Cerebral Cortex Flashcards
What are the 3 functional divisions of the cerebral cortex?
What are the 6 structural divisions of the cerebral cortex?
Archicortex, paleocortex, and neocortex.
Our familiar lobes: Frontal, Parietal, Occipital, Temporal, Limbic, and Insula.
What arteries feed the circle of willis?
Which venous sinuses are bilateral?
The internal carotids, as well as the vertebrals (via the posterior cerebrals).
The transverse and sigmoid sinuses, which drain into the IJVs.
Describe the 6 cellular layers of the neocortex.
The molecular layer is most superficial, atop the external granular, external pyramidal, internal granular, internal pyramidal, and multiform layers.
Describe the structure and significance of a cerebral column.
A column represents a section through all six cellular layers. These are sorts of functional subunits–neuron within them behave similarly and have similar functions. They demonstrate interconnectivity with other columns.
Primary Somatosensory Cortex
Where is it located?
What brodmann’s areas does it cover?
What is the consequence of a lesion?
Primary Somatosensory Cortex
On the post-central gyrus.
3, 1, 2.
Lesion causes contralateral numbness (loss of somesthesis).
Primary Motor Cortex
Where is it located?
What brodmann’s areas does it cover?
What is the consequence of a lesion?
Primary Motor Cortex
On the pre-central gyrus.
4.
Lesion causes contralateral paralysis (spastic, as UMN lesion).
Primary Visual Cortex
Where is it located?
What brodmann’s areas does it cover?
What is the consequence of a lesion?
Primary Visual Cortex
At the occipital pole, extending in deeply.
17.
Lesion causes anopia that varies with nature of lesion; usually contralateral hemianopia but may be quadrantanopia and macula-sparing.
Primary Auditory Cortex
Where is it located?
What brodmann’s areas does it cover?
What is the consequence of a lesion?
Primary Auditory Cortex
It is on the posterior part of the superior temporal gyrus.
41, 42.
Hearing loss occurs with bilateral lesions–due to multiple crossover, lesioning one side does not.
Broca’s Area
Where is it located?
What brodmann’s areas does it cover?
What is the consequence of a lesion?
Broca’s Area
It covers the opercular and triangular frontal gyri.
44, 45.
Lesion on the dominant (usually left) side causes Broca’s aphasia. Lesion on the non-dominant impairs emotional expression in speech.
What structure was lesioned in “lobotomy” patient inmates, and was famously damaged in Phineas Gage’s accident?
What is the consequence of these injuries?
The prefrontal cortex.
It is involved in complex planning as well as working memory and personality.
Association Cortices of Parietal Lobe
Which structures are involved? Which brodmann’s areas?
What is the consequence of a lesion here?
Association Cortices of Parietal Lobe
Posterior parietal lobule (medial), Superior (5/7) and Inferior parietal lobules (inferior divided into supramarginal (40) and angular (39).
A lesion of the dominant side causes loss of stereognosis and aphasia/alexia/agraphia. A lesion on the non-dominant side presents with spatial distortion and contralateral neglect.
Association Cortices of Occipital Lobe
Which structures are involved? What brodmann’s areas?
What is the consequence of a lesion here?
Association Cortices of Occipital Lobe
The secondary visual cortex (18/V2) as well as the “dorsal and ventral streams” (V3/V4).
Lesions can create visual defecits that depend on location of the lesion (eg prosopagnosia)
Association Cortices of Temporal Lobe
Which structures are involved? What brodmann’s areas?
What is the consequence of a lesion here?
Association Cortices of Temporal Lobe
Wernicke’s area, which is also on the superior temporal gyrus (22).
On the dominant side, lesion causes Wernicke’s aphasia. On the non-dominant, comprehension of emotional overtone is impaired.
What types of connections may link different cortices?
Long/short association fibers, as well as callosal fibers.
What are the purposes of the cerebral cortex?
What are the typical causes of dysfunction here?
Sensory perception, motor planning, memory, handling of emotions/behavior, and cognition.
Vascular insult (hemorrhage/infarction) or tumor (glial origin). Probably many others…
