Science Flashcards
(212 cards)
1
Q
neuron
A
- nerve cell (eukaryotic cell)
- main cell for communicating across long distances
2
Q
nucleus
A
- neurons have a nucleus
- where the DNA is stored
3
Q
DNA
A
- deoxyribonucleic acid
- encodes the instructions to build proteins that are the building blocks for organisms
4
Q
soma
A
- cell body
- where the nucleus and other organelles are found
5
Q
neuronal membrane
A
- the layer that separates the neuron from the outside space
6
Q
dendrite
A
- receive synaptic inputs from other neurons
- size and shape impact how it receives inputs
- branch out
- connected to the cell body/soma
7
Q
axon
A
- long “wire” that transmits electrical signals or release packets of chemical transmitters from the neuron
- uniform thickness, some branch, no organelles
8
Q
myelin
A
- a fatty substance formed by glial cells to insulate the axons
- when covering an axon, it can speed up the conduction of the neuron’s electrical signals
9
Q
Nodes of Ranvier
A
- small gaps in the myelin that allow the axon to gain access to fluid outside the cell and send signals
10
Q
axon hillock
A
- where the axon begins at the soma
11
Q
axon terminals
A
- where the axon ends and releases the signal in the form of a neurotransmitter
12
Q
synapse
A
- where one neuron communicates with another neuron
13
Q
synaptic cleft
A
- the space between two neurons where a signal is passed
14
Q
presynaptic neuron
A
- first neuron in the synapse
15
Q
postsynaptic neuron
A
- second neuron that receives the signal
16
Q
neurotransmitters
A
- signalling chemicals
17
Q
interneurons
A
- neurons that work to connect with neurons with each other within the nervous system
18
Q
grey matter
A
- tissue made of cell bodies and dendritic arbors of neurons
- located on the outside in the brain, but inside in the spinal cord
19
Q
white matter
A
- tissue made of myelinated axons of the neurons
- located on the inside in the brain, but outside in the spinal cord
20
Q
glial cells
A
- non-neuronal cells found in the nervous system
- produced throughout the life of the organism
21
Q
oligodendrocytes
A
- myelinating glia that form sheaths around axons in the central nervous system
22
Q
Schwann cells
A
- myelinating glia that form sheaths around axons in the peripheral nervous system
23
Q
astrocyte
A
- regulates the chemical makeup of the extracellular fluid in the space of the cells in the nervous system
- Has long extensions that wrap around blood vessels in the brain to form the blood brain barrier
- most common type of glial cell
24
Q
microglia
A
- immune cells of the neuron, protect neurons from toxins/disease/ invaders
- clear away pathogens or dead/ damaged neurons by consuming them
25
meninges
- the three layers that protect the central nervous system
26
dura mater
- outermost layer
- thick, leathery material
27
epidural space
- space between the dura mater and the skull that contains fats which absorb shocks to the head
28
arachnoid membrane
- right under the dura mater
- long, stringy components
29
subdural space
- between the dura mater and arachnoid
- if there is trauma, then blood pools here and puts pressure on the brain
30
subarachnoid space
- space just below the arachnoid
- filled with cerebrospinal fluid to cushion the brain
- allows blood vessels to access the brain and deliver nutrition
31
pia mater
- innermost layer
- thin, follows every groove of the brain to prevent CSF from entering the brain
- allows blood vessels to travel
32
cerebrum
- contains most of the regions of the brain
33
frontal lobe
- largest in the brain, located in the front of the human head
- contains regions related to complex thinking or cognition
34
motor cortex
- brain plans and sends out instructions for the movements to the rest of the body
- located in the back edge of the frontal lobe
35
prefrontal cortex
- the regions in front of the motor cortex
36
parietal lobe
- located just behind the frontal lobe
- processes the sense of touch from the body, skin, and organs, temperature, pain, and body position
- Understands spatial relations
37
occipital lobe
- back of the cerebrum
- process and analyze visual information from the eyes
38
temporal lobe
- located on both sides of the brain, one under each ear and near the temples
- important for auditory sound and speech processing, music, memory, and object recognition
39
cerebellum
- structure that sits underneath the cerebrum
- helps the organism learn smooth and coordinated movements and new kinds of movements
40
gyri
- bumps on the surface of the brain
41
sulci
- the grooves/folds on the surface of the brain
42
subcortical structures
- structures that are found underneath cerebral cortex, each region is found on both the right and left side of the brain
43
amygdala
- found in the temporal lobe
- major component of the limbic system, regulates emotion and fear, processes threats, stress, reward, and arousal
44
hippocampus
- crucial region for long-term memory and spatial navigation
- Part of the limbic system, first areas to suffer cell death in Alzheimer’s
- memory consolidation
45
memory consolidation
- the change of short-term memories into long-term memories
46
thalamus
- central of the cerebral hemisphere
- all input from the body must first travel through this region before going to the brain – smell is the only exception, goes to the amygdala
- plays a role in consciousness, emotional behaviors, motor control, and cognition
47
pituitary gland
- releases important growth hormones, right next to the hypothalamus
48
hypothalamus
- located right below the thalamus
- mediates the action of the pituitary gland and unconscious functions needed for homeostasis
49
homeostasis
- keeping the body’s systems in a balanced and healthy state
50
basal ganglia
- cluster of nuclei found in the center of the cerebral hemispheres underneath the thalamus
- Made of the caudate nucleus, putamen, and globus pallidus
- help planned, voluntary movements or prevent unwanted or excess movements
51
brainstem
- located at the bottom of the brain, stalk that connects the brain to the spinal cord
- thalamus sits right on top of it
52
midbrain
- topmost part
- contains nuclei that help regulate eye movement and pupillary light reflex
- integrate visual information from the eyes with the auditory information from the inner ear
53
pos
- middle part
- contains nuclei for coordinating facial movements, chewing muscles, hearing, and balance
54
medulla
- bottom part
- contains nuclei dedicated to relaying touch sensations from the face, swallowing food, and vomiting to regulating blood pressure, heart rate, and breathing
55
spinal cord
- the other main section of the central nervous system, encased in vertebrae that make up the spine, conducts information between the brain and body
56
cervical spinal cord
- top section of the spinal cord
- innervates the arm, neck, and shoulders
57
thoracic spinal cord
- carries information to and from the chest and torso
58
lumbar spinal cord
- innervates the hips and front of the legs
59
sacral spinal cord
- innervates the buttocks, back of the legs, and genitalia
60
ventricular system
- series of open holes or cavities inside the central nervous system filled with cerebrospinal fluid
61
peripheral nervous system
- consists of nerves or axons and some clusters of cell bodies (ganglia) that leave the CNS to relay information from the brain to the body
62
somatic nervous system
- all the axons leaving and entering the spinal cord that that bring information to and from the tissues of your body
- under voluntary control
63
autonomic nervous system
- controls involuntary responses to regulate all kinds of aspects of the brain and body
Regulates the function of your internal organs, smooth muscle (such as the ones found in hearts), and glands
64
sympathetic nervous system
- responsible for the “fight or flight” response
- activated by adrenal glands, produces stress and prepares body for it
65
parasympathetic nervous system
- response for “rest and digest”
- when activated the organism is focused on digesting food, growth and cell division, immune responses, energy storage, and other aspects of maintaining homeostasis
66
resting membrane potential
- the electrical charge inside the neuron when the neuron/glia is not sending any signals
67
neuronal membrane
- selective phospholipid bilayer
- allows ionic concentration to be different inside vs. outside the cell due to its selectivity
68
passive transport
- an ion moves from one side to the other side of the membrane due to a natural force, usually the concentration gradient
69
ionic concentration
- number of ions in a particular volume of water forming a solution
70
concentration gradient
- measurement of how the concentration of something changes from one side of the neuronal membrane to another
71
electric potential
- the neuronal membrane may also have a difference in electric charges of the ions on either side
72
ion channels
- proteins that form specialized openings in the neuronal membrane through which ions can pass
73
gating
- a molecule triggers the channel to open
74
voltage-gated ion channels
- open and close when the membrane potential is a certain voltage
74
ligand-gated ion channels
- open when a particular molecule binds to a specific location on the channel
75
active transport
- ion is moved using energy from one side of the membrane to the other and has to go against the concentration gradient
76
ion pump
- a type of channel that uses energy to move ions from one side to the other
77
sodium-potassium pump
- crucial for neurons for establishing the resting membrane potential
78
chemical driving force
- result of the concentration gradient that causes ions to diffuse out of the cell
79
equilibrium potential
- membrane potential at which a particular ion reaches a equilibrium point
80
rising phase
- membrane potential becomes more positive due to the influx of positive ions (depolarization)
80
action potential
- the electric potential across the neuronal membrane when the neuron is active and firing, caused by the rapid opening and closing of ion channels
80
overshoot of the action potential
- membrane potential continues to increase even after it’s been reached, becomes around +30 mV to +40 mV
81
falling phase
- membrane potential becomes more negative due to positive ions leaving the cell (repolarization or hyperpolarization)
82
all-or-none principle
- either the threshold has been reached and the action potential has been fired, or the threshold has not been reached and the action potential has not been fired
83
absolute refractory period
- time period in which the channel is inactivated before it is opened again
84
relative refractory period
- timer period to get membrane potential back up to threshold
85
saltatory conductions
- conduction down a myelinated axon
86
synaptic transmission
- sending a signal from one cell to another
87
synapse
- signaling space between two neurons
88
electrical synpase
- the presynaptic and postsynaptic cell are so close to each other that each set of channels are connected to each other
89
postsynaptic density
- area that is heavily populated by receptors and their attached molecular machinery
90
ionotropic receptors
- membrane-spanning proteins that allow ions to pass through when a ligand is binded
91
excitatory postsynaptic potential
- the brief depolarization that results from the flow of positive ions
92
inhibitory postsynaptic potential
- the brief hyperpolarization that results from the flow of positive ions
93
synaptic integration
- EPSPs and IPSPs coming in from all the synapses across the cell are summed or added together
94
spatial summation
- when multiple EPSPs and IPSPs occur on different times at different spatial locations across dendrites
95
temporal summation
- when multiple EPSPs and IPSPs occur in succession at the same synapse and are summed over time
96
metabotropic receptors
- work much slower but allow for much more complex responses
97
agonist
- the drug’s activity is to enhance the activity of the neurotransmitter
98
competitive agonist
- compete for the binding site of the neurotransmitter, need to be more concentrated
99
noncompetitive agonist
- increase the activity of the neurotransmitter without blocking its binding site
100
partial agonist
- compete for the same binding sites but have a smaller physiological effect on the postsynaptic receptor
101
antagonist
- the drug wants to decrease or fully block the activity of the neurotransmitter
102
competitive antagonist
- block the binding site
103
noncompetitive antagonist
- indirectly block the binding site by binding to a different site that changes the shape of the receptor
104
catecholamines
- group of modulatory neurotransmitters that are all made from the same precursor molecule, tyrosine
105
acetylcholine
- primary neurotransmitter found at the neuromuscular junction
106
seretonin
- 5-hydroxytryptamine (5-HT), produced by nuclei found in the raphe nuclei in the brainstem
107
retina
- many-layered sheet of neurons
- where the transduction of light into an electrochemical signal takes place on the inner surface of the eye
108
iris
- the colored part of the eye
109
pupil
- the little hole through which light enters the eye, can dilate or contract to control how much light is let in
110
crystalline lens
- many-layered, clear structure behind the cornea that refracts the light to focus the image on the retina
111
pigmented epithelial cells
- absorb excess light to not scatter or blur the image, helps the function of the photoreceptor neurons
112
choroid
- brings oxygen and nutrients to the photoreceptor cells, right outside the pigmented epithelial cells
113
fovea
- very center of the retina, where vision is most acute or sharpest
114
rods
- have more discs, sensitive to low levels of light
- Located outside the center of the retina, used for peripheral, low-light, or nighttime vision
- Have rhodopsin
115
cones
- do the most work in bright light settings
- Clustered in the center of the retina, used for full-color vision
- the three types of cones have their own opsin
116
opsin
- different pigments which absorb different wavelengths
117
retinal ganglion axons
- send the visual information to the brain
- they all meet at the start of the optic nerve
118
amacrine cells
- distribute information from one bipolar cell to many ganglion cells
119
horizontal cells
- form connections between one central rod or cone to many other distant photoreceptors or several bipolar cells
120
lateral inhibition
- horizontal cell inhibits the more distant bipolar cells only when a photoreceptor depolarizes a horizontal cell
121
center-surrounded receptive field
- depolarized neurons in the retina that send signals to inhibit the stimulation of surrounding neurons
122
retinofugal pathway
- primary route for visual information to leave the eye, responsible for conscious vision
123
optic chiasm
- the point where the axons from both eyes come together
124
lateral geniculate nucleus
- nucleus where the axons of retinal ganglion cells
- specialized for processing visual input
125
primary visual cortex
- specialized for doing the initial processing of visual input
126
spiny stellate neurons
- dendrites are covered with spines to maximize the number of synapses they can make with inputs, short axons
127
pyramidal cells
- found on other layers, have one long dendrite and one long axon to send signals over longer distances
128
cortical magnification
- the fact that the number of neurons in the visual cortex responsible for processing an object of a given size in the visual field varies as a function of the location of the stimulus in the visual field
129
extrastriate cortex
- all the occipital lobe areas surrounding the primary visual cortex
130
dorsal extrastriate pathway
- higher-order visual regions process aspects of vision such as spatial orientation, depth perception, and the location, direction, and velocity of objects in space
131
direction-selective neurons
- cells that fire action potentials maximally when they detect movement in a particular direction
132
ventral extrastriate pathway
- information about color, shape, and form is sent from V1 to areas in the bottom/ventral part of the occipital and parietal cortex
133
middle ear
- where the eardrum’s movements change the pressure waves of air into physical movements
134
ossicles
- the bones that transmit the movement through the middle ear
- three types: malleus, incus, and stapes
135
eustachian tube
- connects the middle ear to the back of the throat, becomes narrow during illness
136
cochlea
- transduces sound, most of the structure is encased in bone
137
oval window
- the exposed flexible membrane on the outside of the cochlea
138
three fluid cavities within the cochlea
- scala vestibuli at the top
- scala tympani at the bottom
- scala media in the middle
139
basilar membrane
- separates the scala tympani and the scala media
140
organ of Corti
- translates the pressure wave through the fluid into an electrochemical signal
141
semicircular canals
- transducing the movement of the head, critical for balance and a major part of the vestibular system
142
interaural intensity differences
- If the sound comes from the left, then the left input will be louder than the right
143
interaural time differences
- If the sound originates from the left, the neural signal will reach the brainstem faster than the signal from the right
144
medial geniculate nucleus
- auditory portion of the thalamus
145
inferior colliculus
- where the ascending auditory pathways involving many nuclei converge
146
primary auditory cortex
- receives its input from the MGN to the fourth layer of the cortex
- output targets a wide variety of auditory cortical processing areas such as language and speech processing regions
147
taste buds
- smaller cells near and around the papillae
- each has receptors for one of the five basic tastes
148
papillae
- bumps found on our tongues
149
cranial nerves
- bundles of axons that connect the brain to the face and head since these regions of the body do not use the spinal cord to send signals
150
olfactory epithelium
- cluster of cells that line the top and back of the nasal cavity
151
smell receptor neurons
- have dendrites extending into the sensory epithelium with many hair-like cilia extending outward and covered with receptors for odorants
152
glomeruli
- small spherical structures where the olfactory receptor neurons terminate onto the next neuron in the pathway
153
population coding
- large numbers of broadly tuned neurons are used to identify and encode particular stimuli
154
somatosensation
- a sensory category that includes all sensations received from the skin and mucous membranes including pain, temperature, and touch
155
epidermis
- outermost layer of the skin in mammals, serves as a thick barrier for water and pathogens
156
dermis
- thicker layer under the epidermis that contains blood vessels, sweat glands, hair follicles, and other structures
157
subcutaneous layer
- a fatty layer that contains blood vessels, connective tissue, and axons of the sensory neurons
158
mechanoreceptors
- receptors that transduce information by being mechanically manipulative to forcibly open or close channels
159
pacinian corpuscles
- feature many layers of insulation at the tip, allow the receptor to adapt to a touch overtime
160
Meissner's corpuscles
- transduce information about low frequency vibrations or flutters
161
two-point discrimination
- measure of how close two nearby objects can be to one another before your skin cannot tell that they are truly two distinct points
162
dermatome
- skin that is innervated by one level or segment of the spinal cord
163
free nerve endings
- nerve endings with no any specialized receptors
164
nociception
- neural processing of injurious stimuli in response to tissue damage, receptors respond when stimuli are strong enough to damage tissue
165
hyperalgesia
- tissue that has been previously damaged will have a temporarily reduced threshold for pain
166
afferents
- axons that bring information to the brain or a particular region of interest
167
dorsal columns
- bands of white matter in which touch and proprioceptive information travels down the spinal cord
168
medial lemniscus
- pathway that winds through the brainstem to the thalamus
169
primary motor cortex
- work to plan voluntary sequences, coordinating sequences of movements, make decisions about proper movement strategies, and relay commands
170
motor homunculus
- map of the body in the cortex, represents the movements of individual body parts
171
motor planning
- mapping out which limbs and muscles to include in a given motor command to succeed in the behavioral goal
172
corticospinal tract
- runs from the cerebral cortex (primary motor cortex) to the spine
173
rubrospinal tract
- begins in the small region of the midbrain and it decussates at the midbrain
- responsible for the control of muscle tone
174
vestibulospinal tract
- provides information about direction of gravity, spin, and other forces on the body and head
175
tectospinal tract
- allows the organism to instinctually respond to sudden light or sound
176
reticulospinal tract
- extends the muscles to combat the force of gravity, keeps the organism upright
177
basal ganglia
- regulates motivation, or the willingness to initiate movement from a still state
178
direct pathway
- reduces inhibition on the thalamus
179
indirect pathway
- inhibition of the thalamus and reduction in the amount of motor signal allowed back up to the motor cortex
180
cerebellum
- plays a major role in the learning of motor tasks and skills
181
cerebellar deep nuclei
- provide an output for the structure
182
cerebellar cortex
- contains most of the neurons in the cerebellum
183
motor learning
- unconscious form of learning through repetition where the brain and body adapt to ongoing feedback about a motor command
184
Purkinje cell
- dendrites form a coral-like array of branches, almost completely 2D
185
synaptic plasticity
- change that occurs at synapses, underlie the brain’s capacity to learn, develop, store information, and grow
186
monocular deprivation
- a type of experiment where one eye was permanently closed for animals and the development of ocular dominance columns was observed
187
ocular dominance columns
- stripes of tissue across the layer 4C that get their input from one eye only
188
critical periods of development
- time period during which plasticity is uniquely high, development fate is dependent on the environment inputs from this time
189
memory
- information that is stored over time
190
habituation
- learning to ignore a stimulus that lacks meaning
191
sensitization
- strengthening of the behavioral response, opposite of habituation
192
long-term potentiation
- strengthening of synapse that is usually based on changes in the postsynaptic receptors
193
Schaffer's collateral
- crucial for the consolidation of short-term memory into long-term memory
194
fornix
- bring information from the hippocampus to a range of deep brain regions
195
short-term memory
- short-lived and requires conscious attention
196
long-term memory
- the result of encoding, storage, and retrieval of information
197
encoding
- act of learning or acquiring new information
198
storage
- ability of the brain to file away this new information even when you are not paying attention to it
199
explicit memory
- memory that can be consciously recalled
200
implicit memory
- unconscious and unrehearsed memory
201
electrical brain stimulations
- used to investigate the cerebral cortex in animals and in the occasional human subject
202
optogenics
- introduces foreign genes that express the code for ion channels that open or close in response to light
203
transcranial magnetic stimulation
- produces a magnetic field to modulate the excitability of a region in the cortex
204
extracellular recording
- electrode measures the membrane potentials form a population of cells from just outside those cells
205
theory of localization
- particular areas of the brain have particular unique jobs to do
206
electroencephalogram
- to measure the brain’s electrical activity using small metal discs called electrodes
207
magnetic resonance imaging
- medical imaging technique that uses a strong magnetic field to produce detailed images of the inside of the body
208
brain-computer interface
- system that allows a person to control a device or machine using only their thoughts
209
computational neuronal modeling
- use of computer algorithms or simulator programs to model the behavior or neurons to learn more about their processes
