The great and mighty nervous system, or the brain as most of us call it. What makes this organ unique is that within it lies the ability for humans to know oneself. This feature distinguishes and sets the human species apart from the rest of creation. This ability is known as consciousness or intelligence.
To begin, let's look at the primary function of the nervous system. The basic purpose is to coordinate all of the activities of the body. It enables the body to respond and adapt to changes that occur both inside and outside the body. Now the nervous system is actually split into two parts. The central nervous system and the peripheral nervous system.
We'll explore the peripheral later, but first let's look at the central nervous system. The central nervous system is made up of two major structures. The brain. and the spinal cord. As most people know, the brain is found within the cranium or skull.
And there are six main sections among other structures within it. These six sections are the cerebrum, cerebellum, diencephalon, the midbrain, pons, and the medulla oblongata. The first section is the cerebrum. This is the largest section.
It's divided into two major hemispheres which are the right and left hemisphere and the cerebrum is further divided into four lobes. These four lobes are the frontal, the parietal, the temporal, and the occipital. The frontal lobe is primarily responsible for reasoning and thought. The parietal is primarily responsible for integrating sensory information. The temporal is primarily responsible for processing auditory information from the ears, and the occipital is primarily responsible for processing visual information from the eyes.
The second section of the brain is the cerebellum. This is the section located in the back of the head, below the cerebrum, and above the first cervical of the neck. It is responsible for muscle coordination, balance, posture, and muscle tone.
The diencephalon section is found between the cerebrum and the midbrain. It contains two structures, the thalamus and the hypothalamus. The thalamus behaves much like a relay station and directs sensory impulses to the cerebrum.
And the hypothalamus controls and regulates autonomic nervous system functions such as temperature, appetite, water balance, sleep, and blood vessel constriction and dilation. The hypothalamus also plays a role in the emotions such as anger, fear, pleasure, pain, and defection. The midbrain section is located below the cerebrum at the top of the brain stem.
It is responsible for certain eye and auditory reflexes. The pons is located below the midbrain and in the brain stem. It is responsible for certain reflex actions such as chewing, tasting, and saliva production. And the last section is the medulla oblongata.
It's the lowest part of the brainstem, and it connects with the spinal cord and is responsible for regulating heart and blood vessel function, digestion, respiration, swallowing, coughing, sneezing, and blood pressure. It's also known as the center for respiration. Now that we've covered the brain, let's take a look at the other half of the central nervous system, the spinal cord. The spinal cord is the link between the brain and the nerves in the rest of the body.
The spinal cord is divided into four different regions, the cervical, thoracic, lumbar, and the afferent and efferent spinal nerves, which merge to form the peripheral nerves. The afferent spinal nerves are responsible for carrying information from the body to the brain. And the efferent spinal nerves are responsible for carrying information from the brain to the body.
Now within this elaborate system of nerves, neurons, and dendrites, there is a system that regulates the functions of the central nervous system which lie outside its major components such as the brain and the spinal cord. This system is known as the peripheral nervous system and is subdivided into two smaller systems the somatic system and the autonomic nervous system. The somatic nervous system is responsible for carrying motor and sensory information both to and from the central nervous system.
This system is made up of nerves that connect to the skin, sensory organs, and all skeletal muscles. The somatic system is also responsible for nearly all voluntary muscle movements, as well as for processing sensory information that arrives via external stimuli including hearing, touch, and sight. The structures that allow this communication to happen between the nerves throughout the body and the central nervous system are known as the afferent sensory neurons and the efferent motor neurons.
Now afferent simply means conducting inward and efferent means conducting outward. So just like in the spinal nerves, the afferent neurons take information from the nerves to the central nervous system and the efferent neurons take information from the central nervous system to the muscle fibers throughout the body. The Autonomic Nervous System is further divided into the Sympathetic Nervous System and the Parasympathetic Nervous System.
The Sympathetic Nervous System is vital to our survival. Have you ever heard of the fight or flight response to danger? The Sympathetic Nervous System revs up the body when confronted with imminent danger to either defend yourself or to escape the threat. The Parasympathetic Nervous System is the counterbalance to the sympathetic response to danger, whether real or imagined. Once the threat is gone, the parasympathetic brings all the systems of the body back to normal.
Now at this point, you should have a basic understanding of the nervous system. But let's do a quick recap. The basic purpose of the nervous system is to coordinate all the activities of the body. It enables the body to respond and adapt to changes that occur both inside and outside the body. The two major parts of the nervous system are the central nervous system and the peripheral nervous system.
The central nervous system is also divided into two major structures, the brain and the spinal cord. The brain is found within the skull or cranium and it is made up of six main sections. These six sections are The cerebrum, cerebellum, diencephalon, the midbrain, pons, and the medulla oblongata.
The other half of the central nervous system is the spinal cord, and the spinal cord is the link between the brain and the nerves and the rest of your body. The spinal cord is divided into four different regions. The cervical, thoracic, lumbar, and afferent and efferent spinal nerves, which merge to form the peripheral nerves.
Now that we know the brain and spinal cord primarily make up the central nervous system, let's look at the peripheral nervous system. The peripheral nervous system is essentially the nervous system outside of the brain and spinal cord. The peripheral nervous system is then subdivided into two smaller systems called the somatic nervous system and the autonomic nervous system.
So, as you can see, the nervous system is quite complex, and this is just the tip of the iceberg. Thanks for watching. Look for more videos on the nervous system at cteskills.com.