Nervous System, Peripheral Nervous System

Autonomic Nervous System

Fundamentals:

Purpose/Function:=

• Regulation of visceral function in response to external and internal stimuli
• involuntary nervous system, many functions within the body
  • Smooth Muscle

Components:

• Sympathetic/Adrenergic Nervous System SNS-ANS
• Parasympathetic/Cholergenic Nervous System PNS-ANS

Concept:

ANS Organization

• Two neuron system
• PRI neuron - extend from the CNS
• SEC neuron - extend from a ganglion to the nerve's target organ

Cardiac and smooth muslce are both innervated by the ANS Control over BP, ventilation dynamics, urination and digestion Primary difference btwn SNS and ANS

• ANS is a TWO NEURON system
• SNS goes directly to the muscle without synapsing
• ANS works in a series to transmit messages
  • First neuron - preganglionic neuron
  • Second neuron - postganglionic neuron
    • Preganglionic soma is in the CNS whereas axon travels to a ganglion in the PNS
    • Synapses on the cell body of the postganglionic neuron which then affects the target tissue
• ANS can focus its regulation to each organ individually
• SNS cannot focus and is a general bodily preparation phase for stress

Locaiton of ganglia

• The ganglia for the PNS is closer to the target organ compared to the sympathetic so it can counterbalance the general stress reaction of SNS