In this case, we speak about diffuse reflection and diffuse transmission (Fig. 1). Both processes can be accompanied by diffusion (also called scattering), which is the process of deflecting a unidirectional beam into many directions. Neurons are classified as either motor, sensory, or interneurons. Motor neurons carry information from the central nervous system to organs, glands, and muscles. Sensory neurons send information to the central nervous system from internal organs or from external stimuli. Interneurons relay signals between motor and sensory neurons.Reflection is the process by which electromagnetic radiation is returned either at the boundary between two media (surface reflection) or at the interior of a medium (volume reflection), whereas transmission is the passage of electromagnetic radiation through a medium.
They are found in retinal cells and olfactory epithelium. Bipolar neurons are sensory neurons consisting of one axon and one dendrite that extend from the cell body.Unipolar neurons are found in spinal nerve cell bodies and cranial nerves. Unipolar neurons have one very short process that extends from a single cell body and branches into two processes.These neurons have a single axon and many dendrites extending from the cell body. Multipolar neurons are found in the central nervous system and are the most common of the neuron types.They are multipolar, unipolar, and bipolar neurons. There are three main categories of neurons. Both of these systems work together to maintain homeostasis. In contrast, the endocrine system, which uses hormones as its chemical messengers, is typically slow-acting with effects that are long-lasting. Nervous system chemical and electrical signaling allow for quick responses to internal and external changes. After crossing the gap, neurotransmitters bind to receptor sites on the receiving neuron and stimulate an action potential in the neuron. This process is accomplished by exocytosis of the neurotransmitters. At chemical synapses, chemical signals called neurotransmitters are released which cross the gap junction to stimulate the next neuron. At electrical synapses, ions and other molecules pass through gap junctions allowing for the passive transmission of electrical signals from one cell to the other. It is at the synapse where chemical or electrical impulses must cross a gap and be carried to the dendrites of adjacent cells. These branches end at junctions called synapses.
Since axons can have numerous branches, nerve impulses can be transmitted to numerous cells. Nerve impulses are received at neuronal dendrites, passed through the cell body, and are carried along the axon to the terminal branches. Nerve impulses, or action potentials, are electrochemical impulses that cause neurons to release electrical or chemical signals that initiate an action potential in another neuron. These nerves send signals between the brain, spinal cord, and other body organs via nerve impulses. Information is communicated among nervous system structures through nerve signals. Axons and dendrites are bundled together into what are called nerves. They have many synapses in order to receive signal messages from nearby neurons.
Dendrites are usually more numerous, shorter, and more branched than axons. Dendrites typically carry signals toward the cell body.Axons end at junctions known as synapses. Gaps between the myelin sheath are called Nodes of Ranvier. These cells form the myelin sheath which indirectly assists in the conduction of impulses as myelinated nerves can conduct impulses quicker than unmyelinated ones. Some axons are wrapped in an insulating coat of glial cells called oligodendrocytes and Schwann cells. They are long nerve processes that may branch out to convey signals to various areas. Axons typically carry signals away from the cell body.Nerve processes are "finger-like" projections from the cell body that are able to conduct and transmit signals. The cell body produces proteins needed for the construction of other parts of the neuron. The central cell body is the process part of a neuron and contains the neuron's nucleus, associated cytoplasm, organelles, and other cell structures. Neurons contain the same cellular components as other body cells. A neuron consists of two major parts: a cell body and nerve processes.
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