Human Anatomy and Physiology Chapter 11 - Nervous System Fundamentals

These flashcards cover the essential vocabulary and concepts from Chapter 11 on the fundamentals of the nervous system, facilitating review for understanding key terms and their definitions.

Nervous System

The master controlling and communicating system of the body that processes and interprets sensory information.

Sensory Input

Information gathered by sensory receptors about internal and external changes.

Integration

Processing and interpretation of sensory input.

Motor Output

Activation of effector organs (muscles and glands) to produce a response.

Central Nervous System (CNS)

The brain and spinal cord; the integration and control center.

Peripheral Nervous System (PNS)

The portion of the nervous system outside the CNS, consisting mainly of nerves.

Neuroglia

Supportive cells that maintain and support neurons.

Astrocytes

The most abundant type of neuroglia that supports and braces neurons and helps to control their chemical environment.

Microglial Cells

Small cells that monitor and protect neurons from injury by migrating to injured areas.

Ependymal Cells

Cells that line the central cavities of the brain and spinal column, forming a barrier around cerebrospinal fluid.

Oligodendrocytes

Branched cells that wrap CNS nerve fibers, forming myelin sheaths.

Satellite Cells

Neuroglia in the PNS that surround neuron cell bodies and have a supportive role similar to astrocytes.

Action Potential

A brief reversal of membrane potential that occurs in muscle cells and axons of neurons, enabling long-distance signaling.

Resting Membrane Potential

The electrical potential difference across a cell membrane when the cell is not actively signaling.

Depolarization

A decrease in membrane potential, making the inside of the membrane less negative, which increases the likelihood of an action potential.

Hyperpolarization

An increase in membrane potential, making the inside of the membrane more negative, which decreases the likelihood of an action potential.

Synapse

Junctions that mediate transmission of information between neurons or from neurons to effector cells.

Excitatory Postsynaptic Potentials (EPSPs)

Local depolarizations caused by neurotransmitters that make a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potentials (IPSPs)

Local hyperpolarizations caused by neurotransmitters that make a neuron less likely to fire an action potential.

Summation

The process by which multiple EPSPs combine to influence the postsynaptic neuron.

All-or-None Principle

The concept that an action potential either occurs fully or does not occur at all, depending on reaching threshold.