The AUTONOMIC Nervous System *
SOMATIC: Senses – intake – conduct info – from senses to central nervous system
lAUTONOMIC:  Visceral – Gut
Two sub-systems of Autonomic: ˇAny internal “economy” has 2 “forces” lSpenders lSavers
 

Sympathetic system - spenders

ˇ
  • Blood vessels constrict
  • “Fight or flight”
  • Heart beats
  • Stomach, intestines slow down
  • Emergency
  • Dilate pupils – improve vision
  • Hot, inner

Parasympathetic system - savers

  • Blood vessels dilate
  • ˇStomach and intestines work
  • ˇEnergy is stored

 

1) The Sympathetic Nervous System:

  • runs through a network of ganglion that run down each side of the spine.
    Prepares the body for fight and flight

  • Increases activity in the involuntary muscles of the organs

  • Increases heart rate and for increased cardiac output

  • Dilates bronchioles for more oxygen to the lungs and faster exhalation of C02.

  • Raises blood pressure and sugar levels

    • ~ Increases metabolism

  • Slows activity in digestive tract to reduce interference with fight and flight response
    (blood is rerouted to the muscles so they can respond to the increased stress)

  • Dilates pupils to improve vision

Chronic exposure to stress or perceived threats to our well-being can lead to dysfunction of sympathetic effectors and perhaps even to the dysfunction of the ANS itself. This excessive sympathetic output causes most of the stress-related diseases physicians encounter. le. Headaches, gastrointestinal difficulties, high blood pressure, anxiety, muscle tension and aches, and sexual dysfunction.

 

2) The Parasympathetic Nervous System:

  • Consists of the Vagus nerve (extending from brain to neck, chest, and upper abdominal organs) and the Pelvic Nerve (which exits spinal cord around hip and branches into lower abdominal and pelvic organs - therefore this division is referred to as the craniosacral division) Counters the action of the Sympathetic Nervous System Functions as an energy conservation system, which allows our body to rest and restore itself after emergency responses. This results in a relaxation response.

  • Slows down heartrate

  • Constricts eye muscles to focus on near vision Increases glandular secretions

  • Slows breathing

  • Counteracts the adrenergic responses (release of neurotransmitters and hormones) of the SNS.

  • dilation in the female and erection in the male

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    * The Nervous System has two main divisions. The Central Nervous System - CNS (the brain and spinal cord) and the Peripheral Nervous System - PNS - ( all peripheral nerves that branch off the CNS to every organ and area of the body).  The Autonomic Nervous System - ANS - is part of the PNS and controls all internal organs and other self-regulating body functions. It regulates the body's automatic or involuntary functions like breathing, heartbeat and digestion.