why are neurons called excitable cells?mention the special feature of the membrane of the neuron
A neuron is an electrically excitable cell that processes and transmits information through electrical and chemical signals. These signals between neurons occur via specialized connections called synapses. Neurons can connect to each other to form neural networks. Neurons are major components of the brain and spinal cord of the central nervous system (CNS), and of the autonomic ganglia of the peripheral nervous system.
The membrane of neuron serves as a barrier to enclose the cytoplasm inside the neuron, and to exclude certain substances that float in the fluid that bathes the neuron.
The membrane with its mosaic of proteins is responsible for many important functions:
The membrane is made of lipids and proteins - fats and chains of aminoacids. The basic structure of this membrane is a bilayer or sandwich of phospholipids, organized in such a way that the polar (charged) regions face outward and the non polar regions face inward.
The external face of the membrane contains the receptors, small specialized molecular regions which provide a kind of "attachment port" for other external molecules, in a scheme analogous to a a key and a keyhole. For each external molecule there is a corresponding receptor. Whenever receptors become attached to a molecule, some alterations of the membrane and in the interior of the cell ensue, such as the modification of permeability to some ions.
The membrane of neuron serves as a barrier to enclose the cytoplasm inside the neuron, and to exclude certain substances that float in the fluid that bathes the neuron.
The membrane with its mosaic of proteins is responsible for many important functions:
- keeping certain ions and small molecules out of the cell and letting others in,
- accumulating nutrients, and rejecting harmful substances,
- catalyzing enzymatic reactions,
- establishing an electrical potential inside the cell,
- conducting an impulse
- being sensitive to particular neurotransmitters and modulators .
The membrane is made of lipids and proteins - fats and chains of aminoacids. The basic structure of this membrane is a bilayer or sandwich of phospholipids, organized in such a way that the polar (charged) regions face outward and the non polar regions face inward.
The external face of the membrane contains the receptors, small specialized molecular regions which provide a kind of "attachment port" for other external molecules, in a scheme analogous to a a key and a keyhole. For each external molecule there is a corresponding receptor. Whenever receptors become attached to a molecule, some alterations of the membrane and in the interior of the cell ensue, such as the modification of permeability to some ions.