The body is divided into many systems. What elements make up the nervous system, and what are their functions? It would be impossible to breathe, move around, engage in a variety of things without her. This is a system that receives and processes all the information received from all parts of the body. It consists of the brain, spinal cord and neurons. Let's characterize the structure of the nervous system of vertebrates. Perhaps the most important.
Parts and functions of the central nervous system
So, more details. Let's characterize the structure of the nervous system of vertebrates. Its main units are neurons. All cells of the nervous system are made of them. Neurons are able to transmit electrical impulses throughout the body in the form of signals that cause a reaction. There are three types of neurons:
- motor transmit information between organs, glands and muscles.
- sensory send information to the brain and spinal cord from internal organs or external stimuli that are found in parts of the body.
- interneurons act as messengers that connect signals between motor and sensory neurons.
The brain is the control center of the body
The brain and spinal cord are the two main components of the central nervous system. The first is responsible for the adoption and processing of sensory information: thinking, understanding, speech and motor functions. The anterior consists of the thalamus, hypothalamus, brain and cerebral cortex. The posterior functions in maintaining balance and balance, coordinating movement and processing some sensory information, and has parts known as the bridge, cerebellum, and medulla oblongata. The brain stem extends all the way to the spinal cord and is responsible for auditory and visual reactions, as well as motor function.
The structure of the nervous system of the vertebrates also includes the spinal cord, which connects to the brain to send information through the body in the form of electrical signals. It looks like a thick rope. And it consists of nerves that transmit messages between the brain and the rest of the body. It extends from the medulla oblongata to the lower back and is located in the space created by the vertebrae or bones of the spine. All vertebrates have spinal cords, from simple toothless fish to large birds and mammals.
Spinal cord function
The next moment. We characterize the structure of the vertebral nervous system using the example of the spinal cord. Interestingly, it works like a telephone switchboard operator. Helps the brain communicate with various parts of the body and vice versa. His three main roles:
- The transmission of messages from the brain to different parts of the body (usually to the muscles) to perform a specific action.
- The transfer of messages from sensory receptors found throughout the body to the brain.
- Coordination of reflexes (quick responses to external stimuli) that do not pass through the brain and are controlled only by the spinal cord.
General characteristics
In an adult, the spinal cord has a length of about 44 cm and a width - like that of the thumb. It is as thin as a drinking straw at the end. A thick bundle of nerves is protected by three layers of the membrane. Between the core of the nerve bundles and the meninges, there is also cerebrospinal fluid for additional cushioning. The spinal cord ends with a cascade of nerves resembling a horse's tail. The nerve cord consists of five main areas, consisting of 33 segments, each of which contains nerves associated with various parts of the body:
- The cervical margin is connected to the head, neck, upper body, hands.
- The chest area is connected to the arms, fingers, chest, and abdominal muscles.
- The lumbar region is connected to the hips, knees, ankles, and leg muscles.
- The sacral region connects to the legs, toes, bladder and anal muscles.
- The coccygeal region connects to the skin around the coccyx.
The nervous system of vertebrates: a scheme
And finally. Vertebrates are diverse and widespread on Earth, but this has not always been the case. It is difficult to imagine, but due to certain characteristics, a person is connected not only with other mammals, such as dogs, zebras and rabbits, but also with creatures such as fish, snakes and salamanders. In fact, all animals with a spine are vertebrates. This means that they all fall into the same category as people.
These organisms are a diverse group of animals representing many different shapes, sizes, colors, habitats and ecosystems. It is clear that they all differ from each other. However, there are some similarities that allow you to see the connection even between those organisms whose appearance is completely different. For example, there is a head, two pairs of limbs and so on.
We characterize the structure of the nervous system of vertebrates, compared with invertebrates. The former have a completely different type of construction. In invertebrates, it is narrower and more primitive. The central nervous system of vertebrates has the following feature: from the earliest stages of embryo development, the presence of a nodal structure is not characteristic of it.
It has the appearance of a continuous neural tube, differentiating into various parts of the brain. In addition to the central nervous system, there is also a peripheral one, where nerve nodes are located , the function of which is to connect the central nervous system with all parts of the body.