Composition of the nervous system??? Part 2?

The nervous system consists of two parts, the central nervous system and the peripheral nerves, of which the central nervous system includes the brain and spinal cord.

1. The nervous system is composed of two parts: the central nervous system and the peripheral nervous system.

Details: The brain, spinal cord and the nerves they emit make up the nervous system, and the brain and spinal cord are the central part of the nervous system and constitute the central nervous system; The cranial nerves emanating from the brain and the spinal nerves emanating from the spinal cord are the peripheral parts of the nervous system that make up the peripheral nervous system. Therefore, the nervous system consists of two parts: the central nervous system and the peripheral nervous system.

Second, the two parts are introduced in detail.

1. Central nervous system.

It is composed of the brain and spinal cord and is the most important part of the human nervous system. The central nervous system receives afferent information from all parts of the body, and after it is integrated and processed, it becomes a coordinated motor efferent, or it is stored in the central nervous system and becomes the neural basis of learning and memory. The entire central nervous system is located in the dorsal cavity, the brain is in the cranial cavity, and the spinal cord is in the spinal canal; The skull protects the brain, and the spine protects the spinal cord.

The activity of the human mind is also a function of the central nervous system. In the central nervous system, a large number of nerve cells are clustered together to organically form a network or circuit; Its main function is to transmit, store and process information, produce various mental activities, and dominate and control all animal behaviors.

2. Peripheral nervous system.

It is composed of nerve trunks, plexus, ganglia, and nerve terminal devices composed of perinuclear bodies and nerve fibers. Anatomically, it is often divided into three parts: the brain-sensitive nerve, the spinal nerve, and the splanchnic nerve.

Cranial nerves: There are 12 pairs of cranial nerves, which are peripheral nerves that connect to the brain. According to the order of the connection between the cranial nerve and the brain, Roman numerals are used as its serial number, which is described as follows, olfactory nerve, optic nerve, oculomotor nerve, trochlear nerve, etc.

Spinal nerves: The spinal nerves are peripheral nerves that connect to the spinal cord and have a total of 31 pairs. Each pair of spinal nerves is connected to a spinal cord segment that consists of an anterior and posterior root.

Visceral nervous system: The visceral nervous system is one of the components of the nervous system, which can be divided into the central part and the peripheral part according to the different distribution parts. Splanchnic nerves, like somatic nerves, can be divided into sensory and motor types according to the nature of the fibers.

The nervous system is the system that plays a leading role in the regulation of physiological functions and activities in the body, and it is mainly composed of nervous tissue, which is divided into two parts: the central nervous system and the peripheral nervous system. The central nervous system includes the brain and spinal cord, and the peripheral nervous system includes cranial nerves and spinal nerves.

The nervous system is a complex functional system composed of neurons and glial cells, which is the material basis of mental activity. Neurons are the basic functional units that make up the nervous system.

The nervous system is composed of two parts: the central nervous system and the peripheral nervous system.

1. The central nervous system includes the spinal cord located in the spinal canal and the brain located in the cranial cavity; It is usually located in the central axis of the animal body and consists of distinct cranial ganglia, nerve cords, or brain and spinal cords, as well as the connecting components between them.

In the central nervous system, a large number of nerve cells are clustered together to organically form a network or circuit; Its main function is to transmit, store and process information, produce various psychological activities, and control and control all the behaviors of animals.

2. The peripheral nervous system includes peripheral nerves, neuromuscular junctions, muscles, nerve roots, and plexus. It is generally distributed on muscles and limbs, and even internal organs. The main function of the peripheral nervous system is to get the correct movement of the limbs after receiving instructions from the brain, but it needs to cooperate with the central nervous system and the peripheral nervous system to unify the body language.

Neurological disorders are as follows:

1. Cerebrovascular diseases, such as cerebral infarction, cerebral hemorrhage, transient ischemic attack, subarachnoid hemorrhage, etc. Neurodegenerative diseases such as motor neuron disease, Alzheimer's disease. Infectious diseases of the central nervous system, such as herpes simplex virus encephalitis, purulent meningitis, neurosyphilis.

2. Demyelinating diseases of the central nervous system, such as multiple sclerosis, neuromyelitis optica spectrum diseases. Extrapyramidal diseases, also known as movement disorders, are caused by basal nucleus dysfunction, which is mainly manifested as dysfunction of voluntary motor regulation, and muscle strength, sensation and cerebellar function are not affected. Parkinsonism, torsional spasm, chorea, Wilson's disease, etc.

3. Spinal cord diseases, such as acute myelitis and spinal cord compression. Peripheral nerve disorders such as trigeminal neuralgia, idiopathic facial nerve palsy, Guillain-Barré syndrome. Peripheral neuropathy such as sciatic nerve injury, Guillain-Barré syndrome, facial nerve palsy, etc.

Others: such as epilepsy, congenital hydrocephalus, cerebral palsy and other abnormal diseases of nervous system development and autonomic insufficiency.

The nervous system is the dominant system in the body. After receiving various information from the internal and external environment by the receptors, it is transmitted to the centers at all levels of the brain and spinal cord through the peripheral nerves for integration, and then the peripheral nerves control and regulate the activities of various systems and organs of the body, so as to maintain the relative balance between the body and the internal and external environment. The nervous system is made up of nerve cells (neurons) and glia.

The nervous system is divided into two parts: the central nervous system and the peripheral nervous system.

The nervous system can be divided into the following parts according to its location:

1) Central nervous system: including the brain and spinal cord. The brain is located in the cranial cavity and the spinal cord is located in the spinal canal.

2) Peripheral nervous system (peripheral nervous system): includes 12 pairs of cranial nerves connected to the brain and 31 pairs of spinal nerves connected to the spinal cord.

The peripheral nervous system can be further divided into:

1) Somatic nervous system: also known as animal nervous system, contains somatosensory and somatic motor nerves, mainly distributed in the motor system (bone, bony junction and skeletal muscle), and manages the sensation and movement of sensory and motor apparatus.

2) Visceral nervous system: also known as the autonomic nervous system, the autonomic nervous system, which is mainly distributed in the viscera, cardiovascular and glands, and manages their sensations and movements. It contains visceral sensory (afferent) nerves and visceral motor (efferent) nerves, which are divided into sympathetic and parasympathetic nerves according to their functions.

The functions of various organs and systems of the human body are directly or indirectly under the regulatory control of the nervous system, which is the regulatory system that plays a leading role in the whole. The human body is a complex organism, and the functions of various organs and systems are not isolated, they are interconnected and mutually restricted; At the same time, the human body lives in a constantly changing environment, and changes in the environment affect various functions in the body at any time. This requires rapid and perfect adjustment of various functions in the body, so that the body can adapt to changes in the internal and external environment.

The nervous system is primarily the nervous system. Belong to connective tissue.

The basic structure of the nervous system.

The nervous system is made up of nerve cells (neurons) and glia.