellate) ganglion?
Inferior cervical cardiac nerve (to the cardiac plexus)
Ansa Subclavia
Describe the location of the cervicothoracic (stellate) ganglion.
C7-T1, Posterior to the vertebral artery, anterior to transverse process of C7 and neck of first rib
Nerve bundle which loops anterior to the subclavian artery, connecting the vertebral ganglion to the cervicothoracic ganglion
Ansa Subclavia
Large, horizontal part of the mandible
Body
Largest and sturdiest facial bone
Mandible
The upper border of the body, containing the tooth sockets (alveoli)
Alveolar process
Vertically ascending part of the mandible
Ramus
At the posterior terminus of the body of the mandible
Angle
Articulates with the temporal bone to form the temporomandibular joint. What conditions could result from a misalignment of this joint?
Condylar process
- TMJS: temporomandibular joint syndrome
- Migraines
- Arthritis
Area of attachment for muscles of mastication
Coronoid process
Origin of the genioglossus muscle
Superior mental (genial) spine
Origin of the geniohyoid muscle
Inferior mental (genial) spine
Origin of the anterior belly of digastric
Digastric fossa
Origin of the mylohyoid muscle
Mylohyoid line
Location of the sublingual gland
Sublingual fossa
Digastric muscle: O, I, N, F
O: posterior belly from the mastoid process, anterior belly from the digastric fossa
I: Both bellies “insert” into the hyoid bone by an intermediate tendon which connects them. Intermediate tendon is strapped to the hyoid bone by a fibrous loop
N: Posterior belly by the cervical branch of the facial nerve (CN VII), anterior belly by the nerve to mylohyoid (CN V)
F: Elevates the hyoid bone and depresses the mandible when hyoid is fixed
Mylohyoid muscle: O, I, N, F
O: mylohyoid line
I: body of hyoid bone, median raphe
N: Nerve to mylohyoid (CN V)
F: Elevates hyoid bone and floor of the mouth
Geniohyoid muscle: O, I, N, F
O: Inferior mental spine
I: body of hyoid bone
N: C1 fibers through hypoglossal
F: Elevates hyoid bone and bone
Genioglossus muscle: O, I, N, F
O: Superior mental spine
I: Tip and entire undersurface of tongue
N: Hypoglossal nerve
F: draws tongue forward, protrudes tip of tongue
Hyoglossus Muscle: O, I, N, F
O: body and greater horn of hyoid bone (upper surface)
I: sides of the tongue
N: hypoglossal nerve
F: draws tongue downward (say “ah”)
This small portion of hyoglossus may take origin from the lesser horn of the hyoid bone
Chondroglossus
- It is cartilaginous and ossifies through life
Styloglossus Muscle: O, I, N, F
O: Styloid process
I: Sides of the tongue
N: Hypoglossal nerve
F: draws tongue upward and backward (retraction)
Stylohyoid Muscle: O, I, N, F
O: Styloid process
I: body of hyoid bone
N: Facial nerve
F: Elevates hyoid bone and tongue
Name the salivary glands
Submandibular
Parotid
Sublingual
What muscle does the submandibular wrap around?
Mylohyoid muscle
Name the two parts of the submandibular gland. Where does each lie?
Superficial Part: within submandibular triangle and in submandibular fossa
Deep part: small and lies superior to mylohyoid muscle
How long is the submandibular duct? Where does it open? Where is it located?
5 cm
- Oral cavity of the sublingual caruncle
- lateral to the frenulum of the tongue
What innervates the submandibular gland?
Parasympathetic fibers from the facial nerve (CN VII) via the submandibular ganglion
Smallest of the three salivary glands
Sublingual gland
Where does the sublingual gland lie?
Lies superior to the mylohyoid muscle, in the sublingual fossa
Where does the sublingual gland empty?
Floor of mouth by 12 short ducts, located along sublingual fold
What innervates the sublingual gland?
Parasympathetic fibers from the facial nerve (CN VII) via the submandibular ganglion
All intrinsic muscles of the tongue are innervated by which nerve?
Hypoglossal nerve
Name the extrinsic muscles of the tongue. Which nerve is each innervated by?
Genioglossus - hypoglossal
Hyoglossus - hypoglossal
Styloglossus - hypoglossal
Palatoglossus - vagus
Palatoglossus: O, I, N, F
O: soft palate
I: sides of the tongue
N: vagus nerve via the pharyngeal plexus
F: elevates back of tongue
Name the appropriate nerve that innervates the general sensation and taste.
General sensation: lingual nerve, a branch of the mandibular division of the trigeminal (CN V)
Taste: chorda tympani, a branch of the facial nerve (CN VII)
Which nerve innervates the general sensation and taste of the posterior one-third tongue?
Glossopharyngeal nerve (CN IX), which also innervates the vallate papillae
What allows the gag reflex?
Taste fibers from glossopharyngeal nerve (CN IX) that cross the sulcus terminalis to innervate the vallate papillae which allows the gag reflex in response to bitter tastes
Blood supply to the tongue
Lingual artery (from external carotid) Lingual vein (to internal jugular)
What is the function of the teeth?
Break down food material during mastication, in order to increase its surface area to facilitate enzymatic activity and absorption
Name the structures of the teeth
Enamel: hardest substance of human body; covers the crown
Dentin: internal to enamel; makes up most of the tooth
Pulp: fills the central cavity of the tooth; contains blood vessels, nerves, and lymphatics
Cementum: bone-like substance which covers root (part of periodontium)
Name the parts of the teeth
Crown: covered by enamel and projects above gums
Neck: junction btw crown and root
Root: embedded in the alveolar processes of the maxilla and mandible; covered with cementum
Specialized oral mucosa which surrounds the teeth and covers adjacent alveolar bone
Gingivae
Name the types of teeth. Describe each.
Incisors: Single rooted chisel-shaped teether which are used for cutting (front four teeth)
Canines: Single rooted, pointed teeth which are used for puncturing and tearing
Premolars: Single or double rooted teeth with broad chewing surfaces which are used for grinding
Molars: multiple rooted teeth (better anchoring) with very broad chewing surfaces which are used for grinding
Name the surfaces of the teeth.
Labial surface Lingual surface Mesial surface Distal surface Occlusal surface
Describe the labial surface
Side facing the lip or buccal surface (contains incisors and canines)
Side facing the cheek (premolars and molars only)
Describe the lingual surface
Side facing the tongue
Describe the distal surface
Side facing posteriorly or away from the midline
Describe the occlusal surface
The chewing surface
Two incisors, one canine, and two molars in each quadrant, for a total of 20
Deciduous teeth
Replaced by adult premolars
Two incisors, one canine, two premolars, and three molars in each quadrant, for a total of 32
Permanent teeth
Maxillary teeth innervation
Superior alveolar branches from the maxillary division of the trigeminal (CN V)
Mandibular teeth innervation
Inferior alveolar nerve from the mandibular division of the trigeminal
Shooting toothaches are common with this condition
Trigeminal Neuralgia
Common pathway for food and air; funnel-shaped fibromuscular tube, extending from the base of the skull to the inferior border of the cricoid cartilage, considered both a part of the digestive and respiratory pathways
Pharynx
The pharynx lies where?
Posterior to the nasal cavity, oral cavity, and larynx
The three parts of the pharynx
Nasopharynx: posterior to the nasal cavity “C1”
Oropharynx: posterior to the oral cavity “C2/C3”
Laryngopharynx: posterior to the larynx
Communicates with the nasal cavity through the choanae and with the oropharynx through the pharyngeal isthmus
Nasopharynx
Boundaries of the nasopharynx
Superior boundary: the roof of the nasopharynx
Inferior boundary: the soft palate
Anterior boundary: the posterior border of the inferior nasal concha
Posterior boundary: the posterior wall of the pharynx
The pharyngeal tonsils are embedded where?
Posterior wall of the nasopharynx
Another name for the pharyngeal tonsils
Adenoids
May become enlarged, causing difficulty breathing through the nose; second most commonly removed tonsil
Pharyngeal tonsils
Most commonly removed tonsils
Palatine tonsils
The pharyngotympanic (auditory) tube is limited above by this cartilaginous structure
Torus tubarius
Connects the nasopharynx with the middle ear and equalizes pressure between the nasopharynx and the tympanic cavity
Pharyngotympanic (auditory) tube
This infection can spread from the nasopharynx to the middle ear via the pharyngotympanic tube
Otitis media
Small tonsil which lies immediately behind the opening of the pharyngotympanic tube
Tubal Tonsil
Fold which descends from the torus tubarius to the wall fo the pharynx; deep to the fold is the salpingopharyngeus muscle
Salpingopharyngeal fold
Circular arrangement of the tonsils around the oropharynx that is the first line of defense in the salpingopharyngeal fold. What tonsils make it up?
Tonsillar ring
- Lingual, palatine, tubal, and pharyngeal tonsils
What are the boundaries of the oropharynx?
Superior boundary: soft palate
Inferior boundary: superior border of the epiglottis
Anterior boundary: palatoglossal fold
Posterior boundary: posterior wall of the pharynx
Where does the oropharynx lie?
CV2 and CV 3
How does the oropharyx communicate with the oral cavity?
Through the oropharyngeal isthmus (isthmus of fauces)
The Palatine tonsils are found in what area of the pharynx?
Oropharynx
Folds of the oropharynx
Palatoglossal fold: from the soft palate to the tongue; deep to the fold is the palatoglossus muscle
Palatopharyngeal fold: from the soft palate to the wall of the pharynx; deep to the fold is the palatopharyngeus muscle
What is the space between the palatoglossal and palatopharyngeal folds called?
Tonsillar fossa
Longest part of the pharynx
Laryngopharynx
Boundaries of the laryngopharynx
Superior boundary: superior border of epiglottis
Inferior boundary: lower border of the cricoid cartilage where it joins the esophagus
Anterior boundary: posterior surface of larynx
Posterior boundary: posterior wall of the pharynx
Opening into the larynx and is found within the laryngopharynx
Laryngeal inlet
What binds the laryngopharynx?
Laterally, the aryepiglottic folds
Inferiorly, the interarytenoid notch
A recess in the anterior wall of the laryngopharynx located on either side of the laryngeal inlet. Deep pisiform fossa may be responsible for what? (Hint: place where food can easily get lodged)
Piriform Fossa (recess) - Halitoses (bad breath)
Name the muscles of the pharynx
External (Circular) layers of muscle - Inferior constrictor muscle - Middle constrictor muscle - Superior constrictor muscle Longitudinal layers of muscles - Stylopharyngeus muscle - Palatopharyngeus muscle - Salpingopharyngeus muscle
Inferior constrictor muscle: O, I, N, F
O: cricoid cartilage and thyroid cartilage
I: pharyngeal raphe
N: Vagus nerve (CN X) via the pharyngeal plexus and external laryngeal plexus
F: contracts the pharynx during swallowing
Middle constrictor muscle: O, I, N, F
O: the greater and lesser horns of the hyoid bone
I: pharyngeal raphe
N: Vagus nerve (CN X) via the pharyngeal plexus
F: contracts the pharynx during swallowing
Superior Constrictor Muscle: O, I, N, F
Origin: medial pterygoid plate, alveolar part of mandible, side of tongue
I: pharyngeal raphe
N: Vagus nerve (CN X) via the pharyngeal plexus
F: contracts the pharynx during swallowing
Specialized band of muscles formed by the superior constrictor which helps to seal the pharyngeal isthmus during swallowing
Palatopharyngeal sphincter
Stylopharyngeus muscle: O, I, N, F
O: styloid process
I: thyroid cartilage, some fibers blend with those of the constrictors
N: glossopharyngeal nerve (CN IX)
F: elevates pharynx
Palatopharyngeus muscle: O, I, N, F
O: soft palate
I: wall of pharynx, thyroid cartilage
N: Vagus nerve (CN X) via the pharyngeal plexus
F: elevates the pharynx, narrows oropharynx
Salpingopharyngeus muscle: O, I, N, F
O: torus tubarius and opening of the pharyngotympanic tube
I: Wall of pharynx
N: Vagus nerve (CN X) via the pharyngeal plexus
F: Elevates the pharynx, opens pharyngotympanic tube
Which muscles of the pharynx blend in together?
Palatopharyngeus muscle and salpingopharyngeus muscle
What is the control center for swallowing in the pharynx? Where does it lie?
Pharyngeal plexus
- On the middle constrictor
Name the nerves of the pharynx. What does each innervate?
- Pharyngeal branch of the vagus (CN X): motor fibers originate from cranial part of accessory nerve and innervates all pharynx muscles MINUS stylopharyngeus (innervated by glossopharyngeal)
- Pharyngeal branch of the glossopharyngeal (CN IX): sensory to the mucosa of pharynx
- Sympathetic fibers from the superior cervical ganglion
What are the arteries of the pharynx?
Ascending pharyngeal artery
Maxillary artery
Fascia and spaces of the pharynx from DEEPEST to most SUPERFICIAL.
Mucosa of pharynx –> Pharyngobasilar fascia –> constrictor muscle –> Buccopharyngeal fascia
Layer of fascia which surrounds the pharynx external to the muscles of the pharynx; continuous with the pretracheal fascia below; allows infection to spread from pharynx to mediastinum
Buccopharyngeal fascia
A layer of fascia which lies internal to the muscles and external to the mucosa of the pharynx
Pharyngobasilar fascia
A potential space between the buccopharyngeal fascia (or pretracheal fascia) and the prevertebral fascia. Extends downward into the thorax and permits free movement of the pharynx and esophagus during swallowing
Retropharyngeal space
Why is the retropharyngeal space significant?
Hemorrhage from cervical trauma or abscess from pharyngeal infection into the retropharyngeal space may cause the posterior wall of the pharynx to balloon forward, potentially leading to suffocation
Radiology: look for widening of retropharyngeal space in cases of cervical trauma a pharyngeal abscess
What is another term for swallowing?
Deglutition
Explaining the various steps of swallowing
1) Tongue moves bolus into oropharyngeal isthmus
2. ) (a) Palatoglossus and palatopharyngeus muscles squeeze bolus into oropharynx while (b) levator veli palantini and tensor veli palatini muscles elevate the soft palate to close off the pharyngeal isthmus
3. ) (a) Stylopharyngeus, palatopharyngeus, and salpingopharyngeus elevate the walls of the pharynx while (b) suprahyoid muscles elevate the hyoid bone and the larynx under the bulge of the tongue, which flexes the epiglottis back over the laryngeal inlet
4. ) Superior, middle, and inferior constrictor muscles contract in sequence, to move the food through the oropharynx and laryngopharynx and into the esophagus… peristalsis then propels it downward to the stomach
Condition where it is difficult to swallow
Dysphagia
Describe the first step to swallowing
Tongue moves bolus into oropharyngeal isthmus
Describe second step of swallowing
Palatoglossus and Palatopharyngeus muscles squeeze bolus back into the oropharynx
Levator veli palatini and tensor veli palatini muscles elevate soft palate
Describe third step of swallowing
Stylopharyngeus, palatopharyngeus and salpingopharyngeus elevate the walls of the pharynx
Suprahyoid muslces elevate the hoid bone and larynx under the bulge of the tongue, which flexes the epiglottis back over the laryngeal inlet
Describe the fourth step of swallowing
Superior, middle, and inferior constrictor muscles move food through oropharynx and laryngopharynx and into the esophagus
Peristalsis propels food down esophagus to the stomach