Neuroscience

What functional type of neuron is most prevalent in the vertebrate nervous system? a. afferent and efferent neurons b. interneurons c. glial cells d. Renshaw cells

b. interneurons

In most neurons, the cell bodies represents what percent of the cells total volume? a. 10% b. 30% c. 50% d. 70%

a. 10%

The average concentration of Na in the extracellular space is: a. 15 mmol/LH2O b. 150 mmol/LH2O c. 5 mmol/LH2O d. 100 mmol/LH2O

b. 150 mmol/LH2O

Which of the following statements most accurately summarizes RMP? a. it exists only when no ions are moving across the nerve membrane b. its primary cause is potassium efflux c. its primary cause is sodium efflux d. a and b e. b and c

b. its primary cause is sodium efflux

The resting membrane potential of neurons is determined primarily by: a. gated K channels b. non-gated K channels c. both of the above d. gated Na channels e. non-gated Na channels

b. non-gated K channels

If the permeability of a resting nerve cell to potassium ions is increased while the permeability of the cell to sodium ions remains constant the resting membrane potential will: a. be unaffected b. move towards zero (depolarize) c. move away from zero (hyperpolarize)

c. hyperpolarize

The motor molecule responsible for fast anterograde is: a. myosin b. actin c. kinesin d. tropomyosin e. dynein

c. kinesin

The resting membrane potential of glial cells is a. slightly more positive (depolarized) than the equilibrium potential for sodium b. slightly more negative (hyperpolarized) than the equilibrium constant for potassium c. slightly more positive than the equilibrium potential for potassium d. equal to the equilibrium potential for potassium

d. equal to the equilibrium potential for potassium

Somatic efferent (motor neurons) fibers are classified as: a. unipolar cells b. bipolar cells c. pseudo-unipolar cells d. multipolar cells

d. multipolar cells

Microtubules are the essential stationary tract used for what type of axonal transport? a. fast anterograde axonal transport b. slow axonal transport c. fast retrograde transport d. all of the above e. a and c

e. a and c

Astrocytes serve the following functions with the exception of: a. buffering function by taking up certain neurotransmitters from the synaptic area b. nutritive function c. buffering function by taking up excess potassium released during high activity d. act as scavengers and remove neuronal debris e. none of the above since all are functions of astrocytes

e. none of the above