AP Psychology Unit 1A, Part 1 Vocabulary

neuron

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

cell body

contains nucleus, cell’s life support center

dendrites

a neurons bushy, branching extensions that receive messages and conduct impulses toward the cell body

axon

the neuron extensions that passes messages through its branches to other neurons or to muscles or glands

myelin sheath

a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one sausage-like node to the next

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking

action potential

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

threshold

the level of stimulation required to trigger a neural impulse

refractory period

a period of inactivity after a neuron has fired

all-or-none response

a neurons reaction of either firing (with a full-strength response) or not firing

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 synaptic cleft

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons. When released by 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

reuptake

a neurotransmitters reabsorption by the sending neuron

endorphins

“morphine within"--natural opiate-like neurotransmitters linked to pain control and to pleasure

agonist

a molecule that, by binding to a receptor site, stimulates a response

antagonist

a molecule that, by binding to a receptor site, inhibits or blocks a response

nervous system

the bodys speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system

central nervous system (CNS)

the brain and spinal cord

peripheral nervous system (PNS)

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

Nerves

bundled axons that from neural "cables" connecting the central nervous system with muscles, glands, and sense organs

Sensory (afferent) neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

motor (efferent) neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

interneurons

neurons within the brain and spinal cord that communicate internally 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 (ANS)

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, automatic response to a sensory stimulus, such as the knee-jerk response

endocrine system

chemical communication system; a set of glands that secrete hormones into the bloodstream

hormones

chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and affect other tissues

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arous the body in times of stress

pituitary gland

the endocrine systems most influential gland. under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

lesion

tissue destruction. a Brian lesion is a naturally or experimentally causes destruction of brain tissue

EEG (electroencephalogram)

an amplified recording of the waves of electrical activity sweeping across the brains surface. these waves are measured by electrodes placed on the scalp

MEG (magnetoencephalography)

a brain imaging technique that measures magnetic fields from the brains natural electrical activity

CT (computed tomography) scan

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brains structure

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

MRI (magnetic resonance imagine)

a technique that use magnetic fields and radio waves to produce computer generated images of soft tissue. MRI scans show brain anatomy

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, Brian activity by comparing successive MRI scans. fMRI scans show Brian function as well as its structure