The nervous system communicates between the brain, spinal cord, and the rest of the body. This lesson explains how the peripheral nervous system carries messages and how its divisions support movement, sensation, and the regulation of internal organs.
The nervous system has two major subdivisions. The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) connects the CNS to the rest of the body, including the muscles, organs, and sensory systems outside the CNS.
All flashcards
What are the CNS and PNS?
The central nervous system (CNS) is the brain and spinal cord. The peripheral nervous system (PNS) connects the CNS to the rest of the body.
What do afferent and efferent mean?
**Afferent** fibers carry sensory information toward the CNS; **efferent** fibers carry motor instructions away from the CNS.
What does the somatic nervous system do?
It carries sensory information to the CNS and motor instructions from the CNS to muscles, supporting activities often considered conscious or voluntary.
How do the sympathetic and parasympathetic divisions differ?
The sympathetic division prepares the body for stress or high arousal. The parasympathetic division helps restore routine, relaxed bodily functioning afterward.
What is homeostasis, and how do autonomic divisions support it?
Homeostasis is a state of biological balance. The sympathetic and parasympathetic divisions work in tandem, adjusting bodily activity to help maintain that balance.
Quiz questions
What is a nerve in the peripheral nervous system?Answer: A bundle of axons carrying messages between the CNS and the body.
Which functions are associated with the somatic nervous system?Answer: Carrying sensory information to the CNS and motor instructions to muscles.
What does the autonomic nervous system generally regulate?Answer: Internal organs and glands, usually outside voluntary control.
Which set of changes can occur during sympathetic activation?Answer: Dilated pupils, increased heart rate, and glucose release from the liver.
Why might public speaking trigger a bodily stress response?Answer: A psychological stressor can make the body react as if a threat were present.
Based on Psychology 2e by Rose M. Spielman, William J. Jenkins, Marilyn D. Lovett (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.