What is the Autonomic Nervous System (ANS)?
The autonomic nervous system is a control system that supplies smooth muscles and glands, and thus affects the function of internal organs. It controls and acts unconsciously to regulate functions like digestion, blood pressure, heart rate, sexual arousal, respiratory rate, temperature, fluid balance, urination in a human body. The nervous system prepares a body for intense activities and is often referred to as the fight-to-fight response.
The autonomic nervous system is controlled by reflex actions through the brainstem to organs and spinal cord. These functions include cardiac regulation, respiration control and vasomotor, and certain reflex actions like vomiting, coughing, sneezing, swallowing.
The autonomic nervous system is further divided into two divisions Sympathetic Nervous system, the Parasympathetic Nervous system.
Let us explore the key difference between sympathetic and parasympathetic
|The sympathetic nervous system (SNS) is one of the main divisions of the autonomic nervous system (ANS).
|The parasympathetic nervous system (PNS) is another main division of the autonomic nervous system (ANS).
|The primary function is to stimulate a fight-to-fight response.
|The primary function is to control the body’s feed and breed and then rest and digest response.
|It helps in activating the response of fight-or-fight.
|It helps in activating the response of rest-an-digest.
|It decreases saliva production.
|It increases saliva production.
|It helps in decreasing urinary output.
|It helps in increasing urinary output.
|It increases the heartbeat.
|It decreases the heartbeat.
|It helps in increasing the glycogen to glucose conversion for the energy required by muscles.
|There is no involvement by the parasympathetic nervous system.
|It helps in making pupil delight
|It helps in making a pupil contract.
|In this the bronchial tube delight.
|In this the bronchial tube contract.
|It increases the stress on muscles.
|It decreases stress and relaxes the muscles.
Sympathetic Nervous system (SNS)
Sympathetic Nervous System (SNS) is one of the main divisions of the autonomic nervous system, with the primary function of fight-to-fight response. It is described as an antagonist to the parasympathetic nervous system. It is located near the lumbar and thoracic regions. It is found in the spinal cord. The heart rate, respiratory system, pupil response are controlled by the sympathetic nervous system.
Function of Sympathetic Nervous System
The sympathetic nervous system helps in increasing the speed of body, stress and makes the body more alert. It increases the rate and contraction of the heart. It helps in releasing the adrenal from the adrenaline gland. This gland releases adrenaline from the adrenal medulla. It controls the fight-to-fight response of the body. The pre-ganglionic and post-ganglionic are types of neurons that help in the transmission of any signal.
The response of the adrenal gland increases heart rate, cardiac output, skeletal muscle vasodilation, gastrointestinal vasoconstriction. Like other parts of the nervous system, this operates through a series of interconnected neurons. Sympathetic neurons communicate with peripheral sympathetic neurons via sympathetic ganglia.
These Spinal cord sympathetic neurons are known as presynaptic (or preganglionic) neurons. On the other side, peripheral sympathetic neurons are called postsynaptic (or postganglionic) neurons.
These preganglionic neurons release chemical messenger acetylcholine. This chemical helps in binding and activates the nicotinic acetylcholine receptors on postganglionic neurons. In response, noradrenaline is released by postganglionic. This noradrenaline from postganglionic and adrenaline released from the adrenal gland helps in binding the adrenergic receptors. This binding helps to respond in the fight-to-fight process.
The sympathetic nervous system also releases hormones. These hormones help in an acceleration heartbeat or to increase the heart rate. Epinephrine and norepinephrine are hormones released by SNS.
Parasympathetic Nervous System (PNS)
The parasympathetic nervous system (PNS) is another antagonist set of nerves of the autonomic nervous system. It primarily regulates visceral organs. While providing control to many tissues, the parasympathetic system never tries to take control of the maintenance of life. The nerves of this system help in resting, digesting, and reducing heartbeat. These nerves are also known as cranial nerves.
Function of Parasympathetic Nervous System
The nervous system is arranged similarly to the sympathetic nervous system. The main component includes preganglionic and postganglionic neurons. These neurons are found in the brainstem or lateral horn of the spinal cord. This preganglionic axon comes out from the brainstem forecast parasympathetic ganglia.
This ganglia is located near the heart or in the head, fixed in the organs like trachea, gastrointestinal tract, and bronchi or located in the short distance from the urinary bladder.
Parasympathetic controls include glands like lacrimal or tear glands, which supplies tears to the eye cornea; nasal mucous glands that secrete mucus through the nasal air passage, and the salivary gland which provides saliva.
The autonomic nervous system includes the sympathetic and parasympathetic nervous system. The sympathetic system helps in fight-to-fight response on the other side, the parasympathetic nervous system helps in reducing stress and the heart rate.