Structural & Functional Categories
This structural type of neuron has many dendrites and one axon and is the most common neuron in the nervous system.
What is a multipolar neuron?
This part of the neuron contains the nucleus and is responsible for maintaining the cell’s life functions.
What is the cell body (soma)?
This phase of the action potential occurs when sodium channels open and the membrane potential becomes more positive.
What is depolarization?
This is the basic structural and functional unit of the nervous system.
What is a neuron?
These chemical messengers are released from vesicles in the presynaptic neuron.
What are neurotransmitters?
This type of glial cell produces myelin in the central nervous system.
What are oligodendrocytes?
This part of the central nervous system controls basic functions like breathing, heart rate, and blood pressure.
What is the brainstem?
This neuron structure has a single process extending from the cell body that splits into two branches.
What is a unipolar (pseudounipolar) neuron?
These short, branching structures receive incoming signals from other neurons.
What are dendrites?
During this phase, potassium channels open and the membrane potential returns toward its resting level.
What is repolarization?
The two main divisions of the nervous system are the central and this system.
What is the peripheral nervous system?
This part of the neuron releases neurotransmitters into the synapse.
What is the axon terminal (synaptic terminal)?
These star-shaped glial cells help maintain the blood-brain barrier and regulate the extracellular environment.
→ What are astrocytes?
This region of the brain is responsible for coordinating voluntary movement, balance, and posture.
What is the cerebellum?
These functional neurons carry impulses from sensory receptors toward the central nervous system.
What are sensory (afferent) neurons?
This long extension carries electrical impulses away from the cell body.
What is the axon?
This is the approximate membrane potential a neuron must reach to trigger an action potential.
What is the threshold potential (about −55 mV)?
This structure connects the brain and the peripheral nervous system and is protected by the vertebral column.
What is the spinal cord?
These structures store neurotransmitters before they are released into the synaptic cleft.
What are synaptic vesicles?
These glial cells act as the immune defense of the central nervous system.
What are microglia?
This type of neuron carries signals from the spinal cord to muscles and glands to produce a response.
What is a motor neuron?
These neurons transmit signals from the central nervous system to muscles or glands.
What are motor (efferent) neurons?
This fatty insulating layer around the axon helps speed up the transmission of nerve impulses.
What is the myelin sheath?
This stage happens when the membrane potential becomes more negative than the resting potential.
What is hyperpolarization?
Neurons communicate with each other at these specialized junctions.
What are synapses?
These proteins on the postsynaptic membrane bind neurotransmitters and trigger a response.
What are receptors?
These cells produce cerebrospinal fluid in the brain’s ventricles.
What are ependymal cells?
This protective structure surrounds the brain and spinal cord and is filled with cerebrospinal fluid.
What are the meninges?
This type of neuron is found entirely within the central nervous system and connects sensory and motor neurons.
What are interneurons (association neurons)?
The gaps between myelin sheath segments where action potentials “jump” during saltatory conduction.
What are the nodes of Ranvier?
This pump helps restore ion distribution after an action potential by moving sodium out and potassium in.
What is the sodium-potassium pump?
The electrical impulse traveling along a neuron is called this.
What is an action potential?
This ion commonly enters the presynaptic terminal to trigger neurotransmitter release.
What is calcium (Ca²⁺)?
In the peripheral nervous system, these glial cells form the myelin sheath around axons.
What are Schwann cells?
This structure acts as the main relay station for sensory information heading to the cerebral cortex.
What is the thalamus?