UNIT 3 - Biological Bases of Behavior Flashcards
Neuron
nerve cell
Dendrites
A neuron’s branching extensions that receive messages and conduct impulses toward the cell body
Axon
The neuron extension that passes messages through its branches to other neurons/muscles/glands
Myelin sheath
Layer of fatty tissue that speeds axon impulses
Action potential
A neural impulse
Refractory period
a period of inactivity after a neuron has fired
Threshold
The level of stimulation required to trigger a neural impulse
All-or-none response
A neuron’s reaction of either firing (with full strength) or not firing (like guns)
Synapse
Gap between sending neuron and receiving neuron
Neurotransmitters
Chemical messengers released when action potential reaches axon’s terminals
Reuptake
The sending neuron reabsorbs the excess neurotransmitters
Endorphins
natural, opiate-like neurotransmitters linked to pain relief and pleasure
Agonist
A molecule that STIMULATES a response by binding to a receptor site
Antagonist
A molecule that BLOCKS a response by binding to a receptor site
Nervous system
The body’s speedy communication network
Central Nervous System
brain and spinal cord
Peripheral nervous system
Gathers info and transmits CNS decisions to other body parts
Nerves
Bundled axons connecting to the CNS
Sensory (afferent) neurons
Carry messages from tissues and sensory receptors to the CNS
Motor (efferent) neurons
Carry instructions from the CNS to muscles and glands
Interneurons
Neurons within the CNS that communicate internally
Somatic NS
Enables voluntary control of our skeletal muscles
Automatic NS
Self regulated functions; heartbeat, digestion
Sympathetic NS
Arouses and expends energy
Parasympathetic NS
Conserves energy as it calms you
Reflex
Automatic responses to stimuli
Endocrine system
Slow communication system. Set of glands that secrete hormones
Hormones
Chemical messengers
Adrenal glands
Releases hormones (epinephrine and norepinephrine) that arouse the body when stressed
Pituitary gland
Regulates growth
Lesion
Destroying tiny clusters of brain cells
EEG
Recording of waves of electrical brain activity
CT Scan
Takes X-ray of brain
PET Scan
Shows brain’s consumption of glucose
MRI
Uses magnetic fields and radio waves to produce images of soft tissue
fMRI
Reveals brain’s functioning and structure through bloodstream
Brainstem
automatic survival functions
Medula
Heartbeat and breathing; brainstem’s base
Thalamus
Directs messages
Reticular formation
arousal and alertness
Cerebellum
Movement and balance; learning and memory
Limbic system
hippocampus, amygdala, hypothalamus
Amygdala
aggression and fear
Hypothalamus
Emotion and reward; maintenance activities; hormones
Cerebral cortex
Neural cell surface layer that covers the brain
Glial cells
support, nourish, and protect neurons
Frontal lobes
Speaking, muscle movement, making plans and judgements
Parietal lobes
Touch and body position
Occipital lobe
Vision
Temporal lobes
Hearing
Motor cortex
Controls voluntary movements
Somatosensory cortex
Body touch and movement sensations
Association areas
learning, remembering, thinking, speaking
Plasticity
Brain’s ability to change by reorganizing itself (strong during childhood)
Neurogenesis
Formation of new neurons
Carpos callosum
Large band of neural fibers that connects the 2 hemispheres
Split brain
Condition resulting from cutting corpus callosum
Conciousness
our awareness of ourselves and our environment
Environment
Every external influence
Identical twins (monozygotic)
twins who develop from a single fertilized egg that splits into two, creating two genetically identical organisms
Fraternal twins (dizygotic)
twins who develop from separate fertilized eggs. Not identical
Interaction
When the effect of one factor depends on another factor
Epigenetics
the study of environmental influences on gene expression that occur without a DNA change
