Ap psych Unit 3 vocab part 1

Neuron

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

cell body

the part of a neuron that contains the nucleus; the cell's life-support center

Dendrites

a neuron's often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body

Axon

the neuron extension 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 node to the next

gilal cells

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

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

all-or-none response

a neuron's 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

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Reuptake

a neurotransmitter's reabsorption by the sending neuron

Endorphins

"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Agonist

a molecule that increases a neurotransmitter's action

Antagonist

a molecule that inhibits or blocks a neurotransmitter's action

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 (CNS)

brain and spinal cord

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body

nerves

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

sensory 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

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs

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

the body's "slow" 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 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.

EEG (electroencephalogram)

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.

MEG (magnetoencephalography)

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

CT scan

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

PET scan

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

MRI scan

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue

fMRI

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.

Brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull

Medulla

the base of the brainstem; controls heartbeat and breathing

Thalamus

the brain's sensory control center, 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

reticular formation

a nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal

Cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

limbic system

neural system (including the amygdala, hypothalamus, and hippocampus) located below the cerebral hemispheres; associated with emotions and drives

anygdala

two lima bean-sized neural clusters in the limbic system; linked to emotion.

Hypothalamus

a neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion

Hippocampus

a neural center located in the limbic system; helps process explicit memories for storage