Nerve Impulses Are Sent to Slow the Heart's Rate of Contraction

question 4

Multiple Choice

Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

• A) sensory (afferent) division
• B) somatic nervous system
• C) sympathetic division
• D) parasympathetic division

---

Definitions:

Tetanus

A bacterial infection characterized by muscle spasms, caused by the bacterium Clostridium tetani.

Threshold Stimulus

The minimum stimulus needed to cause a depolarization of the membrane and generate an action potential in excitable cells.

Muscle Fatigue

Muscle fatigue is the decline in ability of a muscle to generate force, often experienced after prolonged activity or strain.

Motor Units

A motor unit consists of a single motor neuron and all the muscle fibers it innervates, essential for muscle contraction.