Eye and Ear anatomy Flashcards
What 7 bones form the orbit
Ethmoid Lacrimal Palatine Maxilla Zygomatic Frontal Sphenoid
What passes through the optic foramen
Optic nerve
Ophthalmic artery
What passes through the Superior Orbital Fissure
IV nerve VI nerve Ophthalmic division of V nerve III nerve ophthalmic veins
What passes through the Inferior orbital fissure
Maxillary division of V nerve
What air sinus are in close proximity to the walls of the orbit
Frontal sinus
Ethmoid sinus
Maxillary sinus
What are the main contents of the orbit
Eyeball Extrinsic ocular muscles Ligaments supporting the eye Branches of ophthalmic artery The lacrimal apparatus Blood vessels
The eye: what is in the outer fibrous layer
- Sclera
- Cornea
Complete layer
The eye: what is in the middle vascular layer
- Choroid
- Ciliary body
- Iris
It is incomplete anteriorly
Anterior aperture in the iris is the pupil
The eye: What is in the Inner sensory layer
Retina
Present posteriorly but anteriorly it stops short just in front of equator of the eye
What does the crystalline lens do
Divides the eye into an anterior and posterior segment
What is the watery fluid in the anterior segment called
Aqueous humor
What is the gel in the posterior segment called
Vitreous humor
What part of the eye produces aqueous humour
Fibrous layer
Intrinsic muscles of the eye: where is the ciliaris located, what does it do, and how is it innervated
Location - ciliary body
Action - Accommodation
Innervation - parasympathetic via cranial nerve III
Where is the constrictor papillae located, what does it do, and how is it innervated
Location - Pupillary border of iris
Action - Constricts
Innervation - Parasympathetic via cranial nerve III
Where is the Dilator pupillae located, what does it do, and how is it innervated
Location - radially running muscle in iris
Action - Dilates
Innervation - sympathetic innervation
Eye movements: name the movements of the eye
Elevation (looking up) Depression (looking down) Adduction (Looking medially) Abduction (looking laterally) Intortion (towards the nose) Extortion (away from the nose)
Extrinsic muscles of the eye: action of the medial rectus
Adduction
Action of the Lateral rectus muscle
Abduction
Action of the superior recuts muscle
Elevation
Adduction
Intorsion
Action of the inferior rectus muscle
Depression
Adduction
Extorsion
Action of the superior oblique
Depression
Abduction
Intorsion
Action of the inferior oblique
Extorsion
Elevation
Abduction
Which is the only muscle that doesn’t arise from the posterior aspect of the orbit
Inferior oblique
What ligaments prevent over-adduction and over-abduction o the eye
Medial and lateral check ligament
What is the function of the suspensory ligament of the eye
Fine tune
Focus on near or distant objects
What branch of the ICA supplies the orbit and the eye
opthalmic
The Ear: 4 main structures
- tympanic membrane
- Malleus
- incus
- Stapes
Auditory ossicles = Malleus, Incus and Stapes
What type of joint is found between the ossicles
synovial joint
Which ossicle is in contact with the tympanic membrane
malleus
which ossicle is in contact with the oval window
Stapes (base attached to margins of oval window)
Name 2 muscles that are related to the ossicles
Tensor tympani and stapedius
Within which part of the temporal bone do the middle and inner ear lie
petrous part
What are the bone lined chambers called within the ear
bony labyrinth
What are the series of membranous chambers that are inside the bony labyrinth
membranous labyrinth
What fluid lies within the bony labyrinth
perilymph
What fluid lies within the membranous labyrinth
endolymph
Through which foramen does the facial nerve exit the posterior cranial fossa
internal acoustic foramen
Where does the facial nerve run
In a canal on the medial wall of the middle ear cavity
What is the action of the Tensor tympani muscle?
Reduces amplitude of vibrations (tenses tympanic membrane)
What is the action of the Stapedius muscle?
Reduces oscillatory range, prevents excessive movement of stapes
