Neuro Exam Prep

What's the difference between the absolute and relative refractory period?

• 1. Absolute refractory means an AP will be triggered and relative refractory means an AP might be triggered

• 1. Absolute refractory means no amount of stimulus can cause an AP, and relative means an AP is still possible

• 1. The relative refractory period triggers afterhyperpolarization and the absolute refractory period does not 

• 1. Relative refractory means no amount of stimulus can cause an AP, and absolute refractory means an AP is still possible

The rod system is ____ _________ than the cones system

Bonus: why - raise hand to answer

Why do homunculi look like distorted, human-like figures?

• They represent the amount of cortical area dedicated to motor or somatosensory function of each body part.

• The disproportionate size of some body parts over others reflects their overall importance.

• They depict the human-like form of our ancestors.

• They represent the amount of cortical area dedicated to the motor or sensory function of each body part.

Why can a second action potential be initiated in response to a large stimulus for the relative refractory period, but not the absolute refractory period?

• The voltage-gated K+ channels only close at the end of the falling phase.

• More voltage-gated Na+ channels are in their inactive state during the absolute refractory period.

• More voltage-gated Na+ channels are in their closed state during the absolute refractory period

• Less voltage-gated K+ channels are open during the undershoot phase.

How is the voltage clamp able to establish a desired membrane potential? 

• The clamp resistor varies the resistance in the membrane to establish the desired membrane potential.

• The clamp resistor closes the voltage-gated K+ channels when the membrane potential differs from a desired command potential.

• The clamp amplifier injects a current into the axon through a second electrode when the membrane potential differs from a desired command potential.

• The clamp amplifier induces the opening of voltage-gated Na+ channels when the membrane potential differs from a desired command potential.

What was the main takeaway from Otto Loewi’s famous neurotransmission experiment?

• Synaptic transmission between synapses is caused by the release of discrete packets of neurotransmitters.

• Informational flow at the muscular junction is unidirectional.

• Synaptic signalling relies on electrical impulses.

• Synaptic signalling uses chemical messengers.

Which of the following serves as strong evidence for quantal transmission at the neuromuscular junction?

• Consistent amplitude of action potentials in response to varying stimulus intensities.

• The observation that neurotransmitters release in a continuous flow, rather than discrete packets.

• Spontaneous changes in muscle cell membrane potential 

• Spontaneous changes in muscle cell membrane potential have the same shape as end-plate potentials.

Label the lobes!

(can be short form like temp for temporal lobe)

The main storage difference between small-molecule neurotransmitters and peptide neurotransmitters is…

• Small-molecule neurotransmitters aren't part of larger protein complexes.

• Small molecules are quickly made and released at nerve terminals; peptides are synthesized in the cell body and transported, causing slower release.

• Peptides are quickly made and released at terminals; small molecules are synthesized in the cell body and transported, causing slower release.

• Peptides are stored in large dense-core vesicles for axonal transport; small-molecules in smaller vesicles at the synaptic terminal.

Where do neurons decussate in the Dorsal Column Medial Lemniscal Pathway (DCML)?

• 1. In the dorsal horn

• 2. In the caudal medulla

• 2. In the dorsal column

• In the VPL nucleus