Sturcture & Function of the Nervous System

Neuron

A fundamental unit of the nervous system, consisting of a cell body, dendrites, and an axon.

Dendrites

Branching structures of a neuron that receive signals from other neurons.

Cell body (Soma)

The part of a neuron that integrates incoming signals and contains the nucleus.

Axon

A long, slender projection of a neuron that transmits electrical impulses away from the cell body.

Axon Terminal

The end of an axon, which forms synapses with other neurons.

Myelin

A fatty substance that surrounds and insulates axons to enhance the speed of signal transmission.

Ion Channels

Membrane proteins that allow ions to pass through the membrane, crucial for generating action potentials.

Resting Potential

The electrical potential of a neuron at rest, typically around -70 mV.

Gated Ion Channels

Ion channels that open in response to specific stimuli, such as voltage changes or ligand binding.

Non-Gated Ion Channels

Ion channels that are always open, allowing ions to flow along concentration gradients.

Action Potential

A rapid rise and fall in voltage or membrane potential across a cellular membrane.

All-or-None Law

The principle that an action potential is either triggered or it is not; it does not vary in strength.

Synapse

The junction between the axon terminal of one neuron and the dendrite or cell body of another.

Neurotransmitter

Chemicals released by neurons at synapses to transmit signals to other neurons.

Excitatory Postsynaptic Potential (EPSP)

A postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A postsynaptic potential that makes a neuron less likely to fire an action potential.

Central Nervous System (CNS)

The part of the nervous system that consists of the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that consists of all nerves outside the CNS.

Somatic Nervous System

Part of the PNS associated with voluntary control of skeletal muscles.

Autonomic Nervous System

Part of the PNS that controls involuntary bodily functions.

Epigenetics

The study of changes in gene expression that do not involve alteration of the DNA sequence.

Neurotrophic Factors

Proteins that promote neuron growth, differentiation, and synaptic connections.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins based on the sequence of an mRNA template.