Question 1

Which division of the autonomic nervous system is primarily responsible for the 'fight or freeze' response, and what is its main effect on heart rate?

Accepted Answer

Sympathetic; increases heart rate

Question 2

A patient is experiencing rapid heartbeat and dilated pupils after a car accident. Which branch of the autonomic nervous system is most active, and what neurotransmitter is primarily involved?

Accepted Answer

Sympathetic; norepinephrine

Question 3

Which of the following best describes the antagonistic relationship between the sympathetic and parasympathetic nervous systems?

Accepted Answer

One increases organ activity while the other decreases it

Question 4

During digestion, which division of the autonomic nervous system is most active, and what is its effect on gastrointestinal motility?

Accepted Answer

Parasympathetic; increases motility

Question 5

Which of the following pathways correctly describes the flow of information from the central nervous system to skeletal muscle?

Accepted Answer

Spinal cord → efferent somatic neuron → skeletal muscle

Question 6

A motor unit consists of:

Accepted Answer

A motor neuron and all the muscle fibers it innervates

Question 7

Which neurotransmitter is released at the neuromuscular junction to initiate muscle contraction?

Accepted Answer

Acetylcholine

Question 8

Botox is used to treat certain muscular disorders by interfering with which step in muscle contraction?

Accepted Answer

Preventing acetylcholine release at the neuromuscular junction

Question 9

Which of the following best explains why skeletal muscle cells are multinucleated?

Accepted Answer

They fuse from multiple precursor cells during development

Question 10

If a patient has cerebral palsy and receives Botox injections, what is the expected physiological effect?

Accepted Answer

Decreased muscle contraction due to blocked acetylcholine release

Question 11

Which structure is the plasma membrane of a muscle cell?

Accepted Answer

Sarcolemma

Question 12

What is the correct sequence of events in excitation-contraction coupling in skeletal muscle?

Accepted Answer

Action potential → acetylcholine release → calcium release → muscle contraction

Question 13

Which of the following is NOT a target of the autonomic nervous system?

Accepted Answer

Skeletal muscle

Question 14

A patient presents with dry mouth and reduced tear production. Which division of the autonomic nervous system is likely underactive?

Accepted Answer

Parasympathetic

Question 15

Which equation best represents the relationship between the number of motor units activated and the strength of muscle contraction?

Accepted Answer

$$F \propto n_{MU}$$

Question 16

Which of the following best describes the role of the sarcoplasmic reticulum in muscle contraction?

Accepted Answer

It stores and releases calcium ions

Question 17

Which of the following is a correct real-world application of the antagonistic effects of the autonomic nervous system?

Accepted Answer

During a stressful event, the sympathetic system increases heart rate, while the parasympathetic system later slows it down during recovery

Question 18

Which of the following best describes the function of satellite cells in skeletal muscle?

Accepted Answer

They aid in muscle repair and regeneration

Question 19

Which of the following is the correct formula for calculating the total force produced by a muscle, given the force produced by each motor unit ($$F_{MU}) $$and the number of active motor units ($$n_{MU}$$)?

Accepted Answer

$$F_{total} = F_{MU} 	imes n_{MU}$$

Question 20

Which of the following scenarios best illustrates dual innervation in the autonomic nervous system?

Accepted Answer

The heart receives both sympathetic and parasympathetic input to regulate its rate

Autonomic Nervous System and Muscle Contraction: Structure and Function

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