Chapter 2 Flashcards
what is the NERVOUS SYSTEM?
a network of billions of cells within the brain and the body, that are responsible for all aspects of what you think, feel, and do
what are the THREE BASIC FUNCTIONS of the nervous system?
- (1) receiving SENSORY INPUT from the world through basic senses
- (2) processing information through attention, perception, and memory
- (3) response to information through action
what are the TWO DIVISIONS of NERVOUS SYSTEM?
- CENTRAL NERVOUS SYSTEM (CNS):
- the part of the nervous system that consists of the nerve cells in the brain and the spinal cord
- PERIPHERAL NERVOUS SYSTEM (PNS):
- the part of the nervous system that consists of all the nerve cells throughout the body except those in the brain and spinal cord
both divisions constantly are in contact with one another
what are NEURONS?
- the nerve cells that are the basic units of the nervous system
- help receive, integrate, and transmit info in the nervous system
- operate through electrical impulses, and communicate through chemical signals
what are the specific parts of a NEURON (5)?
- dendrites
- axons
- terminal buttons
- synapse
- neurotransmitters
dendrites
branchlike extensions of the neuron’s cell body with receptors that receive information from other neurons
axons
- a long, narrow outgrowth of a neuron’s cell body that lets the neuron transmit information to other neurons
- can be very long in length
- **nerve is really a bundle of axons
terminal buttons
parts of the neuron at the end of axons that release chemical signals from the neuron into the synapse
synapse
the gap between the terminal buttons of a sending neuron and the dendrites of a receiving neuron
neurotransmitters
chemicals that carry signals from one neuron to another
what are the THREE PHASES OF NEURAL COMMUNICATION?
- PHASE ONE - TRANSMISSION PHASE
- electrical signals created in the cell body travel along axon and release of neurotransmitters in terminal buttons
- PHASE TWO - RECEPTION PHASE
- dendrites of other neurons receive signals from sending neurons
- PHASE THREE - INTEGRATION PHASE
- neurons begin to assess and integrate incoming signals
- all three phases continue to repeat and transmit specific signals
- similar to reposting an instagram post for example
neuron membrane
- barrier that separates the inside of the neuron from the outside environment
- helps regulate neuron’s electrical activity
- semipermeable - ions are able to pass through
ions
- electrically charged chemicals
- ex. sodium and potassium ions
- help neurons communicate
neuron resting state
- the electrical charge INSIDE the neuron is more NEGATIVE than the electrical charge OUTSIDE
- overall difference in charges = creates a BALANCE between the various ions
incoming stimulation
- causes positively charged sodium ions to move INSIDE the MEMBRANE
(more positive on the INSIDE)
- with enough stimulation = creation of an action potential
action potential
neural impulse that travels along the axon and then causes the release of neurotransmitters into the synapse
refractory period
- neuron returns to resting state
- the neuron is LESS RESPONSIVE to incoming stimulation and less likely to fire an action potential
- ex. social battery is dead after a night out, less likely to go out another time
myelin sheath + relation to MS disorder
a fatty material that covers and insulates some axons to allow for faster movement of electrical impulses along the axon
presynaptic neuron
the neuron that sends the signal
postsynaptic neuron
the neuron that receives the signal
receptors
- specialized structures that respond to certain types of neurotransmitters
- ex. lock and key example
- once binded with specific receptors, neurotransmitters are released back into synapse
how to avoid constant stimulation of these neurotransmitters?
- REUPTAKE:
- neurotransmitters are reabsorbed by the presynaptic neuron
- ENZYME DEGRADATION:
- enzymes destroy neurotransmitters within synapse
what signals does the POSTSYNAPTIC NEURON PROCESS?
- EXCITATORY
- signal that excites the neuron — increasing the likelihood of an action potential
- INHIBITORY
- signal that inhibits the neuron — decreasing the likelihood of an action potential
- signals are received in bunches of thousands
- if enough to reach certain threshold — postsynaptic neuron will fire its own action potential
agonist
- drugs that enhance the actions of neurotransmitters
- ex. nicotine (agonist) acts similar to acetylcholine
- binds to acetylcholine receptors
- enhancing motor coord. + attention
antagonists
- drugs that inhibit the actions of neurotransmitters
- ex. drug naloxone (antagonist)
- binds with endorphin receptors—blocks any opioids from binding
acetylcholine
- responsible for MOTOR CONTROL - MUSCLES
- binds with receptors on muscle cells - muscle contraction
- helps attention, memory, learning, and sleeping
norepinephrine
- a neurotransmitter involved in AROUSAL/ALERTNESS/ADERNALINE
- in our bodies; epinephrine (adrenaline)
serotonin
- neurotransmitter involved in wide range of PSYCHOLOGICAL ACTIVITES
- emotional states, impulse control, and dreaming
dopamine
- neurotransmitter important for brain functions
- specifically, MOTIVATION OR REWARD
- production of the DESIRE TO ACT
- ex. Parkinson’s Disease—dopamine-producing neurons slowly die off
GABA + Glutmate
- main INHIBITORY neurotransmitter - GABA (gamma-aminobutyric acid)
- aids in keeping excited neurons out of control
- main EXCITATORY neurotransmitter - GLUTAMATE
- fast-acting neural transmission
endorphins
- aids in INJURY and responsible for NATURAL PAIN REDUCTION
- feeling of pleasure or reward
brain
collection of neurons that interact with one another in massive circuits
PHRENOLOGY:
- the attempt to assess PERSONALITY TRAITS and mental abilities by measuring bumps on the human skull
- studied by Franz Gall and Johann Spurzheim
- found out that certain areas of the brain — correlate to certain THOUGHTS, BEHAVIORS, and FUNCTIONS
*BROCA AREA
MRI
FUNCTIONAL MAGNETIC RESONANCE IMAIGNG
- measures changes in the blood’s oxygen levels
- assessment of the brain’s blood flow
Transcranial Magnetic Stimulation
a very fast and powerful magnetic field to momentarily disrupt activity in a specific brain region
spinal cord
- GATEWAY for information traveling between the brain and body
- carries sensory and motor signals to the brain and back to the body parts
- coordination of REFLEXES
what structures make up the HINDBRAIN?
- medulla
- pons
- substantia nigra
- cerebellum
medulla
controls basic functions of survival, heart rate, breathing, swallowing, vomiting, and urination
pons
regulates sleep and arousal, coordinates left and right sides of the body
substantia nigra
- initiating voluntary movements
- production of dopamine
midbrain
reflexive movement of the eyes and body
cerebellum
- “the little brain”
- essential for proper motor function
- important for motor learning and motor memory, using language, or making plans
- if damaged can affect walking or balance
what MAIN AREAS make up the FOREBRAIN?
- cerebral cortex
- subcortical structures/limbic system
(controlling motivation behavior, emotions, and memory)
thalamus
- SENSORY gateway to the cortex; sight, touch, sound, and taste
- relay station to the cerebral cortex
hypothalamus
- brain’s master regulatory structure—keeps the body in “BALANCE”
- regulates body rhythms, sleeping, body temp., blood sugar etc…
hippocampus
- formation of NEW MEMORIES and navigation of environments
- shaped like a seahorse
amygdala
- processing the emotional significance of stimuli around you (especially in terms of FEAR)
- increases memory processing during EMOTIONAL AROUSAL
cerebral cortex
- site of thoughts and complex behaviors
- divided into two halves; right and left hemispheres
- connected by CORPUS CALLOSUM
brain lobes
- frontal
- parietal
- occipital
- temporal
occipital lobes
distinct visual areas and primary visual cortex
parietal lobes
- evoted to the sense of touch and is the primary somatosensory cortex
- hemispheres receive info in reverse
- spatial awareness
temporal lobes
- primary auditory cortex and memory regions
- facial recognition
frontal lobes
- important for complex thought, planning, and movement
- primary motor cortex + premotor cortex (important for RATIONAL THOUGHT)
- works in reverse sides
brain hemispheres
- left hemisphere - logical thought and language
- right hemisphere - spatial relationships, emotional aspects etc..
split brain
a condition in which the corpus callosum is surgically severed and the two hemispheres of the brain do not recieve information directly from each other
left brain/right brain myth
- LEFT-BRAIN THINKERS:
- more analytical, rational, and objective
- RIGHT-BRAIN THINKERS:
- more creative and subjective
- people are NEITHER left-brain nor right-brain dominant
- utilize both
somatic nervous system
- transmits sensory signals and motor signals back and forth between the CNS and the skin, muscles, and joints
- help initiate or inhibit movements (voluntary)
autonomic nervous system
- transmits sensory signals and motor signals back and forth between the CNS and the body’s glands and internal organs
- regulation of more involuntary processes within the body’s internal environment
- ex. like sweating, heartbeat, digestion, etc…
sympathetic and parasympathetic nervous system
- SYMPATHETIC NERVOUS SYSTEM
- prepares body for action
- PARASYMPATHETIC NERVOUS SYSTEM
- returns body to a resting state
- both provide signals that travel back and forth from CNS, organs, and glands etc…
endocrine system
a bodily communication system that uses hormones to influence many aspects of the body, mental activity, and behavior
main difference between endocrine system and nervous system
- NERVOUS SYSTEM:
- communicates through fast electrochemical signals (neurons, neurotransmitters)
- ENDOCRINE SYSTEM:
- communicates through a slower method—release of chemicals from glands
hormones
chemicals released from endocrine glands that travel through the bloodstream to targeted tissues; tissues later influenced by the hormones
gonads
- sex glands used for reproduction
- male (testes) + female (ovaries)
- both gonads produce androgens (men) and estrogens(women) (but in different quantities in both men and women)
- influences secondary sex characteristics and sexual behavior
growth hormone
promotion of bone, cartilage, and muscle tissue to grow or help them regenerate after injury
natural selection
basis of evolution; the idea that those who inherit characteristics that help them adapt to their particular environments have an advantage over those who do not
genes, genotype, and phenotype
- units of heredity that help determine an offspring’s characteristics
- influence plenty; physical characteristics, predispositions to disease, intelligence etc…
- GENOTYPE:
- all of your genes together
- PHENOTYPE:
- observable physical and psychological characteristics
- can be affected by environmental factors and genes
gene expression
- examining the processes than turn genes “on” and “off”
- environment affects how your genes are expressed
behavioral genetics
the study of how genes and environment interact to influence mental activity and behavior
brain plasticity
- a property of the brain that causes it to change as a result of experience or injury
- brain is extremely adaptable, can re-organize itself
neural pruning
experiences are pruned to find and select stronger connections vs. weaker connections (happens as grow older through adolescence)
