The parasympathetic system largely controls homeostatic functions.

• The parasympathetic system largely controls homeostatic functions.

• Two neurons make-up the parasympathetic component of the AUTONOMIC SYSTEM. It operates out-of the brainstem and sacral cord.

• The source motoneuron is located in the brainstem or sacral cord. These motoneurons are controlled by the hypothalamus.
• The second level parasypathetic neuron is in cranial ganglia or in the wall of the innervated organ.

• The primary motoneuron is located in cranial nerve nuclei 3, 7, 9, 10, or sacral nerves 2-4. The functions are to:

• Constrict the pupil, 3rd nerve
• Glandular saliva production in cranial nerves 7, 9
• Nasal mucosa glands are innervated by cranial nerve 7
• Slows the heart via the vagus nerve 10
• Constricts the bronchi via the vagus nerve 10
• Increases gut secretion & motility 10
• Enhance genital function through sacral nerves 2, 3, 4
• Bladder control via sacral nerves 2, 3, 4