Module 2 - Neurobiological Basis of Psychology

Genes

They are chains of chemicals arranged like rungs on a twisting ladder.

20,000 to 25,000

How many genes does chemical instructions contain?

Chemical Instructions

Program the development of millions of individual parts into a complex body and brain. 

Dendrite

are branchlike extensions that arise from the cell body; they receive signals from other neurons, muscles, or sense organs and pass these signals to the cell body

Soma (Cell body)

is a relatively large, egg-shaped structure that provides fuel, manufactures chemicals, and maintains the entire neurons in working order

Axon

is a single threadlike structure that extends from, and carries signals away from, the cell body to neighboring neurons, organs, or muscles.

Myelin Sheath

looks like separate tubelike segments composed of fatty materials that wraps around and insulates an axon. It prevents interference from electrical signals generated in adjacent axon.

Presynaptic terminals/ End bulb/ terminal bulbs

look like tiny bubbles that are located at the extreme ends of the axon’s branches. Each end bulb is like a miniature container that stores chemical called neurotransmitters, which are used to communicate with the neighboring cells.

Synapse

is an infinitely small spaces (20-30 billionths of a meter) that exists between an end bulb and its adjacent body organ (heart), muscles (head), or cell body.

Peripheral nervous system (PNS)

is made up of nerves which are located throughout the body except in the brain and spinal cord.

Nerves

are stringlike bundles of axons and dendrites that come from the spinal cord and are held together by connective tissue

Central Nervous System

is made up of neurons located in the brain and spinal cord.

Transmitter

is a chemical messenger that carries information between nerves and body organs, such as muscles and heart.

Neurotransmitter

are about a dozen different chemicals that are made by neurons and then used for communication between neurons during the performance of mental or physical activities.

Agonist

molecules increase a neurotransmitter’s action. Some agonists may increase the production or release of neurotransmitters, or block reuptake in the synapse

Antagonist

molecules decrease a neurotransmitter’s action by blocking the production or release

Anandamide

Similar in chemical makeup to THC (tetrahydrocannabinol), the active ingredient in marijuana. This may help people regulate emotions, which would help them better cope with anxiety and stress

Nitric Oxide

Regulates emotions, aggressive and impulsive behaviors.

Orexin (hypocretin)

involved in the brain’s pleasure and reward system; also involved in regulating sleep and wakefulness. Low levels of this neurotransmitter have been linked to a serious sleep disorder called narcolepsy

reflex

is an unlearned, involuntary reaction to some stimulus. The connections or neural network underlying a reflex is prewired by genetic instructions