AUTONOMIC NERVOUS SYSTEM
A
FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM
The autonomic nervous system (also known as the involuntary
nervous system) is responsible for controlling the involuntary
body functions, such as sweating, digestion and heart rate.
SYMPATHETIC SYSTEM
The system affects smooth muscles, such as those of the
airways and the intestine, rather than the striated muscles,
which are under the body’svoluntarycontrol.
PARASYMPATHETIC SYSTEM
Contracts
pupils
Stimulates
salivation
Constricts
bronchi
Slows
heart rate
Stimulates
gastric juice
production
Speeds up
digestive
process
Contracts
bladder
muscles;
relaxes
bladder neck
Relaxes
rectal
sphincter
The autonomic nervous system
The autonomic nervous system is divided into two separate systems: the
sympathetic nervous system and the parasympathetic nervous system.
The sympathetic system is primarily concerned with preparing the body for
action; it predominates at times of stress or excitement. The sympathetic
system stimulates functions such as heart-rate and sweating and dilates
the blood vessels to the muscles so that more blood is diverted to them.
Simultaneously, it subdues the activity of the digestive system. In contrast,
the parasympathetic nervous system is concerned mainly with the body’s
everyday functions such as digestion and the excretion ofwaste products;
this system dominates during sleep. The parasympathetic system slows the
heart rate and stimulates the organs of the digestive tract. Most of the time,
activity is balanced between the two systems, with neither dominating.
Both of the systems play an important part in sexual arousal and orgasm
in both men and women.
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