Central Nervous System

The Nervous System

body’s communication network, consisting of a complete system of nerves, neurons, and specialized cells

Central Nervous System (CNS)

consists of brain and spinal chord:

command center of the body, responsible for processing info, coordinating responses, and regulating bodily functions

Peripheral Nervous System

consists of all nerves and ganglia outside the brain and spinal chord

• communication network, transmits info from body to CNS

Automatic Nervous System

division of peripheral nervous system:

regulates involuntary bodily functions. Operates automatically

• two branches: sympathetic and parasympathetic nervous system

Sympathetic Nervous System

responsible for activating body’s fight or flight response in times of stress or danger

Parasympathetic Nervous System

promoting relaxation and restoring body to calm state after experiencing stress or danger

• slows heart rate, allows body to conserve energy

ex: evacuating to safety

Somatic Nervous System

division of peripheral nervous system:

controls voluntary movements and relaying sensory info from body to CNS

ex: muscle movement and coordination - riding a bike

Neurons

specialized cell that serves as the building blocks of the nervous system

• transmits electrical and chemical signals throughout the body

  • motor neurons: carry outgoing info

  • sensory neurons: carry incoming info

  • interneurons: process info between sensory inputs and motor outputs

Glial Cells

“support cells” of the nervous system, provide structural support, insulation, and nourishment to neurons

• essential role in maintaining brain health and supporting neuron function

Reflex Arc

automatic response to stimulus. rapid and involuntary reaction designed to protect us from harm

ex: knee-jerk