Autonomic nervous system
The ANS consists of two antagonisticActing in opposition. systems:
- sympathetic:
- also known as fight or flight
- increases rate of energy expenditure
- prepares the body for action
- parasympathetic:
- also known as rest and digest
- decreases rate of energy expenditure
- the body enters a calm state
| Sympathetic (fight or flight) | Parasympathetic (rest and digest) | |
| Heart Rate | Increase in rate of contraction of cardiac muscle - cardiac output increases | Decrease in rate of contraction of cardiac muscle - cardiac output decreases |
| Breathing Rate | Smooth muscle of bronchioles relaxes - intake of air increases | Smooth muscle of bronchioles contracts - intake of air decreases |
| Peristalsis | Smooth muscle of digestive tract contracts less - rate of peristalsis decreases | Smooth muscle of digestive tract contracts more - rate of peristalsis increases |
| Intestinal Secretions | Action of glands is inhibited - decrease in production of secretions | Action of glands is stimulated - increase in production of secretions |
| Heart Rate | |
| Sympathetic (fight or flight) | Increase in rate of contraction of cardiac muscle - cardiac output increases |
| Parasympathetic (rest and digest) | Decrease in rate of contraction of cardiac muscle - cardiac output decreases |
| Breathing Rate | |
| Sympathetic (fight or flight) | Smooth muscle of bronchioles relaxes - intake of air increases |
| Parasympathetic (rest and digest) | Smooth muscle of bronchioles contracts - intake of air decreases |
| Peristalsis | |
| Sympathetic (fight or flight) | Smooth muscle of digestive tract contracts less - rate of peristalsis decreases |
| Parasympathetic (rest and digest) | Smooth muscle of digestive tract contracts more - rate of peristalsis increases |
| Intestinal Secretions | |
| Sympathetic (fight or flight) | Action of glands is inhibited - decrease in production of secretions |
| Parasympathetic (rest and digest) | Action of glands is stimulated - increase in production of secretions |