Two main types of cells in nervous system biology essay

Nervous system function

The Cell Membrane The membrane that separates the neuron from other cells and from the extracellular fluid is of extreme importance in understanding neuronal function. When a chemically gated ion channel is activated, it forms a passage that allows specific types of ions to flow across the membrane. With this influx of positive ions, the internal charge of the cell becomes more positive. These scientists approach a closer look on the reactions the nervous system has when humans have neurological, psychiatric and neurodevelopmental disorders. The genetic template is stored as coded strings of deoxyribonucleic acid DNA. They also regulated the flow of ions and larger molecules in the region of the synapses, a fact of unknown significance. For example, the photoreceptors of the eye transform variations in light intensity into electrical and chemical signals that can be read by other nerve cells. The cell body integrates information from the dendrites and other synaptic inputs in determining the messages to be transmitted to other cells through its axon. The oligendrocytes produce myelin, which surrounds the axons of many neurons. One axon can be myelinated by several oligodendrocytes, and one oligodendrocyte can provide myelin for multiple neurons.

It appears that a similar molecular mechanism is involved for widely disparate types of animals, including arthropods as well as vertebrates. Multiple sclerosis MSan autoimmune disorder, involves a large-scale loss of the myelin sheath on axons throughout the nervous system.

Two main types of cells in nervous system biology essay

At the very least, spines increase the synaptic surface of the dendrite, allowing a maximum of synaptic content with a minimum of dendritic volume. For mammals, new neurons also play an important role in learning: about new neurons develop in the hippocampus a brain structure involved in learning and memory each day. An action potential is a distinctive length of the axon. An axon is an extension of a neuron. They are categorized as receptors, interneurons, or effectors, depending on their function. The neuron is a small information processor, and dendrites serve as input sites where signals are received from other neurons. Sweeney, NOAA; credit f: modification of work by NIH Compared to invertebrates, vertebrate nervous systems are more complex, centralized, and specialized. In contrast, the local circuit neurons, with their short dendrites and small axons when present , usually have small, compact cell bodies. Stress can be defined as a stimulus that interrupts homeostasis within the body, either physiologically or psychologically. They talk to dendrites from the cell next to them over something called a synapse. Figure

As it moves, the cytoplasm is pushed forward, leaving only the membrane of the Shwann cell wrapped around the once-naked axon.

Endoplasmic Reticulum and Golgi Apparatus Two other organelles are primarily responsible for the cellular manufacture of proteins, the endoplasmic reticulum and the Golgi apparatus. If the change in electrical potential is large enough to pass the given threshold, it evokes an action potential, which is transmitted along the axon of the receptor cell, into the spinal cord.

Dendrites and axons, both extensions of the cell body, are also referred to as processes.


While there is great diversity among different vertebrate nervous systems, they all share a basic structure: a CNS that contains a brain and spinal cord and a PNS made up of peripheral sensory and motor nerves. Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes.

The brain and the spinal cord make up what is called the central nervous system.

Neuron diagram labeled

It wouldn't know anything that was going on in the outside world and wouldn't be able to control our body. Once neurotransmitters are released into the synapse, they travel across the small space and bind with corresponding receptors on the dendrite of an adjacent neuron. A technique called immunohistochemistry can be used to attach a fluorescent label to the incorporated BrdU, and a researcher can use fluorescent microscopy to visualize the presence of BrdU, and thus new neurons, in brain tissue. The systems process all the collected information and send instructions to the rest of the body; to obtain an appropriate response. Many types of neurons have dendrites with a special form of synaptic connection, dendritic spines. Usually, cells have only one axon, but it may give off collaterals, or branches, to carry the action potential to more than one region of the brain. The electrical charge of the fluids is caused by charged molecules ions dissolved in the fluid. Dendrites carry the signal to the soma. Dendrites Dendrites are responsible for responding to stimuli; they receive incoming signals towards the cell body. There are four major types of neurons, and they share several important cellular components. The nervous system is responsible for managing our thinking process, emotions, and body functions. Although the simplest reflexes may be mediated by circuits lying entirely within the spinal cord, more complex responses rely on signal processing in the brain. Within each endfoot are both mitochondria and synaptic vesicles.

The central nervous system CNS is the main control center of the body that receives sensory input, organizes and synthesizes it then provides instructions for motor output to the rest of the body. Dendrites Dendrites are responsible for responding to stimuli; they receive incoming signals towards the cell body.

two types of nervous tissue

This fold deepens, and then closes up at the top.

Rated 10/10 based on 79 review
Neurons and Glial Cells