T2 L4: The oral and nasal cavity Flashcards
What is the primary function of the nose?
To filter dust entering the respiratory system
What is the main blood supply to the nose?
Branches from the ophthalmic and maxillary artery and the facial vein
Which nerves innervate the nose?
The olfactory nerve (CNI), Ophthalmic nerve (CNV1),
and the Maxillary nerve (CNV2)
What are the 3 projections in the nasal cavity?
The 3 conchae
Which bone do the superior and middle conchae arise from?
The ethmoid bone
Which bone does the inferior conchae arise from?
It’s its individual bone
What are the spaces under the conchae known as?
Meatuses
What is the function of meatuses?
To increase surface area and humidify inspired air
Which 2 cranial nerves arise directly from the brain?
CN1 and CN2
Where does the olfactory nerve arise from?
The cerebrum
Where does the Olfactory nerve exit the cranium?
Through the cribriform plate
Where in the nose are olfactory receptors found?
They line the epithelium in the roof and the walls of the nasal cavity
What is the function of mucous in olfaction?
They allow gases to dissolve into the fluid which can then be detected by olfactory nerves
What are paranasal sinuses?
Air-filled extensions of the nasal cavity that produce mucus
Through which duct do frontal sinuses drain through?
The frontonasal duct
Where do the anterior and middle ethmoidal cells drain into?
Into the middle meatus
Where does posterior ethmoidal cells drain into?
Into the superior meatus
Where do the sphenoidal sinuses drain into?
The sphenoethmoidal recess
Where do the maxillary sinuses drain into?
Into the middle meatus
Which paranasal sinus is most likely to be infected and why?
The maxillary sinus because it can only be drained when lying down due to it’s positioning
What goes through the optic canal?
CN2 and the ophthalmic artery
What goes through the superior orbital fissure?
CN3, CN4, and CN6
What goes through the inferior orbital fissure?
CNV2
What are the 3 chambers of the orbit?
Anterior, posterior, and vitreous chamber
Where is the anterior chamber in the orbit and what is it filled with?
It’s anterior to the iris and is filled with aqueous fluid
Where is the posterior chamber of the orbit and what is it filled with?
It’s posterior to the iris and anterior to the lens and it’s filled with aqueous fluid
Where is the vitreous chamber and what is it filled with?
Its found within the eyeball and it contains a set amount of fluid
What is the name of CNII?
The optic nerve
Which part of the eye receives visual information?
The retina
What is the crossing of visual fields important for?
3D vision and depth perception
Where does the optic nerve exit the skull?
Through the optic canal
Swelling of which gland can impact the optic nerve causing visual disturbances?
The pituitary gland. It sits in the sphenoid bone and it swells upwards which can constrict the optic chiasm
What does vertical movement of the eye muscles result in?
Abduction and adduction of the eyes
What does transverse movement of eye muscles result in?
Elevation and depression of the eyes
What does anteroposterior movement of eye muscles result in?
Internal and external rotation
Where does the oculomotor nerve (CNIII) exit the skull?
Through the superior orbital fissure
What is the somatic motor supply of the oculomotor nerve?
General somatic efferent supply that supplies the extraocular muscles except the superior oblique and lateral rectus
What is the parasympathetic supply of the oculomotor nerve?
General visceral efferent via the short ciliary nerves to ciliary body and sphincter pupillae
Why is the trochlear nerve called that?
It moves through the trochlear
Why is the Abducens nerve called that?
It abducts the eyes
What does the trochlear nerve (CNIV) supply?
The superior oblique muscle
What does the Abducens nerve (CNVI) supply?
The lateral rectus muscle
Injury to which nerve causes drooping eyes (ptosis)?
CNIII
Describe the process of crying
The lacrimal gland secretes lacrimal fluid which is collected by the lacrimal papilla and then the lacrimal sac
Where does the nasolacrimal duct drain?
Into the inferior meatus
What 2 types of innervation supply the lacrimal apparatus?
Sensory and autonomic innervation
Which nerve provides the sensory innervation to the lacrimal gland?
The lacrimal nerve (CNV1)
Which nerve provides the parasympathetic innervation to the lacrimal gland?
Secretomotor function via the facial nerve (CNVII)
Which nerve provides the sympathetic innervation to the lacrimal gland?
Vasoconstrictive via the superior cervical ganglion via the internal carotid
What is the evolutionary purpose of crying?
It get’s rid of extra hormones and makes you feel better that way
What are the 3 divisions of the trigeminal nerve?
Ophthalmic, maxillary, and mandibular
Where does the ophthalmic nerve exit the cranium?
Through the superior orbital fissure
Where does the maxillary nerve exit the cranium?
Through the foramen rotundum
Where does the mandibular nerve exit the cranium?
Through the foramen ovale
Which nerve supplies all the structures of the 1st pharyngeal arch?
The trigeminal nerve. It provides somatic sensory and somatic motor information
What are the 3 divisions of the ophthalmic nerve?
Lacrimal, nasociliary, and frontal
What does the lacrimal branch of the ophthalmic nerve do?
It provides sensory innervation to lacrimal gland, conjunctiva, and upper eyelid. There are parasympathetic fibres
What does the nasociliary branch of the ophthalmic nerve do?
Provides sensory innervation to the eye, bridge of the nose, and mucous membranes of the paranasal sinuses
What does the frontal branch of the ophthalmic nerve do?
Provides sensory innervation to upper eyelid, conjunctiva, forehead, and scalp
