Organization of the Nervous System

A set of flashcards covering key concepts in the organization of the nervous system, the functions of neurons and neuroglia, membrane potentials, and nerve impulse conduction.

What are the three main functions of the nervous system?

1. Receives sensory input, 2. Integrates sensory information, 3. Coordinates motor output.

What is the difference between neurons and neuroglia?

Neurons conduct electrical signals for communication; neuroglia support and protect neurons but do not conduct signals.

What are the types of neuroglia in the CNS?

Astrocytes, Oligodendrocytes, Microglia, and Ependymal cells.

What are the classifications of neurons by structure?

Unipolar, Bipolar, and Multipolar.

What is the primary role of astrocytes in the CNS?

To isolate and protect neurons, maintain the blood-brain barrier, and assist in tissue repair.

What is resting membrane potential?

The membrane potential when a neuron is not actively sending signals, typically around -70 mV.

What are action potentials?

Rapid changes in membrane potential that propagate signals along neurons.

What is saltatory conduction?

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

What is the all-or-none principle in nerve impulses?

Once a threshold is reached, a neuron will fire an action potential at full strength or not at all.

What are EPSP and IPSP?

EPSP (excitatory postsynaptic potential) increases the likelihood of a neuron firing; IPSP (inhibitory postsynaptic potential) decreases that likelihood.

What do Schwann cells do in the PNS?

They myelinate axons to facilitate faster electrical signal transmission.

What is the role of the sodium-potassium ATP-ase pump in membrane potential?

It helps maintain resting membrane potential by pumping sodium out and potassium into the cell.

What are neuron pools?

A group of interconnected neurons that work together for a specific function or response.

What defines the features of a graded potential?

A localized change in membrane potential that varies in size and occurs in response to stimuli.

Outline the steps of action potential generation.

1. Resting state, 2. Depolarization (sodium channels open), 3. Rapid depolarization, 4. Repolarization (potassium channels open), 5. Hyperpolarization.

What distinguishes the sympathetic and parasympathetic divisions of the ANS?

Sympathetic mobilizes systems for 'fight or flight'; parasympathetic conserves energy for 'rest and digest'.