Brain, Mind & Behavior Exam #1 Flashcards
(122 cards)
1
Q
Neuron
A
Basic unit of the nervous system.
2
Q
What are the 4 functional zones of the neuron
A
Input, integration, conduction, output
3
Q
Explain Input (one of 4 functional zones of the neuron)
A
dendrites receive information from other cells
4
Q
Explain integration (one of 4 functional zones of the neuron)
A
cell body (or soma)- integrates the information it receives
5
Q
Explain conduction (one of 4 functional zones of the neuron)
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a single axon (nerve fiber) conducts output information away from the cell body as an electrical impulse
6
Q
Explain output (one of 4 functional zones of the neuron)
A
axon terminals at the end of the axon communicate activity to other cells
7
Q
What are the 3 shapes of neurons
A
Motor Neurons, Sensory neurons, inter-neurons
8
Q
Motor Neurons
A
large, have long axons + stimulate muscles
9
Q
Sensory Neuron
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have various shapes that best respond to specific environments stimuli such as odor, light, or touch
10
Q
Interneurons
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have tiny axons + analyze input from one set of neurons and communicate w/others
11
Q
Multipolar Neurons
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One axon, many dendrites; most common
12
Q
Bipolar Neurons
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1 axon, one dendrite
13
Q
Unipolar Neurons
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a single extension branches in 2 directions forming an input and output zone
14
Q
How do the neuronal cell body and dendrites interact?
A
Neuronal cell body + dendrites receive information across synapses. info is transmitted from the presynaptic neuron to the post-synaptic neuron
15
Q
Presynaptic membrane -
A
on the axon terminal of the presynaptic neuron
16
Q
postsynaptic membrane-
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on the dendrite or cell body of the post synaptic neuron
17
Q
synaptic cleft-
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the gap that separate the membranes
18
Q
synaptic vesicles
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small spheres in presyntaptic axon terminals that contain a neurotransmitter
19
Q
when are neurotransmitters released
A
they are released in response to electrical activity in the axon
20
Q
neurotransmitter receptors
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in the postsynaptic membrane. they are specialized proteins that react to neurotransmitter molecules
21
Q
Neuroplasticity
A
continual remodeling of neuronal connections
22
Q
axon hillock
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a cone shaped area of the cell body that gives rise to the axon. converts input into eletrical signals that travel down the axon and innervate target cells
23
Q
axon collateral
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a branch of an axon that also ends in terminals
24
Q
axon transport
A
the bidirectional movement of materials with an axon
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glial cells
assist neuronal activity by providing raw materals, chemical signals and structure and also participate in information processing
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what is myelin
a fatty insulation layer that wraps around axons
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what are the two types of myelin
oligodendrocytes and schwann cells
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oligondendrocytes
form the myelin sheaths in the brain and spinal cord (its like glue)
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Schwann cells
provide myelin to neurons outside the brain and spinal cord
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Two other types of glial cells
astrocytes and microglial cells (microglia)
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astrocytes
star-shaped cells with many processes that stretch around and between neurons and sometimes blood vessels;
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Central Nervous System (CNS)
consists of brain and spinal cord
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Peripheral nervous system (PNS)
includes all other parts of the nervous system outside the brain and spinal cord. consists of bundles of nerves
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microglial cells (microglia)
tiny mobile cells that remove debris from injured or dead cells
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Motor nerves
transmit information from spinal cord to muscles and glands
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sensory nerves
convey info from body to CNS
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nerves of the body are divided into 2 segments
somatic nervous system and autonomic nervous system
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somatic nervous system
nerves that interconnect the brain and major muscles and sensory systems of the body
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autonomic nervous system
nerves that connect to the viscera (internal organs). main system for controlling the body's organs
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what are the two divisions of the autonomic nervous system
sympathetic and parasympathetic
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sympathetic nervous system
has axons that innervate the sympathetic gonglia (small clusters of neurons outside CNS)- responsible for 'fight or flight' response. prepares body for action
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parasympathetic nervous system
helps body relax and recuperate. neurons extend longer distances from CNS to parasympathetic ganglia, which are usually close to the organ they work with.
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cerebral cortex
outermost layer of brain. is has gyri (ridged portions) and sulci (valley). It has 4 lobes
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what are the 4 lobes of the cerebral cortex
frontal, paretal, occipital, temporal
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frontal lobe
front obviously. it controls the motor systems
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parietal lobe
between frontal and occipital. (like the crown region ish) controls sensations and body awareness.
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occipital lobe
back region. controls visual processing
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temporal lobe
below the parietal lobe (lateral region). controls auditory processing
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what are the 2 types of brain tissue
gray and white matter
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gray matter
contains more cell bodies and dendrites, which lack myelin
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white matter
consists mostly of axons with white myelin sheaths
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basal ganglia
a group of structures near the center of your brain that form important connections. important in motor control and consist mainly consist of the caudate nucleus, putamen, and Globus
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limbic system
includes structures important for emotion and learning
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what are the 6 parts of the limbic system
amygdala, hippocampus and fornix, cingulate gyrus, olfactory bulb, thalamus, and hypothalamus
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amygdala
emotion regulation and perception of odor
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hippocampus and fornix
learning
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cingulate gyrus
attention
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olfactory bulb
sense of smell
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thalamus
a cluster of nuclei that relay sensory info
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hypothalamus
contain nuclei with many functions; also control the pituitary
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midbrain tectum
a section of the midbrain between the hindbrain and the forebrain. contains superior colliculi and interior colliculi
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superior colliculi
visual processing
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interior colliculi
auditory processing
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substantia nigra
part of the basal ganglia
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recticular formation
part of midbrain. involved with sleep and arousal
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periaqueductal gray
part of midbrain. pain perception
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Meninges
protective layer that surrounds brain and spinal cord
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3 parts of meninges
dura mater, pia mater, arachnoid membrane
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dura mater
tough outermost layer
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pia mater
delicate innermost layer
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arachnoid membrane
lies between the other two; filled with cerebrospinal fluid (CSF)
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what 3 cranial nerves are exclusively sensory
olfactory, optic, vestibulochlear
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how many cranial nerves are there
12 pairs
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olfactory nerve
smell
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optic nerve
vision
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vestibulochlear nerve
hearing and balance
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what 5 nerves are motor pathways from the brain?
oculomotor, trochlear, abducens, spinal accessory, hypoglossal
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oculomotor nerve
eye movement
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trochlear nerve
eye movement
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abducens nerve
eye movement
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spinal accessory
neck muscles nerves
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hypoglossal
tongue nerves
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what 2 nerves have sensory and motor functions
trigeminal, vagus
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trigeminal
facial sensation, chewing muscles
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vagus
innervates heart, liver, and intestines
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Computer axial tomography (CAT)
a measure of x-ray absorption at several positions around the head. CT scans generate an anatomical map of the brain based on tissue density
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magnetic resonance imaging (MRI)
higher resolution images, fewer damaging effects than CT. when protons relax, they emit radio waves that differ by tissue density
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Functional MRI (fMRI)
detects small changes in brain metabolism, such as oxygen use, in active brain areas. fMRI can show how networks of brain structures collaborate
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Positron emission tomography (PET)
gives images of brain activity. Emissions of radioactive chemicals in the bloodstream indicate their destination. identifies which brain regions contribute to specific functions
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Neurophysiology
the study of life processes of neurons.
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explain resting neuron
a resting neuron is polarized, meaning there is a difference in electrical charge between the inside and outside of cell
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ions
electricity charged molecules
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anions
negatively charged
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cations
positively charged
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ion channels
proteins that span the membrane and can allow ions to pass through. some are gated, opening and closing in response to signals. others stay open all the time, such as the one in neurons that allow only potassium ions (K+) to cross the membrane
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how do action potentials 'move'?
they are actively propogated along the axon. each adjacent section is depolarized and a new action potential occurs. action potentials can only travel in one direction because of the refractory state of the membrane after depolaization
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conduction velocity
the speed of propogation of action potentials, varies with axon diameter
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what happens when action potential reaches the end of axon
causes the release of neurotransmitter into synapse
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excitatory postynaptic potential (EPSP)
a small local depolarizing potential in the postsynaptic membrane that pushes the cell closer to the action potential threshold, increasing the likelihood that the neuron will fire an action potential. (in EPSPs, Na+ channels open, letting positive ions into the cell
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inhibitory postsynaptic potential (IPSP)
a hyperpolarizing potential in the postsynaptic membrane that pushes the cell further away from threshold, decreasing likelihood of the neuron firing an action potential
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when do IPSP happen
(these result when chloride ions (Cl-) rush into the cell making the inside more negative)
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spatial summation
the summary of all the potentials that reach axon hillock from locations across the cell body. If the overall depolarization (sum of IPSP and EPSP) reaches or exceeds threshold, an action potential is produced
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the sequence of transmission
1. Action potential arrives at the presynaptic axon terminal
2. voltage fated calcium channels in the terminal membrane open and ca2+ ions enter
3. Ca2+ ions cause synaptic vesicles filled with neurotransmitters to fuse with the presynaptic membrane, releasing the transmitter into the synaptic cleft
4. transmitters bind to postsynaptic receptor molecules, causing ion channels to open and leading to an EPSP or IPSP
5. EPSP or IPSP spread toward the postsynaptic axon hillock. If threshold is reached, an action potential will occur
6. Synaptic transmission is rapidly stopped- accurately reflecting the activity of the presynaptic cell.
7. transmitter may activate presynpatic receptors that decrease trasmitter release
104
Ligands
molecules that fit into receptors and activate or block them. A synapse that uses acetylcholine (ACh) has ligand-binding sites for ACh on neurotransmitter receptor molecules in the postsynaptic membrane. The post-synaptic receptors determine the action of the transmitter. ACh can be excitatory, opening Na+ and K+ channels or it can be inhibitory, opening Cl- channels
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how does nicotine work?
some chemicals can fit on receptors in place of a neurotransmitter. nicotine can mimic ACh on receptors acting like the transmitter agonist
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how can transmitter action be halted?
degradation and reuptake,
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synaptic delay
the delay between an action potential reaching the axon terminal and creating a postsynaptic potential
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degradation
the rapid breakdown and inactivation of transmitter by an enzyme (AChE)
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Reuptake
transmitter is cleared from the sunapse by being absorbed back into the presunaptic axon terminal.
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what are transporters
special receptors that bring the transmitter back inside
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types of synapses
axo-dendritic, axo-somatic, aso-asonic, dendro-dentritic
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axo-dendritic
the axon terminal synapses on a dendrite
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axo-somatic
synapse between axon and cell body (soma)
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axo-axonic
synapse between two axons
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dendro-dendritic
synapse between 2 dendrites
116
knee jerk reflex
- sensory and motor axons are myelinated and large
- sensory cells synapse directly onto motor neurons
- both the central synapse and the neuromuscular junction are fast synapses
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Electroencephalogram (EEG)
recording of spontaneous brain potentials (brain waves)
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event-related potentials (ERPs)
they are EEG responses to a single stimulus such as a flash of light or loud sound. they can distinguish between sleep states and provide data for diagnosing seizure disorders
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types of seizures
- Tonic-Clonic or Grand mal Seuzure
- simple, absence or petit mal seizure
- complex partial seizures
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Tonic-Clonic or Grand mal Seuzure
abnormal EEG activity throughout the brain
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simple, absence or petit mal seizure
brain waves show patterns of seizure activity for 5 to 15 seconds, may occur several times a day
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complex partial seizures
do not involve entire brain, often preceded by an unusual sensation
