Biological Bases of Behavior

Neuron

Nerve cell specialized for communication

Dendrite

Branchlike parts of a neuron that are specialized to receive information.

Axon

A threadlike extension of a neuron that carries nerve impulses away from the cell body.

Synapse

gaps between neurons

Neurotransmitter

Chemical messenger specialized for communication from neuron to neuron

Synapse

Space between two connecting neurons through which messages are transmitted chemically

Synaptic cleft

A gap into which neurotransmitters are released from the axon terminal

Glial cell

Cell in nervous system that plays a role in the formation of myelin and the blood-brain barrier, responds to injury, removes debris, and enhances learning and memory

Threshold

Membrane potential necessary to trigger an action potential.

Action potential

A neural impulse; a brief electrical charge that travels down an axon.

Absolute refractory period

Cardiac cells have not completely repolarized

Receptor site

Locations on a receptor neuron into which a specific neurotransmitter fits like a key into a lock.

Reuptake

A neurotransmitter's reabsorption by the sending neuron

Endorphin

"Morphine within" - natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Plasticity

Ability of brain tissue to modify itself and take on new functions.

Neurogenesis

Creation of new neurons in the adult brain

Glutamate

Main excitatory neurotransmitter in the nervous system; participates in relay of sensory information and learning

Gamma-aminobutyricvcacidc(GABA)

Main inhibitory neurotransmitter in the nervous system

Acetylcholine (ACh)

Muscle contraction (PNS) Cortical arousal (CNS)

Norepinephrine (NE)

Brain arousal and other functions like mood, hunger, and sleep

Dopamine

Motor function and pleasure reward

Serotonin

Mood and temperature regulation, happiness

Central nervous system (CNS)

A system that includes the brain and spinal cord, controlling voluntary and involuntary acts

Peripheral Nervous System

nerves that lie outside the brain and spinal cord.

Cerebral Cortex

outermost part of forebrain, responsible for

analyzing sensory processing and higher brain functions

Forebrain (Cerebrum)

forward part of the brain that allows advanced intellectual abilities

Cerebral Hemispheres

Divided into right and left by the cerebrum.

Corpus Callosum

A thick band of nerve fibers that connects large areas of the cerebral cortex on each side of the brain and supports communication of information across the hemispheres.

Frontal Lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

Motor cortex

An area at the rear of the frontal lobes that controls voluntary movements

Prefrontal cortex

part of frontal lobe responsible for thinking, planning, and language

Broca's area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

Parietal Lobe

upper middle part of the cerebral cortex lying behind the frontal lobe that is specialized for touch and perception

Temporal lobe

lower part of cerebral cortex that plays roles in hearing, understanding language, and memory

Wernicke's Area

part of the temporal lobe involved in understanding speech

Occipital Lobe

back part of cerebral cortex specialized

for vision

Primary Sensory Cortex

regions of the cerebral cortex that initially

process information from the senses

Limbic System

emotional center of brain that also plays roles in smell, motivation, and memory

Thalamus

A forebrain structure that processes sensory information for all senses, except smell, and relays it to the cerebral cortex.

Hypothalamus

Structure below the thalamus, responsible for maintaining a constant internal state

Amyglada

part of limbic system that plays key roles in

fear, excitement, and arousal

Hippocampus

part of the brain that plays a role in spatial

memory

Cerebellum

Balance and coordination

Brain Stem

part of the brain between the spinal cord and cerebral cortex that contains the midbrain, pons, and medulla

Midbrain

part of the brain stem that contributes to

movement, tracking of visual stimuli, and

reflexes triggered by sound

reticular activating system (RAS)

brain area that plays a key role in arousal

Hindbrain

region below the midbrain that contains the

cerebellum, pons, and medulla

Pons

part of the brain stem that connects the

cortex with the cerebellum

Medulla oblongata

part of brain stem involved in basic functions, such as heartbeat and breathing

Spinal Cord

thick bundle of nerves that conveys signals

between the brain and the body

Interneuron

neuron that sends messages to other neurons nearby

Reflex

an automatic motor response to a sensory

stimulus

somatic nervous system

part of the nervous system that conveys

information between the CNS and the

body, controlling and coordinating voluntary

movement

autonomic nervous system

part of the nervous system controlling the

involuntary actions of our internal organs and glands, which (along with the limbic system) participates in emotion regulation

sympathetic nervous system

division of the autonomic nervous system

engaged during a crisis or after actions

requiring fight or flight

parasympathetic nervous system

division of autonomic nervous system that

controls rest and digestion

endocrine system

system of glands and hormones that

controls secretion of blood-borne chemical

messengers

Hormone

chemical released into the bloodstream that

influences particular organs and glands

Pituitary Gland

master gland that, under the control of the

hypothalamus, directs the other glands of

the body

adrenal gland

tissue located on top of the kidneys that

releases adrenaline and cortisol during states of emotional arousal

electroencephalograph (EEG)

recording of brain's electrical activity at the

surface of the skull

computed tomography (CT)

(CAT scan) a scanning technique using multiple X-rays to construct three-dimensional images

magnetic resonance imaging (MRI)

technique that uses magnetic fields to

indirectly visualize brain structure

positron emission tomography (PET)

imaging technique that measures consumption of glucose-like molecules, yielding a picture of neural activity in different regions of the brain

functional MRI (fMRI)

technique that uses magnetic fields to visualize brain activity using changes in blood oxygen level

split-brain surgery

procedure that involves severing the corpus callosum to reduce the spread of epileptic seizures

Afferent Neurons

neurons that send signals to the brain

Efferent Neurons

neurons that send signals away from the brain

All-or-Nothing Principle

a neuron can release all of its neurotransmitters or none

Antagonist

locks into a receptor site like the neurotransmitter it mimics

Agonist

blocks a neurotransmitter

Sensory Cortex

portion of the brain which interprets body sensations

Right Hemisphere

part of the brain responsible for logic, spatial and holistic

Left Hemisphere

part of the brain responsible for language, math and analyzing

soma

cell body of neuron? nucleus & vital organelles