biological psychology
a branch of psychology concerned with the links between biology and behavior
neuron
a nerve cell; basic building block of the nervous system
dendrites
branching extensions of a neuron that receive messages and conduct impulses toward the cell body
axon
extension of a neuron, ending in terminal fibers through which messages pass information to other neurons, muscles, or glands
myelin sheath
layer of fatty tissue segmentally encasing the fibers of many neurons; enables faster transmission of neural impulses
action potential
a nerve impulse; a brief electrical charge that travels down an axon
threshold
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
neurotransmitters
chemical messengers that cross the synaptic gap between neurons; travel across synaptic gap to receptor sites
acetylcholine (Ach)
type of neurotransmitter that enables muscle action, learning, and memory
endorphins
natural opiate-like neurotransmitters linked to pain control and pleasure
nervous system
body's speedy electrochemical communication network consisting of all the nerve cells of the peripheral and central nervous systems
central nervous system (CNS)
the brain and spinal cord
peripheral nervous system (PNS)
sensory and motor neurons that connect the central nervous system to the rest of the body
nerves
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs
somatic (skeletal) nervous system
division of the peripheral nervous system that controls the body's skeletal muscles
autonomic nervous system
part of the peripheral nervous system that controls the glands and the muscles of the internal organs
sympathetic nervous system
division of autonomic nervous system that arouses the body; mobilizes its energy in stressful situations
parasympathetic nervous system
division of the autonomic nervous system that calms the body; conserves its energy
reflex
a simple, automatic response to a sensory stimulus
endocrine system
body's slow chemical communication system; a set of glands that secrete hormones into the blood stream
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the blood stream, and affect other tissues
adrenal glands
located just about the kidneys; secrete hormones that help arouse the body in times of stress
pituitary gland
most influential gland; regulates growth and controls other endocrine glands
lesion
tissue destruction
electroencephalogram (EEG)
amplified recording of the waves of electrical activity that sweep across the brain's surface
PET scan
visual display of brain activity that detects where a radioactive form of glucose goes with the brain performs a given task
MRI
technique that uses magnetic fields and radio waves to produce computer generated images of soft tissues; shows brain anatomy
fMRI
technique for revealing blood flow and brain activity by comparing successive MRI scans; shows brain function
brain stem
oldest part and central core of the brain; begins where the spinal cord swells as it enters the skull; responsible for automatic survival functions
medulla
base of the brain stem; controls heartbeat and breathing
reticular formation
nerve network in the brain stem that plays an important role in controlling arousal
thalamus
brain's sensory switchboard located at the top of the brain stem; directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
cerebellum
located at rear of brain stem; processes sensory input and coordinates movement output and balance
limbic system
neural system located below the cerebral hemispheres; associated with emotions and drives
amygdala
2 lima bean sized neural clusters in the limbic system that are linked with emotion
hypothalamus
neural structure below the thalamus that directs eating, drinking, body temperature, and helps govern the endocrine system via the pituitary gland; linked to emotion and reward
cerebral cortex
interconnected neural cells covering the cerebral hemispheres; body's ultimate control and information processing center
glial cells
cells in the nervous system that help support, nourish, and protect neurons
frontal lobes
portion of cerebral cortex just behind the forehead; involved in speaking, muscle movement, and in making plans and judgments
parietal lobes
portion of the cerebral cortex at the top of the head and toward the back; receives sensory input for touch and body position
occipital lobes
portion of the cerebral cortex at the back of the head; includes areas that receive information from visual fields
temporal lobes
portion of the cerebral cortex above the ears; receive information primarily from the opposite ear
motor cortex
area at the rear of the frontal lobes that controls voluntary movements
sensory cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions but are involved in higher mental functions such as learning, remembering, thinking, and speaking
plasticity
the brain's ability to change by reorganizing after damage or by building new pathways based on experience
neurogenesis
formation of new neurons
corpus callosum
large band of neural fibers connecting 2 brain hemispheres and carrying messages to the between them
split brains
condition resulting from surgery that isolates the brain's 2 hemispheres by cutting the fibers of the corpus callosum
agonist
mimics neurotransmitters or blocks their reuptake; excites
antagonists
blocks neurotransmitters; inhibits