Lecture 5 PQs Flashcards
True or False: CN are peripheral nerves
True
What type of neurons are the motor branches on the CN?
multipolar
What type of neurons are the somatosensory branches on the CN?
pseudounipolar
What type of neurons are the special sensory on the CN most of the time?
bipolar
What are the layers of a peripheral nerve from out to in? What do they consist of in each layer?
(OUT)Epineurium- groups of fascicles; contains blood vessels
Perineurium- groups of axons
(IN) Endoneurium- nerve fiber
Which CNs have both sensory and motor pathways?
CN V, VII, IX, X
Where can the olfactory sensory receptor cells be located?
Olfactory Epithelium
What is the function of basal stem cells in the olfactory epithelium?
regulate new olfactory receptors
How does CN 1 get through the skull to the olfactory bulb in the sensory pathway?
via small foramina aka cribriform plate
What are the cortices that the olfactory tract project to?
amygdala, entorhinal cortex, hippocampus, prefrontal cortex, insula, temporal lobe
Which CNs open and close the lids?
open lids- CN 3
Close lids-CN 7
What structures are in the fibrous outer layer?
sclera and cornea
What structures are in the vascular middle layer?
choroid, ciliary body, and iris
What structures/layers are in the retinal inner layer?
7 layers:
pigment epithium -> photoreceptor layer (contains rods and cones)-> outer and inner nuclear layers-> outer and inner synaptic layers->ganglion cell layer
Other structures:
optic disc and macula lutea
what is the function of the lens?
to bend light to focus on image on retina
Where is the vitreus body/humor located?
between lens and retina
What is in the anterior cavity of the eye?
aqeuous humor- filters plasma and nourishes lens and cornea
In the optic pathway, where do the neurons end following the synapse of 2nd neuron and before the 3rd neuron synapse?
majority terminate at lateral geniculate of thalamus
minority travel to superior colliculus and pretectal nucleus in midbrain
F/u question from previous question; after the superior colliculus and pretectal nucleus, where do the nerves travel to next?
superior colliculus -> primary and supplementary visual areas and numerous brainstem areas
pretectal nucleus-> primary and supplementary visual areas and parasympathetic nuclei controlling pupils
Right visual field input
Left temporal and right nasal retinal input
Left visual field
Right temporal and left nasal retinal input
Left primary visual cortex
Right visual field
Right primary visual cortex
Left visual field
Oculumotor innervates what eye muscles? What are their actions?
Medial rectus - adduction
Superior rectus- elevation and intorsion
Inferior rectus-depression and extorsion
inferior oblique- extorsion and elevation
Trochlear innervates what eye muscles? What are their actions?
Superior oblique - intorsion and depression
Abducens innervates what eye muscles? What are their actions?
lateral rectus - abduction
What muscles are in the superior and inferior divisions of the Oculomotor pathway?
Superior: superior rectus and levator palpebrae
Inferior: inferior rectus medial rectus and inferior oblique
Which regions does the somatosensory branch of V1 trigeminal nerve bring sensation to?
forehead, upper eyelid, cornea, nose
Which regions does the somatosensory branch of V2 trigeminal nerve bring sensation to?
lower eyelid, cheeks, temples, upper lip region, and upper teeth
Which regions does the somatosensory branch of V3 trigeminal nerve bring sensation to?
part of external ear, lower lip, chin, anterior 2/3 of tongue, lower teeth
In the motor pathway what muscles does the mandibular branch of CN V innervate?
masseter, temporalis, medial and lateral pterygoid muscles and tensor tympani
motor trigeminal nuclei
gives rise to efferent to muscles of mastication
principle sensory trigeminal nuclei aka main sensory nuclei
afferent to discriminate touch, light touch, proprioception to face, and dental pressure
mesencephalic trigeminal nuclei
afferent proprioception to jaw
spinal trigeminal nuclei
afferent crude touch, pain, temperature of face
5 major branches to muscles of facial expression
temporal, zygomatic, buccal, mandibular, and cervical
what reflex would cause bilateral eye blinking? what cranial nerves are involved?
corneal reflex; CN V and IV
what reflex functions to prevent aspiration of solid foods? what cranial nerves are involved?
gag reflex; CN IX and X
