Structural, Metabolic and Functional Characteristics of Cerebral-Cerebral Blood Supply Deficiency

The brain is composed of hundreds of millions of nerve cells and more than 65,438+0,065,438+0.4 synapses. It has a very complex and subtle structure and function. The brain is the center that regulates the functions of various systems and organs, and participates in higher nervous activity of learning, memory, comprehensive analysis and consciousness. Abnormal brain function will affect people's spirit, emotion, behavior, consciousness and almost all organ functions to varying degrees.

Structural, metabolic and functional characteristics of the brain

The brain is located in the cranial cavity. On the one hand, this structural feature protects the brain; On the other hand, the limitation of skull on brain tissue is often the structural basis of intracranial hypertension and cerebral hernia. At the cellular level, the brain is composed of neurons and glia. The former is the executor of various brain functions, while the latter plays the role of nourishing and protecting neurons. The blood supply of the brain comes from paired vertebral arteries and internal carotid arteries, and their branches form a vascular network to ensure adequate blood supply. The substances in the blood first pass through the blood-brain barrier, and the anatomical basis of the blood-brain barrier includes endothelial cell layer, basement membrane, glial processes and tight junctions. Everything that is combined with protein can basically not pass through the blood-brain barrier, so it will not enter the brain tissue; Substances with strong fat solubility can enter brain tissue quickly, and substances with weak fat solubility or insoluble in fat can enter brain tissue very slowly or completely; The rate at which certain substances enter the brain depends on the metabolic needs of these special substances in the brain region. For example, when myelin sheath is produced, cholesterol accumulates in the brain, and once myelin sheath is formed, the cholesterol content in the brain will decrease.

The brain is the most active organ of energy metabolism in the body, with large blood flow and large oxygen consumption. Glucose is the main energy source of brain tissue, and almost all the energy needed by the brain comes from the oxidation of glucose. However, due to the small storage of oxygen and glucose in the brain, it needs to be continuously absorbed from the blood. A variety of injury factors can affect the energy metabolism of the brain, resulting in abnormal structure and function of the brain.