4.3: Brainstem & Cranial Nerves

brainstem: connects __ & ___

-ascending & descending tracts

-site of _____ & __ control centers

-includes: ____

diencephalon, spinal cord, cranial nerve nuclei (group of neurons together), autonomic control, midbrain, pons, medulla oblongata

midbrain:

-superior colliculi is responsible for: ____

-inferior colliculi is responsible for: ___

coordination of head & eye movements, relaying auditory info from inner ear to brain & startle reflex

pons:

-tracts (group of axons going to same region) connecting ___ to ____ & _

cerebrum, spinal cord, cerebellum

medulla oblongata:

-all ascending & descending tracts pass through

-pyramids carry __ fibers from cerebrum

-descending fibers cross midline

-right & left __ __ control opposite side

motor, motor cortices

reticular formation:

-brainstem functional system

-widespread connections to: ____

-____ aka RAS: continuous stream of stimuli to cerebrum maintains __

-habituation: repetitive stimuli filtered out

-inhibited by __

-severe injury can led to permanent coma

-cerebrum, diencephalon, cerebellum

-reticular activating system, alertness

-hypothalamic sleep centers

spinal cord: continuous connection between __ & _

-shorter than vertebral column: ends ~L12

brain, body

spinal cord gray matter:

-dorsal (posterior) horn contains ___ nerves

-dorsal nerve root contains only ___ fibers

-ventral horn contains ___ neurons

-ventral root nerve contains only ___ fibers

-lateral horn: T2-L1: ___ neurons

sensory, sensory, motor, motor, sympathetic

spinal cord white matter types: ____

-divided into 3 columns containing white matter (myelinated nerve fibers) called tracts/ fisciculi

-types of tracts: ascending & descending

-ascending tracts: __

-descending tracts: ___

-many tracts ___ aka cross over midline

dorsal, lateral, ventral

send sensory info from body to brain, send motor info from brain to spinal cord, decussate

ascending tracts: 3-neuron relay

-send __ (afferent/ efferent) stimuli from body to brain

-first order neurons: ___ stimulus, communicate with second order neuron at ___

-second order neurons: carry signal to ___

-third order neurons: carry signal from ___ to ____

afferent, detect, spinal cord, thalamus, thalamus, sensory cortex

ascending tract types

dorsal column-medial lemninscal (DCML):

-carries sensory info like ____

-sensory info to ___

spinothalamic tract:

-carries sensory info like ____

-sensory info to ____

visceral pain, vibration, proprioception, contralateral cortex

somatic pain, pressure, temp, contralateral cortex

descending tracts: 2-neuron relay

-upper motor neurons: originate in ___ or ___

-synapse at ___ or ____

-lower motor neurons: synapse in ___ or ___

brainstem, cerebral cortex, brainstem, spinal cord, muscle fiber, gland

descending tract types

corticospino tract:

-general____ motor control

-decussate at _____

technospinal tracts:

-originate in ___

-coordinate head movements in response to visual/ auditory stimuli (usually in the form of reflex)

voluntary, pyramidal decussation, midbrain

cranial nerves:

-innervate ____

-12 pairs, numbered ___ to ___

-mneumonic: on, on, on, they traveled and found voldemort guarding very ancient horcruxes

-6 types of cranial nerves:

head & viscera (internal orgnas), anterior, posterior, optic, trigeminal, facial, vagus, accessory, hypoglossal

optic nerve cranial nerve:

CN#___

*-technically tract bc of white matter and same region of CNS

-first order cells: ____ cells

-second order neurons: ___ nerve

-half of fibers decussate at ___

-third order neurons: ____

-sensory function: vision

2, bipolar, optic, optic chiasm, optic radiations

trigeminal (CNS) cranial nerve:

-V1: ophthalmic: sensation from _____

-V2: maxillary: sensation from ___

V3: mandibular: general sensation from ___

-___ motor innervation of muscles of _____

superior face & scalp, nasal/ conjunctional mucosa

mid & lateral face & upper teeth

lateral & inferior face, lower teeth & anterior 2/3 of tongue

somatic, mastication

facial cranial nerve:

-CN # ____

-___ nerve function: facial expression

-____ motor function:

-lacrimal glands: tears

-submandibular & sublingual glands produce: ___

-nasla & palatine glands produce: ____

-special sensory function: ___

7 (VII), somatic, visceral, saliva, mucous, taste sensation from anterior 2/3 tongue

vagus cranial nerve:

CN#__

-”wanderer”

-somatic motor fibers to ____

-visceral motor fibers to _____ for regulation of heartbeat, breathing, etc

-___ sensation from external ear, pharynx, larynx

-___ sensation from aortic ANS sense organs

10, pharynx & larynx, thoracoabdominal viscera, general, visceral

accessory cranial nerve:

CN #___

-located in: ____

-somatic motor fibers to: _____

-help to flex, roatte head, retract, rotate scapula

11 (XI), soma in C1-C5 ventral horn, trapezius & sternocleidomastoid muscles

hypoglossal cranial nerve (XII):

-somatic motor fibers to: ____

-help with chewing, swallowing, speech

intrinsic & extrinsic tongue muscles

superior colliculi & inferior colliculi

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gray matter in deeper portions of spinal cord

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white matter: superficial covering over gray matter in spinal cord

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ascending tracts

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descending tracts

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