1.1) External topography of the brain

Phases of prenatal development

zygote, embryo, fetus

around week 9 what develops

the nervous system

at about 18 days after conception the embryo

begins to implant in the uterine wall

The uterine wall consists of three layers

- endoderm

- mesoderm

- ectoderm

thickening of the ectoderm leads to the development of

the neural plate

the neural groove begins to develop at

20 days

at 22 days the neural groove

closes along the length of the embryo making the neural tube

at around 24 days of development what is observed

the 4 major divisions of the brain

- telencephalon

- diencephalon

- mesencephalon

- rhombencephalon

4 subdivisions of the neural tube

prosencephalon

mesencephalon

rhombencephalon

spinal cord

at 5 weeks, prosencephalon divides into...

telencephalon and diencephalon

telencephalon becomes the

cerebral hemispheres

cerebral cortex

The mesencehpalon becomes the

midbrain

Diencephalon becomes the

thalamus

hypothalamus

epithalamus

at 5 weeks, rhombencephalon divides into...

metencephalon and myelencephalon

metencephalon becomes the

pons and cerebellum

myelencephalon becomes the

medulla

Cerebrum (telencephalon) has two hemispheres which contain

cerebral cortex

subcortical white matter

subcortical nuclei (basal ganglia)

ventricles (CSF filled spaces)

grey matter

Predominantly cell bodies

What is white matter primarily composed of?

Mostly myelinated axons

What is the function of white matter in the brain?

Allows different areas of the cerebral cortex to communicate with each other

Which structures does white matter connect with?

The brainstem and spinal cord

What is the surface of the cerebrum called?

Cerebral cortex (composed of grey matter)

What are groups of cell bodies embedded within the white matter of the cerebrum called?

Deep grey matter

names of the deep grey matter in the cerebrum

- basal ganglia

- basal forebrain nuclei

- claustrum

- amygdala

white matter of the cerebrum

-association fibers

-commissural fibers

-projection fibers

association fibers connect

different parts of the same hemisphere

commissural fibers connect

cortical areas of right and left hemispheres

projection fibers run

vertically, ascending and descending to and from the spinal cord

falxi cerebri

the extension of the cranial dura mater between the hemispheres.

medial longitudinal fissure

separates hemispheres

corpus callosum function

connects left and right hemispheres of the brain

gyrus

hills of the cerebral cortex (made of grey matter)

sulcus

valley in the cerebral cortex (made of grey matter)

when a suclus is really deep it is called a

fissure

from the superolateral surface we can see

frontal lobe

parietal lobe

temporal lobe

occipital lobe

two main sulci that help us distinguish the 4 lobes of the brain

lateral sulcus

central sulcus

frontal lobe sucli

precentral sulcus

superior frontal sulcus

inferior frontal sulcus

superior frontal sulcus and inferior frontal sulcus help divide the frontal lobe into

superior frontal gyrus

middle frontal gyrus

inferior frontal gyrus

3 parts of the inferior frontal gyrus

orbital, opercular, triangular

sulci of the parietal lobe

postcentral sulcus

intraparietal sulcus

intraparietal sulcus divides the parietal lobe into

superior parietal lobule

inferior parietal lobule

gyri of the inferior parietal lobule

supramarginal gyrus and angular gyrus

main sulcus of the occipital lobe

lunate sulcus

tip of the occipital lobe is called the

occipital pole

2 main sulci of the temporal lobe

superior temporal sulcus

inferior temporal suclus

the sulci of the temporal lobe divide it into what gyri?

superior temporal gyrus

middle temporal gyrus

inferior temporal gyrus

when looking at the brain from the medial surface, we can see which gyrus and sulcus

cingulate gyrus

cingulate sulcus

midline structures of the diencephalon

hypothalamus

epithalamus

how many thalami do we have

2

- one on each side of brain

on the inferior surface we should focus on

parahippocampal gyrus

primary motor cortex function

voluntary control of skeletal muscles

primary somatosensory cortex function

registers and processes sensory information from receptors in the body

premotor cortex and SMA are in charge of

motor planning

damage to the area of broca leads to

Patient cannot speak

Damage to Wernicke's area

leads to difficulty in comprehending speech

cingulate sulcus is responsible for

emotional behavior

visual association area is responsible for

interpretation of visual stimulus

primary auditory cortex is responsible for

receiving auditory stimuli

parahippoccampal area is responsible for

memory