Lecture 4: Forebrain

forebrain

made up of the telencephalon and diencephalon

telencephalon

part of brain that is involved in higher order functions like learning and memory

diencephalon

part of brain that integrates all information passing from brainstem to cerebral cortex and some visceral and motor activities

dorsal

top or superior

ventral

inferior or bottom

anterior

front, towards the forehead

posterior

back or towards back of head

epithalamus

more of a region above the thalamus

pineal gland

produces and secretes melatonin

parenchymal cells

similar history to rods and cones - main cells of epithalmus

non-parenchymal cells

astrocytes in the epithalamus

habenula

connection between thalamus and brainstem just rostral to pineal gland; input from thalamus, output to midbrain RF

subthalamus

subthalamic nuclei

part of basal nuclei

thalamus

“egg-shaped” inner chamber that makes up most of the diencephalon; forms mass bordering lateral aspect of third ventricle; “gatekeeper” for all sensory information goig to cerebral cortex

anterior thalamus

has anterior nucleus

medial thalamus

DM nucleus

lateral thalamus

two tiers, dorsal and ventral

third ventricle

fluid-filled cavity; continuous with cerebral aqueduct and lateral ventricles

hypothalamus

orchestrates visceral and drive-related activities

anterior hypothalamus

region above the optic chiasm

tuberal hypothalamus

region most directly superior to infindibulum

posterior hypothalamus

portion of hypothalamus that contains mammillary bodies

infindibulum

fibery stalk that connects the hypothalamus to the pituitary gland

telencephalon

the “highest” thinking part of the brain

gyri

swellings

sulci

grooves

lateral sulcus

separates frontal and parietal lobes from other lobes “Sylvian fissure”

central sulcus

separates frontal and parietal lobes “fissure of Ronaldo”

pre-central & post-central gyri

anterior and posterior to central sulcus, respectively

parieto-occipital sulcus

separates parietal lobe from the occipital lobe

cingulate sulcus

demarcates cingulate gyrus

callosal sulcus

separates cingulate gyrus from corpus callosum

cingulate gyrus

part of limbic lobe

olfactory bulb

olfactory tract

mammillary body

optic chiasm

optic nerve

optic tract

lateral ventricle

basal nuclei

collection of subcortical nuclei involved in motor movement

internal capsule

whole band of myelinated axons where information is relayed between cerebral cortex and thalamus and some other structures

parenchymal pineal tumors

causes excess melatonin; hypogonadism and therefore delayed puberty

Non-parenchymal pineal tumor

low melatonin production, precocious puberty (6-7 years old)

hydrocephalus

pineal tumors can block cerebral aqueduct preventing the CSF from draining

capsular stroke

caused when a pineal tumor cuts blood flow off from internal capsule