Cerebral cortex

Question 1

What is the Central sulcus also known as?

Answer 1

Central sulcus of rolando

Question 2

What is another name for the lateral sulcus?

Answer 2

Sylvian Fissure

Question 3

How much does the brain weigh?

Answer 3

1600 g in Males
1400 g in Females

With about 10-25 billion neurons in cerebral cortex.

Question 4

Who was theodor Von Bishop?

Answer 4

19th century scientist claiming men are more intelligent than women because of brain weight.

Question 5

The gray matter of the forebrain refers to…?

Answer 5

Cortex and the deep nuclei

Question 6

What are the two principal cell types present in the neocortex?

Answer 6

Pyramidal and stellate cells

Question 7

What are pyramidal cells?

Answer 7

Principal output neurons

Betz cells are the largest pyramidal cells.

Question 8

What are stellate cells?

Answer 8

Also known as granular cells. Principal interneurons of Cortex.

Question 9

What are the histology cell layers of the cortex?

Answer 9

1. Plexiform (molecular) layer
2. Outer granular layer (small pyramidal &stellate cells)
3. Outer pyramidal cell layer
4. Inner granular layer (densely packed stellate cells)

5 inner pyramidal cell layer/ ganglion cell layer (Betz cells & few stellate)

6. Multiform cell layer

Question 10

What are the six types of cortical neurons?

Answer 10

1. Retzius-Cajal cells - only in most superficial layer
2. Cells of Martinoti
3. Basket cells
4. Stellate cells (only in 4th layer!)
5. Fusion cells - only in deepest layer
6. Principal/pyramidal cells

Question 11

Where are pyramidal neurons found

Answer 11

Layers 3 & 5

Question 12

Where are granular neurons found?

Answer 12

In layers 2 & 4

Question 13

Describe the cytoarchitecture of the brain

Answer 13

Cortex is organized into functional units (cortical columns) specialized to process specific inputs/outputs differing by function

Question 14

What Is each cerebral hemisphere divided into?

Answer 14

5 lobes:

1. Frontal
2. Parietal
3. Temporal
4. Occipital
5. Limbic

Question 15

Cerebral white matter is made of three types of fibers…?

Answer 15

1. Commissural- connect corresponding areas of both hemispheres
2. Association fibers - Connect different parts of same hemisphere usually U-shaped
3. Projection fibers - fibers to and from cerebral cortex

Question 16

Commissural Fibers

Answer 16

• cross at midline
• mainly corpus callosum
• anterior commissure (connect temporal lobes)
• hippocampal commissure

Question 17

Callostomy

Answer 17

• done on pts with severe epileptic seizures
• section corpus callosum to prevent discharge from reaching other hemisphere
• “split-brain”

Question 18

Association fibers

Answer 18

Main bundles

1. Arcuate fibers (u-fibers)
2. Cingulum
3. Arcuate Fasiculus (superior longitudinal)
4. Inferior longitudinal Fasiculus
5. Superior occipitofrontal Fasiculus
6. Inferior occipitofrontal Fasiculus
7. Uncinate Fasiculus

Question 19

conduction aphasia

Answer 19

• damage to Arcuate Fasiculus connecting Wernicke’s and Broca’s areas.
• verbal output fluent, but misuse words
• language comprehension is normal but cannot repeat words or execute verbal commands
• aware of defect

Question 20

Projection fibers

Answer 20

• concentrated in internal capsule and fan out as corona radiata
• establish many reciprocal connections

Composed of:
• anterior limb - anterior nucleus and cingulate gyrus, dorsomedial nucleus and prefrontal cortex, frontopontine fibers
• genu - fibers via VA and VL with premotor/motor cortex, corticobulbar fibers to cranial nerve nuclei
• posterior limb - VA and VL w/ premotor/motor. Corticospinal and corticobulbar. VPL and VPM to postcentral gyrus
• retrolentiform part - optic radiations
• sublentiform part