The autonomic nervous system is concerned with regulating the functions of body organs and coordinating and integrating their activities. Its crucial role in many homeostatic mechanisms is complemented by the activities of the endocrine system. In turn, both of these regulatory systems are themselves coordinated by the hypothalamus.
In general terms, the parasympathetic division activates "housekeeping functions":
? salivation (production and secretion of saliva for digestion)
? lacrimation (production and secretion of tears for cleansing the eyes)
? urination (emptying the bladder of stored urine)
? defecation (emptying the bowel of feces)
The sympathetic division readies the body for emergencies (the "fight or flight" reaction) by:
? increasing heart rate and blood pressure
? increasing blood flow to the heart, skeletal muscles, liver, adipose tissue and skin
? decreasing blood flow to other organs
? increasing rate and depth of breathing
? increasing blood glucose concentration
? increasing secretion of adrenaline from the adrenal medulla
? decreasing the activities of other organs (such as digestion)
Many, but not all organs are innervated by both divisions of the ANS. Such dual innervation mostly provides for two-way control of ...
This solution describes the Autonomic Nervous System, including the pre and postganglionic neurotransmitters and each of their functions