Gross 1 Exam part 2

What is the nerve supply of digastric muscle?

posterior belly by the cervical branch of the facial nerve

anterior belly by the nerve to mylohyoid (CN V)

What is the function of the digastric muscle?

elevates the hyoid bone

depresses the mandible

What is a raphe?

fibrous strand into which fibers from two sides interweave

What is the nerve supply to the mylohyoid muscle?

Nerve to mylohyoid (CN V)

What is the function of the mylohyoid?

elevates hyoid bone and floor of the mouth

What is the nerve supply of the geniohyoid?

C1 fibers through hypoglossal

What is the function of the geniohyoid?

elevates hyoid bone and tongue

What is the nerve supply of the genioglossus?

hypoglossal nerve

What is the function of the genioglossus muscle?

draws tongue forward, protrudes tip of tongue

What is the nerve supply of the hyoglossus muscle?

hypoglossal nerve

What is the function of the hyoglossus muscle?

draws tongue downward

What is the small portion of hyoglossus that may take origin from the lesser horn of the hyoid bone?

Chondroglossus

What is the nerve supply of stylohyoid muscle?

Facial nerve (CN VII)

What is the function of the stylohyoid muscle?

elevates hyoid bone and tongue

What is the stylohyoid muscle pierced by?

the intermediate tendon of digastric muscle

What is the submandibular gland?

One of the three large paired salivary glands- wraps around posterior border of the mylohyoid

What are the two parts of the submandibular gland?

Superior part- large and lies in submandibular triangle

Deep part- small and lies superior to the mylohyoid muscle

What is the innervation of the submandibular gland?

parasympathetic fibers from the facial nerve via the submandibular ganglion

What is the sublingual gland?

smallest salivary gland

lies superior to the mylohyoid muscle in the sublingual fossa

empties into the floor of the mouth by 12 short ducts located along sublingual fossa

What is the innervation for sublingual gland?

parasympathetic fibers from the facial nerve via the submandibular ganglion

What nerves are associated with the mandible?

1. lingual nerve

2. glossopharyngeal nerve

3. hypoglossal nerve

What blood vessels are associated with the mandible?

1. lingual artery and vein

2. facial artery and vein

What does the lingual nerve cross under on the way to the tongue?

submandibular duct

What are the functions of the nasal cavity?

1. provide an airway

2. olfaction

3. warming and moistening of the inspired air

4. cleansing of inspired air

Where does the nasal cavity extend to? What is it divided into?

extends from the nostrils anteriorly to the choanae posteriorly

divided into left and right chambers of the nasal septum

What is the choanae?

posterior apertures of the nasal cavity which opens into the nasopharynx

What does the external nose consist of?

1. Tip: free end of the nose

2. Root: connects the nose to the forehead

3. Nares

4. Alae: bound the nares laterally

What is the roof boundary of the nasal cavity?

formed by the nasal bone, frontal bone, cribriform plate of the ethmoid bone, and the body of the sphenoid bone

What is the floor boundary of the nasal cavity?

formed by the palatine process of the maxilla and the horizontal plate of the palatine bone

these two bones together form the hard palate

What is the medial wall of the nasal cavity?

formed by the septal cartilage, perpendicular plate of the ethmoid bone, and the vomer

What is a deviated septum?

when the nasal septum doesn’t lie in the median plane

when severe, can touch lateral wall and cause breathing difficulty

exacerbates snoring

What are the causes of a deviated septum?

1. congenital malformation

2. birth injury

3. postnatal trauma (most common)

What is the lateral wall of the nasal cavity?

formed by nasal bone, frontal process of the maxilla, lacrimal bone, ethmoid bone, inferior nasal concha, perpendicular plate of the palatine bone, and the medial pterygoid plate of the sphenoid bone

What structures are in the lateral wall of the nasal cavity?

1. Superior nasal concha

2. Middle nasal concha

3. Inferior nasal concha

What are the functions of the nasal concha?

1. increases surface area

2. Increase turbulence of air- olfaction and other functions of nasal cavity

What is an anatomical variation of the lateral wall of the nasal cavity?

a highest nasal concha is present above the superior nasal concha.

it is a part of the ethmoid bone

What is the sphenoethmoidal recess?

small space located above and behind the superior nasal concha

receives opening of the sphenoid sinus

What is the superior meatus?

space below the superior nasal concha

receives opening of the posterior ethmoidal cells

What is the middle meatus?

space below the middle nasal concha

receives openings of the frontal sinus, maxillary sinus, the middle ethmoidal cells and the anterior ethmoidal cells

What is the ethmoidal bulla?

rounded projection into the middle meatus

middle ethmoidal cells open onto this structure

What is the hiatus semilunaris?

a curved slit lying below the ethmoidal bulla within the middle meatus

frontonasal duct, anterior ethmoidal cells and maxillary sinus open into the slit

What is the inferior meatus?

space below the inferior nasal concha

receives the opening of the nasolacrimal duct

What does the nasolacrimal duct connect?

connects the lacrimal sac of the orbit to the nasal cavity

What is the nasal vestibule?

area just inside each nostril

contains hair, sebaceous glands, and sweat glands

What are the three regions of the nasal cavity?

1. Nasal vestibule

2. Respiratory Region- lower two thirds of nasal cavity

3. Olfactory Region- superior nasal concha and upper one third of nasal septum

What does the olfactory region contain?

fibers of the olfactory nerve (CN 1), which pass down through the cribriform plate

What is the innervation of the olfactory region?

special sensory innervation is from the olfactory nerve (CN 1)

What is the rate of olfactory receptor lose?

people over 50 yrs lose olfactory receptors at the rate of 1% per year

cocaine abuse causes permanent loss of olfaction

What is anosmia?

loss of olfaction

What is the general sensory innervation for the nasal cavity?

branches of the maxillary and ophthalmic divisions of trigeminal nerve (CN V)

What is the autonomic innervation of the nasal cavity?

pterygopalatine ganglion

What is the primary blood supply to the nasal cavity?

1. sphenopalatine branch of the maxillary artery

2. anterior ethmoidal branch of the ophthalmic artery

T/F Nasal mucosa is richly vascularized?

True

What is epistaxis?

Nosebleed- common due to the richness of blood supply

What are the two forms of epistaxis?

1. Mild form- small branches in or near vestibule. Caused by minor trauma or low humidity

2. Severe form- involves spurting arterial blood. Caused by major trauma or rupture of sphenopalatine artery

What are some causes of epistaxis?

1. Hypertension

2. Blood disorders

3. Cocaine abuse

What are the paranasal sinuses?

Frontal sinus

Maxillary sinus

Sphenoidal sinus

Ethmoidal sinus

Where is the frontal sinus?

lies in the frontal bone

opens into the hiatus semilunaris of the middle meatus via frontonasal duct

Where is the maxillary sinus?

LARGEST of the paranasal sinuses

lies within the maxilla on each side, lateral to the nasal cavity and inferior to the orbit

opens into the hiatus semilunaris

What is the formation of paranasal sinuses related to?

1. Wolff’s Law: bone is reabsorbed where not needed and deposited where needed

2. Reduces weight of skull

What sinus is most frequently prone to infection?

Maxillary sinus

What is the only paranasal sinus that may be present at birth?

maxillary sinus

What is the sphenoidal sinus?

lies within the body of the sphenoid bone

opens into the sphenoethoidal recess

What is the ethmoidal sinus?

several groups of ethmoidal cells which lie within the ethmoid bone between the orbit and the nasal cavity

What does the ethmoidal sinus include?

1. Posterior ethmoidal cells: open into the superior meatus

2. Middle ethmoidal cells: open into ethmoidal bulla within the middle meatus

3. Anterior ethmoidal cells: open into hiatus semilunaris within the middle meatus

Where can infections of the nasal cavity spread into?

1. Anterior cranial fossa via cribriform plate- meningitis or brain abscess

2. Nasopharynx- acute pharyngitis

3. Middle ear infection via pharyngotympanic tube- otitis media

4. Paranasal sinuses- sinusitis

5. Lacrimal Apparatus and conjunctiva via nasolacrimal duct- conjunctivitis (pink eye)

6. Mastoid air cells via Aditus and Antrum from middle ear- mastoiditis

What is a halo sign?

When there is a clear circle in the blood during a nosebleed that indicates CSF dripping out

What is the roof boundary of the oral cavity?

the palate

What is the floor boundary of the oral cavity?

the tongue and oral mucosa, supported by the mylohyoid and geniohyoid muscles

What is the anterior and lateral boundaries of the oral cavity?

the lips and cheeks

What is the posterior boundary of the oral cavity?

oropharyngeal isthmus demarcated by the palatoglossal arch

What are the two parts of the oral cavity?

1. Oral vestibule

2. Oral Cavity Proper

Where is the oral vestibule?

lies between the lips and gums, or cheek and gums

external to the tooth rows

What are the openings into the oral vestibule?

1. Labial Gland: small salivary glands

2. Parotid Duct: opens lateral to the maxillary second molar within the vestibule

Where is the oral cavity proper?

lies internal to the tooth rows

What are the lips?

two mobile Musculo fibrous folds which bound the opening of the mouth?

What is the philtrum?

the median groove seen externally which extends from the nose to the vermilion border of upper lip

What does the frenulum of the upper lips attach?

ridge that attaches upper lip to gums

What does the frenulum of the lower lips attach?

ridge that attaches bottom lip to gums

What does the palate form?

forms both the roof of the mouth and the floor of the nasal cavity

What are the two parts of the palate?

hard palate: anterior 2/3rds of palate

soft palate: posteriori 1/3 of the palate

What does the hard palate consist of?

1. Palatine process of the maxilla (anteriorly)

2. Horizontal plate of the palatine bone (posteriorly)

What foramina are present in the hard palate?

1. Incisive foramen- transmits nasopalatine nerves

2. Greater palatine foramen- transmits nerve/vessels of same name

3. Lesser palatine foramen

What is the hard palate covered by?

mucoperiosteum

What are the transverse palatine folds?

extend laterally within the mucoperiosteum and aid in gripping food against the tongue during mastication

What is the soft palate?

mobile fibromuscular fold suspended from the posterior border of the hard palate

T/F The soft palate is depressed during swallowing to close opening between the nasopharynx above the oropharynx below?

False- elevates during swallowing

What are the two arches of the soft palate?

1. Palatoglossal arch

2. Palatopharyngeal Arch

What is the palatoglossal arch made up of?

1. Palatoglossal fold

2. Palatoglossus muscle

What is the palatopharyngeal arch made up of?

1. Palatopharyngeal fold

2. Palatopharyngeus muscles

What is the uvula?

median projection of the soft palate

Where does the tonsillar fossa lie?

between the palatoglossal and palatopharyngeal arches on each side

contains the Palatine Tonsil

What is the nerve innervation for musculus uvulae and levator veli palatini?

Vagus nerve via the pharyngeal plexus

What is the nerve innervation of the tensor veli palatini?

mandibular division of the trigeminal nerve

What’s the function of the musculus uvulae?

elevates the uvula

What’s the function of the levator veli palatini?

elevates the soft palate

What is the function of the tensor veli palatini?

tenses soft palate, opens pharyngotympanic tube

What muscles tenses and causes ears to pop?

Tensor Veli Palatini

What is the innervation of the hard palate?

greater palatine and nasopalatine nerves

What is the innervation of the soft palate?

lesser palatine nerve