Anatomy & Physiology
Autonomic Nervous System Functions
The autonomic nervous system regulates involuntary physiological processes including heart rate, blood pressure, and digestion.
Sympathetic Nervous System (SNS)
- 'Fight or Flight' response; mediated by norepinephrine and epinephrine.
- Increases heart rate and myocardial contractility.
- Causes bronchodilation to improve oxygen exchange.
- Decreases gastrointestinal motility and secretions.
Parasympathetic Nervous System (PNS)
- 'Rest and Digest' response; mediated by acetylcholine.
- Decreases heart rate and myocardial contractility.
- Promotes salivation, digestion, and glucose storage.
- Constricts pupils and stimulates bladder emptying.
Clinical Application
- Beta-blockers antagonize SNS effects to lower heart rate and blood pressure.
- Anticholinergics inhibit PNS effects, often causing tachycardia and urinary retention.
Like what you see?
Subscribe to unlock all 360 Study Cards and 15,000+ flashcards, track your progress, and study anywhere.