Have you ever wondered how you are able to perform the tasks that you do? What is the reason behind your body’s effective functioning? How does your body function the way it does? One of the main systems in our body, the nervous system, ensures our body performs all the tasks effectively as it controls everything we do.
From sensory to motor actions that we perform, all are through the nervous system. Our nervous system comprises billions of tiny neurons that transmit electrical signals from the brain to the body parts. Notably, it is the transmission of electrical signals between the brain and the rest of the body that allows for actions, such as walking, digesting, talking, thinking, sleeping, etc.
Central Nervous System
Our central nervous system constitutes our spinal cord and brain. Its common name is the “control center of the human body” because it takes responsibility for most body functions. Similar to a computer, our brain interprets all the data gathered from the environment.
The central nervous system also involves our brain’s thinking and emotional processes while also controlling the voluntary actions of our body, such as walking, speech, etc. Unlike other systems and organs, the central nervous system uses our spinal cord as a bridge between our brain and body in order to control the movement and prevent itself from injuries. If the spinal cord experiences damage, the central nervous system might be dysfunctional (paralysis can occur).
Peripheral Nervous System (PNS)
Nerve fibers, the axons, work to connect our body and brain via the spinal cord. Bundles of axons create a vast network that we know as the peripheral nervous system. It is outside the brain, spinal cord, and cranial nerve tissues; it carries the name “peripheral.”
This system works in conjunction with the central nervous system. The conjunction occurs when this system’s sensory receptors send signals to the central nervous system after detecting changes in the external and internal environment. Likewise, the body’s control center sends signals back to it to carry out voluntary and/ or involuntary body response. In addition, PNS falls into two further subdivisions.
1. Somatic Nervous System
The somatic nervous system contains the efferent and afferent nerves or sensory and motor nerves. Moreover, the somatic nervous system is in charge of the voluntary physical movement of the body through the skeletal muscles.
2. Autonomic Nervous System
The autonomic nervous system is majorly responsible for involuntary body tasks such as controlling cardiovascular activities, including cardiac muscle contraction (and expansion), blood vessels, and internal organ functions.
Additionally, it is also responsible for our respiratory functions, perspiration, digestion, heart rate, sexual arousal, urination, and even pupil dilation or constriction. However, the task of breathing often accompanies conscious thoughts. Conversely, subsystems of the autonomic nervous system take responsibility for sets of different voluntary and involuntary functions of our body.
• Parasympathetic Nervous System
The duty of the parasympathetic nervous system is to control digestion, rest, feeding, waste elimination, and heart rate when our body is relaxed. It acts as a remedy to the effects of the sympathetic nervous system under stressful situations.
• Sympathetic Nervous System
You might have heard of the “fight or flight” response. Well, it’s time to know that the sympathetic nervous system of our body entails functions such as stress, excitement, anger, embarrassment, exercise, and all other related emotions. It is responsible for sending signals to the brain to release adrenaline into our body. Over that, it reduces the digestion rate, elevates heart rate, and respiration in order to encounter such situations.
• Enteric Nervous System
The enteric nervous system directly regulates, maintains, and controls the digestive organs along with the entire digestion process of our body. Commonly named “brain of the gut,” the enteric nervous system in our body is capable of functioning independently without the need for any external output.
Fun fact – the number of neurons in our spinal cord is equal to the number of neurons in our enteric nervous system. Therefore, medical studies often regard the enteric nervous system as our body’s second brain. Typically, it receives signals from the central nervous system and the peripheral nervous system in conjunction.
What Part Do Neurons Play in the Nervous System?
At the heart of our nervous system lies an extensive and comprehensive network of special cells, “neurons.” Neurons contain thin fiber linings that enable them to penetrate an extensive range of tissues for effective signal transmission. The fiber linings (axons) and dendrite (extensive branch of the cell containing a nucleus) communicate with several other neuron cells via electrical and/ or chemical impulses.
This process, known as “synapses” or “electrical synapses,” is highly effective due to neuroglia in the brain ventricles. Neuroglia is responsible for nourishing and protecting the neuron cells in the brain. Did you know that there are more than 100 billion neurons inside your brain?
Functions of the Nervous System
Sensation is among the prime functions of our nervous system. It gathers data from external factors to certain output information regarding what is happening outside and inside the body. Sensations are a standard function because they record changes in homeostasis or stimulus.
First and foremost, chemical substances create the stimulus for our senses, such as taste and smell. Meanwhile, touch is a physical and mechanical stimulus, and hearing is the stimulus from sound waves. Lastly, sight is the stimulus that occurs due to light.
In addition, there are more senses that our body perceives than the ones above. For example, a stretch or a tear inside an organ wall or tube may create a stimulus that will require our nervous system to send pain signals to our brain.
When our sensory receptors receive the stimuli and communicate them to our nervous system via signal transmission, the integration process occurs. During integration, the current stimuli data forms a comparison with previous data such as the memories of old stimuli or even with the condition of our body for at a specific time. Subsequently, our nervous system relays back signals to ensure voluntary or involuntary responses to our body.
Per the stimuli, our nervous system sends back signals to generate a response. What do you think these responses include? Clearly, holding a hot pan will produce the stimuli of burning, which will make your nervous system respond with the action of immediately withdrawing from the hold. Similarly, there are a lot of uses for the term “response.” However, our nervous system is capable of moving all three types of body muscles mentioned below:
1. Cardiac Muscles
2. Skeletal Muscles
3. Even Muscle Contractions
These responses fall under the categories of voluntary (skeletal muscles) and involuntary (smooth muscle contractions) responses that somatic and autonomic nervous systems control, respectively.
Apart from that, our nervous system also can regulate chemical glands in our body. For instance, adrenaline glands secrete adrenaline upon receiving the stimulus of excitement. Moreover, sweat glands produce chemicals that secrete sweat from our skin upon receiving the stimulation of stress.
The motor responses fall under the somatic nervous system. While some motor responses such as running away after seeing a car speeding at you or punching a wall in stress are voluntary, others aren’t. For instance, a jump-scare might make you fall off your feet, but you didn’t plan to get startled, right?
Furthermore, the body’s responses are also internal. For example, the slight movement of the organs to function efficiently is an example of an involuntary response based on the stimuli from the sensory receptors.
Here’s some latest news: Scientists might be able to hack your nervous system! With medical knowledge, experience, and expertise, along with modern technology, scientists are trying to hack the human nervous system. Yes, it is true! With the ability to control the nervous system, there can be impeccable advances in medicine and disease treatments. Further, it will help doctors and experts to learn how the immune system of our body works.
However, the studies are still underway, and methods are in development to aid the process. In addition to that, when the working and mystery behind the groups of neurons in our brain become understandable, connections to other medical aspects of the human body might also become easy to understand.