Nerve cell that transmits messages throughout the body.
Active cells of the nervous system that transmit and receive messages.
A cell in the nervous system which transmits nerve impulses.
A nerve cell consisting of a central cell body, plus tentacle-like structures which carry messages either towards the central body or away towards another neuron.
A nerve cell; the basic structural and functional unit of the nervous system, neurons are specialized to carry information in the form of electrochemical impulses from one part of the body to another. Each neuron is composed of a cell body containing a nucleus and one or more processes: dendrites that carry impulses toward the cell body and axons that carry impulses away from the cell body. Sensory neurons transmit impulses from sense organs to the brain and spinal cord; motor neurons transmit impulses from the brain and spinal cord to muscles and glands.
The functional unit of the nervous system responsible for conducting impulses; includes the axion, cell body, and dendrites.
A nerve cell; the basic conducting cell of every structure in the nervous system. Neurons receive, interpret, and transmit information in the form of electrochemical impulses.
One of the basic functional units of the nervous system: a cell specialized to transmit electrical nerve impulses and so carry information from one part of the body to another. Each neuron has an enlarged portion, the cell body (perikaryon), containing the nucleus; from the body extend several processes (dendrites) through which impulses enter from their branches. A longer process, the nerve fiber, extends outward and carries impulses away from the cell body. This is normally unbranched except at the nerve ending. The point of contact of one neuron with another is known as a synapse.
Also known as a nerve cell, this is the basic cellular building-block of the nervous system, which contains billions of neurones linked in a complex network and acting in different combinations to keep the body informed about the outside world, and then to organize and activate appropriate responses.
A nerve cell, the structural and functional unit of the nervous system. A neuron consists of a cell body (perikaryon) and its processes, an axon and one or more dendrites. Neurons function in initiation and conduction of impulses. They transmit impulses to other neurons or cells by releasing neurotransmitters at synapses. Alternatively, a neuron may release neurohormones into the bloodstream.
A specialized cell that receives and sends electrical signals.
Primary structural unit of the nervous system, consisting of cell body, nucleus, dendrites, and axon.
The basic nerve cell of the nervous system. A neuron consists of a nucleus within a cell body and one or more processes (extensions) called dendrites and axons.
An exceptional category of cells discovered in both the brain and body, possessing specialized capabilities to interpret and convey information.
A standard neuron is made up of a cell body, multiple branch-like extensions named dendrites, and a thread-like projection known as an axon or nerve fiber. The axon ends in branches, creating terminals that convey nerve signals to specific cells.
Most axons have a protective insulating layer called the myelin sheath, which enhances the speed of nerve signal transmission. This sheath has intervals known as nodes of Ranvier that aid in signal transmission. Since the myelin sheath doesn’t conduct electricity, the exchange of ions (or depolarization) takes place solely at these nodes. As a result, signals jump from one node to the next along the axon’s length.
The nervous system is composed of billions of neurons that fall into three primary categories: sensory neurons that relay signals from sensory receptors to the central nervous system (CNS); motor neurons that convey messages from the CNS to muscles or glands; and interneurons, which create the intricate electrical networks inside the CNS.
When a neuron sends a nerve impulse, it releases a neurotransmitter from its axon terminals at the synapses, which are connections with other neurons. This neurotransmitter can trigger a muscle cell to contract, prompt an endocrine gland to produce a hormone, or influence a neighboring neuron.
Different triggers activate various types of neurons. For instance, sensory neurons might be stimulated by physical factors like cold, pressure, or specific light wavelengths. The activity of most neurons is regulated by neurotransmitters released from neighboring neurons. Some neurotransmitters cause a rapid shift in the electrical balance within and outside the cell, leading to an “action potential” that rapidly moves along the cell’s membrane. Conversely, other neurotransmitters stabilize the neuron’s membranes, blocking the action potential. As a result, how a neuron fires depends on the mix of stimulating and inhibiting factors affecting it.
If a neuron’s cell body is harmed or deteriorates, the cell perishes and isn’t replaced. A newborn enters the world with its peak number of neurons, and this count gradually drops over a lifetime. Still, given the vast number of neurons we start with, complications usually emerge when factors like diseases, injuries, or chronic alcohol misuse impact the CNS, leading to a significantly accelerated loss of neurons.
When a peripheral nerve suffers damage, its individual nerve fibers possess the capability to heal and regenerate.