Unit 01 Flashcards
(232 cards)
1
Q
Although it was a pseudoscience, phrenology helped establish the concept of
A
localization of function
2
Q
Neurons communicate with each other across tiny gaps called
A
synapses
3
Q
Which part of the neuron receives information from other neurons and converts chemical signals to electrical signals?
A
dendrites
4
Q
The presynaptic side of the synapse contains _____ filled with neurotransmitters.
The postsynaptic side of the synapse contains _______.
A
synaptic vesicles; receptors
5
Q
Myelin is produced by ________ in the central nervous system and by _______ in the peripheral nervous system
A
oligodendrocytes; Schwann cells
6
Q
(T/F) In the peripheral nervous system, sensory nerves transmit information from the central nervous system to the muscles and glands, and motor nerves transmit information from the body to the central nervous system
A
false
7
Q
The longitudinal fissure separates the two hemispheres. Which lobe does not border it?
A
temporal lobe
8
Q
Which layer of the meninges is the tough outermost layer?
A
dura matter
9
Q
What is behavioral neuroscience?
A
behavioral neuroscience = physiological psychology = biological psychology (biopsychology) = brain and behavior
10
Q
Definition of behavioral neuroscience
A
study of the biological bases of psychological processes and behavior
11
Q
Why study behavioral neuroscience?
A
- can provide general knowledge about the brain and behavior
- fundamental discoveries in biological psychology research may contribute to a greater understanding of brain disorders and the development of effective treatments
12
Q
List the stats for people with neurological/psychiatric illness
A
at least one person in five
13
Q
What did the ancient egyptians, indians, chinese, and greeks thought was the center of thoughts and emotions?
A
the heart
14
Q
During Greece 300s BCE, who wrote about the brain controlling thoughts, emotions, and intelligence?
A
Hippocrates
15
Q
During Greece 300s BCE, who believed the heart was the root of consciousness?
A
Aristotle
16
Q
What did Aristotle think the function of the brain was?
A
a cooling system for the blood
17
Q
During Greece 100s CE, who treated brain-injured gladiators?
A
Galen
18
Q
What did Galen propose after treating brain-injured gladiators?
A
behavior results from connections between the brain and the body
19
Q
What happened during the scientific revolution?
A
major developments in math and science starting towards the end of the renaissance, where the scientific method was established
20
Q
Which renaissance artist/scientist pioneered anatomical drawings by relying on direct observation?
A
Leonardo de Vinci
21
Q
Which renaissance artist/scientist pioneered anatomical drawings by relying on direct observation?
A
Leonardo de Vinci
22
Q
What did Rene Descartes propose?
A
concept of spinal reflexes and their neural pathways; explained control of behavior in terms of the nervous system acting as a machine
23
Q
What is dualism?
A
concept that humans have a nonmaterial soul and material body; soul governs behavior through a point of contact (i.e. pineal gland)
24
Q
What is phrenology?
A
belief that bumps on the skull result from enlargements of brain regions responsible for certain behavioral faculties
25
What is localization of function?
concept that different brain regions specialize in specific behaviors
26
What did Broca note that damage to a particular region on the left side of the brain can do?
impairs speech production (broca's aphasia)
27
Who invented cell staining technique?
Golgi
28
Who made detailed drawings of many types of nerve cells using Golgi staining?
Ramon y Cajal
29
What did Hebb describe about neuronal connections in relation to experience?
neural connections strengthen as a consequence of experience
30
What are Hebbian synapses?
plastic neuronal connections; they change in strength through use
31
What is the basic unit of the nervous system?
neurons (nerve cells)
32
What is a neuron composed of?
dendrites (receptive extensions), soma (cell body), axon, and axon terminal
33
List the steps for cell communication
1) Input: dendrites receive information from other neurons
2) Integration: cell body integrates (decides to produce a neural signal) the information
3) Conduction: a single axon conducts information away from the cell body as an electrical signal
4) Output: axon terminals at the end of the axon communicate activity to other cells
34
What part of the neuron receives chemical signals from other neurons and then converts them to an electrical signal?
dendrites
35
What does the soma do?
- integrates/combines information that has been received at dendrites
- sums together the electrical signals
36
What is the function of the axon?
carries the electric signal (action potential) away from the cell body and to the terminals
37
Where is the action potential generated?
axon hillock
38
What is the function of the axon terminals?
makes synaptic contact with other cell's dendrites
39
Are information signals BETWEEN neurons chemical or electrical?
chemical
40
Are information signals WITHIN a neuron chemical or electrical?
electrical
41
Describe a multipolar neuron
one axon, many dendrites
42
Describe a bipolar neuron
one axon, one dendrite
43
Describe a unipolar neuron
one extension branching in two directions
44
What is a synapse/synaptic cleft?
junction between two neurons
45
What is the presynaptic membrane?
axon terminal of the presynaptic neuron; releases neurotransmitters
46
What is the postsynaptic membrane?
dendrite or cell body of the postsynaptic neuron; receives neurotransmitters
47
What happens at the presynaptic side of the synapse?
axon terminal contains synaptic vesicles that contain neurotransmitter; neurotransmitter is released by an action potential
48
What happens at the postsynaptic side of the synapse?
receptors respond to the neurotransmitters
49
What are the four classes of glia?
- oligodenrocytes
- schwann cells
- astrocytes
- microglia
50
Which two types of glia cells wrap around axons to provide a fatty insulation layer (myelin) and where are they located?
- oligodendrocytes (in the central nervous system)
- schwann cells ( in the peripheral nervous system)
51
What is the function of astrocytes?
stretches around neurons, synapses, and sometimes blood vesicles = secrete chemicals
52
WHat is the function of microglia?
removes debris from injury
53
What is the central nervous system (CNS)?
brain and spinal cord
54
What is the peripheral nervous system (PNS)?
all other parts of the nervous system aside from the brain and spinal cord
55
What does the PNS consist of?
- motor nerves: transmits info from CNS to muscles + glands
- sensory nerves: convey info from body to the CNS
56
What are the two distinct systems of the PNS?
- somatic nervous system (SNS): nerves that interconnect the brain and the major muscles and sensory systems of the body
- autonomic nervous system (ANS): nerves that connect to the internal organs
57
What does the SNS includes?
- cranial nerves (12 pairs): connects brain = head, neck, visceral organs
- spinal nerves (31 pairs): connects spinal cord = muscles, organs
58
What components do cranial nerves have?
motor and sensory
59
What components do spinal nerves have?
- motor fibers project from the spinal cord
- sensory fibers enter the spinal cord
60
What are the two divisions of the ANS?
- symapthetic nervous system: prepares the body for action = fight-or-flight
- parasympathetic nervous system: helps the body relax = rest-and-digest
61
Describe horizontal plane of dissection
divides the body/brain into upper and lower
62
Describe sagittal plane of dissection
divides body/brain into right or left hemisphere
63
Describe coronal plane of dissection
divides body/brain into front and back
64
Describe medial/lateral
toward middle/toward side
65
Describe ipsilateral/contralateral
same/opposite side
66
Describe proximal/distal
near/far
67
Describe superior/inferior
up/down
68
Describe anterior/posterior
front/back
69
Describe rostral/caudal
beak/tail
70
Describe dorsal/ventral
back/belly
71
What is the outermost, convoluted layer of the brain?
cerebral cortex
72
Describe the cortex's gyri
ridged or raised portions
73
Describe the cortex's sulci
furrows
74
List and describe the four lobes of each cerebral hemisphere
1) frontal lobe: attention, planning, motor (most anterior)
2) parietal lobe: touch, other (b/w frontal and occipital lobe)
3) occipital lobe: visual processing (posterior)
4) temporal lobe: auditory processing, memory (lateral)
75
Describe longitudinal fissure
separates left/right hemispheres
76
Describe sylvian fissure
boundary of temporal lobe
77
Describe central sulcus
divides frontal/parietal lobes
78
Describe precentral gyrus
located in the frontal lobe; important for motor control
79
Describe postcentral gyrus
located in the parietal lobe; important for touch
80
Describe gray matter
- mostly cell bodies and dendrites that lack myelin
-nuclei
81
Describe white matter
- mostly axons with white myelin sheaths (fatty)
- tracts (bundles of axons)
82
What is a bundle of axons that connects the two cerebral hemispheres?
corpus callosum
83
What three subdivisions does the neural tube develop into?
- forebrain
- midbrain
- hindbrain
84
What does the forebrain develop into?
- telencephalon
- diencephalon
85
What does the midbrain develop into?
midbrain
86
What does the hindbrain develop into?
cerebellum, pons, and medulla
87
What is the function of the cerebral cortex?
sensory, motor, associative, cognitive
88
What is the function of the basal ganglia?
control of movement and actions
89
What is the limbic system important for? Name its parts
important for emotion and learning
- hippocampus and fornix
- amygdala
- cingulate gyrus
- olfactory bulb
90
What is the function of hippocampus and fornix?
learning
91
What is the function of the amygdala?
emotional regulation; perception or odor
92
What is the function of the cingulate gyrus?
attention
93
What is the function of the olfactory bulb?
sense of smell
94
What is the function of the thalamus?
relays almost all sensory information to the cortex
95
What is the function of the hypothalamus?
motivated behavior, homeostasis, regulating autonomic nervous system + controls pituitary gland
96
What are the two parts of the tectum in the midbrain and their functions?
- superior colliculi: visual processing
- inferior colliculi: auditory processing
97
Name the part of the tegmentum in the midbrain and describe its function
- substantia nigra: source of dopamine to basal ganglia
98
What are "other" midbrain systems? What are their functions?
- reticular formation: involved with sleep and arousal
- periaqueductal gray: pain perception
99
What is the pons in the hindbrain?
sensory and motor nuclei
100
What is the function of the medulla in the hindbrain?
- essential processes such as respiration and heart rate
101
Where is the medulla located in the brain?
At the transition from brain to spinal cord
102
What is the function of the cerebellum?
motor coordination/control
103
What are meninges?
protective membranes that surround the brain and spinal cord
104
List and describe the three layers of the meninges
1) dura mater: tough
2) arachnoid membrane: lies b/w pia and dura; filled with cerebrospinal fluid (CSF)
3) pia mater: delicate innermost layer
105
What membrane in the lateral ventricle produces CSF?
choroid plexus
106
Which system consists of a series of chambers filled with CSF?
ventricular system
107
Describes the directional flow of CSF
from the lateral ventricles into the third ventricle at the midline = into the fourth ventricle = then exists to circulate over the brain and spinal cord
108
What is the function of CSF?
provides buoyancy, protection, exchange of nutrients/waste b/w blood and brain
109
Besides CSF, what else does the brain depend on?
oxygenated blood from the cerebral arteries
110
What are strokes caused by?
rupture or blockage of blood vessels = causes insufficient oxygen supply
111
What is the function of the blood-brain barrier (BBB)?
filters blood before it enters brain tissue; it is selectively permeable
112
Why is the BBB selectively permeable?
keep the brain environment as stable as possible + keep bacteria/viruses out
113
Define computerized axial tomography (CAT/CT)
map of the brain based on tissue density and X-ray absorption; best for strokes, tumors
114
Define magnetic resonance imaging (MRI)
uses magnetic fields and radio waves to map tissue density; best for high resolution images
115
Define diffusion tensor imagine
variant of MRI, can visualize axon fiber tracts
116
Define functional MRI (fMRI)
detects small changes in brain metabolism in active brain areas; can show how networks of brain structures collaborate
117
Define position emission tomography (PET)
gives images of brain activity using radioactive chemicals in the bloodstream; identifies wich brain regions contribute to specific functions
118
What can magnetism be used for?
study brain activity
119
Describe transcranial magnetic stimulation (TMS)
briefly stimulate discrete cortical regions; scientists can record observed changes in behavior
120
Describe magnetoencephalography (MEG)
measures the tiny magnetic fields given off by active neurons during cognitive processing
121
What happens at dendrites (input zone)?
neurotransmitter binding causes local changes in electrical activity (post synaptic potentials)
122
What happens when the change in electrical activity enough to reach the soma (integration zone)?
an action potential is generated down the axon (condition zone)
123
How would you describe the electrical signal of an action potential?
all-or-nothing
124
How would you describe a resting neuron?
polarized = difference in electrical charge when comparing inside vs. outside of the cell
125
Is the inside of a resting neuron negative or positive?
negative
126
How many mV is the resting potential?
-50 to -80
127
How do ions pass through the cell membrane?
via ion channels
128
Which ion channels are gated?
sodium channels open and close in response to signals
129
Which ion channels stay open all the time?
potassium channels allow for K+ to enter and leave freely
130
Describe chemical pressure (diffusion)
causes ions to spread out in a uniform manner (concentration gradient)
131
Describe electrostatic pressure
causes ions to flow towards oppositely charged areas (electrical gradient)
132
Describe the function of the sodium potassium pump
pushes Na+ ions out; pulls K+ ions in
133
What does the sodium-potassium pump cause?
causes K+ ions to accumulate inside the cell + Na+ ions outside the cell
134
What kind of pressure drives K+ ions out?
chemical
135
What kind of pressure pulls k+ ions in?
electrical
136
What is the equilibrium potential?
electrical charge that balances the two opposing forces: concentration gradient and electrostatic pressure
137
What is the resting potential of a neuron and what is it based on?
- around -65 mV
- based on equilibrium potential for K+ created by Na+/K+ pumps and K+ ion channels
138
Describe hyperpolarization
interior of the cell becomes more negative
139
Describe depolarization
interior of the cell becomes less negative
140
Describe a graded response
greater the stimulus, greater the response
141
Describe a local potential
in dendrites and soma, the signal diminishes as it spreads further away
142
What happens when the stimulus depolarizes the membrane to the threshold (about -40 mV)?
triggers a brief action potential/spike
143
What happens during an action potential?
membrane potential reverses, and the inside of the cell becomes more positive
144
Where do action potentials originate?
in the initial segment of the axon, just after axon hillock
145
What is the relation of the amplitude to the action potential?
independent of stimulus size; increased stimulus strength = more action potentials
146
What is the action potential caused by?
a sudden rush of Na+ ions into the axon
147
At its peak, where does the action potential approach?
equilibrium potential for Na+
148
What triggers voltage-gated Na+ channels to open?
sufficient depolarization (threshold); for Na+ ions there are strong ionic forces to drive it into the cell
149
What pressure(s) drives for Na+ ions to enter?
chemical and electrostatic pressure
150
After the Na+ ions enter, what mV does the membrane potential reach?
+40 mV (Na+ equilibrium potential)
151
What happens as the inside of the cell becomes more positive?
voltage-gated K+ channels open; K+ rushes out and the resting potential is restored
152
Describe absolute refractory phase
no action potentials can be produced; due to the voltage-gated Na+ channels being inactivated
153
Describe relative refractory phase
only very strong stimulation can produce an action potential; due to voltage-gated K+ channels still being open, which causes hyperpolarization (afterpotential or afterhyperpolarization)
154
How many directions can an action potential travel?
only one
155
Why can an action potential only travel in one direction?
due to the absolute refractory state of the membrane after depolarization (when voltage gated Na+ channels are inactivated)
156
What causes conduction velocity to vary?
- axon diameter; larger diameter = faster speed
- myelination; enhances speed and conduction
157
What are nodes of ranvier?
small gaps in the myelin; voltage-gated Na+ channels are located at the nodes
158
What is saltatory conduction?
term used to describe the action potential traveling down the axon and jumping from node to node
159
What happens once an action potential reaches the axon terminals?
causes the release of neurotransmitter into the synapse
160
Describe the direction neurotransmitters as they move across the synapse
FROM: the axon terminal of the presynaptic neuron
TO: receptors on the dendrites/soma of the postsynaptic neuron
161
What causes local postsynaptic potentials or brief changes in the membrane potential?
neurotransmitters binding to the receptors
162
Is excitatory depolarization or hyperpolarization?
depolarization
163
Is inhibitory depolarization or hyperpolarization?
hyperpolarization
164
What is excitatory postsynaptic potential (ESPS)?
small depolarizing local 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
165
What channels are open in EPSPs?
sodium (Na+) ion channels; letting positive ions into the cell
166
What is inhibitory postsynaptic potential (IPSP)?
small hyperpolarizing local potential in the postsynaptic membrane that pushes the cell further away from the threshold, decreasing the likelihood of the neuron firing an action potential
167
What channels are open in IPSPs?
chloride (Cl-) ion channels open; making inside more negative
168
What is spatial summation?
summing of all the potentials that reach the axon hillock from locations across the soma and dendrites
169
What happens if the overall depolarization reaches/exceeds the membrane threshold?
action potential is produced
170
T/F: the closer together in time the potentials arrive, the greater their impact and likelihood of producing an action potential
true
171
What happens at the presynaptic side of synapse?
axon terminal contains synaptic vesicles that contain neurotransmitter
172
What happens at the postsynaptic side of synaose?
receptors respond to the neurotransmitters
173
List the sequence of transmission
1) action potential arrives at the presynaptic axon terminal
2) voltage-gated calcium (Ca2+) channels open in the terminal and calcium ions enter
3) calcium ions cause synaptic vesicles filled with neurotransmitter to fuse with the presynaptic membrane, releasing neurotransmitter into the synaptic cleft
4) transmitters bind to postsynaptic receptors, causing ion channels to open and leading to an EPSP or IPSP
5) EPSPs or IPSPs spread toward the postsynaptic axon hillock; if threshold is reached, an action potential will occur
6) synaptic transmission is rapidly stopped via reuptake or degradation
7) transmitter may also activate presynaptic receptors (autoreceptors) that decrease transmitter release (negative feedback)
174
List and describe the two ways neurotransmitter actions are rapidly halted
- degredation: the rapid breakdown and inactivation by an enzyme
- reuptake: when transmitter is cleared/recycled from the synapse by transporters (special proteins) in presynaptic terminal or nearby glia
175
What are ligands?
molecules that fit into receptors and activate/block them
176
T/F: ligands includes neurotransmitters and drugs
true
177
What determines the action of the transmitter?
receptor (excitatory or inhibitory)
178
How are ACh and nicotine agonists?
they activate the receptor = causes channels to open
179
How are curare and bungarotoxin antagonists?
they block the receptor
180
Describe axo-dendritic synapse
axon terminal synapses on a dendrite
181
Describe axo-somatic synapse
synapse between axon and cell body
182
Describe axo-axonic synapse
synapse between two axons
183
Describe dendro-dendritic synapse
synapse between two dendrites (not common)
184
What is an electroencephalogram (EEG)?
recording of spontaneous brain potentials
185
What is an event-related potentials (ERPs)?
EEG responses to a single stimulus
186
Is brain activity desynchronized or synchronized during brain activity?
desynchronized
187
What is a seizure?
a wave of abnormally synchronous electrical activity in the brain
188
What are the three cell layers that a human embryo develops?
- endoderm (inner layer): becomes internal organs, gut lining
- mesoderm: becomes muscles, bones, circulatory system
- ectoderm (outer layer): becomes nervous system, epidermis (skin)
189
What happens during embryonic development?
a groove forms at the midline = the crests of the neural groove join, forming the neural tube, the beginning of the central nervous system
190
What are the three subdivisions of the anterior part of the neural tube?
- forebrain (cortical regions, thalamus, hypothalamus)
- midbrain
- hindbrain (cerebellum, pons, medulla)
191
What part becomes the ventricles of the brain and the central canal of the spinal cord?
interior of neural tube
192
T/F: There is NOT dramatic brain growth during fetal development (cortex gyri/sulci in humans) and after birth also
false
193
List the stages of brain development
1) neurogenesis: the birth of new neurons
2) cell migration: cells move toward their destination
3) cell differentiation: cells change into distinctive types of neurons or glia
4) synaptogenesis: establishment of synaptic connections
5) neuronal cell death: selective death of many neurons
6) synapse rearrangement: pruning and fine-tuning of synapses
194
The sodium-potassium pump ________ and _________.
pushes Na+ ions out, pulls K+ ions in
195
In a resting neuron, chemical pressure ____ ____ K+ ions, whereas electrostatic pressure _____ ______ K+ ions.
drives out; pulls in
196
Na+/K+ pumps and open K+ ion channels are associated with
the resting membrane potential
197
Who drives Na+ to enter the neuron when Na+ ion channels open?
chemical and electrostatic pressure
198
Action potentials begin in the
initial segment of the axon
199
IPSPs are
inhibitory
200
The opening of voltage-gated K+ ion channels are associated with
the falling phase of the action potential
201
T/F: Synaptic transmission is rapidly stopped via reuptake or degradation of neurotransmitter
true
202
Which of the following is an example of neurotransmitter degradation?
A) curare is an antagonist at acetylcholine receptors
B) dopamine is cleared from the synapse by the dopamine transporter (DAT)
C) acetylcholine is inactivated by the enzyme acetylcholinesterase (AChE)
D) nicotine is an agonist at the acetylcholine receptors
C
203
________ are molecules that fit into receptors and activate or block them
ligands
204
T/F: neurogenesis can occur in adults, especially in the dentate gyrus of the hippocampus
true
205
Cell differentiation is the process of
stem cells becoming distinctive types of neurons or glia
206
What is released by target cells that encourage the survival of cells and synapses?
neurotrophic factors
207
What do neurons compete for at target structures?
synaptic connections
208
What is synapse rearrangement?
loss or development of synapses
209
T/F: Synapse rearrangement continues throughout adulthood
true
210
What results in postnatal brain growth?
growth in the size of neurons and branching, increased myelin, and new glia
211
T/F: In the human cortex, there is NO net loss of synapses from late childhood until mid-adolescence
false
212
Describe the direction of the thinning process
continues from caudal to rostral throughout maturation, reaching the prefrontal cortex last
213
What is the period during development, when visual experience is crucial for proper development?
sensitive period
214
What happens if there is binocular deprivation during development?
reduced synapses in visual cortex
215
T/F: After deprivation for several weeks during sensitive period, eyesight CAN be recovered
false
216
What happens if there is monocular deprivation?
ocular dominance is disrupted = cortical neurons respond to only one eye, not both
217
Describe Hebbian synapses
218
What is genotype?
sum of an individual's intrinsic, genetic information; constant
219
What is phenotype?
physical characteristics and traits; changes constantly based on extrinsic effects on genes
220
Define epigenetics
study of the factors that change gene expression without changing the gene sequence
221
What was the result of poor maternal care in the brain during the animal experiment?
induces methylation of the glucocorticoid receptor gene
222
What happens as a result of induced methylation on rodent pups?
become hyperresponsive to stress
223
Since memory impairments are observed with aging, what does it correlate to in terms of the hippocampus?
severity of memory loss correlates with hippocampal shrinkage
224
Describe the process of Alzheimer's disease as it is a form of dementia
- begins with memory loss of recent events
- eventually, memory impairment is so extensive that conversation is impossible
- cortex shows atrophy and reduced metabolism
225
List the cellular changes in Alzheimer's
- amyloid plaques = formed by clumps of beta-amyloids in extracellular space
- neurofibrillary tangles = formed from filaments inside neurons
- loss of acetylcholine neurons in the basal forebrain
226
The electrical charge that balances the opposing forces of concentration gradient and electrostatic pressure is called
equilibrium potential
227
The opening of voltage-gated Na+ ion channels is associated with
the rising phase of the action potential
228
Postsynaptic potentials take place in the _________; action potentials take place in the __________
dendrites/soma; axon
229
T/F: The amplitude (size) of an action potential can change
false
230
When the inside of a neuron becomes even more negative, this is known as
hyperpolarization
231
On the postsynaptic side of the synapse, _______ respond to neurotransmitter
receptors
232
Which of the following developmental processes still continues on a large scale after birth in humans?
synaptic rearrangement
