Nervous System

Question 1

Resting membrane potential

Answer 1

Protein channels in the cell membrane enable certain ions to move down their concentration gradient across the membrane (passive transport); active transport pumps embedded in the outer membrane of neurons hydrolyze ATP to provide energy to transport molecules against the gradient

Question 2

Botulism poisoning

Answer 2

Blocks acetylcholine from entering the synaptic cleft, resulting in under-stimulation of postsynaptic ACh receptors

Question 3

Nerve agents

Answer 3

Inhibit acetylcholinesterase from degrading excess ACh in the synaptic cleft; they do not block the presynaptic reuptake of ACh

Question 4

Excess ACh

Answer 4

Continues stimulating postsynaptic ACh receptors, causing persistent muscle fiber contraction

Question 5

Steps involved in the synaptic transmission of action potential across a synapse

Answer 5

1. Presynaptic AP triggers Ca2+ ion influx into the presynaptic terminal
2. Reuptake of ACh through presynaptic neuronal membrane
3. Ca2+ ions trigger neurotransmitter release

Question 6

ACh is involved in:

Answer 6

• Stimulation of peristalsis
• Voluntary muscle contraction
• Slowing of heart rate

Question 7

Neurotransmitter responsible for increasing intestinal peristalsis (PNS)

Answer 7

Acetylcholine

Question 8

Creutzfeldt-Jakob disease

Answer 8

Impacts the central nervous system, especially the cerebrum, while sparing the PNS, so things affected would be cognition, speech, and short-term memory

Question 9

Validating that thymectomy is an appropriate trx for myasthenia gravis will choose outcome variables like:

Answer 9

Ability to lift weights, strength of reflexes, and respiratory rate before and after exercise