Chapter 3 Flashcards
neurons
individual cells in the nervous system that receive, integrate and transmit information
soma
cell body of neuron, contains the cell nucleus and much of the chemical machinery common to most cells
dendrite
parts of the neuron that are specialized to receive information
axon
a long, thin fiber that transmits signals away from the soma to other neurons or to muscles and glands, wrapped in cells of myelin
myelin sheath
insulates some axons and speeds up transmission
terminal buttons
small knobs that secrete neurotransmitters
synapse
a junction where information is transmitted from one neuron to another
glia
glue that provides support to neurons, small but outnumber neurons 10:1, 50% of brain’s volume, some can send signals and may contribute to memory
Hodgkin and Huxley
studied squid, learned that neural impulse is a complex electrochemical reaction, positive sodium and potassium against negative chloride
resting potential
a neuron’s stable, negative charge when the cell is inactive, -70 millivolts
action potential
brief shift in a neuron’s electrical charge that travels along an axon
absolute refractory period
minimum length of time after an action potential during which another action potential cannot begin
neurotransmitters
chemicals that transmit information from one neuron to another
postsynaptic potential (PSP)
a voltage change at a receptor site on a postsynaptic cell membrane
number of synapses…
decreases after age 1
acetylcholine
Released by motor neurons controlling skeletal muscle, regulation of attention, arousal and memory, Alzheimer’s
Dopamine
Control of voluntary movement, Cocaine elevates, Parkinsonism Schizophrenia and addiction
Norepinephrine
Mood and arousal, cocaine elevates, depression
Serotonin
Regulates sleep and wakefulness, deppression OCD and eating disorders
GADA
inhibitory transmitter, regulates anxiety and sleep/arousel, valium, Anxiety disorders
Glutamene
Excitatory transmitter, learning and memory, Schizophrenia
Endorphins
Opiate drugs, pain relief and response to stress, eating behavior
agonist
mimics action of neurotransmitter
antagonist
opposes action of neurotransmitter
monoamines
dopamine, norepinephrine, serotonin
peripheral nervous system
all nerves (bundles of axons) that lie outside the brain and spinal cord
somatic nervous system
nerves that connect to voluntary skeletal muscles and sensory receptors
afferent nerve fibers
carry information to central nervous system
efferent nerve fibers
carry information outward
autonomic nerve system
nerves that connect the heart, blood vessels, smooth muscles and glands
sympathetic division
part of autonomic, mobilizes resources for emergencies
parasympathetic
part of autonomic, conserves resources
central nervous system (CNS)
brain and spinal cord
electroencephalograph (EEG)
device that monitors electrical activity of the brain over time using recording electrodes attached to the scalp
lesioning
destroying a part of the brain
transcranial magnetic stimulation (TMS)
allows scientists to temporarily enhance or depress activity in a specific area of the brain, non-invasive but can’t study deep in brain
PET, CT and MRI scans
CT shows structure, PET shows function and neurotransmitters, MRI better shows structure
male vs. female arousal
men are more stimulated visually than women
hindbrain
cerebellum, medulla, pons
forebrain
thalamus, hypothalamus, limbic system and cerebrum
cerebrum
largest part of brain, sensing, thinking, learning, emotion, consciousness and voluntary movement
corpus callosum
bridge of fibers passing information between hemispheres of brain
thalamus
handles incoming and outgoing signals
cerebellum
coordinates fine muscle movement, balance
reticular formation
carry stimulation for sleep and arousal through brainstem
spinal cord
simple reflexes, transmits info between brain and body
medulla
unconscious functions
pons
sleep and arousal
hippocampus
learning and memory, limbic system
pituitary gland
regulates other glands
hypothalamus
hunger, thirst, temperature control, basic needs
limbic system
a loosely connected network of structures located along border between cerebral cortex and deeper subcortical areas
cerebral cortex
folded outer layer of the cerebrum
mirror neurons
activated by performing an action or by seeing another monkey or person perform the same action
occipital lobe
visual processing
parietal lobe
sense of touch
temporal lobe
auditory processing
frontal lobe
movement of muscles
neurogenesis
formation of new neurons
split-brain surgery
corpus callosum cut,
left hemisphere
right hand, speach
right hemisphere
left hand, puzzles, recognition
perceptual asymmetries
left-right imbalances between the cerebral hemispheres in the speed of visual or auditory processing
family studies
researchers assess the hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait
epigenetics
study of heritable changes in gene expression that do not involve modifications to DNA sequence
ocytocin
regulates reproductive behaviors, hormone from pituitary
