Neuroscience and Behavior Vocabulary

biological psychology

A branch of psychology concerned withthe links between biology and behavior

neuron

A nerve cell; the basic building block of the nervous system

dendrite

The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

axon

The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next

action potential

A neural impulse; a brief electrical charge that travels down on an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane

threshold

The level of stimulation required to trigger a neural impulse.

synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or cleft

neurotransmitters

Chemical messengers that traverse the synaptic gaps between neurons. When released by the sending neuron, Neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate

acetylcholine (Ach)

A neurotransmitter that enables learning and memory and also triggers muscle contractions

endorphins

Morphine within" -natural, opiatelike Neurotransmitters linked to pain control and to pleasure

nervous system

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

central nervous system

The brain and the spinal cord

peripheral nervous system

The sensory and motor sensory neurons that connect the central nervous system to the rest of the body

nerves

Neural "cables" containing axons. These bundled axons, which are part of the peripheral nervous system, connect the central nervous system with muscles, glands, and sense organs.

sensory neurons

Neurons that carry incoming information from the sense receptors to the central nervous system

motor neurons

Neurons that carry outgoing information from the central nervous system to the muscles and glands

interneurons

Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs

somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system.

autonomic nervous system

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

The division of the autonomic nervous system that calms the body, conserving its energy

reflex

A simple, autonomic, inborn response to a sensory stimulus, such as the knee-jerk response

neural networds

Interconnected neural cells. With experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results. Computer simulations of neural networks show analogous learning

endocrine system

The body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

hormones

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

adrenal glands

A pair of endocrine glands just above the kidneys. The adrenals secrete the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline), which help to arouse the body in times of stress

pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

lesion

Tissue destruction. A brain lesion is a naturally occurring or experimentally caused destruction of brain tissue

electroencephalogram (EEG)

(EEG) an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp

PET (positron emission tomography) scan

(Position emission tomography) a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging)

(Magnetic resonance imaging) a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

fMRI (functional MRI)

(Functional magnetic resonance imaging) a technique used for revealing blood flow and, therefore, brain activity be comparing successive MRI scans. MRI scans show brain anatomy; fMRI scans show the brain functions.

brainstem

The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

medulla

The base of the brainstem; controls heartbeat and breathing

reticular formation

A nerve network in the brainstem that plays an important role in controlling arousal.

thalamus

The brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

cerebellum

The "little brain" attached to the rear of the brainstem; its functions include processing sensory input and coordinating movement output and balance

limbic system

A doughnut-shaped system of structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex. Includes the hippocampus, amygdala, and hypothalamus.

amygdala

Two Lima bean-sized neural clusters that are component of the limbic system and are linked to emotion

hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion.

cerebral cortex

The intricate fabric of interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information processing center

glial cells

Cells in the nervous system that support, nourish, and protect neurons

frontal lobes

The portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements

parietal lobes

The portion of the cerebral cortex lying at the back of the head and toward the rear; receives sensory input for touch and body position.

occipital lobes

The portion of the cerebral cortex lying at the back of the head; includes visual areas, which receive visual information from the opposite visual field.

temporal lobes

The portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each of which receives auditory information primarily from the opposite ear.

motor cortex

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

sensory cortex

The area at the front of the parietal lobes that register and processes body touch and movement sensations

association areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

aphasia

Impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to wernicke's area (impairing understanding).

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.

Wernicke's area

Controls language reception- a brain area involved in language comprehension and expression; usually in the left temporal lobe.

plasticity

The brain's capacity for modification, as evident in brain reorganization following damage (especially in children) and in experiments on the effects of experience on brain development.

corpus callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them

split brain

A condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them.