PSYCH 1520 Module 5 Chapter 3

Acetylcholine (ACh)

Released by motor neurons controlling skeletal muscles Contributes to the regulation of attention, arousal, and memory

action potential

very brief shift in a neuron's electrical charge that travels along an axon

all or none law

Either the neuron fires or it doesn't, and its action potentials are all the same size. They do so by varying the rate at which they fire action potentials

axon

long, thin fiber that transmits signals away from the soma to other neurons or to muscles or glands

dendrite

parts of a neuron that are specialized to receive information.

Dopamine

Contributes to control of voluntary movement Dopamine circuits in medial forebrain bundle characterized as "reward pathway". Associated with Parkinson's disease and schizophrenia

Endorphins

Resemble opiate drugs in structure and effects Play role in pain relief and response to stress

excitatory postsynaptic potential

positive voltage shift that increases the likelihood that the postsynaptic neuron will fire action potentials

GABA

Serves as widely distributed inhibitory transmitter, contributing to regulation of anxiety and sleep/arousal Valium and similar antianxiety drugs work at GABA synapses

glia

cells found throughout the nervous system that provide various types of support for neurons

graded potential

they vary in size, and they increase or decrease the probability of a neural impulse in the receiving cell in proportion to the amount of voltage change

inhibitory postsynaptic potential

negative voltage shift that decreases the likelihood that the postsynaptic neuron will fire action potentials

lock and key

The system that characterizes that a specific neurotransmitter can bind only to receptor sites that its molecular structure will fit into

myelin sheath

insulating material that encases some axons

neuron

individual cell in the nervous system that receives, integrates, and transmits information

neurotransmitter

chemical that transmits information from one neuron to another

Norepinephrine

Contributes to modulation of mood and arousal. Associated with depression

postsynaptic potential (PSP)

voltage change at a receptor site on a postsynaptic cell membrane and act in which neurotransmitters bind to the receptor sites of the postsynaptic neuron

presynaptic

the neuron that sends a signal across the syanptic cleft

receptor site

specifically "tuned" to recognize and respond to some neurotransmitters but not to others on the postsynaptic cell.

resting potential

stable, negative charge when the cell is inactive

reuptake

process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane

Serotonin

Involved in regulation of sleep and wakefulness, eating, aggression Prozac and similar antidepressant drugs affect serotonin circuits

Soma

cell body, contains the cell nucleus and much of the chemical machinery common to most cells

synapse

junction where information is transmitted from one neuron to another

synaptic cleft

microscopic gap between the terminal button of one neuron and the cell membrane of another neuron.

synaptic vesicle

small sacs containing neurotransmitters within the terminal buttons

terminal button

small knobs that secrete chemicals called neurotransmitters.

autonomic nervous system (ANS)

made up of nerves that connect to the heart, blood vessels, smooth muscles, and glands

brain

part of the central nervous system that fills the upper portion of the skull

central nervous system (CNS)

consists of the brain and the spinal cord

parasympathetic division

branch of the autonomic nervous system that generally conserves bodily resources

peripheral nervous system

nerves that lie outside of the brain and spinal cord

somatic nervous system

made up of nerves that connect to voluntary skeletal muscles and to sensory receptors

spinal cord

connects the brain to the rest of the body through the peripheral nervous system.

sympathetic division

branch of the autonomic nervous system that mobilizes the body's resources for emergencies

auditory cortex

cortex associated with hearing

cerebellum

involved in the coordination of movement and is critical to the sense of equilibrium, or physical balance

cerebral cortex

convoluted outer layer of the cerebrum

cerebral hemispheres

are the right and left halves of the cerebrum

cerebrum

largest and most complex part of the human brain. It includes the brain areas that are responsible for our most complex mental activities, including learning, remembering, thinking, and consciousness itself.

corpus callosum

is the major structure that connects the two cerebral hemispheres

CT (computerized tomography) scan

computer-enhanced X-ray of brain structure. Multiple X-rays are shot from many angles, and the computer combines the readings to create a vivid image of a horizontal slice of the brain

Electrical stimulation of the brain (ESB)

involves sending a weak electric current into a brain structure to stimulate (activate) it

forebrain

largest and most complex region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.

frontal lobe

the largest lobe in the human brain. It contains the principal areas that control the movement of muscles, the primary motor cortex.

Functional magnetic resonance imaging (fMRI)

consists of several new variations on MRI technology that monitor blood flow and oxygen consumption in the brain to identify areas of high activity

hindbrain

includes the cerebellum and two structures found in the lower part of the brainstem: the medulla and the pons

hippocampus

responsible for the consolidation of memories for factual information and perhaps other types of memories

hypothalamus

structure found near the base of the forebrain involved in the regulation of biological needs

Lesioning

involves destroying a piece of the brain.

limbic system

loosely connected network of structures on the border between the cerebral cortex and subcortical areas

medulla

controls largely unconscious but essential functions, such as breathing, maintaining muscle tone, and regulating circulation.

midbrain

the segment of the brainstem that lies between the hindbrain and the forebrain

motor cortex

cortex associated with motor movement

MRI (magnetic resonance imaging)

magnetic fields, radio waves, and computerized enhancement to map out brain structure

occipital lobe

at the back of the head, includes the cortical area where most visual signals are sent and visual processing is begun

parietal lobe

It includes the area that registers the sense of touch, called the primary somatosensory cortex.

PET (positron emission tomography) scan

use radioactive markers to map chemical activity in the brain over time.

plasticity

anatomical structure and functional organization of the brain are more flexible

pons

several clusters of cell bodies involved with sleep and arousal.

somatosensory cortex

cortex associated with touch

temporal lobe

contains an area devoted to auditory processing, the primary auditory cortex.

thalamus

structure in the forebrain through which sensory information passes to get to the cerebral cortex

visual cortex

cortex associated with seeing

hemispheric specialization

Overall, the data suggest that the two hemispheres handle certain types of cognitive tasks better than the other

left hemisphere

is usually better on tasks involving verbal processing, such as language, speech, reading, and writing

right hemisphere

exhibits superiority on many tasks involving nonverbal processing, such as most spatial, musical, and visual recognition tasks

split-brain surgery

the bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.

adoption studies

assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents.

family studies

researchers assess hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait.

twin studies

researchers assess hereditary influence by comparing the resemblance of identical twins and fraternal twins with respect to a trait

Adaptation

an inherited characteristic that increased in a population (through natural selection) because it helped solve a problem of survival or reproduction during the time it emerged.

Evolutionary psychology

relatively new theoretical perspective in the field that analyzes behavioral processes in terms of their adaptive significance.

Fitness

refers to the reproductive success (number of descendants) of an individual organism relative to the average reproductive success in the population

natural selection

theory that advantageous heritable characteristics are more likely to be passed on to subsequent generations

Reproductive Success

a specific heritable trait contributes to an organism's survival, organisms with that trait should produce more offspring than do those without the trait

amygdala

play a central role in the learning of fear responses and the processing of other basic emotions

Broca's area

plays an important role in the production of speech

Wernicke's area

plays an important role in the comprehension of speech