Cerebral cortex

Question 1

What are the two largest divisions of the brain?

Answer 1

The two cerebral hemispheres.

Question 2

What structure links the two cerebral hemispheres?

Answer 2

The corpus callosum.

Question 3

What are the convolutions and furrows of the cerebral cortex called?

Answer 3

Convolutions = gyri; furrows = sulci or fissures.

Question 4

Name the three surfaces of the cerebral hemispheres.

Answer 4

Superolateral, medial, and basal (inferior).

Question 5

Name the five lobes of the cerebrum.

Answer 5

Frontal, parietal, temporal, occipital, and limbic lobes.

Question 6

What are the two main types of cells in the cerebral cortex?

Answer 6

Pyramidal cells and non-pyramidal (stellate or granule) cells.

Question 7

What are the six layers of the cerebral cortex (neocortex)?

Answer 7

Molecular (plexiform) layer

External granular layer

External pyramidal layer

Internal granular layer

Ganglionic (internal pyramidal) layer

Multiform layer

Question 8

What is the difference between granular and agranular cortex?

Answer 8

Granular cortex (sensory): Many stellate cells, few pyramidal neurons; layers III and V poorly developed.

Agranular cortex (motor): Diminished layers II and IV; prominent pyramidal neurons.

Question 9

What are the three types of white matter fibers in the cerebrum?

Answer 9

Association fibers, commissural fibers, and projection fibers

Question 10

What is the function of the precentral gyrus?

Answer 10

Primary somato-motor cortex; controls voluntary movements (motor homunculus).

Question 11

Where is Broca’s area located, and what is its function?

Answer 11

Located in the frontal lobe; responsible for motor speech production.

Question 12

What are the functions of the prefrontal cortex?

Answer 12

ntelligence, social behavior, adaptation, initiative, mood, concentration, and tidiness.

Question 13

What is the primary function of the post-central gyrus?

Answer 13

Primary somatosensory cortex; processes tactile and proprioceptive information.

Question 14

What is the striate cortex, and where is it located?

Answer 14

Primary visual cortex; located in the occipital lobe.

Question 15

What are the functions of the temporal lobe?

Answer 15

Acoustic processing, vestibular functions, language (Wernicke’s area), memory, mood, and visceral regulation.

Question 16

What is cerebral asymmetry?

Answer 16

The hemispheres are not mirror images; the left hemisphere is dominant for language/analytical tasks, while the right is involved in holistic/musical functions.

Question 17

What artery supplies the medial aspect of the cerebral cortex rostral to the parieto-occipital sulcus?

Answer 17

Anterior cerebral artery.

Question 18

A patient presents with non-fluent, effortful speech but understands language. Which area is likely damaged?

Answer 18

Broca’s area (left frontal lobe). Clinical correlation: Expressive aphasia.

Question 18

Which white matter fibers connect homologous areas of opposite hemispheres?

Answer 18

Commissural fibers (e.g., corpus callosum, anterior commissure).

Question 18

Which artery occlusion would affect the medial cortex rostral to the parieto-occipital sulcus?

Answer 18

Anterior cerebral artery. Easy-to-miss detail: Supplies medial frontal/parietal regions.

Question 18

A patient cannot recognize objects by touch (astereognosis). Which lobe is affected?

Answer 18

Parietal lobe (somatosensory association area).

Question 18

What structure is lesioned if a patient has contralateral hemiplegia?

Answer 18

Corticospinal tract in the internal capsule (projection fibers).

Question 18

A lesion in the post-central gyrus causes what deficit?

Answer 18

Loss of tactile sensation/proprioception (somatosensory cortex damage).

Question 18

Which cortical layer is absent in agranular (motor) cortex?

Answer 18

Layers II and IV. High-yield histology detail.

Question 19

Which area is responsible for motor planning of axial/proximal muscles?

Answer 19

Premotor cortex (area 6, frontal lobe). Often confused with primary motor cortex.

Question 19

Which cortical layer receives thalamocortical inputs?

Answer 19

Layer IV (internal granular layer). Key for sensory processing.

Question 19

A right-handed patient has trouble interpreting metaphors and prosody. Which hemisphere is dysfunctional?

Answer 19

Right hemisphere (holistic processing, non-verbal communication).

Question 19

A stroke damaging the left temporal lobe would most affect what function?

Answer 19

Language comprehension (Wernicke’s area).

Question 20

A patient has quadrantanopia. Which artery is likely occluded?

Answer 20

Posterior cerebral artery (supplies occipital lobe/visual cortex).

Question 21

What distinguishes granular vs. agranular cortex microscopically?

Answer 21

Granular: Rich in stellate cells (sensory); Agranular: Pyramidal cells dominate (motor).

Question 22

A lesion in the temporal lobe could cause deficits in:

Answer 22

Memory (hippocampus), language (Wernicke’s), or auditory processing.

Question 23

Which commissure connects the hippocampi?

Answer 23

Hippocampal commissure. Easy-to-miss detail vs. corpus callosum.

Question 24

The striate cortex is notable for what feature despite its small size

Answer 24

Contains 10% of brain neurons (occupies only 3% of surface).

Question 25

Damage to the prefrontal cortex would impair:

Answer 25

Social behavior, judgment, initiative, and concentration.

Question 26

Which fibers connect adjacent gyri?

Answer 26

Short association (arcuate) fibers. Key for local cortical integration.

Question 27

Betz cells are found in which cortical layer and region?

Answer 27

Layer V (ganglionic layer) of the precentral gyrus (primary motor cortex).