Cerebral Cortex From Cells to Function

Question 1

What are the vast majority of nerve cells in the CNS?

Answer 1

Multipolar (lots of dendrite branches)

Question 2

WHat are extensively branched neurons called?

Answer 2

Multipolar neurons

Question 3

What type of cell is the dorsal root ganglion cell?

Answer 3

Pseudounipolar cell

Question 4

What are bipolar nerve cells common in?

Answer 4

Special sense organs (ear, eye, nose)

Question 5

How many axons do multipolar nerve cells have?

Answer 5

1 (many dendrites)

Question 6

What are interneurons for?

Answer 6

Local processing

Question 7

What are pyramidal cells used for?

Answer 7

Sending info from the cerebral cortex

Question 8

What are examples of unmyelinated axons?

Answer 8

Sensory fibres carrying pain, temperature, itch

Question 9

What is multiple sclerosis?

Answer 9

Phasic disease:
- Immune attack by T cells and macrophages on myelin which causes its degeneration - this then causes conduction blocks, crosstalk (paraesthesia)

Question 10

Myelinated nerve fibres are what colour?

Answer 10

White (unmyelinated are grey)

Question 11

How many more glial cells are there than neurons?

Answer 11

10x

Question 12

What are the functions of astrocytes?

Answer 12

• Control water distribution
• K+ buffering
• ROS scavenging (ROS stands for reactive oxygen species)
• Define architecture
• Regulate migration/pruning/synaptogenesis
• Help maintain but do not make up the BBB

Question 13

How do astrocytes differ when in grey vs white matter?

Answer 13

White matter: more fibrous

Grey matter: Protoplasmic/blobby

Question 14

What is the blood-brain barrier made up of?

Answer 14

• Endothelial cells and tight junctions
• Astrocytes help maintain
• Integrity highly dependent on astrocyte end feet

Question 15

What are the functions of microglial cells?

Answer 15

• Phagocytosis and antigen presentation (immune response)

- Synaptic pruning

Question 16

Describe the structure of ependymal cells

Answer 16

Ciliated cuboidal epithelial cells

Question 17

What is the function of ependymal cells?

Answer 17

Secrete and reabsorb CSF

Question 18

How many layers are there in most cerebral cortexes?

Answer 18

6 layers

Question 19

What cells make up the granular layers?

Answer 19

Stellate interneurons (multipolar short axon)

Question 20

What cells make up the pyramidal layers?

Answer 20

Pyramidal neurons

Question 21

In what cortex are interneurons more numerous?

Answer 21

Sensory cortex

Question 22

In what cortex is the pyramidal output more marked?

Answer 22

Motor cortex

Question 23

Where does more long distance signalling take place; is it more peripheral or deeper layers of the cortex?

Answer 23

Deeper layers have more long distance sending

Question 24

How can you visualise different areas of the brain’s activity?

Answer 24

fMRI

Question 25

What is somatotopy?

Answer 25

Point-for-point correspondence of an area of the body to a specific point on the central nervous system. Typically, the area of the body corresponds to a point on the primary somatosensory cortex

Question 26

What is the function of the premotor cortex?

Answer 26

Preperation for action - posture and gait (integration of spatial information and planned movement, grasping)

Question 27

What is the function of the posterior parietal cortex?

Answer 27

Integrating visual information to formulate motor commands

Question 28

What happens as you move posteriorly in the parietal lobe?

Answer 28

More higher order principles - i.e, orientation, rearrangement of memories, number processing etc.

Question 29

What can damage to the frontal lobes cause?

Answer 29

Disorders of personality and motivation

Question 30

What is Broca's area responsible for?

Answer 30

Executing language

Question 31

What is Wernicke's area responsible for?

Answer 31

Understanding language

Question 32

What is receptive aphasia?

Answer 32

Unable to understand/generate meaningful language. Associated with damage to Broca's or Wernicke's area

Question 33

What do Broca's and Wernicke's areas communicate via?

Answer 33

Arcuate fasiculus

Question 34

What is conduction aphasia?

Answer 34

Difficulty repeating words/phrases (associated with damage to arcuate fasiculus)

Question 35

In what hemisphere does the majority of language processing take place?

Answer 35

Left (96%) (the ones who control with the right usually have damaged left hemisphere)

Question 36

WHat is the right hemisphere more associated with?

Answer 36

- Drawing, music, spatial perception