Psychology Chapter 2 The Biology of the Mind

biological psychology

a branch of psychology concerned with the links between biology and behavior. (Some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists.) (Myers Psychology 9e p. 48)

neuron

a nerve cell; the basic building block of the nervous system. (Myers Psychology 9e p. 49)

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord. (Myers Psychology 9e p. 49)

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands. (Myers Psychology 9e p. 49)

interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs. (Myers Psychology 9e p. 49)

dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body. (Myers Psychology 9e p. 49)

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands. (Myers Psychology 9e p. 49)

myelin [MY-uh-lin] 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. (Myers Psychology 9e p. 49)

action potential

a neural impulse; a brief electrical charge that travels down an axon. (Myers Psychology 9e p. 49)

threshold

the level of stimulation required to trigger a neural impulse. (Myers Psychology 9e p. 50)

synapse

[SIN-aps] 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 synaptic cleft. (Myers Psychology 9e p. 51)

neurotransmitters

chemical messengers that cross 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 a neural impulse. (Myers Psychology 9e p. 51)

reuptake

a neurotransmitter's reabsorption by the sending neuron. (Myers Psychology 9e p. 51)

endorphins [en-DOR-fins]

"morphine within"-natural, opiate like neurotransmitters linked to pain control and to pleasure. (Myers Psychology 9e p. 53)

nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems. (Myers Psychology 9e p. 55)

central nervous system (CNS)

the brain and spinal cord. (Myers Psychology 9e p. 55)

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body. (Myers Psychology 9e p. 55)

nerves

bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs. (Myers Psychology 9e p. 55)

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system. (Myers Psychology 9e p. 55)

autonomic [aw-tuh-NAHM-ik] 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. (Myers Psychology 9e p. 55)

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations. (Myers Psychology 9e p. 55)

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy. (Myers Psychology 9e p. 56)

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response. (Myers Psychology 9e p. 57)

endocrine [EN-duh-krin] system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream. (Myers Psychology 9e p. 58)

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues. (Myers Psychology 9e p. 58)

adrenal [ah-DREEN-el] glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress. (Myers Psychology 9e p. 59)

pituitary gland

the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands. (Myers Psychology 9e p. 59)

lesion [LEE-zhuhn]

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue. (Myers Psychology 9e p. 61)

electroencephalogram (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. (Myers Psychology 9e p. 61)

PET (positron emission tomography) scan

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task. (Myers Psychology 9e p. 62)

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy. (Myers Psychology 9e p. 62)

fMRI (functional magnetic resonance imaging)

a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function. (Myers Psychology 9e p. 62)

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. (Myers Psychology 9e p. 63)

medulla [muh-DUL-uh]

the base of the brainstem; controls heartbeat and breathing. (Myers Psychology 9e p. 63)

reticular formation

a nerve network in the brains tern that plays an important role in controlling arousal. (Myers Psychology 9e p. 63)

thalamus [THAL-uh-muss]

the brain's sensory switchboard, located on top of the brain stem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla. (Myers Psychology 9e p. 64)

cerebellum [sehr-uh-BELL-um]

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance. (Myers Psychology 9e p. 64)

limbic system

neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives. (Myers Psychology 9e p. 65)

amygdala [uh-MIG-duh-la]

two lima bean-sized neural clusters in the limbic system; linked to emotion. (Myers Psychology 9e p. 65)

hypothalamus [hi-po-THAL-uh-muss]

a neural structure lying below (hypo) 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 and reward. (Myers Psychology 9e p. 66)

cerebral [seh-REE-bruhl] cortex

the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center. (Myers Psychology 9e p. 68)

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons. (Myers Psychology 9e p. 68)

frontal lobes

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments. (Myers Psychology 9e p. 68)

parietal [puh-RYE-uh-tuhl] lobes

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position. (Myers Psychology 9e p. 68)

occipital [ahk-SIP-uh-tuhl] lobes

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields. (Myers Psychology 9e p. 68)

temporal lobes

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear. (Myers Psychology 9e p. 68)

motor cortex

an area at the rear of the frontal lobes that controls voluntary movements. (Myers Psychology 9e p. 69)

sensory cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations. (Myers Psychology 9e p. 71)

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. (Myers Psychology 9e p. 72)

plasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience. (Myers Psychology 9e p. 73)

neurogenesis

the formation of new neurons. (Myers Psychology 9e p. 74)

corpus callosum [KOR-pus kah-LOW-sum]

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them. (Myers Psychology 9e p. 75)

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them. (Myers Psychology 9e p. 75)