neuro 31-36 Flashcards by SOPHIA ANNE MANUBAY

Component of CN I

Purely Sensory
SSA - Smell

How well did you know this?

Not at all

Perfectly

CN 1 Pass through

cribriform plate

How well did you know this?

Not at all

Perfectly

coarse peripheral process that passes to the surface of the membrane and a fine central process

Small bipolar nerve cell

How well did you know this?

Not at all

Perfectly

arise from peripheral process and project into the mucus membrane

Short cilia (olfactory hairs)

How well did you know this?

Not at all

Perfectly

fine central process; unmyelinated and covered by Schwann cells

Olfactory nerve fiber

How well did you know this?

Not at all

Perfectly

Ovoid structure

Olfactory Bulb

How well did you know this?

Not at all

Perfectly

Olfactory bulb contains many diff types of cells:

Mitral cells, tufted cells and granular cells

How well did you know this?

Not at all

Perfectly

Synaptic glomeruli

Olfactory Bulb

How well did you know this?

Not at all

Perfectly

Receives axons from contralateral olfactory bulb through olfactory tract

Olfactory bulb

How well did you know this?

Not at all

Perfectly

Runs from olfactory bulb beneath the inferior surface of the frontal lobe

Olfactory Tract

How well did you know this?

Not at all

Perfectly

contains Axons of mitral and tufted cells of the bulb and some centrifugal fibers from the opposite olfactory bulb

Olfactory Tract

How well did you know this?

Not at all

Perfectly

Divides to medial and lateral olfactory striae near the anterior perforated substance

Olfactory Tract

How well did you know this?

Not at all

Perfectly

(olfactory tract) sends axons to olfactory area of cerebral cortex (which are the periamygdaloid and prepiriform areas)

Lateral striae

How well did you know this?

Not at all

Perfectly

(Olfactory tract) contains / carries fibers that cross in the anterior commissure to pass to the contralateral olfactory bulb

Medial striae

How well did you know this?

Not at all

Perfectly

Periamygdaloid and prepiriform areas

Primary Olfactory Cortex

How well did you know this?

Not at all

Perfectly

aka Entorhinal area (area 28) of parahippocampal gyrus

Secondary Olfactory Cortex

How well did you know this?

Not at all

Perfectly

Appreciation of olfactory sensation

Secondary Olfactory Cortex

How well did you know this?

Not at all

Perfectly

Does not synapse directly with the thalamus

Secondary Olfactory Cortex

How well did you know this?

Not at all

Perfectly

Component of CN 2

Purely Sensory
SSA - Vision

How well did you know this?

Not at all

Perfectly

Photoreceptors form the outermost layer, farthest from the lens

OPTIC NERVE (CN II)

How well did you know this?

Not at all

Perfectly

other layers of the retina are not present, allowing light to reach the photoreceptors without distortion

Fovea

How well did you know this?

Not at all

Perfectly

Axons of ganglionic layer of the retina, converge on the optic disc and exit from the eye

Optic nerve

How well did you know this?

Not at all

Perfectly

3-4 mm to the nasal side of its center

Optic nerve

How well did you know this?

Not at all

Perfectly

Myelinated by oligodendrocytes

Optic nerve

How well did you know this?

Not at all

Perfectly

Leaves via optic canal

Optic nerve

Union of 2 optic nerves

Optic Chiasm

Located at the junction of the anterior wall and floor of the 3rd ventricle

Optic Chiasm

Anterolateral angles are continuous with the

optic nerves

Posterolateral angles are continuous with

optic tracts

cross midline and enter the optic tract on the opposite side

Nasal half of retina and nasal half of macula

pass posteriorly in optic tract of same side

Temporal half of retina and temporal half of macula

Emerges from optic chiasm and pass posterolaterally around the cerebral peduncle

Optic Tract

Terminate by synapsing with lateral geniculate body (LGB)

Optic Tract

Some pass through pretectal nucleus and superior colliculus for light reflex

Optic Tract

Small ovoid swelling dorsal to pulvinar of thalamus

Lateral Geniculate Body (LGB)

Axons leaving the LGB

optic radiation

Passes posteriorly through the retrolenticular part of the internal capsule and terminates in the visual cortex (area 17)

Optic Radiation

Area 17

Visual Cortex

Upper and lower lips of the calcarine sulcus

Visual Cortex

Area 18 and 19

Visual Association Cortex

Object recognition and color perception

Visual Association Cortex

specialized receptors in retina

Rods and cones

connect rods and cones to ganglion cells

Bipolar neurons

axons pass to IGB

Ganglion cells

axons pass to the cerebral cortex

Neurons of LGB

Binocular Vision Right and left fields of vision are projected on portions of both

retinae

Binocular Vision the axons from these two retinal halves are combined to form the left optic tract in

optic chiasma

Binocular Vision project the complete right field of vision on the visual cortex of the left hemisphere and the left visual field on the visual cortex of the right hemisphere.

GB neurons

Binocular Vision project on the lower wall of the calcarine sulcus

lower retinal quadrants

Binocular Vision project on the upper wall of the sulcus.

upper retinal quadrants

Visual Reflexes (5)

Direct and Consensual Light Reflex Accommodation Reflex Corneal Reflex Visual Body Reflexes Pupillary Skin Reflex

constriction of the pupil where light is shone

Direct Light Reflex

constriction of contralateral pupil

Consensual Light Reflex

Synapse with

pretectal nucleus

Bilateral Edinger-Westphal (EDW) nuclei (PSY nuclei of CNIII)

= Direct and Consensual Light Reflex =

Fibers travel through CN Ill and synapse with ciliary ganglion

= Direct and Consensual Light Reflex =

Postganglionic PSY fibers pass through short ciliary nerves to the constrictor pupillae muscle of iris

= Direct and Consensual Light Reflex =

For near vision

= Accommodation Reflex =

aims the visual axes onto the near fixation point

medial recti

restrict the light waves to the thickest central part of the lens

Pupillary constriction by pupillary constrictor muscles of the iris (PSY)

increase lens refractive power

Lens thickening by contraction of the ciliary muscles (PSY)

Lens is normally under tension from the suspensory ligament to relax, producing a rounder more convex lens shape

= Accommodation Reflex =

Visual cortex is connected to

frontal eye field

Arrange the course of oculomotor nerve Oculomotor nerve to medial recti muscles Cortical fibers descend through to oculomotor nuclei → internal capsule

Cortical fibers descend through internal capsule to oculomotor nuclei → Oculomotor nerve to medial recti muscles

Ciliary ganglion → Ciliary muscle and constrictor pupillae → Short ciliary nerves Some fibers synapse with Edinger-Westphal nuclei on both sides

Some fibers synapse with Edinger-Westphal nuclei on both sides → Ciliary ganglion → Short ciliary nerves → Ciliary muscle and constrictor pupillae

Light touching of the cornea or conjunctiva causes blinking

= Corneal Reflex =

Afferent impulse from: CN V (V1)

= Corneal Reflex =

= Corneal Reflex = Efferent

CN VII

= Corneal Reflex = Afferent impulses from

ophthalmic division (V1) of trigeminal nerve

= Corneal Reflex = Internuncial neurons connect with motor nucleus of facial nerve on both sides through

medial longitudinal fasciculus (MLF)

= Corneal Reflex = Facial nerve supply orbicularis oculi

eyelid closure

Automatic scanning movements of eyes and head during reading

= Visual Body Reflex =

Automatic movement of eyes, head and neck toward source of visual stimulus

= Visual Body Reflex =

Protective closing of eyelids

= Visual Body Reflex =

= Visual Body Reflex = Afferent impulses from optic tracts to

superior colliculus

Relayed to tectospinal and tectobulbar tracts

= Visual Body Reflex =

Purely Motor Parasympathetic

OCULOMOTOR NERVE (CN III)

GSE in function - raises upper eyelid, turns eyeball upward, downward and medially

OCULOMOTOR NERVE (CN III)

OCULOMOTOR NERVE (CN III) parasympathetic so GVE

pupillary constriction, accommodation (ie edinge-westphal)

Extraocular Muscles OCULOMOTOR NERVE (CN III)

Lateral rectus (LR) Medial rectus (MR) Superior rectus (SR) Inferior rectus (IR) Superior oblique (SO) Inferior oblique (IO)

Extraocular Muscles originate from a tendinous ring at the orbital apex and insert to sclera

Inferior rectus (IR)

Extraocular Muscles originate in sphenoid bone in posterior medial orbit and passes anteriorly through the trochlea then inserts on superior surface of eye to produce intorsion

Superior oblique (SO)

Extraocular Muscles torsional movements

Inferior oblique (IO)

no trochlea, originates on anteromedial orbital wall and inserts on inferior surface for extorsion

Inferior oblique (IO)

Oculomotor nerve supplies all EOMs except

SO and LR

After entering the orbit, divides into:

Superior division: SR and levator palpebrae superioris Inferior division: MR, IR, 10 and preganglionic PSY fibers to pupillary constrictor muscles and ciliary muscles

innervates SO

Trochlear nerve CN4

innervates LR

Abducens nerve CN6

2 motor nuclei: = Oculomotor Nerve Nuclei =

Main motor nucleus Edinger-Westphal (EDW) nucleus =

Parasympathetic nucleus of CN III

Edinger-Westphal (EDW) nucleus

Anterior part of gray matter surrounding the cerebral aqueduct

Main Oculomotor Nucleus

At the level of superior colliculus

Main Oculomotor Nucleus

Supply all extrinsic eye muscles except superior oblique and lateral rectus

Main Oculomotor Nucleus

Oculomotor nerve pass anteriorly through red nucleus and emerge on the interpeduncular fossa between the PCA and SCA

Main Oculomotor Nucleus

Main Oculomotor Nucleus Receives corticonuclear fibers from both

cerebral hemispheres

Main Oculomotor Nucleus Receives tectobulbar fibers from

superior colliculus

Receives fibers from MLF (connected to CN IV, VI and VIII)