Control and Coordination Concept 1 Vocabulary Flashcards
Soma (cell body)
The main part of a neuron that contains the nucleus and other organelles, responsible for maintaining the cell’s metabolic activities.
Dendrites
Branch-like extensions of a neuron that receive incoming signals from other neurons or sensory receptors.
Axon
A long, slender projection of a neuron that conducts electrical impulses away from the cell body towards other neurons, muscles, or glands.
Ganglion
A cluster of nerve cell bodies located outside the central nervous system (CNS), typically associated with sensory neurons.
Nerve
A bundle of axons (nerve fibers) enclosed within connective tissue, which transmits electrical impulses between the central nervous system (CNS) and other parts of the body.
Axon terminal
The end of an axon where neurotransmitters are released to communicate with adjacent neurons or effector cells.
Myelin sheath
A fatty, insulating layer formed by Schwann cells (in the peripheral nervous system) or oligodendrocytes (in the central nervous system) around axons, which increases the speed of nerve impulse transmission.
Nodes of Ranvier
Gaps in the myelin sheath along the axon where action potentials are regenerated during saltatory conduction.
Sensory neurons
Neurons that transmit sensory information from sensory receptors to the central nervous system (CNS).
Motor neurons
Neurons that transmit signals from the central nervous system (CNS) to muscles or glands, causing them to contract or secrete.
Interneurons
Neurons located entirely within the central nervous system (CNS) that integrate and relay signals between sensory and motor neurons.
Resting membrane potential
The difference in electrical charge across the membrane of a neuron when it is not transmitting a signal, typically around -70 millivolts (mV).
Graded potential
Small changes in membrane potential that occur in dendrites or the cell body, which may either depolarize (excitatory) or hyperpolarize (inhibitory) the neuron.
Threshold
The membrane potential at which an action potential is initiated, typically around -55 millivolts (mV).
Action potential
A rapid and transient change in membrane potential that propagates along the axon of a neuron, allowing for long-distance communication.
Nerve impulse
The transmission of an action potential along the length of a neuron’s axon.
Depolarization
The temporary reversal of membrane potential from negative to positive due to the influx of positively charged ions (e.g., sodium ions) into the neuron.
Repolarization
The restoration of the membrane potential to its resting state following depolarization, typically involving the efflux of potassium ions out of the neuron.
Hyperpolarization
An increase in the negative charge inside the neuron beyond its resting membrane potential, making it less likely to generate an action potential.
Synapse
The junction between two neurons or between a neuron and an effector cell, where neurotransmitters are released and signal transmission occurs.
Meninges
Protective membranes that surround the brain and spinal cord, providing cushioning and support.
Ventricle
Fluid-filled cavities within the brain that produce and circulate cerebrospinal fluid (CSF), providing buoyancy and nourishment to the central nervous system.
Cerebrum
The largest part of the brain responsible for higher cognitive functions, sensory perception, and voluntary motor control.
Cerebellum
A region of the brain located beneath the cerebrum, responsible for coordinating voluntary movements, balance, and posture.
Brain stem
The portion of the brain that connects the cerebrum to the spinal cord, controlling basic life functions such as breathing, heart rate, and consciousness.
Neurotransmitter
Chemical messengers released by neurons at synapses to transmit signals to other neurons, muscles, or glands.
Hormone
Chemical messengers secreted by endocrine glands into the bloodstream to regulate physiological processes and maintain homeostasis.
