chapter 3 Flashcards
Central nervous system (CNS) consists of
consists of the brain and spinal cord
Peripheral nervous system (PNS) consists of
the other nerve cells in the rest of the body
Somatic nervous system
voluntary behavior
Autonomic nervous system
non voluntary actions of the body (heart rate, and other bodily functions, reflexes)
Functions of the CNS and PNS are anatomically separate but they are interdependent
Neurons
basic units of the nervous system. Receive, integrate, and transmit information STUDY REST IN OUTLINE
Dendrites
short, branch like appendages that detect chemical signals from neighboring neurons
Cell body/soma
the information received via the dendrites from thousands of other neurons is collected and integrated
Axon
a long narrow outgrowth of a neuron by which information is conducted from the cell body to the terminal buttons
Terminal buttons
at the end of axons; small nodule that release chemical signals from the neuron into the synapse
Synapse
site where chemical communication occurs between neurons Neurons do not touch each other so they communicate by sending chemical signals through synapses
Membrane
the fatty barrier on the outer surface of the neuron
Selectively permeable
Action potential (neural firing)
is the electrical signal that passes along the axon
Action potential summary
when a neuron fires it opens the sodium gates which allows sodium in therefore making the neuron more positively charged than the outside which causes the action potential. Then the potassium channels open to allow potassium inside the cell membrane. This pushes the sodium out of the cell while returning the neuron to its negatively charged form
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Resting membrane potential
electrical charge of the neuron when it is not active
When the neuron is not active there is a more negative charge inside the neuron than outside
Polarized
when a neuron has more negative ions inside than outside
Creates electrical energy necessary to power the firing of the neuron
Sodium-potassium pumps
increases potassium and decreases sodium inside the neuron
Excitatory signals
depolarize the cell membrane
Decreasing the negative charge inside the cell relative to the outside
Increase the likelihood of the neuron firing
Inhibitory signals
hyper polarize the cell Increasing
Increasing the negative charge inside the cell relative to the outside
Decrease the likelihood of the neuron firing
Excitatory and inhibitory signals
The firing of the signals are not determined by whether an inhibitory and excitatory signal gets their first but the frequency of those signals
Relative refractory period
brief period of time following the action potential when a neuron’s membrane potential is more negative or hyperpolarize making it harder to fire again
all-or- none principle
dictates that a neuron fires with the same potency each time
Either fires or does not
The stronger the stimulation the more frequently action potentials are generated
Absolute refractory period
the brief period of time following the action potential when the ion channel is not able to respond again
Followed by relative refractory period
Action Potential
always moves in one direction down the axon away from the cell body to the terminal buttons
Myelin sheath
encases and insulates many axons which allows faster movement of electrical impulses down the axon (made of glial cells)
Demyelination
slows down neural impulses and interrupts normal neural communication
Nodes of Ranvier
small gaps of exposed axon where action potential takes place
Presynaptic neuron: sends the signal
Neurotransmitters
are made
chemicals that are made in the axon or cell body and stored in vesicles. Transmits signals from one neuron to another
inside the terminal button
Postsynaptic neuron
does what?
receives the signal
Acetylcholine
motor control over muscles, learning, memory sleeping, and dreaming
Norepinephrine
controls
arousal, vigilance, and attention
Serotonin
emotional states and impulsiveness, dreaming
Dopamine
gives a person a sense of
reward and motivation , motor control over voluntary movement
GABA (gamma-aminobutyric-acid)
inhibition of action potentials, anxiety reduction
Glutamate
enhances?
enhancements of action potentials, learning and memory
Endorphins
decreases?
pain reduction, reward
Receptors
are specialized protein molecules located on the postsynaptic membrane that specifically respond to the chemical structure of the neuron available in the synapse
A NEUROTRANSMITTER CANNOT BIND WITH A RECEPTOR IF IT CANNOT FIT
How neurotransmitters work
Neurotransmitters are made in the axon
Neurotransmitters are stored in vesicles
Action potentials cause vesicles to fuse to the presynaptic membrane and release their contents into the synapse
Released neurotransmitters bind to the postsynaptic receptors
Neurotransmission is terminated by reuptake, enzyme deactivation or autoreception
Reuptake
occurs when the neurotransmitter is taken back into the presynaptic terminal buttons (recycling)
Enzyme deactivation
when an enzyme destroyed the neurotransmitter in the synapse
Different enzymes breaks different neurotransmitters
Autoreception
neurotransmitters can bind with receptors on the presynaptic neuron
Monitor how much neurotransmitter has been released into the synapse
Agonists
drugs and toxins that enhance the actions of neurotransmitters
Antagonists
inhibit
inhibit the actions of drugs and toxins
Agonists and antagonists
alters?
can alter a neurotransmitter’s action in many ways
Agonist enhance action of neurotransmitters
helps produce
Introducing a substance that helps produce the neurotransmitter (precursor) thus increasing the amount of neurotransmitter made and released by the presynaptic neuro blocks recpetors that trigger reuptake making the neurotransmitter last longer in the synape
Antagonist
reduces
Introducing a substance that reduces the amount of neurotransmitter made and released into the synapse which also facilitates the destruction of neurotransmitters thus reducing the time it is in the synapse
Broca’s Theory
Left frontal region is crucial for the production of language
Electroencephalogy
measure electrical activity in the brain
Event-related potential (ERP)
provides information about the speed at which the brain processes events and their timing
Positron Emission Tomography (PET)
a method of brain imaging that assesses metabolic activity by using a radioactive substance injected into the bloodstream
Negative: the patient needs to be injected with a radioactive substance
Functional Magnetic Resonance Imaging (fMRI)
an imaging technique used to examine changes in activity of the working human brain by measuring changes in the blood oxygen’s level
MRI
a method of brain imaging that uses a powerful magnetic field to produce high-quality images of the brain
Transcranial Magnetic Stimulation (TMS)
the use of strong magnets to briefly interrupt normal brain activity as a way to study brain regions
Can be used for only short amounts of time
Cerebral Cortex
the outer layer of the cerebral hemisphere and gives the brain its distinctive wrinkled appearance
Lateral fissure
Central fissure
Frontal
function
thought, planning, movement
prefrontal cortex
function
directing and maintaining attention
Indispensable for rational activity
Feel empathy, sense of self, feeling guilty, concerned with social functions
Primary motor cortex
initiates
initiate complex voluntary movements
Temporal
function
hearing, memory
Primary auditory cortex
function
responsible for hearing
Fusiform face area
intersection between the temporal lobe and occipital lobe
More active when people look at faces (recognition of people)
Parietal
function
touch, spatial relations
Primary somatosensory cortex
groups nearby sensations
The left hemisphere receives touch information from the right side of the body
The right hemisphere receives touch information from the left side of the body
Occipital
function
vision
Primary visual cortex
major destination for visual information
Corpus callosum
a massive bridge of millions of myelinated axons (white matter) connects the hemispheres and allows information to flow between them
Split-brain
a condition that occurs when the corpus callosum is surgically cut and the two hemispheres of the brain do not receive information directly from each other
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Insula
location
Insula lies deep within the lateral fissure
Subcortical structures
thalamus, hypothalamus, the hippocampus, basal ganglia, and amygdala
Insula
Houses primary gustatory cortex
Sense of taste, perceiving disgust
Aware of bodily states (emotions)
Experience pain, feeling empathy for other people’s pain
Thalamus
Gateway to the cortex
Receives almost all incoming sensory information, organizes it, and relays it to the cortex
Only exception is the sense of smell (has a direct route to the cortex)
Partially shuts the gates when sleeping to allow the brain to rest
Hypothalamus
Brains main regulatory structure
Indispensable to an organism’s survival
Receives input from and projects its influence to almost everywhere on the body and brain
Affects internal organs (regulating body temperature, body rhythms, blood pressure, blood glucose level) (Homeostasis)
Thirst, hunger, sexual desire all regulated
Hippocampus
Formation of new memories
How we remember the arrangements of places and objects in space
Amygdala
Learning about biologically relevant stimuli
Responding to stimuli that elicit fear
Evaluating a facial expression emotional significance
Intensifies the function of memory during times of emotional arousal
Basal Ganglia
crucial for?
System of subcortical structures crucial for planning and producing movement
Receive input from the entire cerebral cortex
Send these inputs to the motor centers of the brain
Spinal Cord
Carry sensory information up to the brain and carry motor signals from the brain to the body parts below to initiate action
Brain Stem
Extension of the spinal cord
Controls functions crucial to survival
Heart rate, breathing, swallowing, vomiting, urination, and orgasm
Houses the medulla oblongata, the pons, and the midbrain
Cerebellum
A large convoluted protuberance at the back of the brainstem, it is essential for coordinated movement and balance
Motor learning and motor memory, operates unconsciously
Somatic nervous system (SNS)
Transmits sensory signals and motor signals to the CNS via nerves
Specialized receptors in the skin, muscle, and joints send this sensory information to the spinal cord which relays it to the brain
CNS sends signals to the SNS to muscles, joints, and skin to initiate, modulate or inhibit movement
Autonomic nervous system (ANS)
Regulates the body’s internal environment by by stimulating glands and by maintaining internal organs
Nerves in the ANS also carry somatosensory signals from the glands and internal organs to the CNS
Sympathetic nervous system (fight or flight)
Prepares your body for action
Fight or flight response
Parasympathetic nervous system (rest and digest)
Returns the body to a resting state
Rest and digest
Endocrine system
Communication network that uses hormones to influences thoughts, behavior, and actions
Slower at communication than the nervous system
Hormones
chemical substances released into the bloodstream by the endocrine glands such as the pancreas, thyroid, adrenal glands, and testes or ovaries
Hypothalamus
function
controls motivation and regulates body function (primarily controls the endocrine system)
Pituitary
controls release of hormones (located at the base of the hypothalamus)
Control center of the endocrine system
Thyroid
controls
controls how body burns energy
Parathyroid
function
controls calcium levels
Thymus and Adrenal
governs immune system
Pancreas
controls digestion
Plasticity
the ability to change in response to experience or injury
Decreases with age
Social environment and stress can highly affect brain plasticity
Neurogenesis
Production of new neurons
Gene expression
whether a particular gene is turned on or off
Allows us to sense, learn, and fall in love
Dominant Gene
gene that is expressed whenever it is present
Recessive Gene
gene that is only expressed when matched with the same recessive gene
Genotype
organism’s genetic makeup
Phenotype
organism’s observable characteristics and is always changing
Polygenic
traits are influenced by many genes and environment
Heredity
transmission of characteristics from parents to offsprings through genes
