Psychology Core Concepts Chapter 2: Biopsychology, Neuroscience and Human Nature

biopsychology

The specialty in psychology that studies the interaction of biology, behaviour, and mental processes.

evolution

The gradual process of biological change that occurs in a species as it adapts to its environment.

natural selection

The driving force behind evolution by which the environment "selects" the fittest organisms.

genotype

An organism's genetic makeup.

phenotype

An organism's observable physical and behavioral characteristics.

genome

The complete set of genetic information contained within a cell.

DNA (deoxyribonucleic acid)

A long, complex molecule that encodes genetic characteristics.

gene

Segment of chromosome that encodes the directions for the inherited physical and mental characteristic of an organism. Genes are the functional units of a chromosome.

chromosome

Tightly coiled threadlike structure along which the genes are organised, like beads on a necklace. Chromosomes consist primarily of DNA.

sex chromosomes

The X and Y chromosomes that determine our physical sex characteristics.

neuron

Cell specialized to receive and transmit information to other cells in the body - also called a nerve cell. Bundles of many neurons are called nerves.

sensory neuron

A nerve cell that carries messages toward the central nervous system from sense receptors; also called afferent neurons.

motor neuron

A nerve cell that carries messages away from the central nervous system toward the muscles and glands; also called efferent neurons.

interneuron

A nerve cell that relays messages between nerve cells, especially in the brain and spinal cord.

dendrite

Branched fiber that extends outward from the cell body and carries information into the neuron.

soma

The part of a cell (such as a neuron) containing the nucleus, which includes the chromosomes; also called the cell body.

axon

In a nerve cell, an extended fiber that conducts information from the soma to the terminal buttons. Information travels along the axon in the form of an electric charge called the action potential.

resting potential

The electrical charge of the axon in its inactive state, when the neuron is ready to "fire".

action potential

The nerve impulse caused by a change in the electrical charge across the cell membrane of the axon. When the neuron "fires," this charge travels down the axon and causes neurotransmitters to be released by the terminal buttons.

all-or-none principle

Refers to the fact that the action potential in the axon occurs either completely or not at all.

synapse

The microscopic gap that serves as a communications link between neurons. Synapses also occur between neurons and the muscles or glands they serve.

terminal buttons

Tiny bulblike structures at the end of the axon that contain neurotransmitters that carry the neuron's message into the synapse.

synaptic transmission

The relaying of information across the synapse by means og chemical neurotransmitters.

neurotransmitter

Chemical messenger that relays neural messages across the synapse. Many neurotransmitters are also hormones.

reuptake

The process by which unused neurotransmitters are drawn back into the vesicles of their originating neuron.

plasticity

The nervous system's ability to adapt or change as the result of experience. Plasticity may also help the nervous system adapt to physical damage.

glial cell

One of the cells that provide structural support for neurons. Glial cells also provide an insulating covering (the myelin sheath) of the axon for some neurons, which facilitates the electrical impulse.

nervous system

The entire network of neurons in the body, including the certain nervous system, the peripheral nervous system, and their subdivisions.

central nervous system (CNS)

The brain and the spinal cord.

reflex

Simple unlearned response triggered by stimuli - such as the knee-jerk reflex set off by tapping the tendon just below your kneecap.

contralateral pathways

Sensory and motor pathways between the brain and the rest of the body cross over to the opposite site en route, so messages from the right side of the body are processed by the left side of the brain and vice versa.

peripheral nervous system (PNS)

All parts of the nervous system lying outside the central nervous system. The peripheral nervous system includes the autonomic and somatic nervous systems.

somatic nervous system

A division of the peripheral nervous system that carries sensory information to the central nervous system ans also sends voluntary messages to the body's skeletal muscles.

autonomic nervous system

The portion of the peripheral nervous system that send communications between the central nervous system and the internal organs and glands.

sympathetic division

The part of the autonomic nervous system that sends messages to internal organs and glands that help us respond to stressful and emergency situations.

parasympathetic division

The part of the autonomic nervous system that monitors the routine operations of the internal organs and returns the body to calmer functioning after arousal by the sympathetic division.

endocrine system

The hormone system - the body's chemical messenger system, including the endocrine glands: pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, and testes.

hormones

Chemical messengers used by the endocrine system. Many hormones also serves as neurotransmitters in the nervous system.

pituitary gland

The "master gland" that produces hormones influencing the secretions of all other endocrine glands, as well as a hormone that influences growth. The pituitary is attached to the brain's hypothalamus, from which it takes its orders.

agonists

Drugs or other chemicals that enhance or mimic the effects of neurotransmitters.

antagonists

Drugs or other chemicals that enhance or mimic the effects of neurotransmitters.

neural pathways

Bundles of nerve cell that follow generally the same route and employ the same neurotransmitter.

electroencephalograph (EEG)

A device for recording brain waves, typically by electrodes placed on the scalp. The record produced is known as an electroencephalograph (also called an EEG).

CT scanning, or computerized tomography

A computerized imaging technique that uses X-rays passed through the brain at various angles and then combined into an image.

PET scanning, or positron emission tomography

An imaging technique that relies on the detection of radioactive sugar consumed by active brain cells.

MRI, or magnetic resonance imaging

An imaging techniques that relies on cell's responses in a high-intensity magnetic field.

fMRI, or functional magnetic resonance imaging

A newer form of magnetic resonance imaging that records both brain structure and brain activity.

brain stem

The most primitive of the brain's three major layers. It includes the medulla, pons, and the reticular formation.

medulla

A brain-stem structure that controls breathing and heart rate. The sensory and motor pathways connecting the brain to the body cross in the medulla.

pons

A brain-stem structure that regulates brain activity during sleep and dreaming. The name pons derives from the Latin word for "bridge".

reticular formation

A pencil-shaped structure forming the core of the brain stem. The reticular formation arouses the cortex to keep the brain alert and attentive to new stimulation.

thalamus

The brain's central "relay station," situated just atop the brain stem. Nearly all the messages going into or out of the brain pass through the thalamus.

cerebellum

The "little brain" attached to the brain stem. The cerebellum is responsible for the coordinated movements.

limbic system

The middle layer of the brain, involved in emotion and memory. The limbic system includes the hippocampus, amygdala, hypothalamus and other structures.

hippocampus

A component of the limbic system, involved in establishing long-term memories.

amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

hypothalamus

A limbic structure that serves as the brain's blood-testing laboratory, constantly monitoring the blood to determine the condition of the body.

cerebral hemispheres

The large symmetrical halves of the brain located atop the brain stem.

corpus callosum

The band of nerve cells connecting and enabling communication between the two cerebral hemispheres.

cerebral cortex

The thin gray matter covering the cerebral hemispheres, consisting of a 1/4 inch layer dense with cell bodies of neurons. The cerebral cortex carries on the major portion of our "higher" mental processing, including thinking and perceiving.

frontal lobes

Cortical regions at the front of the brain that are especially involved in movement and in thinking.

motor cortex

A narrow vertical strip of cortex in the frontal lobes lying in front of the central fissure; controls voluntary movement.

mirror neuron

A recently discovered class of neuron that fires in response to ("mirroring") observation of another person's actions or emotions.

parietal lobes

Cortical areas lying toward the back and top of the brain; involved in touch sensation and in perceiving spatial relationships (the relationships of objects in space).

somatosensory cortex

A strip of the parietal lobe lying behind central fissure. The somatosensory cortex is involved in sensations of touch.

temporal lobes

Cortical lobes that process sounds, including speech. The temporal lobes are probably involved in storing long-term memories.

occipital lobes

The cortical regions at the back of the brain that house the visual cortex.

visual cortex

The visual processing areas of cortex in the occipital and temporal lobes.

association cortex

Cortical regions through the brain that combine information from various other parts of the brain.

cerebral dominance

The tendency of each brain hemisphere to exert control over different functions, such as language or perception of spatial relationships.