diencephalon and telencephalon structures

mamillary bodies

optic chaism

borders of the diencephalon (ventral surface)

thalamus

hypothalamus

epithalamus

subthalamus

internal structures of the diencephalon

epithalamus

primarily made up of the pineal gland

circadian rhythm

melatonin

sympathetic nervous system 

pineal gland is a midline, unpaired structure

regulates the BLANK BLANK

endocrine gland that secretes BLANK in response to light cues 

under control of the BLANK BLANK BLANK

melatonin

derived from serotonin and secreted at a high rate in the dark

preganglionic sympathetic neurons in intermediolateral cell column of spinal cord

postganglionic sympathetic neurons in superior cervical ganglion

pineal gland

melatonin release

where there is no light stimulus; in the dark, the SCN is not activated and the inhibition is removed → thus melatonin is secreted (in the dark)

retinal ganglion cells

suprachaismatic nucleus of hypothalamus

preganglionic sympathetic neurons in intermediolateral cell column in spinal cord 

postganglonic sympathetic neurons in superior cervical ganglion

pineal gland

reduced melatonin release 

light stimulus pathway - activates the SCN, which then inhibits the pineal gland and reduces melatonin release

lateral ventricles

dorsal border of the thalamus

third ventricle

medial border of the thalamus

internal capsule

lateral border of the thalamus

thalamus

gatekeeper of transmitting information to the cerebral cortex; each system (general sensory, special sensory, motor, limbic) uses specific portion of this structure; thus it functionally divides into specific nuclei

internal medullary lamina

subdivides the thalamus into medial, lateral and anterior divisons

anterior nucleus

dorsomedial nucleus

reciprocal connections with prefrontal cortex and limbic system

ventral anterior nucleus

ventral lateral nucleus

relay motor information to motor cortex (pre-central gyrus)

ventral posterior lateral nucleus

ventral posterior medial nucleus

relay general and special sensory information from the body (VPL) and face (VPM) to the sensory cortex in parietal lobe

lateral geniculate nucleus

medial geniculate nucleus

relay special sensory info. of vision (LG) and auditon (MG) to the occipital lobe and temporal lobe

pulvinar nucleus

projects to association areas in the temporal, occipital and parietal lobes

posterior communicating arteries

provide blood supply to diencephalon

medial lemniscus

spinothalamic tract (spinal)

→ ventral posterior lateral → primary somatosensory cortex

medial lemniscus

spinothalamic tract (trigeminal)

→ ventral posterior medial → primary somatosensory cortex

brachium of the inferior colliculus

→ medial geniculate → primary auditory cortex 

optic tract

→ lateral geniculate → primary visual cortex

1. cortical

2. subcortical

3. limbic

3 divisions of the forebrain

subcortical nuclei

areas of gray matter within subcortical region

internal capsule

corpus callosum

anterior commissure 

superior longitudinal fasiculus

fiber tracts associated with the cerebral cortex 

lateral sulcus

parieto-occiptal sulcus

central sulcus

pre-central sulcus

post-central sulcus

major sulci of the lateral cortex

pre-central gyrus

primary motor cortex where voluntary movements are intiated

inferior frontal

contains the broca’s area

broca’s area

speech production

orbital cortex

involved in higher cognitive functioning (decision making, personality)

post-central gyrus

primary somatosensory cortex

superior temporal gyrus

process auditory information

• contains wernicke’s

wernicke’s area

speech comprehension

lateral occipital gyri

contain visual association areas

insular cortex

buried deep in the lateral sulcus; covered by gyri from the temporal, parietal and frontal lobes

• contain gustatory, autonomic, pain and vestibular areas

parieto-occipital sulcus

cingulate sulcus

calcarine sulcus

major sulci of the medial cortex

cingulate gyrus

part of the limbic system

parahippocampal gyrus

continus with cingulate gyrus; overlies the hippocampus

primary visual cortex

located in the walls of the calcarine sulcus

cortex

outer layer, consist of neurons distributed in 3-6 layers

• 2 divisions: neocortex and allocortex

neocortex

allocortex

divisions of the (cerebral) cortex:

neocortex

6 layers; all of the cortex seen on the outside of the brain, recently evolved and plays a critical role in abilties and activitis that reach highest level of development in humans

allocortex

3 layers, oldest part of the brain, consist of the limbic and olfactory centers

layer 3 of neocortex

interconnect different regions of the cerebral cortex ipsilaterally and contralaterally

association projections

ipsilateral connections of layer 3

comissural projections

contralateral connections of layer 3

layer 4 of neocortex

primary area where afferent/sensory axons from the thalamus terminate

• large in the primary sensory cortex (post-central gyrus)

layer 5 of neocortex

leave cerebral cortex and project to other regions of the CNS

• large in primary motor cortex (pre-central gyrus)

layer 6 of neocortex

project back to thalamus to regulate thalamic output

brodmann

used differences in cytological organization of the cortex to define areas (brodmann’s areas)

intrahemispheric tract

link cortical areas on the same hemisphere

• superior longitudinal fasiculus

superior longitudinal fasiculus

intrahemispheric; links the broca’s area with the wernicke’s area

interhemispheric tract

connect the left and right hemispheres; link related areas

• corpus callosum

• anterior commissure 

corpus callosum

links the frontal, parietal, caudal temporal and occipital lobes - interhemispheric tract

anterior comissure

links related areas of the inferior temporal lobe; interhemispheric tract

internal capsule

all afferent and efferent fibers related to the cortex transverse through this region

corona radiata

fan-shaped bundle of white nerve fibers that connects the cerebral cortex with the interal capsule

anterior cerebral artery

posterior cerebral artery

2 arteries that supply blood to medial cortex

middle cerebral artery

supplies blood to the lateral cortex

anterior cerebral artery

supplies blood to frontal and parietal lobes

posterior cerebral artery

supplies blood to the occpital lobe and medial temporal lobe

middle cerebral artery - 2

supplies blood to lateral portions of the cerebral cortex - 2