Chapter 4 part 2: Neurophysiology Review Flashcards

This set of vocabulary flashcards covers the fundamentals of neurophysiology, including the electrogenic pump, neuron structure zones, action potential generation, and the divisions of the nervous system as detailed in the lecture notes.

Electrogenic Pump

A mechanism, such as the $Na^+/K^+$ ATPase, that helps set the resting membrane potential ($E_m$) by creating an electrical charge imbalance across the membrane.

Na+/K+ ATPase

A pump that moves $3 \text{ Na}^+$ out of the cell and $2 \text{ K}^+$ into the cell to help create a resting membrane potential ($E_m$) of $-70 \text{ mv}$.

Graded Potentials

Local changes in membrane potential, such as EPSPs and IPSPs, caused by ions moving down their concentration gradients when specific channels open or close.

EPSP

Excitatory Postsynaptic Potential; a type of graded potential that moves the membrane potential toward the threshold.

IPSP

Inhibitory Postsynaptic Potential; a type of graded potential that typically moves the membrane potential away from the threshold.

Dendrites

The part of the neuron that functions as the input zone, responsible for receiving incoming signals from other neurons.

Axon

The part of the neuron that functions as the output or conducting zone, carrying signals away from the cell body.

Axon Hillock

The 'trigger zone' of the neuron where all graded potentials are summated and action potentials are initiated if the stimulus reaches the threshold.

Threshold

The critical membrane potential level that, when reached, causes all voltage-gated $Na^+$ channels to open and generates an action potential.

Action Potential (AP)

A rapid sequence of changes in the membrane potential where $Na^+$ channels open and then close, followed by $K^+$ channels opening and then closing.

Saltatory Conduction

The rapid method of action potential propagation that occurs in myelinated axons, where the impulse 'jumps' between nodes.

Synaptic Transmission Signaling

The process described as 'Chemical - Electrical - Chemical' signaling, involving nerve impulses and neurotransmitter release.

Synaptic Vesicles

Structures within the presynaptic terminal that contain neurotransmitter molecules to be released into the synaptic cleft.

Synaptic Cleft

The narrow space between the presynaptic terminal and the postsynaptic membrane where neurotransmitters are released.

Input Zone

The part of the neuron, consisting of the dendrites and cell body, where incoming signals from other neurons are received.

Trigger Zone

The part of the neuron (axon hillock) where action potentials are initiated.

Conducting Zone

The part of the neuron (axon) that conducts action potentials in an undiminishing fashion, often over long distances from $1 \text{ mm}$ to more than $1 \text{ m}$ long.

Output Zone

The part of the neuron (axon terminals) that releases neurotransmitters to influence other cells.

Central Nervous System (CNS)

The division of the nervous system consisting of the brain and spinal cord, responsible for information processing and higher-order functions like memory and learning.

Peripheral Nervous System (PNS)

The division of the nervous system consisting of cranial and spinal nerves that links the CNS to receptors and effectors.

Somatic Nervous System

A division of the efferent nervous system that sends motor commands to skeletal muscles (effectors).

Autonomic Nervous System

A division of the efferent nervous system consisting of the sympathetic and parasympathetic divisions that control smooth muscle, cardiac muscle, and glands.