Chapter 11- Diencephalon, Brain Stem, + Cranial Nerves

diencephalon

between hemispheres, superior to brainstem, gray matter; thalamus, hypothalamus, optic chiasma, glands; modulates sensory motor and cognitive functions

thalamus

receives and sends out sensory impulses, synchronizes action potentials

hypothalamus

maintains homeostasis, regulates heart rate + blood pressue, body temp, hunger, sleep + wakefulness AUTONOMIC FUNCTIONS

limbic system

guides behavior based on emotions

optic tracts

neurons taking visual information to the thalamus, optic nerves after crossing optic chiasma

optic chiasma

optic nerve fibers crossing over (X)

infundibulum

funnel attaching pituitary gland

pituitary gland

“master gland” that secretes hormones

mammillary bodies

behavior responses, smell reflexes

pineal gland

secretes melatonin regulated by circadian rhythm (sleep-wake cycle)

brainstem

connects brain to spinal cord; midbrains, pons, medulla oblongata

midbrain

between diencephalon + pons, bundles of myelinated nerve fibers, lots of gray matter, contains cerebral aqueduct; sleeping rhythms

midbrain four nuclei

superior collliculi + inferior colliculi

superior colliculi

visual reflexes, fixing eyes while head turns

inferior colliculi

auditory reflexes, move head to hear sounds more distinctly

red nucleus

part of brain stem that communicates with cerebellum, maintains posture, rich in blood vessels

pons

full thickness of brainstem, relay sensory info with medulla and cerebrum, control breathing

medulla oblongata

continuation of spinal cord at foramen magnum, heart rate, vasomotor function (blood pressure), rhythm of breathing, coughing/sneezing/swallowing/vomiting, digestion

reticular formation

network of nerve fibers in brainstem; connect parts of brain, activates and wakes up cerebral cortex, pain modulation, motor activities

Non-REM sleep

restful and dreamless, reduced blood pressure and respiratory rate

REM sleep

eyes move, dreaming, lasts 5-15 minutes

cranial nerves

originate from brain, communicate with rest of body, 12, smell and vision, motor, or mixed

motor cranial nerves

limited function, proprioreceptors

cranial nerve types

olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facialvestibucochlear, glossopharyngeal, vagusaccessory, hypoglossal,

olfactory nerves (I)

smell, sensory neurons, upper nasal cavity, move along olfactory tracts from bulbs

optic nerves (II)

vision, eyes to brain, pass through optic foramina

oculomotor nerves (III)

midbrain to eyes, raise eyelids + move eyes, adjust eyes to light + focus lenses

trochlear nerves (IV)

midbrain to external eyes muscles

trigeminal nerves (V)

largest, arise from pons, mixed, ophthalmic, maxillary, and mandibular divisions

ophthalmic division

tear gland, scalp forehead + upper eyelid

maxillary

sensory in upper teeth, upper gum, upper lip

mandibular

mixed, jaw, lower teeth.gum/lip, mastication

abducens nerves (VI)

pons near medulla oblongata, motor to external eye muscles

facial nerves (VII)

mixed, taste receptors on anterior tongue, tear glands + salivary glands

vestibulocochlear nerves (VIII)

medulla oblongata, auditory, hearing receptors

glossopharyngeal nerves (IX)

tongue + pharynx, mixed, tonsils, salivary glands + swallowing

vagus nerves (X)

mixed, larynx + pharynx, speech + swallowing

accessory nerves (XI)

pharynx, larynx, soft palate, motor

hypoglossal nerves (XII)

tongue, speaking chewing and swallowing, motor