Nervous system
Nervous system

How the Nervous System Works

- The nervous system responds to stimuli to maintain homeostasis.
- To move from one neuron to another, an impulse crosses a synapse.

The Central Nervous System

- The brain controls all body activities.
- Spinal neurons carry impulses from all parts of the body to the brain.

The Peripheral Nervous System

- The somatic system controls voluntary actions and the autonomic system controls involuntary actions.

Safety and the Nervous System

- The spinal cord controls reflex responses.

Drugs and the Nervous System

- Many drugs affect your nervous system.
  • Homeostasis: regulation of an organisms internal, life maintaining conditions
  • Neuron: basic functioning unit of the nervous system, made up of a cell body, dendrites, and axons.
  • Dendrites: neuron structure that receives messages and sends them to the cell body.
  • Axon: neuron structure that carries messages away from the cell body.
  • Synapse: Small space across which an impulse moves from an axon to the dendrites or cell body of another neuron.
  • Central Nervous System: Division of the nervous system, made up or the brain and spinal cord.
  • Peripheral Nervous System: division of the nervous system made up of all the nerves outside the CNS; connects the brain and spinal cord to other body parts.
  • Cerebrum: the largest part of the brain, where memory stored, and movements are controlled, and impulses from the senses are interpreted.
  • Cerebellum: part of the brain that controls voluntary muscle movements, maintains muscle tone, and helps maintains balance.
  • Brain Stem: Connects the brain to the spinal cord and it is made up of the midbrain, the pons, and the medulla.
  • Reflex: simple innate behavior, such as yawning or blinking, that is an automatic response and does not involve a message to the brain; Automatic, involuntary response to a stimulus; Controlled by the spinal cord.