3: Anatomy - orbital autonomics Flashcards
Which two bones of the bony orbit is the suspensory ligament attached to?
Lacrimal (medially)
Zygoma (laterally)
If the zygoma is fractured, what happens to the suspensory ligament and the eye?
What symptom does this cause?
Suspensory ligament ruptures and eye drops
Diplopia (double vision)
Which cranial nerve is response for the sensation of the face?
CN V
(Trigeminal nerve)
Which nerves are responsible for sensation of
a) mandible and TMJ
b) maxilla
c) angle of mandible
d) cornea, conjunctiva and bridge of nose
a) CN V3
b) CN V2
c) C2 and C3
d) CN V1
What are the names of
a) CN V1
b) CN V2
c) CN V3?
a) Ophthalmic divison of trigeminal nerve
b) Maxillary division of “” ““
c) Mandibular division of “” ““
Which cranial nerves are responsible for the
a) sensory
b) motor
parts of the blink reflex?
a) CN V1
b) CN VII
Which cranial nerve supplies the orbicularis oculi?
CN VII (Facial nerve)
Which part of the orbicularis oculi is responsible for blinking?
Palpebral part
Which nerves pass through the
a) supraorbital notch / foramen
b) infraorbital notch
and which cranial nerves do they belong to?
a) Supraorbital nerve from CN V1
b) Infraorbital nerve from CN V2
Which fluid nourishes the cornea and washes away debris?
Lacrimal fluid
Which structures control
a) pupil diameter
b) lens shape?
a) Iris
b) Ciliary body
Where do sympathetic nerves originate?
Autonomic centres in the brain
At which levels do sympathetic nerves exit the spinal cord?
T1 - L2
Sympathetic nerves exit the spinal cord from __ - __.
T1 - L2
After exiting the spinal cord, where do sympathetic nerves go?
Sympathetic chain
How do sympathetic nerves reach somatic areas e.g the skin from the sympathetic chain?
Alongside spinal nerves
How do sympathetic nerves reach visceral areas i.e the organs?
In splanchnic nerves:
cardiopulmonary splanchnic nerves
abdominopelvic splanchnic nerves
How do sympathetic nerves reach
a) organs
b) the skin?
a) Splanchnic nerves
b) Spinal nerves
At which spinal level do sympathetic nerves exit the spinal cord to supply the head and neck?
T1
The sympathetic nervous system travels in the ___ outflow before reaching the sympathetic chains.
thoracolumbar outflow
T1 to L2
Where do sympathetic nerves synapse in the head and neck?
Superior, middle and inferior cervical ganglia
Sympathetic nerves for the head and neck exit the spinal cord at __ and travel in the sympathetic chains before synapsing where?
T1
Superior, middle and inferior cervical ganglia
After they synapse at the cervical ganglia, which structures do sympathetic nerves travel alongside?
Arteries
In peri-arterial plexuses
Which artery transports post-synaptic sympathetic nerves to the orbit?
Ophthalmic artery
Which cranial nerves do parasympathetic nerves come from?
CN III (Oculomotor)
CN VII (Facial)
CN IX (Glossopharyngeal)
CN X (Vagus)
CN III, VII, IX and X all transmit (sympathetic / parasympathetic) fibres.
parasympathetic
Apart from cranial nerves, which area transmits parasympathetic fibres?
Sacrum
The parasympathetic nervous system has a ___ outflow - why?
craniosacral
Parasympathetic nerves originate from CN III, VII, IX and X plus the sacral spinal nerves
Where as the sympathetic nervous system has a thoracolumbar outflow because its nerves come from T1 - L2 spinal nerves only
The (sympathetic / parasympathetic) nervous system supplies the body wall.
sympathetic
Which internal organs are supplied by parasympathetic fibres of
a) CN III
b) CN VII
c) CN IX
d) CN X
e) Sacral spinal nerves?
a) Eye
b) Submandibular, sublingual and lacrimal glands
c) Parotid glands
d) Neck, chest and abdominal organs up to midgut
e) Hindgut, pelvic and perineal organs
Through which hole in the bony orbit does CN III exit?
Superior orbital fissure
Which extraocular muscles are supplied by CN III?
Medial rectus
Superior rectus
Inferior rectus
Inferior oblique
Levator palpebrae superioris
CN III’s (sympathetic / parasympathetic) fibres control muscles of the ___ and synapse at which ganglion?
parasympathetic fibres
eye
ciliary ganglion
CN III splits into superior and inferior ___ to supply muscles of the eye.
divisions
Which extraocular muscles are supplied by the
a) superior division
b) inferior division
of CN III?
a) Superior rectus, Levator palpebrae superioris
b) Medial rectus, Inferior rectus, Inferior oblique
Which nerves supply sympathetic and parasympathetic fibres to control the diameter of the iris and the shape of the lens?
Long ciliary nerve (superior)
Short ciliary nerve (inferior)
The eyes have a lot of involuntary __ in response to different stimuli.
reflexes
Sympathetic fibres…
(open / close) the eyes
get (more / less) light into the eyes
focus on (near / far) objects
produce lacrimal fluid in response to (debris / emotions)
OPEN the eyes
get MORE light in
focus on FAR objects
produce lacrimal fluid in response to EMOTIONS
Parasympathetic fibres…
get (more / less) light into the eyes
focus on (near / far) objects
LESS light into the eyes
focus on NEAR objects
Which muscle opens the upper eyelid?
Which cranial nerve supplies it?
Which type of autonomic fibres cause it to open in a reflex?
Levator palpebrae superioris
CN III
Sympathetic
What structure is the levator palpebrae superioris attached to?
Superior tarsus
Which autonomic fibres dilate the pupils?
Sympathetic fibres
A non-physiologically dilated pupil is called a ___ pupil.
mydriatic
Which muscle dilates the pupil?
Dilator pupillae
Which autonomic fibres constrict the pupils?
Parasympathetic fibres
Which muscle constricts the pupils?
Sphincter pupillae
In which light conditions does the pupil
a) constrict
b) dilate?
a) Bright light
b) Low light
A non-physiologically constricted pupil is called a ___ pupil.
miotic pupil
Mydriatic pupils are abnormally ___.
Miotic pupils are abnormally ___.
dilated
constricted
Which syndrome, caused by reduced sympathetic impulses to the head and neck, causes miotic pupils?
Horner’s syndrome
Which drugs cause miosis?
Opiates
A fixed-dilated pupil is a sign of problems with which cranial nerve?
CN III
What is the pupillary light reflex?
Pupils BILATERALLY constrict into response to bright light
Is the pupillary light reflex unilateral or bilateral?
Bilateral
Which nerves control the
a) sensory
b) motor
parts of the pupillary light reflex?
a) CN II
b) CN III
The pupillary light reflex is a _ neurone chain.
4 neurone chain
Which ganglia do impulses from the optic nerve travel through?
Retinal ganglia
Which part of the midbrain do impulses synapse at in the pupillary light reflex?
Pretectal ganglia
Which specific part of the pretectal nucleus do nerve impulses synapse at in the pupillary light reflex?
Edinger-Westphal nucleus
Which cranial nerve has parasympathetic fibres in the Edinger-Westphal nucleus?
CN III
Oculomotor nerve
After synapsing at the EW nucleus, parasympathetic nerves then synapse in ___ ganglia before travelling along which nerve to the sphincter pupillae muscles?
ciliary
short ciliary nerves
Which structures are responsible for the shape of the lens?
Suspensory ligament
Ciliary muscles
What do ciliary muscles do to focus the lens on near objects?
Which autonomic nerves control this?
Contract
Parasympathetics
What do ciliary muscles do to focus the lens on far objects?
Which autonomic nerves control this?
Relax
Sympathetic
When the ciliary muscles contract, the lens (flattens / becomes spherical) to focus on (near / far) objects.
contraction
becomes spherical
near objects
When the ciliary muscles relax, the lens (flattens / becomes spherical) to focus on (near / far) objects.
relaxation
flattens
far objects
Which cranial nerve controls the ciliary muscles?
CN III
Oculomotor nerve
What is the accomodation reflex?
Focusing of eyes on object coming towards you in the midline
In the accommodation reflex, CN III controls three different actions. What are they?
1. Bilateral pupillary constriction by sphincter papillae muscles
2. Adduction of eyes towards midline by medial rectus muscles
3. Focusing of lens on near object by ciliary muscles
Which fluid nourishes the cornea?
Lacrimal fluid
Lacrimal fluid is also known as what?
Tears
Which cranial nerves control the
a) sensory
b) motor
components of the reflex production of lacrimal fluid?
a) CN V1 - ophthalmic division of trigeminal nerve
b) CN VII - facial nerve (which supplies lacrimal glands)
With regard to the eyes and face, what are the functions of CN VII?
Glands: lacrimal, submandibular, sublingual
Muscles: orbicularis oculi (and other muscles of facial expression)
What are the symptoms of Horner’s syndrome?
Miosis (constricted pupil unilaterally)
Ptosis (droopy eyelid ipsilaterally)
Reduced sweating (anhydrosis)
Increased warmth and redness
