John Is a Sprinter Who Specializes in Quick and Powerful

question 92

Multiple Choice

John is a sprinter who specializes in quick and powerful bursts of speed followed by periods of rest. Jim is a marathon runner who specializes in long, steady runs. Compared to John's muscles, how are Jim's most likely to differ?

• A) Jim's muscles will have more glycogen stored in his type IIb muscle fibers.
• B) Jim's muscles will have more mitochondria in his type I and IIa muscle fibers.
• C) Jim's muscles will have less myoglobin in his type I muscle fibers.
• D) Jim's type IIb fibers will be larger in diameter.
• E) Jim will have a greater proportion of type II muscle fibers and a lower proportion of type I fibers than John.

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Definitions:

EPSPs

Excitatory Postsynaptic Potentials, which are temporary increases in postsynaptic membrane potential caused by the flow of positively charged ions into the postsynaptic cell.

IPSPs

Inhibitory Postsynaptic Potentials (IPSPs) are synaptic potentials that make a postsynaptic neuron less likely to generate an action potential.

Neuronal Membrane

The lipid bilayer that surrounds a neuron, maintaining the ionic environment essential for neurotransmission.

Distant Dendrite's Tree

The elaborate branching structure at the end of a neuron's axon, allowing for connections with other neurons.