Regional Anatomy III (6) (last for test 1)

hypothalamus general function

principal modulator of autonomic system → receives sensory info about physiological status and regulates based on this to maintain homeostasis (often by regulating hormal effectors)

3 main regions of hypothalamus

lateral hypothalamic area

medial hypothalamic area

periventricular area

lateral hypothalamic area location, regions

along rostro-caudal axis, has no discrete nuclei

medial hypothalamic area location, regions

from rostral to caudal, 3 regions: chiasmatic, tuberal, mammillary

periventricular area location

faces third ventricle

label hypothalamic regions

lateral hypothalamic area general function

involved in motivation-reward, feeding (hunger center), sleep-wake control (wakefulness)

chiasmatic/supraoptic region general function

regulates hormone release in pituitary gland

maintains water concentration in EC fluid, stress response, cardiovascular function, body temp, food intake, circadiuan rhythms

nuclei in the chiasmatic/supraoptic region release…

CRH (corticotropin-releasing hormone → stress response)

TRH (thyrotropin-releasing hormone → maternal behavior, lactation)

GnRH (gonadotropin-releasing hormone → ovulation or testosterone, depeding M or F)

oxytocin, vasopressin, somatostatinn

tubural area functions

food intake regulation (hunger, especially satiety master switch), senses chemicals for full/empty stomach indication, releases growth hormone-releasing hormone (GHRH)

mammillary area function

regulation of memory formation, spatial navigation, thermoregulation (shivering/vasoconstriction

periventricular area function

analgesia, production of GnRH, THR, somatostatin

label 3 regions

green: chiasmatic/supraoptic

gray: tuberal

pink: mammillary body and nuclei

label optic chiasm and nerve, infundibulum, pituitary stalk

main inputs to hypothalamus

fornix (from HC)

stria terminalis (from amygdala)

CVOs

nucleus of solitary tract

main outputs of hypothalamus

major efferent bundles: medial forebrain bundle, dorsal longitudinal fasciculus

output control of pituitary gland/hypophosis

label major afferents/efferents, portions of brain, pituitary gland

main sources of blood supply to diencephalon

willis circle, PCA branches

branches from ACA and ACom supply…

optic chiasm, chiasmatic and tuberal hypothalamus

branches from PCA and PCom supply…

caudal hypothalamus

most of the thalamus’ blood is supplied from…

PCom artery branches (thalamoperforating and thalamogeniculate)

label thalamus, midbrain, pons

label parts of brainstem

midbrain from, includes

derived from mesencephalon, includes tectum and tegmentum

pons derived from, includes

derived from metencephalon, includes pons tegmentum, basilar pons, cerebellar peduncles

medulla derived form, includes

derived from myelencephalon, the spinal cord merges into medulla at pyramidal decussations

main sources of blood supply to brainstem

basilar artery, vertebral artery and branches

the basilar artery supplies blood to…

ventral and lateral cerebellum, pons, choroid plexus of 4th ventricle

the PCA supplies blood to…

midbrain

the vertebral artery and branches supply blood to…

medulla, part of cerebellum, posterior dura

label brainstem blood sources

cellular structures located throughout all the brainstem

cranial nerve nuclei (sensory and motor)

fiber tracts

reticular formation

raphe nuclei

ascending v descending fiber tracts

ascending convey information toward forebrain, descending convey information toward spinal cord

structures located specifically in midbrain

superior and inferior colliculi, red nuclei, substantia nigra

structures located specifically in pons

pontine nuclei, superior olivary nucleus

structures located specifically in medulla

inferior olivary nuclei, dorsal column nuclei

ratio between cranial nerve nuclei and nerves

NOT 1:1 → nerves may be associated with multiple nuclei/travel through multiple locations (esp if carrying multiple kinds of info, ie sensory and motor, must stop in multiple nuclei)

general information about efferent cranial nerves

closer to midline, derive from Basal plate (motor), typically innervate muscles

General somatic efferent nerve nuclei …

adjacent to midline

innervate skeletal muscles (derive from somites)

what are skeletal muscles

derive from somites

main GSE nuclei

Oculomotor, trochlear, abducens, hypoglossal

oculomotor nucleus

movement of eye/eyelid, control of pupil

trochlear nucleus

movement of eye

abducens nucleus

movements of eye

hypoglossal nucleus

control of tongue

general visceral efferent nerve nuclei…

GVE, innervate smooth muscles, cardiac muscles, glands

adjacent/lateral to GSE

general, special, visceral

‘visceral’ → internal organs

general: not in the head

special: in the head

visceral: internal organs

main GVE nuclei

Edinger-Westphal, superior and inferior salivatory nuclei, dorsal vagal

Edinger-Westphal nucleus

related to oculomotor → eye/eyelid movement, pupil control

superior salivary nucleus

control of face → facial expression muscles, control of salivary glands, sensation of taste and olfaction

inferior salivatory nucleus

relates to glossopharyngeal → control of throat muscles, salivary glands, 1/3 tongue (sensation of taste), detection of blood pressure in aorta

dorsal vagal nucleus

control of heart, lungs, abdominal organs; sensation of pain from viscera; control of throat muscles

special visceral efferent nerve nuclei…

innervate muscles derived from pharyngeal arches, adjacent/lateral to GVE

pharyngeal arches are…

muscles of pharynx, larynx, facial expression (only in head)

main SVE nuclei

trigeminal motor, facial motor, ambiguus (in spine), accessory

trigeminal motor nucleus

sensation of touch to the face, control of mandibular muscles

facial motor nucleus

control facial expression muscles, sontrol of salivary glands, sensation of taste and olfaction

ambiguus nucleus

related to glossopharyngeal & vagus: throat muscles, salivary gland, 1/3 tongue (taste), blod pressure in aorta detection, hear/lung/abdominal organ control, pain from viscera

accessory nucleus

control of throat and neck muscles (spinal accessory)

label GVE, GSE, SVE

label GVA, SVA, GSA, SSA

general info about afferents

derive from Alar plate (sensory)

GVA info

general visceral afferent, sensory input from internal organs, glands, blood vessels

GVA nucleus

nucleus of the solitary tract

SVA info…

special visceral afferent, input from special chemical or visceral senses (gustative/taste)

SVA nucleus

nucleus of solitary tract

SSA info…

special somatic afferent, input from special ‘non-visceral’ senses (vision, hearing, balance)

SSA nuclei

vestibular, cochlear

GSA info…

general somatic afferent, input from skin, muscle, tendons

GSA nucleus

trigeminal - mesencephalic, principal, spinal parts

functional group of brainstems are…

nuclei that process information of the same functional modality; tend to be located in the same topological location across brainstem, grouped by columns on rostro-caudal axis

functional group away from sulcus limitans toward posterior

alar plate; somatic function, afferent

functional group close to sulcus limitans

visceral function

functional group away from sulcus limitans towards anterior

basal plate; somatic function, efferent

label nuclei (efferents)

label nuclei groups

label