Fundamentals of the Nervous System and Nervous Tissue

These flashcards cover key vocabulary and concepts related to the nervous system and nervous tissue as outlined in the lecture notes.

Nervous System

Master controlling and communicating system of the body.

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) that produces a response.

Central Nervous System (CNS)

Consists of the brain and spinal cord; functions as integration and control center.

Peripheral Nervous System (PNS)

The portion of the nervous system outside the CNS; consists mainly of nerves.

Afferent Division

Sensory division that conveys impulses to the CNS from sensory receptors.

Efferent Division

Motor division that transmits impulses from the CNS to effector organs.

Neuroglia

Small cells that surround and wrap delicate neurons; support functions.

Astrocytes

Most abundant glial cells that support and brace neurons.

Microglial Cells

Ovoid cells that monitor neurons and can transform to phagocytize debris.

Ependymal Cells

Ciliated cells that line cavities and circulate cerebrospinal fluid (CSF).

Oligodendrocytes

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

Neurons

Large, specialized cells that conduct impulses and are excitable.

Action Potential

A brief reversal of membrane potential that serves as a long-distance signal.

Resting Membrane Potential

The potential difference across membrane of a resting cell; approximately -70 mV.

Graded Potentials

Localized changes in membrane potential that vary with stimulus strength.

Threshold

The membrane potential that must be reached for an action potential to occur.

All-or-None Phenomenon

An action potential either occurs completely or does not occur at all.

Myelination

The process of forming a myelin sheath around nerve fibers, which increases impulse speed.

Refractory Period

The period after an action potential when a neuron cannot respond to another stimulus.

Saltatory Conduction

Rapid propagation of action potentials in myelinated axons, jumping from gap to gap.

Multiple Sclerosis (MS)

An autoimmune disease that destroys myelin sheaths in the CNS, affecting impulse conduction.

Nerve Fiber Classification

Categorization based on diameter, degree of myelination, and speed of conduction.