Question

contrast the sympathetic and parasympathetic divisions of the autonomic nervous system and their effects

Answer 1

Ans- The autonomic nervous system works without a person's conscious effort and controls various body functions like digestion, circulation of blood, breathing, urination, heartbeat, etc. thus maintaining the internal body environment. There are two types of autonomic nervous system-

1. Sympathetic nervous system- It is part of ANS located near thoracic and lumbar regions in the spinal cord. It's primary function is to stimulate fight or flight response during any potential danger.

2. Parasympathetic nervous system- It is located in between spinal cord and medulla. This system inhibits the body from overworking and restores the body to calm and composed state.

Following are the major differences and actions of both systems-

	Parasympathetic nervous system	Sympathetic nervous system
Introduction	The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system (ANS). Its general function is to control homeostasis and the body's rest-and-digest response	The sympathetic nervous system (SNS) is one of two main divisions of the autonomic nervous system (ANS). Its general action is to mobilize the body's fight-or-flight response
Function	Controls the body's response while at rest	Controls the body's response during percieves threat
Originates in	Sacral region of spinal cord, medulla, cranial nerves 3,7,9 and 10	Thoracic and lumbar regions of spinal cord
Activates response of	Rest and digest	Fight or flight
Neuron pathways	Longer pathways, slower system	Very short neurons, faster system
Neurotransmitters	Acetylcholine in both preganglionic and postganglionic nerve fibres	Acetylcholine in preganglionic and adrenaline in postganglionic nerve fibres except sweat glands
General body response	Counterbalance, restores body to state of calm	Body speeds up, tenses up, more alert. Functions not critical to survival shut down
Cardiovascular system	Decreases heart rate	Increases contraction, heart rate
Pulmonary system( lungs)	Constriction of brochial tubes	Dialation of brochial tubes
Musculoskeletal system	Muscles relax	Muscles contract
Pupils	Constrict	Dialates
Gastrointestinal system	Increases stomach movement and secretions	Decreases stomach movement and secretions
Salivary glands	Saliva production increases	Saliva production decreases
Adrenal glands	No involvement	Releases adrenaline
Glycogen to glucose conversion	No involvement	Increases, converts glycogen to glucose for muscle energy
Urinary response	Increase in urinary output	Decrease in urinary output