Nervous System 101
Name the two main divisions of the nervous system
CNS and PNS
What part of a neuron receives incoming signals?
Dendrites
Name the neurotransmitter used at cholinergic synapses.
Acetylcholine
What structures make up the CNS?
The brain and spinal cord
What is the typical threshold voltage for triggering an action potential?
-55mV
Which division of the nervous system is responsible for gathering sensory information?
Sensory (afferent) division
What is the role of the axon hillock?
Initiating action potentials
Which amino acid neurotransmitter is the most important excitatory neurotransmitter in the brain?
Glutamate
What is the main role of the PNS sensory division?
Transmitting sensory information to the CNS
What happens to the membrane potential during depolarization?
It becomes more positive
What are the two types of motor divisions within the PNS?
What are the somatic motor and autonomic nervous systems?
Name the three functional regions of a neuron.
The receptive, conducting, and secretory regions
Which neurotransmitter is associated with mood regulation and is often a target for antidepressants?
Serotonin
What are clusters of neuron cell bodies in the CNS called?
Nuclei
Name the two main factors influencing conduction speed in neurons.
Axon diameter and the presence of a myelin sheath
Which type of nervous tissue is highly vascularized and composed of cell bodies, dendrites, and unmyelinated axons?
Gray matter
Which type of neurons are responsible for relaying information within the CNS?
Interneurons
Name the neurotransmitter class that includes norepinephrine and dopamine.
Biogenic amines (catecholamines)
Which neuroglial cells are responsible for forming myelin in the PNS?
Schwann cells
What type of conduction occurs in myelinated axons?
Saltatory conduction
What is the primary structural difference between cranial nerves and spinal nerves?
Cranial nerves originate from the brain, and spinal nerves originate from the spinal cord
What is the role of neurofibrils in a neuron?
Provides structural support and aides in chemical transport
What enzyme breaks down acetylcholine in the synaptic cleft?
Acetylcholinesterase
What is the function of the blood-brain barrier?
Protecting the brain by preventing harmful substances in the blood from reaching brain tissue
What is the "all-or-none" principle in action potentials?
The concept that an action potential either occurs fully or not at all once threshold is reached