ICL 2.3: Overview of the Human Brain Flashcards
what is the grey matter of the brain?
aka the cerebral cortex!! it’s the outer most layer of the brain
it’s the neuron cell bodies
ex. ganglia and nuclei
what is the white matter of the brain?
aka the cerebral white matter; it’s the inner layer of the brain under the cerebral cortex
the myelinated axons from the neuron cell bodies
what are the 3 poles of the brain?
- frontal pole
- temporal pole
- occipital pole
they are found in the anterior, middle and posterior cranial fossas, respectively
what would the brain of someone with Alzheimer’s or dementia look like?
the gyri and sulci wouldn’t be tight
the sulci would be dilated and the gyri would be small and atrophied
which sulcus seperates the frontal and parietal lobes?
central sulcus
what would cause the brain to be flattened?
edema
edema in the cranial cavity could cause the lobes of the brain to become squished against the skull and appear flattened
what are the gyri of the frontal lobe?
- superior frontal gyrus (closest to midline)
- middle frontal gyrus
- inferior frontal gyrus
- precentral gyrus
slide 14; go look at the picture
what are the subdivisions of the inferior frontal gyrus?
- pars opercularis
- pars triangularis
- pars orbitalis
what are the sulci of the frontal cortex?
- superior frontal sulcus
- inferior frontal sulcus
- precentral sulcus (superior and inferior)
what is the importance of the central sulcus?
it separates the frontal lobe from the parietal lobe but more importantly it separates functional areas!
the motor cortex fibers all originate from the frontal lobe while all the sensory information we receive is in the parietal lobe
so when a patient has a tumor one of the things the surgeon will do is identify the central sulcus to find the somatosensory cortex of the parietal love vs. the motor cortex of the frontal lobe
what are the gyri of the parietal lobe?
- postcentral gyrus
- superior parietal lobule
- inferior parietal lobule
the inferior parietal lobule is comprised of the supramarginal gyrus and the angular gyrus
how can you locate the specific gyri of the inferior parietal lobule?
the inferior parietal lobule is composed of the supramarginal gyrus and the angular gyrus
if you follow the superior temporal gyrus it will lead you to the supramarginal gyrus
if you follow the superior temporal sulcus it will lead you to the angular sulcus
what are the sulci of the parietal lobe?
- postcentral sulcus
2. intraparietal sulcus
what are the gyri of the temporal lobe?
- superior temporal gyrus
- middle temporal gyrus
- inferior temporal gyrus
- fusiform gyrus (underneath)
what are the sulci of the temporal lobe?
- superior temporal sulcus
2. inferior temporal sulcus
what is the tentorium cerebelli?
it’s the dural reflection that the occipital lobe sits on
it covers the cerebellum
what is the insula?
aka the insular cortex
you can find it deep to the frontal and temporal lobes and it’s like a second mini brain = “hidden lobe”
people think that pain and auditory elements are processed here as well
what structure separates the left and right hemisphere?
longitudinal cerebral fissure
which structure separates the temporal lobe from the frontal and parietal lobes?
lateral sulcus aka fissure of sylvius
if you dissected through the lateral sulcus you’d find the insural cortex
what is the function of Broca’s area?
execution and fluency of speech
what is the function of Wernicke’s area?
comprehension of speech
what is conductive aphasia?
Broca’s area and Wernicke’s area have to be in constant communication in order for you to understand what is being said to you and respond back
so if there’s a disruption between them then you get conductive aphasia
which sulcus splits the occipital lobe into superior and inferior portions?
calcarine sulcus
which sulcus separates the occipital and parietal lobes?
parieto-occipital sulcus
you can only see on a sagittal cut of the brain
what are commissures? what are the two commissures of the brain?
- corpus callosum
- anterior commissure
commissures are points of connection between the right and left hemispheres so that they can communicate
what is the corpus callosum?
a commissure of the brain that’s a large bundle of axons connecting left and right cerebral hemispheres
when tumors metastasize from one side of the brain to the other it’s because they use the corpus callosum to get there
a thin corpus callosum indicates white matter atrophy or degeneration of myelin
side note: on a coronal section you will only see the corpus callosum once but in the sagittal section you’ll see the whole curve