The Autonomic Nervous System
The two divisions of the autonomic nervous system:
Sympathetic nervous system - stimulates effectors and so speeds up activities, heightening awareness
Parasympathetic nervous system - inhibits effectors and so slows down activity, conserving energy
These two systems are antagonistic.
Control of Heart Rate
Changes in heart rate are controlled by the medulla oblongata.
It has two centres: -increases heart rate by impulse to SAN via sympathetic nervous system
-decreases heart rate by impulse to SAN via parasympathetic nervous system
These centres recieve information from two types of receptor, which respond to chemical changes in the blood and pressure changes in the blood.
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