Nervous System

Question 1

What’s the body of a nerve cell called?

Answer 1

soma

Question 2

Which cells produce myelin?

Answer 2

Oligodendrocytes in the CNS and Schwann cells in the PNS

Question 3

What are the breaks in the myelin sheath called?

Answer 3

Nodes or Ranvier

Question 4

Describe an action potential

Answer 4

Membrane maintained at -70mV with K+/Na+ pump, 3 Na+ out for 2 K+ in. If threshold voltage of -55 mV is reached at the axon hillock, AP triggered. Voltage gated Na+ channels rapidly open, gradient forces Na+ in and cell becomes positive. When potential about +35mV, Na+ channels rapidly close. Positive potential triggers K+ channels to open, K+ rushes out and repolarizes membrane, often overshooting because they’re slow to respond.

Question 5

What is a neuron called that signals a gland muscle?

Answer 5

Effector cell

Question 6

How are neurotransmitters removed from the synapse?

Answer 6

Enzymatic digestion, diffusion (NO2), reuptake carriers (e.g. dopamine/ serotonin)

Question 7

How are neurons classified based on directionality?

Answer 7

Towards brain: Afferent
Away from brain: Efferent
Local circuits: Interneurons

Question 8

What are clusters of soma called?

Answer 8

Ganglia in the PNS, nuclei in the CNS

Question 9

How are hemispheres of the brain connected?

Answer 9

Corpus collosum

Question 10

How can one imagine the thalamus?

Answer 10

Gateway to the brain; all sensory info passed through thalamus before relayed to cortex