Science · Body foundations
Nervous System and Neural Signaling
Estimated time includes reading and one quiz. Take the time you need.
Start here: key ideas
- The CNS processes information; the PNS carries signals to and from it.
- Neurons receive, conduct, and transmit signals.
- Neurotransmitters carry a signal across a synapse.
- A reflex follows a short sensory-to-motor pathway.
What you’ll be able to do
- Compare nervous system divisions.
- Explain neuron and synapse signaling.
- Trace sensory, reflex, and motor paths.
Follow information from a receptor to the CNS and back to an effector.
Optional review
If you’d like to review the basics, visit Anatomical Orientation, Organization, and Homeostasis. You can start this lesson without completing those first.
A hierarchy by location and control
The central nervous system (CNS) is the brain and spinal cord. It processes information. The peripheral nervous system (PNS) is the nerves outside the CNS. Sensory, or afferent, pathways carry information toward the CNS. Motor, or efferent, pathways carry commands away. Somatic motor control targets skeletal muscle. Autonomic control targets smooth muscle, cardiac muscle, and glands. Sympathetic activity supports action; parasympathetic activity supports rest and digestion.
The autonomic system has two main branches. The sympathetic branch raises heart rate and redirects energy during challenge. The parasympathetic branch slows the heart and supports digestion during rest. They often have opposite effects on the same organ, but both are involuntary motor pathways.
You've used your 1 free study guide
Your free topic allowance is shared across Reading, Math, Science and English. This first section is a preview. Unlock every study-guide
topic — full lessons, inline checks, the complete practice bank +
timed exam simulation — with a free trial.
Your one free topic stays free, always.
$0 today — card required to start your trial. Cancel anytime before day 3.
Already subscribed? Log in.