HNS 4 Flashcards
function of the meatus
vascularised and warms and humidies air and traps pathogens
what nerves innervate the nasal cavity?
I, V, VII, T1 sympathetic nerves of spinal cord
what is the function of olfactory (I) nerve in the nasal cavity
olfaction (smell)
what is the function of trigeminal (V) nerve in the nasal cavity
general sensation
V1: anterior region
V2: posterior region
what is the function of facial (VII) nerve in the nasal cavity
glands via parasympathetic fibres
what is the function of sympathetic nerves from T1 of spinal cord in the nasal cavity
vascular smooth muscle
what vessels supplies the nasal cavity
internal carotid artery and branches of external carotid
why is there a risk of infection from the nasal cavity to the cranial cavity
some blood vessels that drain the nasal cavity pass through the cavernous sinus-> cranial cavity
what are the paranasal sinuses and their innervations
V1: frontal sinuses
V1 and V2: ethmoid air cells and sphenoid sinuses
V2: maxillary sinus
function of paranasal sinuses
-air-filled spaces (with some being mucus secreting) that decreases weight of skull, acting as crumple zones, increasing resonance of voice + humidifying and heating inhaled air
how does the facial nerve runs through the ear?
runs through the middle ear from internal acoustic meatus and continues into the opening to nasal cavity, via pharyngotympanic tube (has branch in middle ear called chorda tympani for a2/3 (t) that goes down and joins facial nerve out o& stylomastoid foramen)
where does the facial nerve originate?
lateral surface of brainstem between pons and medulla
motor functions of facial nerve (large)
-muscles of facial expression
-stapedius (ear)
-posterior belly of digastric muscle
-stylohyoid
sensory and motor functions of facial nerve (smaller-intermediate)
-taste in A2/3 tongue
-hard + soft palates
-general from external acoustic meatus (ear canal) and deeper parts of auricle
-(motor)parasympathetic glands of nasal cavity (lacrimal, mucous) and sublingual and submandibular glands
function of chorda tympani (branch of facial nerve)
taste of anterior 2/3 of tongue
parasymp innervation to sublingual and submandibular glands
origin of all rectus muscles
common tendinous ring
what nerve innervates the rectus muscles
Oculomotor (III) except lateral rectus (abducens CN VI)
what are the muscles of the eye
-rectus (superior, inferior, lateral, medial)
-obliques (superior, inferior)
-levator palpebrae superioris
what innervates inferior oblique
Oculomotor III
origin of inferior oblique
orbital surface of maxilla
what innervates superior oblique
Trochlear (IV)
origin of superior oblique
body of sphenoid
origin of superior oblique
body of sphenoid
describe the isolated muscle actions for each muscle of the eye
LR: laterally
MR: medially (towards nose)
SR: superior medially
IR: inferior medially
IO: superior laterally
SO: inferior laterally (down and out muscle)
how do we test eye muscle actions clinically for superior rectus? What about superior oblique?
-ask patient to look outwards and then ubpwards showing an abducted movement
-ask patient to look inwards than downwards showing adducted movement
how do we test eye muscle actions clinically for superior rectus? What about superior oblique?
-ask patient to look outwards and then ubpwards showing an abducted movement
-ask patient to look inwards than downwards showing adducted movement
function of oculomotor III nerve on the eye
innervates number of muscles that move the eye and contain autonomic fibres that alters thickness of lens and pupil size
what ganglion allows parasympathetic and sympathetic changing on pupil size and lens thickness
ciliary ganglion of oculomotor nerve (III)
what supplies lacrimal gland
sensation: lacrimal nerve of opthalmic division V1
motor: facial nerve
what are all the nerves of the orbit?
vision: optic (II)
lens thickness + pupil size: oculomotor (III) ciliary ganglion
movement of eye: III, IV, VI, oculomotor, trochlear and abducens
lacrimal gland: V1 (s) and VII (pm)
what nerves are found in the cavernoius sinous
superior -> inferior
-oculomotor nerve iii
-trochlear nerve iv
-abducent nerve vi
-opthalmic division of trigeminal nerve v1
-maxillary division of trigeminal nerve v2
what is inferior to the cavernous sinus?
sphenoidal (paranasal) sinus
function of the lacrimal system
production and (medial) movement + drainage (via nasolacrimal duct) of fluid from surface of eye
