Sympathetic and Parasympathetic Nervous System
The two main parts of the nervous system of bilateral animals are the central nervous system (CNS) and the peripheral nervous system (PNS). The peripheral nervous system consists of the ganglia and nerves outside of the spinal cord and brain. This nervous system has two main parts, which are the somatic nervous system and the autonomic nervous system. The autonomic nervous system was previously called the vegetative nervous system.
It is the subsystem of the peripheral nervous system to supply smooth glands and muscle. It influences the functions of the internal organs of the animal body. The autonomic nervous system controls several internal body processes such as blood pressure, digestion, body temperature, urination, breathing rates, sexual arousal, etc.
Anatomy of Autonomic Nervous System
The Autonomic Nervous System is one of the main two parts of the peripheral nervous system, which supplies the body’s internal organs such as the heart, stomach, liver, bladder, intestine, kidneys, lungs, digestive glands etc. This nervous system has two subsystems, which are the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
When the ANS receives information about the external environment on the body, it responds through the sympathetic nervous system (by stimulating body processes) or the parasympathetic nervous system (by inhibiting the body processes). Generally, SNS neurons prepare the body to react to something. Neurons within the PNS regulate bodily functions. To know more about anatomy, you can read any autonomic nervous system ppt.
Autonomic Nervous System Function
The autonomic nervous system controls several internal body processes such as respiratory rate, heart rate, digestion, pupillary response, blood pressure, body temperature, urination, digestion, sexual arousal, metabolism, etc. All these body processes are controlled by the sympathetic nervous system (SNS) for the parasympathetic nervous system (PNS) or both of them. Some organs are affected oppositely by the SNS and the PNS. For example, the SNS increases blood pressure, and the PNS decreases it.
These two subsystems work together and balance the body processes so that the body can respond to different situations properly. Generally, the SNS controls the heart rate, blood pressure, muscular strength, pupillary response, sweat, digestion, and urination. On the other hand, the PNS controls heart rate, blood pressure, and digestion. By observing the autonomic nervous system diagram, you can learn more about the function of the ANS.
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Autonomic Disorders
Nervous disorders that result from the damage of the autonomic nerves or the parts of the ANS are called autonomic disorders. It affects the internal body processes. There are several causes of autonomic disorders. The common causes are diabetes, ageing, peripheral nervous disorders, Parkinson's disease, etc. Other less common causes are autonomic neuropathy, pure autonomic failure, multiple system atrophy, spinal cord disorders, drugs acting on the autonomic nervous system, nerve injuries, etc. Some autonomic disorders are orthostatic hypertension, postprandial hypotension, multiple system atrophy, pure autonomic failure, afferent baroreflex failure, familial dysautonomia, etc.
Symptoms of Autonomic Disorders
Now, we are going to discuss the symptoms of autonomic disorders. Some general symptoms are difficulty in emptying the bladder, dizziness or lightheadedness, disturbing pains, erectile dysfunction, fatigue and inertia, faintness, gastrointestinal symptoms, lack of pupillary response, hypotension, lack of sweat, numbness, tingling, tachycardia, severe anxiety and depression, urinary incontinence, etc. Apart from these, there are many other symptoms of autonomic disorders noticeable in the animal body.
Diagnosis and Treatment of Autonomic Disorders
Autonomic disorders should be treated seriously. Otherwise, it can lead to paralysis or permanent nervous disorders. If you face any symptoms of the autonomic disorder, you must visit a doctor as early as possible. Generally, autonomic disorders are detected through doctor's evolution, electrocardiography, sweat testing, and other tastes of the internal body processes. After the diagnosis of the disease, the treatment processes are different for different symptoms.
Through this article, students will be able to hold a strong grasp over the topics such as the anatomy of the autonomic nervous system, autonomic nervous system function, autonomic nervous system diagram in detail.
FAQs on Autonomic Nervous System
1. What is the Autonomic Nervous System (ANS)?
The Autonomic Nervous System (ANS) is a component of the peripheral nervous system that functions involuntarily, meaning it operates without conscious control. It is responsible for regulating the functions of internal organs and glands, such as the heart, stomach, and intestines. Its primary role is to control vital bodily processes like heart rate, digestion, respiratory rate, pupillary response, and urination, thereby maintaining a stable internal environment.
2. What are the two primary divisions of the Autonomic Nervous System?
The Autonomic Nervous System is composed of two main divisions with largely opposing functions:
The Sympathetic Nervous System (SNS): This division prepares the body for high-stress situations, often referred to as the 'fight-or-flight' response. It increases heart rate, directs blood flow to muscles, and raises alertness.
The Parasympathetic Nervous System (PNS): This division controls bodily functions during times of rest and is known as the 'rest-and-digest' system. It slows the heart rate, enhances digestion, and conserves energy.
3. What is the difference between the Autonomic and the Somatic Nervous System?
The key difference lies in the type of control and the muscles they target. The Autonomic Nervous System (ANS) governs involuntary actions by controlling smooth muscles, cardiac muscle, and glands. In contrast, the Somatic Nervous System (SNS) manages voluntary actions by controlling the skeletal muscles responsible for movement, like walking or picking up an object.
4. How do the sympathetic and parasympathetic systems create opposite effects on an organ like the heart?
The two systems achieve opposite effects by releasing different neurotransmitters at the target organ. The sympathetic nerves release noradrenaline (norepinephrine), which binds to receptors on the heart muscle, causing it to beat faster and more forcefully. Conversely, the parasympathetic nerves (specifically the vagus nerve) release acetylcholine, which binds to different receptors on the heart, causing it to slow down. This dual control allows for precise regulation of heart rate based on the body's needs.
5. Why is the Autonomic Nervous System essential for maintaining homeostasis?
The ANS is crucial for homeostasis—the maintenance of a stable internal body environment. It acts as an automatic balancing system. For example, if your body temperature rises, the ANS triggers sweating to cool you down. If your blood pressure drops when you stand up, the ANS constricts blood vessels to raise it back to normal. This constant, unconscious adjustment by the sympathetic and parasympathetic divisions ensures that vital parameters like body temperature, blood pH, and blood pressure remain within a narrow, life-sustaining range.
6. What are some common examples of functions controlled by the Autonomic Nervous System?
The ANS controls a wide array of vital, involuntary functions. Some important examples include:
Regulation of heart rate and blood pressure.
Control of digestion, including saliva secretion and peristalsis.
Adjustment of breathing rate and bronchial diameter.
Control of the pupillary light reflex (constriction and dilation).
Regulation of body temperature through sweating and shivering.
Control over bladder function (urination).
7. What happens if the Autonomic Nervous System gets damaged?
Damage to the autonomic nerves, a condition known as autonomic neuropathy or dysautonomia, can disrupt the body's involuntary functions. This can be caused by diseases like diabetes, Parkinson's disease, or physical injury. Symptoms vary depending on which nerves are affected but can include dizziness and fainting upon standing (orthostatic hypotension), digestive problems, inability to regulate body temperature, urinary issues, and abnormal heart rates. Since the ANS controls many vital processes, such disorders can be serious.
