# Introduction to psychology/Key words for chapter three

This is a list of jargon for psychology. There is a short statement about what the term is and possibly a link to wipedia or wiktionary.

#### Action Potential

    A signal passing through a neuron is considered an action potential.

#### Afferent

    In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system.

#### All-or-none principle

    Theory that once a signal is started that it will always travel the length of a neuron at a fixed intensity, not getting stronger or weaker.

#### Amygdala

    The part of the limbic with a primary role in the processing and memory of emotional reactions.

#### Autonomic nervous system

    The part of the peripheral nervous system that controls the function of many glands and smooth-muscle organs.
    It is divided into the sympathetic and parasympathetic systems.

#### Axon

    The single long fiber extending from the cell body of a neuron; carries the signal to the synapse

#### Saltatory conduction

cell body aka Soma

#### Central nervous system (CNS)

    The brain and the spinal cord.

#### Cerebellum

    Region of the brain that plays an important role in the integration of sensory perception and motor output.

#### Cerebrum

    The cerebrum deals with language and communication, movement, olfaction (smelling), memory formation, and emotion.

#### Computed tomography

    A medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation.
    Helps reveal structural abnormalities.

#### Corpus callosum

    The corpus callosum connects the left and right cerebral hemispheres.
    Most (but certainly not all) communication between regions in different halves of the brain are carried over the corpus callosum.

#### Cortex

    The outer layer of the cerebral hemispheres; controls complex cognitive processes.

#### Cortical lobes

    Four arbitirarily deignated divisions of the cortex.

#### Dendrite

    The recieving portion of a neuron

#### Depolarization

    A process that the nueron goes through after the passage of an action potential.
    Depolarization is when a cell is moving farther away from 0mV while hyperpolarization is when the cell is moving closer to 0mV.

#### Efferent

    In the nervous system, efferent nerves – otherwise known as motor or effector neurons – carry nerve impulses away from the central nervous system to effectors such as muscles or glands.

#### Neurotransmitter

    Neurotransmitters are used to relay, amplify and modulate electrical signals between a neuron and another cell.
    Amino acids are an example of a neurotransmitter.

#### Neuron

    The basic unit of the nervous system. It is composed of a soma, dendrite, and axon.

#### Nodes of Ranvier

    Nodes of Ranvier are regularly spaced gaps in the myelin sheath around an axon or nerve fiber.

#### Organelle

    An organelle is a discrete structure of a cell having specialized functions.

#### Refractory phase

    After the action potential the refractory phase marks a period where the neuron is less excitable.

#### Synapse

    Synapses, or chemical synapses, are specialized junctions through which cells of the nervous system signal to one another and to non-neuronal cells such as muscles or glands.

### Synaptic vesicle

In a neuron, synaptic vesicles, also called neurotransmitter vesicles, store the various neurotransmitters that are released during calcium-regulated exocytosis at the presynaptic terminal into the synaptic cleft of a synapse.