basic nerve cell in centeral nervos systemname

#BASIC NERVE CELL IN CENTERAL NERVOS SYSTEMNAME FREE#

Neurones are responsible for sensing change in their environment and communicating with other neurones via electrochemical signals. The nervous system comprises of two groups of cells, glial cells and neurones. Their apical surfaces are covered with cilia and microvilli, which allow for the circulation and absorption of CSF respectively. The main function of these cells is the production of cerebrospinal fluid (CSF) as a part of the choroid plexus. This lining is made up of ependymal cells, the basal membranes of which are attached to astrocytes. The ependyma is the thin lining of the ventricular system of the brain and spinal cord. If needed, microglia are also able to function as antigen-presenting cells. They are activated in response to tissue damage and have the capability to recognise foreign antigens and initiate phagocytosis to remove foreign material. These cells form the resident immune system of the brain. Microglial cells make up between 10 and 15% of cells within the brain and are of a mesodermal origin, unlike the other glial cells which are of ectodermal origin. Further information on the myelin sheath can be found here.īy Neuron_with_oligodendrocyte_and_myelin_sheath.svg: *Complete_neuron_cell_diagram_en.svg: LadyofHatsderivative work: Andrew c (Neuron_with_oligodendrocyte_and_myelin_sheath.svg), via Wikimedia Commonsįig 2 – Diagram showing the axon of a neuron in relation to the associated oligodendrocyte and myelin sheath Microglia They are equivalent to the Schwann cells in the peripheral nervous system. They carry out this function by producing a myelin sheath that enwraps around a part of the axon.Ī single oligodendrocyte has the capacity to myelinate up to 50 axonal segments. These cells are responsible for insulating the axons in the central nervous system.

Promotion of myelination by oligodendrocytes.

Hence, adenosine and other substances released by glial cells act as gliotransmitters modulating the synaptic activity.

Modulation of synaptic transmission – In some regions of the brain, for example, the hippocampus, astrocytes release ATP in order to increase the production of adenosine, which in turn inhibits synaptic transmission.

Neurotransmitter uptake – Astrocytes contain specific transporters for several neurotransmitters such as glutamate. A rapid removal of neurotransmitters from the extracellular space is required for the normal function of neurones.

Astrocytes, thus, remove excess potassium ions from the extracellular space following neuronal activation.

Regulation of extracellular ionic environment – High extracellular concentrations of ions such as potassium can result in spontaneous depolarisation of the neurone.

Astrocytes can also store lactate which is useful as fuel during periods of high energy consumption or ischaemia. This is overcome by the fact that astrocytes store glycogen which can be broken down to glucose to provide fuel for neurones.

Metabolic support – The neurones have a constant requirement for nutrients such as glucose but they are unable to store or produce glycogen themselves.

They contain various neurotransmitters which are released into the synapses to allow signal transmission from one neuron to the next.Īstrocytes are star-shaped glial cells within the brain and spinal cord, depending on the method used they make up between 20 and 40% of all glial cells. These make synaptic connections with other neurones.

Axon terminal – Distally the axon branches forming axon terminals.

Schwann cells – These insulate the axon with myelin sheath which facilitates the rapid transmission of action potentials along the axon.The action potentials are conducted along the axon to the axon terminal. Axon – It arises from the soma, specifically from an area called the axon hillock, where action potentials are initiated.They transmit signals received from other neurones to the soma. Dendrites – these processes originate from the soma and extend outwards.

#BASIC NERVE CELL IN CENTERAL NERVOS SYSTEMNAME FREE#

These are granules containing rough endoplasmic reticulum and free ribosomes, making it the site of protein synthesis. Cell body or Soma – this contains the nucleus and the neurone’s intracellular organelles (such as the mitochondria and Golgi apparatus).The neurone is made up of several components as follows:

Basic nerve cell in centeral nervos systemname