Our emotions are determined in part by responses of the sympathetic nervous system, the division of the autonomic nervous system that is involved in preparing the body to respond to threats by activating the organs and the glands in the endocrine system. Follow this article to learn about how many divisions are there in the nervous system and which division of the nervous system is working when we experience emotions?
You have conscious or voluntary control over the sensory and motor systems of your central nervous system. The sensory branch of your central nervous system receives and transmits information from the outside world through your five senses (sound, sight, smell, taste and touch) to your brain. So, you can perceive the physical world around you while the motor branch of your central nervous system carries internal signals from your brain to your body, making it possible for you to walk, talk and perform actions in the world around you.
The autonomic branch of your nervous system is non-conscious or involuntary, meaning you have no apparent control over its function. Your autonomic nervous system operates at a subconscious level to control all the functions of your internal organs and glands which secrete hormones. It is your autonomic nervous system that is involved in your ability to feel emotions.
Your autonomic nervous system has two branches of activity. The sympathetic (fight/flight) branch which speeds up your heart rate as it signals you to prepare for action, and the parasympathetic (relaxation) branch which slows down heart rate as it signals you for rest and recovery.
Table of Contents
What is the nervous system?
Your nervous system is your body’s command center. Originating from your brain, it controls your movements, thoughts and automatic responses to the world around you. It also controls other body systems and processes, such as digestion, breathing and sexual development (puberty). Diseases, accidents, toxins and the natural aging process can damage your nervous system.
Your nervous system guides almost everything you do, think, say or feel. It controls complicated processes like movement, thought and memory. It also plays an essential role in the things your body does without thinking, such as breathing, blushing and blinking. Your nervous system affects every aspect of your health, including your:
- Thoughts, memory, learning, and feelings.
- Movements, such as balance and coordination.
- Senses, including how your brain interprets what you see, hear, taste, touch and feel.
- Sleep, healing and aging.
- Heartbeat and breathing patterns.
- Response to stressful situations.
- Digestion, as well as how hungry and thirsty you feel.
- Body processes, such as puberty.
This complex system is the command center for your body. It regulates your body’s systems and allows you to experience your environment. A vast network of nerves sends electrical signals to and from other cells, glands, and muscles all over your body. These nerves receive information from the world around you. Then the nerves interpret the information and control your response. It’s almost like an enormous information highway running throughout your body.
What are the basic types of cells present in the nervous system?
Although the nervous system is very complex, there are only two main types of cells in nerve tissue. Two basic types of cells are present in the nervous system;
- Neurons
- Glial cells
Neurons:
Neurons or nerve cells, are the main structural and functional units of the nervous system. Every neuron consists of a body (soma) and a number of processes (neurites). The nerve cell body contains the cellular organelles and is where neural impulses (action potentials) are generated. The processes stem from the body, they connect neurons with each other and with other body cells, enabling the flow of neural impulses. There are two types of neural processes that differ in structure and function;
- Axons are long and conduct impulses away from the neuronal body.
- Dendrites are short and act to receive impulses from other neurons, conducting the electrical signal towards the nerve cell body.
Every neuron has a single axon, while the number of dendrites varies. Based on that number, there are four structural types of neurons; multipolar, bipolar, pseudounipolar and unipolar.
Glial cells:
Glial cells, also called neuroglia or simply glia, are smaller non-excitatory cells that act to support neurons. They do not propagate action potentials. Instead, they myelinate neurons, maintain homeostatic balance, provide structural support, protection and nutrition for neurons throughout the nervous system.
How many divisions are there in the nervous system?
The nervous system is a network of neurons whose main feature is to generate, modulate and transmit information between all the different parts of the human body. This property enables many important functions of the nervous system, such as regulation of vital body functions (heartbeat, breathing, digestion), sensation and body movements. Ultimately, the nervous system structures preside over everything that makes us human; our consciousness, cognition, behavior and memories.
The nervous system consists of two divisions;
- Central nervous system
- Brain
- Spinal cord
- Peripheral nervous system
- Motor neurons
- Somatic nervous system
- Autonomic nervous system
- Sympathetic division
- Parasympathetic division
- Sensory neurons
- Motor neurons
Central nervous system:
Central nervous system (CNS) is the integration and command center of the body. The central nervous system (CNS) is made up of the brain and spinal cord. It is one of 2 parts of the nervous system. The other part is the peripheral nervous system, which consists of nerves that connect the brain and spinal cord to the rest of the body. The central nervous system is the body’s processing center.
The tissue of the central nervous system is made up of grey matter and white matter. Grey matter is made up of neurons, cells and blood vessels. White matter is made up of axons, which are long cords that extend from the neurons. They are coated in myelin, which is a fatty insulation.
Brain:
The brain is made up of different parts. These include the cerebrum, the cerebellum, the thalamus, the hypothalamus and the brainstem. The cerebrum is the largest part of the brain. It controls intelligence, memory, personality, emotion, speech, and ability to feel and move. It is divided into left and right hemispheres, linked by a band of nerve fibers in the center of the brain called the corpus callosum. Each hemisphere is divided into 4 lobes, or sections, which are all connected.
- The frontal lobes control movement, speech and some of the functions of the mind like behavior, mood, memory and organization.
- The temporal lobes play an important part in memory, hearing, speech and language.
- The parietal lobes play an important part in taste, touch, temperature and pain, and also in the understanding of numbers, awareness of the body and feeling of space.
- The occipital lobes are vital for being able to see clearly.
Deep inside the brain are the thalamus and the hypothalamus. The thalamus moves information to and from the lobes, and controls movements and memory. The hypothalamus controls appetite, thirst and body temperature, and produces hormones that control the release of other hormones in the pituitary gland. At the base of the brain is the brainstem. It is important for breathing, blood pressure and how the body reacts to danger.
Spinal cord:
The spinal cord is a long bundle of nerve tissue. In an adult, it’s about 18 inches long and 1/2-inch thick. It extends from the lower part of the brainstem down the back. The spinal cord has three sections that run the length of the spine. Each section’s name describes the part of the spine it passes through: cervical, thoracic, and lumbar-sacral. They send off smaller nerves to parts of the body nearby:
- The cervical spinal cord sends nerves to the face and neck.
- The thoracic spinal cord sends nerves to the arms, chest, and abdomen.
- The lumbar-sacral spinal cord sends nerves to the lower body.
Peripheral nervous system:
Peripheral nervous system (PNS) represents the conduit between the CNS and the body. It is further subdivided into the somatic nervous system (SNS) and the autonomic nervous system (ANS). Your peripheral nervous system (PNS) is that part of your nervous system that lies outside your brain and spinal cord.
It plays a key role in both sending information from different areas of your body back to your brain, as well as carrying out commands from your brain to various parts of your body. Some of those signals, like the ones to your heart and gut, are automatic. Others, like the ones that control movement, are under your control.
Motor neurons:
These neurons carry command signals from your brain to various parts of your body. They only carry information away from your brain. The motor neuron connections are on the front of your spinal cord; meaning, these nerves are for sending muscle movement commands only. Motor neurons control the somatic nervous system and autonomic nervous system.
Somatic nervous system:
The somatic nervous system includes the sensory nervous system and the somatosensory system and consists of sensory nerves and somatic nerves, and many nerves which hold both functions. In the head and neck, cranial nerves carry somatosensory data. There are twelve cranial nerves, ten of which originate from the brainstem, and mainly control the functions of the anatomic structures of the head with some exceptions.
One unique cranial nerve is the vagus nerve, which receives sensory information from organs in the thorax and abdomen. The other unique cranial nerve is the accessory nerve which is responsible for innervating the sternocleidomastoid and trapezius muscles, neither of which are located exclusively in the head. For the rest of the body, spinal nerves are responsible for somatosensory information. These arise from the spinal cord. Usually these arise as a web (“plexus”) of interconnected nerve roots that arrange to form single nerves. These nerves control the functions of the rest of the body.
Autonomic nervous system:
The autonomic nervous system (ANS) controls involuntary responses to regulate physiological functions. The brain and spinal cord of the central nervous system are connected with organs that have smooth muscle, such as the heart, bladder, and other cardiac, exocrine, and endocrine related organs, by ganglionic neurons.
The most notable physiological effects from autonomic activity are pupil constriction and dilation, and salivation of saliva. The autonomic nervous system is always activated, but is either in the sympathetic or parasympathetic state. Depending on the situation, one state can overshadow the other, resulting in a release of different kinds of neurotransmitters.
Sympathetic division:
The sympathetic system is activated during a “fight or flight” situation in which mental stress or physical danger is encountered. Neurotransmitters such as norepinephrine, and epinephrine are released, which increases heart rate and blood flow in certain areas like muscle, while simultaneously decreasing activities of non-critical functions for survival, like digestion. The systems are independent to each other, which allows activation of certain parts of the body, while others remain rested.
Parasympathetic division:
Primarily using the neurotransmitter acetylcholine (ACh) as a mediator, the parasympathetic system allows the body to function in a “rest and digest” state. Consequently, when the parasympathetic system dominates the body, there are increases in salivation and activities in digestion, while heart rate and other sympathetic responses decrease. Unlike the sympathetic system, humans have some voluntary controls in the parasympathetic system. The most prominent examples of this control are urination and defecation.
Sensory neurons:
These neurons carry information to your brain and spinal cord. They either connect directly to your brain through your cranial nerves or carry information to your spinal nerves, which then feed into your spinal cord. The sensory nerve connections to your spinal cord are on the back of your spinal cord.
What conditions can affect your nervous system?
Thousands of disorders and conditions can affect your nerves. An injured nerve has trouble sending a message. Sometimes it’s so damaged that it can’t send or receive a message at all. Nerve injury can cause numbness, a pins-and-needles feeling or pain. It may be difficult or impossible for you to move the area that’s injured.
Nerve damage can happen in several ways. Some of the most common causes of nerve damage include:
- Disease – Many infections, cancers, and autoimmune diseases like diabetes, lupus and rheumatoid arthritis can cause nervous system problems. Diabetes can lead to diabetes-related neuropathy, causing tingling and pain in the legs and feet. A condition called multiple sclerosis attacks the myelin around nerves in the CNS.
- Stroke – A stroke happens when one of the brain’s blood vessels becomes blocked or suddenly bursts. Without enough blood, part of the brain dies. Then it can’t send messages via nerves. A stroke can cause nerve damage ranging from mild to severe.
- Accidental injury – Nerves can be crushed, stretched, or cut in an accident. Car crashes and falls are common injuries that can damage nerves anywhere in your body.
- Pressure – If a nerve is pinched or compressed, it can’t get enough blood to do its job. Nerves can be pinched or trapped for many reasons, such as overuse (as in carpal tunnel syndrome), a tumor, or structural problems like sciatica.
- Toxic substances – Chemotherapy medicines, illegal drugs, excessive alcohol and poisonous substances can cause peripheral neuropathy or nerve damage. People with kidney disease are more likely to develop nerve damage because their kidneys have a hard time filtering out toxins.
- Aging process – As you get older, your neurons’ signals may not travel as fast as they used to. You may feel weaker, and your reflexes may slow down. Some people lose sensation in their fingers, toes or other parts of their body.
What are the signs of neurological illness that you must not ignore?
The human body is no less than a miracle. Made up of complex yet incredible systems, its unbelievable functions can even leave doctors and scientists confounded. One such system is the neurological system of the human body. With billions of nerve cells or neurons, our body performs various voluntary and involuntary activities helping us in our daily tasks.
However, if there is any problem in the neurological system, a person can have difficulties in moving, speaking, swallowing, breathing, or learning. According to the doctors, there are over 600 neurologic diseases including Huntington’s disease, Migraines, Degenerative diseases, epilepsy, brain tumors and meningitis to name a few.
Having a neurological disease can leave a deep impact not just on the patient’s life but on the life of others related to them as well. It is very crucial that one should seek medical assistance from the best neurologist in India as soon as possible when detected any neurological symptoms.
- Pain
- Memory loss
- Numbness
- Sleeping issue
- Partial or complete loss of vision
Pain:
It is one of the most common symptoms of neurological diseases. The individual may suffer from different types of pain such as back pain, neck pain, or the pain in the muscles and joint. Chronic headaches are also a part of neurological symptoms. There are cases where the chronic pain might be an age-related change. However, one cannot skip the fact that it may also be the sign directing the problem in the nervous system.
Memory loss:
If there is a difficulty in memorizing information due to lack of concentration power, then a person might have a progressive neurological disease such as Agnosia. As the individual cannot concentrate on what is being said, he/she will not be able to process the information and hence will not remember anything. There are times when the long-term memory often remains intact, but the short-term memories fade away from the person’s mind.
Numbness:
Another symptom is numbness, i.e., partial or complete loss of sensation. In such a situation, the person is not able to feel any sensation whether it is related to touch, pain, vibration or temperature. They may not be able to use their body parts properly and hence have difficulties in balance, coordination, walking, and driving or doing any other physical work. If the numbness continues to affect the person for a long time, then one should immediately consult a doctor to prevent any other major problem.
Sleeping issue:
Like numbness, sleep problems are also related to neurological symptoms. Insomnia and Hypersomnia are the two commonly known sleep disorders that can critically affect your health. While in insomnia, you will not be able to sleep, hypersomnia makes you sleep excessively. These disorders then give way to anxiety that again is another symptom of neurological disorders.
Partial or complete loss of vision:
When there is some damage to the brain’s occipital lobe that controls the vision, a person may get affected by the partial or complete loss of vision. This neurological vision impairment is associated with symptoms such as blurry or hazy vision, double vision, photophobia (a problem in bright light), etc. The person is also not able to perceive and interpret his/her surroundings making it difficult for him/her to interact with people.
What division of the nervous system is working when we experience emotions?
Emotional states are accompanied by arousal, our experiences of the bodily responses created by the sympathetic division of the autonomic nervous system. Your sympathetic nervous system is part of your autonomic nervous system. It could be called your “autonomic” nervous system, as it is responsible for many functions that you don’t have to think about to control. This can include control of your heart rate, blood pressure, digestion, urination and sweating, among other functions.
Your sympathetic nervous system is best known for its role in responding to dangerous or stressful situations. In these situations, your sympathetic nervous system activates to speed up your heart rate, deliver more blood to areas of your body that need more oxygen or other responses to help you get out of danger.
Our emotions are determined in part by responses of the sympathetic nervous system (SNS)—the division of the autonomic nervous system that is involved in preparing the body to respond to threats by activating the organs and the glands in the endocrine system. The SNS works in opposition to the parasympathetic nervous system (PNS), the division of the autonomic nervous system that is involved in resting, digesting, relaxing, and recovering.
When it is activated, the SNS provides us with energy to respond to our environment. The liver puts extra sugar into the bloodstream, the heart pumps more blood, our pupils dilate to help us see better, respiration increases, and we begin to perspire to cool the body. The sympathetic nervous system also acts to release stress hormones including epinephrine and norepinephrine. At the same time, the action of the PNS is decreased.
We experience the activation of the SNS as arousal—changes in bodily sensations, including increased blood pressure, heart rate, perspiration, and respiration. Arousal is the feeling that accompanies strong emotions. I’m sure you can remember a time when you were in love, angry, afraid, or very sad and experienced the arousal that accompanied the emotion. Perhaps you remember feeling flushed, feeling your heart pounding, feeling sick to your stomach, or having trouble breathing.
The experience of emotion is also controlled in part by one of the evolutionarily oldest parts of our brain—the part known as the limbic system—which includes several brain structures that help us experience emotion. Particularly important is the amygdala, the region in the limbic system that is primarily responsible for regulating our perceptions of, and reactions to, aggression and fear.
The amygdala has connections to other bodily systems related to emotions, including the facial muscles, which perceive and express emotions, and it also regulates the release of neurotransmitters related to stress and aggression. When we experience events that are dangerous, the amygdala stimulates the brain to remember the details of the situation so that we learn to avoid it in the future.
Conclusion:
Your emotions are invisible energies in motion, swiftly coursing through you and sending signals of pleasure or pain. Like brush strokes on a canvas, they add contrast and meaning to your world, often appearing to have a life of their own.
It was once believed that emotions were solely mental activities controlled by the brain, with little influence from our conscious will. Today, we understand that emotions are as much about the body as the brain. The outdated notion of the body and brain as separate entities has been replaced by a holistic model, recognizing the interconnectedness of mind, body, and spirit.
You have voluntary control over the sensory and motor systems of your central nervous system. The sensory branch collects and transmits information from the outside world through your five senses—sound, sight, smell, taste, and touch—allowing you to perceive your surroundings. The motor branch sends internal signals from your brain to your body, enabling you to walk, talk, and interact with the world.
In contrast, the autonomic branch of your nervous system operates involuntarily, beyond your conscious control. This system functions at a subconscious level, managing the operations of your internal organs and glands that secrete hormones.
While the methods for reconditioning your mind and emotions are simple, your commitment to practicing them consistently is crucial. By making these practices second nature, you can effectively reduce long-term stress patterns and promote overall health and well-being. The positive impact of one person’s choice to manage their emotions and neutralize negativity is profound and far-reaching.
