What is the function of the three parts of a neuron..
Answers
Explanation:
Neurons (nerve cells) have three parts that carry out the functions of communication and integration: dendrites, axons, and axon terminals. They have a fourth part the cell body or soma, which carries out the basic life processes of neurons.
Explanation:
Function of neurons
Neurons send signals using action potentials. An action potential is a shift in the neuron’s electric potential caused by the flow of ions in and out of the neural membrane.
Action potentials can trigger both chemical and electrical synapses.
Chemical synapses
In a chemical synapse, action potentials affect other neurons via a gap between neurons called a synapse. Synapses consist of a presynaptic ending, a synaptic cleft, and a postsynaptic ending.
When an action potential is generated, it’s carried along the axon to a presynaptic ending. This triggers the release of chemical messengers called neurotransmitters. These molecules cross the synaptic cleft and bind to receptors in the postsynaptic ending of a dendrite.
Neurotransmitters can excite the postsynaptic neuron, causing it to generate an action potential of its own. Alternatively, they can inhibit the postsynaptic neuron, in which case it doesn’t generate an action potential.
Electrical synapses
Electrical synapses can only excite. They occur when two neurons are connected via a gap junction. This gap is much smaller than a synapse, and includes ion channels which facilitate the direct transmission of a positive electrical signal. As a result, electrical synapses are much faster than chemical synapses. However, the signal diminishes from one neuron to the next, making them less effective at transmitting.
Types of neurons
Neurons vary in structure, function, and genetic makeup. Given the sheer number of neurons, there are thousands of different types, much like there are thousands of species of living organisms on Earth.
In terms of function, scientists classify neurons into three broad types: sensory, motor, and interneurons.
Sensory neurons
Sensory neurons help you:
taste
smell
hear
see
feel things around you
Sensory neurons are triggered by physical and chemical inputs from your environment. Sound, touch, heat, and light are physical inputs. Smell and taste are chemical inputs.
For example, stepping on hot sand activates sensory neurons in the soles of your feet. Those neurons send a message to your brain, which makes you aware of the heat.
Motor neurons
Motor neurons play a role in movement, including voluntary and involuntary movements. These neurons allow the brain and spinal cord to communicate with muscles, organs, and glands all over the body.
There are two types of motor neurons: lower and upper. Lower motor neurons carry signals from the spinal cord to the smooth muscles and the skeletal muscles. Upper motor neurons carry signals between your brain and spinal cord.
When you eat, for instance, lower motor neurons in your spinal cord send signals to the smooth muscles in your esophagus, stomach, and intestines. These muscles contract, which allows food to move through your digestive tract.
Interneurons
Interneurons are neural intermediaries found in your brain and spinal cord. They’re the most common type of neuron. They pass signals from sensory neurons and other interneurons to motor neurons and other interneurons. Often, they form complex circuits that help you to react to external stimuli.
For instance, when you touch something hot, sensory neurons in your fingertips send a signal to interneurons in your spinal cord. Some interneurons pass the signal on to motor neurons in your hand, which allows you to move your hand away. Other interneurons send a signal to the pain center in your brain, and you experience pain.