Fundamentals of the Nervous System and Nervous Tissue

These flashcards cover key terms and definitions related to the functions, structure, and processes within the nervous system as discussed in Chapter 11.

Neuroglia

Supporting cells in the nervous system that segregate and insulate neurons and assist them in various ways.

Neurons

Nerve cells that are excitable and transmit electrical signals; the basic building blocks of the nervous system.

Action Potential

A large, brief depolarization signal that underlies long-distance neural communication, it is an all-or-none phenomenon.

Resting Membrane Potential

The voltage difference across a cell membrane when a neuron is at rest, typically around -70mV.

Graded Potentials

Local changes in membrane potential that can be either depolarizations or hyperpolarizations, often leading to action potentials.

Chemical Synapses

Synapses that transmit information via the release of neurotransmitters, which cross the synaptic cleft and interact with receptor sites on the postsynaptic neuron.

Electrical Synapses

Synapses that consist of gap junctions allowing ions to flow directly from one neuron to another, enabling rapid communication.

Neurotransmitters

Chemical signals released by neurons that transmit information across the synapse to the postsynaptic cell.

Excitatory Postsynaptic Potential (EPSP)

A local depolarization of the postsynaptic membrane that brings the neuron closer to the action potential threshold.

Inhibitory Postsynaptic Potential (IPSP)

A local hyperpolarization of the postsynaptic membrane that drives the neuron away from the action potential threshold.

Sodium-Potassium Pump

A enzyme that regulates sodium and potassium ion concentrations across the membrane, critical for maintaining resting membrane potential.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to another in myelinated axons, speeding up signal propagation.

Synaptic Cleft

The small gap between the axon terminal of one neuron and the dendrite of another across which neurotransmitters are released.

Neuronal Pools

Groups of interconnected neurons that process and integrate information in the nervous system.

Diverging Circuit

A circuit in which one input generates several outputs, amplifying the signal.

Converging Circuit

A circuit where multiple inputs lead to a single output, concentrating the signal.

Reverberating Circuit

A circuit where an impulse is sent along a chain of neurons that feed back to previous ones, leading to rhythmic activities.

Neurotrophins

Chemical signals that guide the growth cones of axons toward their target cells during development.

Amitotic

The inability of neurons to divide and replicate, a characteristic feature of mature nervous tissue.

Plasticity

The ability of the nervous system to change in response to experience or environmental changes.

Myelin Sheath

An insulating layer formed around the axon of a neuron that increases the speed of action potential propagation.