Axolemma (Axolemma)

Axolemma is a thin cellular (plasma) membrane surrounding the protoplasm of the axon. The axolemma is visible only under an electron microscope.

The axolemma performs an important function - it separates the internal environment of the axon from the extracellular space. It regulates the flow of nutrients into the axon and the removal of waste from it. In addition, the axolemma conducts nerve impulses along the axon due to the presence of ion channels and pumps in it.

Thus, the axolemma plays a key role in the functioning of the axon, the process of a nerve cell that carries signals from the cell body to other nerve cells or muscles. Without the axolemma, the transmission of nerve impulses and normal functioning of the nervous system are impossible.

Axolemma: Thin cellular (plasma) membrane surrounding the protoplasm of the axon

In neurobiology, the axolemma, also known as the axonal membrane, is a thin cell membrane that surrounds the protoplasm of the axon. It plays an important role in the functioning of the nervous system by providing electrochemical insulation of the axon and maintaining its structural integrity.

The axolemma consists of two layers of lipid bilayer: outer and inner. The lipid bilayer forms a bilayer structure known as the phospholipid bilayer, which contains various proteins, glycoproteins, and glycolipids that play important roles in axon functionality.

One of the key functions of the axolemma is to maintain electrical insulation of the axon. Axons transmit electrical impulses, called action potentials, from cell to cell, and the axolemma acts as a barrier that helps prevent electrical charge from leaking out. This is achieved through the specialized structure of the axolemma and the presence of ion channels that control the flow of ions across the membrane.

In addition, the axolemma plays an important role in maintaining the structural integrity of the axon. It provides mechanical support for the axon and protects it from external damage. Thanks to the axolemma, the axon is able to extend over long distances without losing its functionality.

It is impossible to directly observe the axolemma without using an electron microscope. Thanks to the high resolution of electron microscopes, the researchers were able to obtain a detailed understanding of the structure of the axolemma and its components. This allowed us to better understand its functional role in the nervous system and expand our knowledge of the mechanisms of nerve signal transmission.

In conclusion, the axolemma is an important component of the axon, providing electrochemical insulation and maintaining its structural integrity. Its role in transmitting nerve impulses and protecting the axon from damage makes it an integral part of the nervous system. Thanks to modern research methods, we can more deeply understand the structure and function of the axolemma, which contributes to the development of our knowledge of the functioning of the nervous system and its role in the body.

The cell membrane is a very dense internal environment of the cell, which causes difficulties in observing and studying its structure. One way to solve this problem is to use chemical or physical methods to destroy cells. One of the methods that allows one to observe the structure of the axolemma is fixation of the cell with radioactive iodine and its subsequent irradiation. The ion beam destroys the less dense cell membrane (cytolemma), but does not damage the membrane structures of the axon. As a result, it becomes possible to observe thin membranes like axolemmata. Under normal conditions, the contents of the cytoplasm are under fairly high osmotic pressure. Thus, isoionicity is maintained in axons, which prevents the accumulation of K+, Na+, etc. in the cytoplasm. It has been shown that a significant portion of these ions flow into the axon simultaneously with Na+ through special fast Na+-K+ ATPases. The direct analogue of the axoleima is the apical one,