In 4 or 5 sentences, describe the anatomy of the basic unit of the nervous system, the neuron. Include each part of the neuron and a general overview of electrical impulse conduction, the pathway it travels, and the net result at the termination of the impulse. Be specific and provide examples.
- Answer the following (listing is acceptable for these questions):
o What are the major components that make up the subcortical structures?
o Which component plays a role in learning, memory, and addiction?
o What are the two key neurotransmitters located in the nigra striatal region of the brain that play a major role in motor control?
- In 3 or 4 sentences, explain how glia cells function in the central nervous system. Be specific and provide examples.
- The synapse is an area between two neurons that allows for chemical communication. In 3 or 4 sentences, explain what part of the neurons are communicating with each other and in which direction does this communication occur? Be specific.
- In 3–5 sentences, explain the concept of “neuroplasticity.” Be specific and provide examples.
Full Answer Section
The cell body, also known as the soma, houses the neuron's nucleus, mitochondria, and other organelles. It is the metabolic center of the neuron, responsible for maintaining its structure and function. Dendrites, short, branching extensions of the cell body, act as antennae, receiving signals from other neurons. These signals are in the form of electrical impulses or neurotransmitters, chemical messengers that transmit information across synapses, the junctions between neurons.
The axon, a long, slender fiber extending from the cell body, is responsible for transmitting electrical impulses away from the cell body. It is covered by a myelin sheath, an insulating layer that speeds up the transmission of electrical signals. The axon terminates in axon terminals, which form synapses with other neurons or muscle cells.
Electrical impulse conduction, the process by which neurons communicate, is a complex process involving the movement of charged ions across the neuron's cell membrane. When a neuron receives an excitatory signal, causing an influx of positively charged sodium ions into the cell, the membrane potential, the difference in electrical charge between the inside and outside of the cell, becomes less negative. If this depolarization reaches a threshold level, an action potential, a rapid spike in electrical potential, is triggered.
The action potential travels along the axon, fueled by the movement of sodium ions, and eventually reaches the axon terminals. At the axon terminals, the electrical signal is converted into a chemical signal through the release of neurotransmitters into the synaptic cleft, the space between the presynaptic (transmitting) and postsynaptic (receiving) neurons. These neurotransmitters bind to receptors on the postsynaptic neuron, either
Sample Answer
The neuron, the fundamental unit of the nervous system, is responsible for transmitting electrical and chemical signals that allow us to think, feel, and move. A typical neuron consists of three main parts: the cell body, dendrites, and an axon.