Orbit and Cavernous Sinus Flashcards
complete ptosis
destruction of the Oculomotor (III) n. or one of its branches to LPS
slight ptosis
horner’s syndrome is loss of postganglionic sympathetic fibers from the cervical ganglion
leads to loss of innervation of the tarsal mm
parasympathetic inn to lacrimal gland
PRE - superior salviatory nucleus to facial, greater superficial petrosal, and vidan n to sphenoplatine ganglion
POST - sphenopalantine ganglion to maxillary, zygomatic, and lacrimal n to lacrimal gland
sympathetic inn to lacrimal gland
POST - superior cervical ganglion to internal carotid plexus to deep petrosal, greater superficial petrosal and Vidian n. through the sphenopalatine ganglion to the maxillary, zygmatic, and lacrimal n. to the lacrimal gland
traumatic optic neuropathy
intracanilicular portion of optic n can loose blood supply from ophthalmic a after an orbital fracture
blow out fracture
damage of the floor of the orbit
cause herniation of certain orbital structures into the maxillary sinus
(periobita, inferior oblique and inferior rectus m, orbital fat pad)
Le Forte Type I
transverse fractures of the maxillae just above the alveolar processes
Le Forte Type II
pyramidal-shaped fractures of the maxillae involving part of the medial margin of one orbit
Le Forte Type III
extensive transverse fractures of the face involving many facial bones and both orbits (panda bear)
face has been separated from the base of the skull
levator palpebrae superioris (LPS)
inn: superior division of III
paralysis: complete ptosis
superior rectus (SR)
inn: superior division of III
paralysis: inability to ABduct and elevate the affected eye
medial rectus (MR)
inn: inferior division of III
paralysis: inability to ADduct the affected eye
inferior rectus (IR)
inn: inferior division of III
paralysis: inability to ABduct and depress the affected eye
inferior oblique (IO)
inn: inferior division of III
paralysis: inability to ADduct and elevate the affected eye
superior oblique (SO)
inn: IV
paralysis: inability to ADduct and depress the affected eye
lateral rectus (LR)
inn: VI
paralysis: inability to ABduct the affected eye
increased intracranial pressure may compress VI leading to paralysis of LR
direct and consensual corneal reflexes
IN BY 5 OUT BY 7 stimulus: touching the cornea R: nacked n endings in cornea Afferent: nasociliary n Sensory nucleus: descending nucleus of V Motor nucleus: facial nucleus Efferent fibers: facial n Effector: obicularis oculi m Response: blinking
central retinal a
infero-medial to the optic n and constitutes main supply to the retina
sphincter pupillae m
when contracted decrease the diameter of the pupil
inn by POST parasympathetic axons from ciliary ganglion
dilator pupillae m
when contracted increase the diameter of the pupil
inn by POST sympathetic branch from the ciliary ganglion
direct light reflex
light in one eye leads to pupillary constriction of stimulated eye
mediated at the level of the brainstem via PARAsypmathetics
consensual light reflex
light in one eye leads to pupillary constriction of contralateral eye
same as direct light reflex
involved the POSTERIOR COMMISSURE
pupillary dilation response
decrease amount of light leads to bilateral reflex dilation of the pupils
SYMPATHETIC response mediated through the brainstem and upper spinal cord
horner’s syndrome
leads to ipsilateral pupillary constriction, slight ptosis, and anhydrosis, blushing of the face
