The human brain coordinates and regulates all body functions that are important for normal functioning, and also controls behavior. Desires, thoughts, feelings - everything is connected with the work of the brain. If this organ does not function, the person becomes a "plant."
Human brain: characteristic
The brain is a symmetrical structure, however, like many other organs. The brain weight at birth is about three hundred grams; in adulthood, it weighs one and a half kilograms. Considering the structure of the human brain, you can immediately find two hemispheres, which underneath hide deep formations. The hemispheres are covered with peculiar convolutions that increase the outer cerebral layer. Behind is the cerebellum, below is the trunk passing into the spinal cord. Both nerve endings branch from the trunk and from the spinal cord itself, it is through them that information from receptors flows to the brain, it is through them that the human brain sends signals to glands and muscles.
Inside the brain there is a white substance, which is a nerve fiber that connects various parts of an organ to each other and forms nerves that extend to other organs, and a gray matter that forms the cerebral cortex and consists mainly of bodies of nerve cells. The human brain is protected by a skull - a bone case. The substances inside the organ and the bone walls are separated by three shells: solid (external), soft (internal) and thin arachnoid. The resulting space between the membranes is filled with cerebrospinal (cerebrospinal) fluid similar in composition to blood plasma. The liquid itself is produced in the ventricles of the brain - the cavities inside it, its role is to supply the human brain with the necessary nutrients.
The carotid arteries provide cerebral blood supply, they are divided at the base into large branches that extend to different parts of the brain. Surprisingly, 20 percent of all the blood circulating in the body continuously enters the brain, although the weight of the organ itself of the total weight of a person is only 2.5 percent. Together with blood, oxygen enters the brain, supplying them is extremely important, since the body’s own energy reserves are very small.
Brain cells
Of the cells called neurons, the central nervous system consists. They are responsible for processing information. The human brain includes from 5 to 20 billion neurons. In addition to them, glial cells are present in the organ, which are approximately 10 times more than neurons. Glial cells form the skeleton of nerve tissue and fill the space between neurons. Like any other cell, neurons are surrounded by a plasma membrane. The processes - axons (most often, one cell has one axon from a couple of centimeters to several meters long) and dendrites (each neuron has many dendrites, they are branching and short) leave the cells.
Human brain: departments
Conventionally, the brain is divided into three departments: the front brain, trunk, cerebellum. The forebrain consists of two hemispheres, the thalamus (the sensory nucleus, which receives information from the organs and transfers it to the sensory cortex) and the hypothalamus (the region that controls homeostatic functions), the pituitary gland - an important gland. Hemispheres are the largest parts of the brain connected by a corpus callosum - a bundle of axons. Each hemisphere has an occipital, parietal, temporal and frontal lobes. The trunk includes the medulla oblongata (the lower part of the trunk, passing into the spinal cord), the Varolian bridge (connected to the cerebellum by nerve fibers) and the midbrain (motor paths go through the spinal cord through it). The cerebellum is located under the occipital lobes of the cerebral hemispheres, it controls the position of the trunk, limbs, head, plays a large role in the development of motor skills.