Cerebral Hemispheres and Cortex (Neuroanatomy Lab) - Spring 2025

-brain

-spinal cord

What are the 2 divisions of the CNS?

-cerebrum

-diencephalon

-cerebellum

-brainstem

What are the 4 divisions of the brain?

-epithalamus

-thalamus

-hypothalamus

What are the 3 divisions of the diencephalon?

-mesencephalon

-pons

-medulla oblongata

What are the 3 divisions of the brainstem?

-cortex

-basal ganglion

-hippocampus

-amygdala

What are the divisions of the cerebral hemispheres?

-frontal lobe

-parietal lobe

-temporal lobe

-occipital lobe

-limbic system

What are the divisions of the cortex?

coordinating movements

What is the function of the cerebellum?

thalamus

A majority of signals from the diencephalon flow into where?

-thalamus

-epithalamus

-hypothalamus

circadian rhythm

What is the function of the epithalamus?

-maintaining homeostasis

-endocrine system function

What is the function of the hypothalamus?

tremors

Lesions on the basal ganglion cause what?

hippocampus

What part of the brain is in control of unconscious memory?

amygdala

What part of the brain is in control of the salience of memories (PTSD)?

The bridge between the mesencephalon and the medulla oblongata

What is the function of the pons?

midbrain

What is the mesencephalon?

-forebrain

-midbrain

-hindbrain

forebrain

What is the prosencephalon?

-forebrain

-midbrain

-hindbrain

hindbrain

What is the rhombencephalon?

-forebrain

-midbrain

-hindbrain

-telencephalon

-diencephalon

In embryology, the prosencephalon will differentiate into what 2 structures?

cerebral hemispheres

The telencephalon will differentiate into what structure?

thalamus, epithalamus, hypothalamus

The diencephalon will differentiate into what structures?

none

In embryology, the mesencephalon will differentiate into what structure?

-metencephalon

-myelencephalon

In embryology, the rhombencephalon will differentiate into what 2 structures?

pons and cerebellum

The metencephalon will differentiate into what structures?

medulla oblongata

The myelencephalon will differentiate into what structure?

geri, sulci, lobes

What are the anatomical divisions of the cortex of the brain?

52 Brodmann areas

What are the histological divisions of the cortex of the brain?

motor cortex, premotor cortex, visual cortex, etc.

What are the functional divisions of the cortex of the brain?

While there is significant overlap between the 3 methods, they are not in 100% agreement

Are the 3 methods of classifying the cortex (anatomical, histological, and functional) in 100% agreement? Is there overlap in these methods?

no -- the left one is larger (in all Right handed individuals, some Left handed)

Are the right and left hemisphere equal in size? If no, which one is larger?

right hemisphere tends to be larger or equivalent in size to the left

In left handed individuals, which hemisphere is larger?

Yes

Do the right and left hemisphere of the brain try to inhibit each other?

-frontal

-parietal

-temporal

-occipital

What are the 4 lobes of the brain?

central sulcus

What sulcus differentiates the frontal from the parietal lobe?

lateral sulcus

What sulcus differentiates the frontal from the temporal lobe?

-precentral gyrus

-superior frontal gyrus

-middle frontal gyrus

-inferior frontal gyrus

The frontal lobe is divided into what 4 gyri?

-opercular

-triangular

-orbital gyrus

What are the 3 divisions of the inferior frontal gyrus?

-post-central gyrus

-superior parietal lobule

-inferior parietal lobule

What are the divisions of the parietal lobe?

-supramarginal gyrus

-angular gyrus

What are the divisions of the inferior parietal lobule?

processing location and distance of vision

What is the primary sensory Cortex important for?

-superior temporal

-inferior temporal

What are the 2 major sulci of the temporal lobe (on lateral view)?

-superior temporal

-middle temporal

-inferior temporal

What are the 3 major gyri of the temporal lobe (on lateral view)?

-inferior temporal

-lateral occipitotemporal

-medial occipitotemporal

-parahippocampal

What are the 4 major gyri of the temporal lobe (from an inferior view)?

uncus -- goes to the hippocampus

What is an important structure/gyri connected to the parahippocampal gyrus?

-involved heavily in language and hearing

-imporant in visual identification

What is the function of the temporal lobe?

everything posterior to the line connecting the parietooccipital sulcus and the preoccipital notch

Where is the occipital lobe located in a lateral view of the brain?

posterior to the parietooccipital sulcus

Where is the occipital lobe located in a medial/mid-saggital view of the brain?

-divided in half by the calcarine sulcus

Cuneus = above

Lingual gyrus = below

In the midsaggital view, the occipital lobe is divided in half by what? What 2 lobes does it divide into?

grey

Cortex of the brain is ______ matter with capillaries

divided into 6 distinct layers, due to varying densities of cell body types within each layer

The cortex of the brain is divided into how many layers? Why is it divided into layers?

stellate, pyramidal

What are the 2 primary cell types in the cortex of the brain?

white

______ matter lies internal to the grey matter of the cortex of the brain

Layers of the cortex of the brain pic

stellate cells

These cells of the cortex RECEIVE impulses from other areas. There are numerous dendrites

in the regions of cortex associated with signal input

Where are stellate cells heavily concentrated in the cortex of the brain?

pyramidal cells

These cells of the cortex SEND impulses to other areas. Have 1 apical and 2 basal dendrites with a large axon

in regions of the cortex associated with sending output

Where are pyramidal cells heavily concentrated in the cortex of the brain?

2 and 4

What are the layers of the cortex that are associated with input?

3 and 5

What are the layers of the cortex that are associated with output?

association fibers

fibers in the white matter of the brain that connect one part of a hemisphere to another area of the SAME hemisphere

commissural fibers

fibers in the white matter of the brain that connect one part of the cortex to another part of the cortex in the OTHER hemisphere

occipitofrontal tract, occipitoparital tract, occipitotemporal tract

**vision comes INTO the occipital and information is sent to be analyzed in many other regions

What are the 3 examples given for commissural fibers?

projection fibers

Fibers in the white matter of the brain that connect cortex to thalamus, brainstem, and spinal cord

-geniculocortical

-thalamic radiations

What are the examples of corticopedal (afferent) projection fibers in the white matter of the brain?

-corticobulbar

-corticospinal

What are the examples of corticofugal (efferent) projection fibers in the white matter of the brain?

molecular layer

What is the name of Layer 1 of the cortex of the brain?

very few cells

Does Layer 1 of the cortex have a lot or few cells?

receives dendrites from internal layers so it may actually function as a coordinating center where layers can communicate action

What does Layer 1 of the cortex do?

1

Every layer sends densities to Layer ____?

1

What layer serves as the "water cooler" of the brain?

external granular layer

What is the name for layer 2 of the cortex of the brain?

receives input from other cortical regions

What is the function of Layer 2 of the Cortex of the brain?

Stellate

What type of cells (stellate/pyramidal) would be most concentrated in Layer 2?

external pyramidal layer

What is the name for layer 3 of the cortex of the brain?

sends output to the other cortical layers

What is the function of Layer 3 of the cortex of the brain?

pyramidal

What type of cells (stellate/pyramidal) would be most concentrated in Layer 3 of the brain?

Layers 2 and 3

What layers are associated with association and commissural fibers?

Layer 3 - axons of cell bodies

Layer 2 - synapse into target areas in Layer 2

What part of the axons is in Layer 2/ in layer 3?

Layer 3 - external pyramidal layer

All axonal cel bodies for association and commissural fibers lie within what layer of the Cortex of the brain?

internal granular

** or called the striate cortex because it is so thick that you can see a line through this layer even in unstrained brain slides

What is the name for the 4th layer of the cortex of the brain?

receives input from the thalamus, geniculocortical layer, and other brainstem areas

What is the function for the 4th layer of the Cortex of the brain?

very thick within the vision, auditory, and somatosensory areas

Is Layer 4 thick or thin within SENSORY areas of the cortex?

Internal pyramidal

What is the name for Layer 5 of the cortex of the brain?

sends axons to the brainstem (corticobulbar) and spinal cord (corticospinal)

What is the function of Layer 5 of the cortex of the brain?

in motor areas of the cortex?

Where is layer 5 very thick in the brain?

the frontal lobe -- very motor heavy

What lobe of the brain will have a thick layer 5 of the cortex of the brain?

the multiform layer

What is the name of layer 6 of the cortex of the brain?

-sends axons back to the thalamus through corticogeniculate fibers

-modulates what information the thalamus sends to the cortex to control the strength of the signal received and modulate what you pay attention to

What is the function of layer 6 of the cortex of the brain?

no

Is layer 6 a motor layer?

without knowledge?

What are a priori decisions?

Yes, Layer 6 allows the cortex to make these decisions with corticogeniculate fibers

Can Layer 6 of the cortex of the brain make a priori decisions?

Symptoms experienced by TBI

Damage to Layer 6 of the cortex of the brain can play a role in what symptoms?

cerebral cortex on the basis of histological sections

What did Brodmann study?

52 distinct regions of the cortex based on the thickness of cell layers alone

What did Brodmann find?

2-5

What layers of the cortex of the brain did Brodmann find were variable in histological sections?

function

In the 52 Brodmann areas, structure lens itself to ______

4, 6, 8, 44/45

What are the important Brodmann areas of the frontal lobe?

motor movements

What is the function of Brodmann area 4?

2 and 5

What layers of the cortex are thick in Brodmann area 4?

helps coordinate activity in the motor cortex (opposing muscle groups)

What is the function of Brodmann area 6?

2 and 3

What layers of the cortex are thick in Brodmann area 6?