Intro to CNS Organisation

Question 1

What comprises white matter?

Answer 1

myelinated axons and glia

Question 2

What comprises grey matter?

Answer 2

neuron somata (cell bodies) and glia

Question 3

Pyramidal neurons

Answer 3

have extensive neurons/axons that cross over the 6 layers of the cortex and communicate with other parts of the cortex

aka projection neurons

Question 4

Interneurons

Answer 4

provide local circuits within one patch of cortex where pyramidal cells can coordinate their activity

Question 5

What is the function of the cerebellum?

Answer 5

• key element in motor control
  
  • compares motor plan/intention & actual motor action
  • refines execution of motor program
• contains half of all neurons in the brain

Question 6

What is the function of the basal ganglia?

Answer 6

• important in motor control
• communicates with motor cortex to select and initiate motor programs for voluntary movement

Question 7

What is the function of the thalamus?

Answer 7

• part of diencephalon
• major sensory relay to the cortex from afferent neural inputs

Question 8

What are the 3 projections of thalamic nuclei?

Answer 8

• relay of sensory information to the cortex
• relay of non-sensory info from cortex and basal ganglia to the cortex
• global projections to cortex of arousal and sleep

Question 9

What is the function of the hypothalamus?

Answer 9

• part of the diencephalon
• regulates homeostasis
• controls pituitary (endocrine) gland

Question 10

What is the function of the brainstem?

Answer 10

• control of:
  
  • facial muscles
  • sensation from face and head
  • cardiorespiratory control
  • arousal, sleep/wake cycle

Question 11

Cell bodies of ventral root axons are located

Answer 11

within the ventral horn

Question 12

Cell bodies of dorsal root axons are located

Answer 12

within dorsal root ganglia

Question 13

CSF is produced by

Answer 13

choroid plexus in the ventricles; flows out at fourth ventricle

Question 14

What is the falx?

Answer 14

vertical extension of meninges down into longitudinal fissure

Question 15

What is the tentorium?

Answer 15

horizontal extension of meninges; separates the cerebellum from occipital lobe

Question 16

What comprises the BBB?

Answer 16

endothelial cells of capillaries; prevents free diffusion (tight tight-junctions); transport of water-soluble molecules is active e.g. glucose; fat-soluble molecules have free access through BBB