Bio- The nervous system I

What are the functions of the nervous system?

1. sense stimulation both inside and outside the body (feeling)

2. integrates and processing sensory information (integration)

3. issues response and commands structures to carry out necessary action (response)

What does the central nervous system consist of?

the brain and spinal cord

What does the peripheral nervous system consist of?

nerves and ganglia

Sensory division

part of the PNS

composed of nerves collecting data from all parts of the body to the brain and spinal cord

consists of afferent nerves

Motor division

part of the PNS

takes orders from the brain and spinal cord away to the rest of the body

consists of efferent nerves

Somatic motor division

coordinates voluntary movements and carries signals to skeletal muscles

Autonomic motor division

coordinates unvoluntary movements and carries signals to cardiac muscles, smooth muscles, and glands

Sympathetic division

part of the ANS

prepares the body for action and is activated by fear

“fight or flight”

Parasympathetic division 

part of the ANS

calms the body and slows the heartbeat

“relax and digest”

Structure of a neuron

• neurosoma (cell body)

control center

• dendrites

receive the date

• axon

sends stimulation away from neuron; surrounded by myelin sheath segments

Multipolar neurons 

neuron with more than two extensions or dendrites

integrating neurons

Bipolar neurons

neurons with just two extensions (1 axon and 1 dendrite)

located in the sense organs

Unipolar neurons

neuron with just one extension leading from the cell body

sensory receptors

Sensory neurons

collect data and send to the brain and spinal cord

afferent neurons

Interneurons

receive data and make response decision

found in the brain and spinal cord

Motor neurons

carry signals to the muscles or effectors

efferent neurons