Chapter 3: Neuroscience Flashcards
________ is associated with Parkinson’s disease, whereas ________ is associated with certain forms of schizophrenia.
A) Too little dopamine; too much dopamine
B) Too much dopamine; too little dopamine
C) Too little dopamine; too much serotonin
D) Too much serotonin; too much dopamine
Answer: A) Too little dopamine; too much dopamine
A main function of the medulla is to
A) regulate the functioning of the pons.
B) control sleep and dreaming.
C) coordinate fine motor movement in the fingers and face.
D) control automatic functions such as respiration and heart rate.
Answer: D) Control automatic functions such as respiration and heart rate.
Messages from the eyes are relayed to the visual cortex through the ________ of the ________.
A) medial geniculate nucleus; hypothalamus
B) lateral geniculate nucleus; thalamus
C) lateral geniculate nucleus; striatum
D) medial geniculate nucleus; thalamus
Answer: B) lateral geniculate nucleus; thalamus
Which of the following reflects the correct order for the structure of a neuron?
A) cell body — dendrite — terminal button — axon
B) terminal button — dendrite — cell body — axon
C) axon — cell body — terminal button — dendrite
D) dendrite — cell body — axon — terminal button
Answer: D) dendrite- cell body- axon- terminal button
________ is to into the brain as ________ is to away from the brain.
A) Sensory; autonomic
B) Autonomic; sensory
C) Afferent; efferent
D) Efferent; afferent
Answer: C) Afferent; efferent
The gap between two neurons where neurotransmission takes place is called the
A) terminal gap.
B) neurochemical gap.
C) synapse.
D) terminal cleft.
Answer: C) synapse
The frontal, parietal, temporal, and occipital lobes make up the
A) subcortical area of the brain.
B) association areas of the brain.
C) reticular formation.
D) cerebral cortex.
Answer: D) cerebral cortex
An action potential is generated
A) in the cell body.
B) in the axon.
C) at the point where the axon leaves the cell body.
D) in the dendrites.
Answer: C) at the point where the axon leaves the cell body.
This structure, which is part of the hindbrain, is involved in respiration, movement, waking, sleep, and dreaming.
Incorrect Response
A) reticular formation
B) medulla
C) cerebellum
D) pons
Answer: D) pons
The Nodes of Ranvier are
A) regularly spaced gaps of unmyelinated portions of an axon.
B) fluid-filled sacs containing neurotransmitters.
C) areas of an axon that are wrapped in myelin.
D) networks of neurons working in unison to produce patterns of neural activity.
Answer: A) Regularly spaced gaps of unmyelinated portions of an axon
Two pathways for incoming sensory information:
- Receptors in skin feel touch-> Afferent sensory neurons ->Dorsal
root -> Spinal cord (Dorsal horn)-> sensory nerves->Brain-
>Motor neurons->Ventral horn-> Effector motor neuron->
Muscles of arm to remove spider (shakes arm to remove
spider) - Receptors in skin feel touch-> Afferent sensory neurons ->Dorsal
root of Spinal cord-> Interneurons->Ventral horn -> Effector
motor neurons-> Muscles (Reflex arc pathway) Reflex shaking
arm to remove spider from arm
Central Nervous System:
Brain understands the information
given to it by the PNS. CNS also consists of the Spinal cord.
Peripheral Nervous System:
Sends information from body’s
sensory receptors to CNS; Brain understands information-> PNS relays
information out to body parts.
Somatic Nervous System:
–involved in voluntary movement;
sensory neurons carry impulses to spinal cord then to brain and
back for movement; or to spinal cord then movement.
E.g., You feel the touch of a spider on your arm, signal sent to
brain, you see the spider, then make motor movement to
remove spider.
Autonomic Nervous System (ANS):
neurons that control the heart,
intestines, and other organs.
E.g., Your heart rate increases because of the spider on your arm
The spinal cord:
The spinal cord carries information from various parts of the body to and from the brain.
Spinal cord controls simple reflexes, but is very important for carrying sensory information up to the
brain and motor information back out to the body.
e.g., Individual in severe car accident, suffers
injury to spinal cord. As a result, can’t move legs.
Has to undergo rehabilitation.
Quadriplegic:
A person paralyzed everywhere but the head and neck, likely due to breaking neck and damaging spinal
cord close to brain, losing touch and pain sensation everywhere but their heads and faces.
Paraplegic:
Damage to spinal cord farther down the back, retain sensation and usage of the upper limbs and torso.
The brain:
The brain plays a central role in the control of most
bodily and cognitive functions, including awareness,
movements, sensations, thoughts, speech, and
memory.
Frontal:
Reasoning, Memory &
Planning
Parietal:
Touch, Pain, &
Attention
Temporal:
Language, Memory, &
Auditory processing
Occipital:
Visual processing
The Nervous System: On Being Wired
The nervous system:
- is a system of nerves that control thought processes,
heartbeat, visual–motor coordination, and many
other abilities - contains the brain, spinal cord, and other parts,
enabling us - to receive information from the world outside, and
- to act on that world
Neurons: A complex living network:
Neurons:
* are specialized cells of the nervous system
* receive and transmit electrochemical signals to and from neighbouring neurons
* signal by “firing”
Function of the Neuron:
- Neuron: Receives, assimilates, analyzes and transmits information via action
potentials. Many types of neurons: Sensory, motor and interneurons found in central
nervous system (CNS) and peripheral nervous system (PNS). - A neuron is composed of three main parts:
- A cell body: Cellular machinery for production of proteins and cellular
macromolecules - Dendrites: Receive information from neighboring neurons, spines on dendrites. Many
dendrites also have spines, little knobs where dendrites receive inputs from the
neurons. - Axon: Information flows from the dendrites through the cell body to the axon.
Transmission through synapses - Axon collaterals: Can transmit signals to more than one cell.
- Myelin: Fatty substance that wraps axons, essential for accelerating signal
transmission.
Glia- Astrocytes or Astroglia
- Wrap around the synapses of functionally related axons.
-By surrounding connection between neurons, astrocyte shields axons
from chemicals circulating in surround. Astroglia are important for
creating blood-brain barrier
-By taking up ions and neurotransmitters released by axons and releasing
them back, astroctyes helps synchronize closely related neurons, enabling
their axons to send messages in waves.
-Responsible for dilating blood vessels to bring more nutrients into brain
areas with heightened activity.
Glia- Microglia
Remove waste material, viruses, and fungi from the brain
Also remove dead, dying, or damaged neurons
Proliferate or increase in number after brain damage, removing dead
or damaged neurons.
Glia- Oligodendrocytes and Schwann cells
- Oligodendrocytes (in central nervous system- brain and spinal cord)
and 4. Schwann cells (in the periphery of the body)
Build the myelin sheath that surrounds and insulates certain
vertebrate axons
Glia- Radial glia
-Guide the migration of neurons and the growth of their
axons and dendrites during embryonic development.
-When embryonic development finishes, most radial
glia differentiate into neurons and a smaller number
differentiate into astrocytes and oligodendrocytes
The Neural Impulse: “The Body Electric”
Neural impulses are:
- electrochemical messages that travel within neurons
- In myelinated neurons, this impulse can travel at a
speed of up to 360 km/hr.
Three key terms to understand the generation of the
neural impulse: - Resting Potential, Depolarization, Action Potential
How is resting potential maintained in a neuron and how does it changes?
Electrostatic gradient or Electrostatic pressure: The force that drives ions
that are of a similar charge away from one another or attracts two ions of
opposite charges toward each other.
E.g., Sodium is positively charged, inside of neuron is more negatively
charged.
Concentration gradient: the difference in concentration of ions inside and
outside of a neuron.
E.g., Sodium is more concentrated outside, than inside.
How is action potential (i.e., Neutral impulse) generated?
- When the neuron is at rest, (Sodium) Na + ions and (Chloride) Cl- ions are
higher in concentration outside of the cell than inside, and K+ ions and anions
(A-) are higher in concentration inside than outside the cell. When the neuron
is at rest, it’s more negative inside than outside cell. - The entry of Na+ ions into the cell causes the inside of cell to be less negative
than outside, resulting in depolarization associated with generation of the
action potential. After which, there is repolarization (Sodium channels are
closed, potassium ions going to outside of cell), a refractory period (i.e.,
Hyperpolarization due to lots of potassium ions going to the outside of the
cell) where neuron does not fire action potential and finally neuron is back at
resting state due to action of sodium-potassium pump.
The Neural Impulse: “The Body Electric”
An Electrochemical Voyage
* Neural impulses travel by electrical and chemical processes.
- Polarization is the difference in electrical charge that readies a neuron for
firing. - An internal negative charge is created in relation to the body fluid outside the cell
membrane.
How is signal transmitted across neuron or neurons? Depolarization leads to an action potential
- The action potential is a large amount of electrical activity that is created by
a depolarizing current. - This means that some event (a stimulus) causes the resting potential to
move toward 0 mV. That is, there is an entry of Sodium ions into the cell. - When the depolarization reaches about -40mV to -55 mV a neuron will fire
an action potential.
The Neural Impulse: “The Body Electric” An Electrochemical Voyage
Resting potential is a neuron’s electrical potential when it is not responding to
other neurons. Usually at -70mV.
The Neural Impulse: “The Body Electric” Depolarization
Depolarization occurs when an area on the surface of the resting neuron is
chemically stimulated by other neurons. Threshold is between -40 mV to
-55mV.
The Neural Impulse: “The Body Electric” Action potential
Action potential is the electrical potential when a neural impulse is being
conducted along a neuron’s axon. It is generated when a stimulus changes the
membrane potential to values of threshold potential, around -40 to -55 mV.
Firing: How Messages Voyage from Neuron to Neuron
- Firing is the conduction of a neural impulse along the length of a neuron.
- Works on the all-or-none principle
- The neural impulse is always of the same strength whenever action potential is triggered.
- Refractory period follows, is a recovery period during which the neuron does not
fire.
Excitatory Postsynaptic Potentials (EPSPs)
depolarize the
neuron and increase the likelihood of an action potential.
Inhibitory Postsynaptic Potentials (IPSPs)
hyperpolarize
the neuron and decrease the likelihood of an action
potential.
Neurotransmitters and their functions- Glutamate:
Neurotransmitter: Glutamate-> Function: Learning and movement-> Associated Drugs-> Ketamine
Neurotransmitters and their functions: GABA
Neurotransmitter: GABA-> Function: Learning and anxiety regulation-> Associated drugs-> Valium (diazepam, used to relieve anxiety, muscle spasms); Ambien (Zolpidem, used to treat insomnia)
Neurotransmitters and their function: Acetylcholine (ACh)
Neurotransmitter: Acetylcholine->Function: Learning and attention-> Associated drugs: Nicotine
Neurotransmitter and their function: Dopamine
Neurotransmitter: Dopamine-> Function: Movement and reward learning-> Associated drugs: Cocaine, heroin, and methamphetamine
Neurotransmitter Function: Serotonin
Neurotransmitter: Serotonin-> Function: Mood regulation-> Associated Drugs: Ecstasy (MDMA); LSD (hallucinogen); monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs; antidepressants)
Neurotransmitter Function: Norepinephrine
Neurotransmitter: Norepinephrine-> Function: Attention and arousal-> Associated Drugs: Adderall (a stimulant made up of dextroamphetamine and amphetamine)
Neural network:
Neurons form circuits or networks that
expand the communication among different brain
regions. This image shows axons and dendrites (red)
extending from the neuronal cell bodies (shown in blue
Structures of the brain: The Hindbrain (part of the brain closest to the spinal cord):
Medulla, pons, cerebellum, reticular formation
Structures of the Brain: The Midbrain (sits above the pons)
Substantia Nigra
Structures of the Brain: The Forebrain:
-Thalamus, Hypothalamus, Pituitary Gland, basal Ganglia
- Limbic system (comprises the Hippocampus, Amygdala, Hypothalamus, parts of Thalamus)
Medulla’s function:
Medulla - regulates heartbeat, breathing, sneezing,
and coughing
- Damage to medulla due to stroke or trauma is fatal
(i.e., can cause death). - High levels of alcohol suppresses (i.e., blocks)
medulla activity and causes respiratory failures.
Pons function:
and cerebellum.
* Important for waking, sleep, breathing, eye
movements, and facial sensation and
expression.
* Contains the locus coeruleus (LC), neurons
of LC project throughout brain and spinal
cord.
* LC neurons use neurotransmitter
norepinephrine and are important for
arousal and attention.
Reticular formation:
- Reticular formation - regulates sleep/wake cycle
(i.e., plays a role in wakefulness and level of
arousal). - Many general anesthetics work by reducing
activity in the reticular formation and rendering
the patient unconscious. - Neurons of RF are primary brain source of
neurotransmitter serotonin.
Cerebellum:
Cerebellum - important for motor coordination and certain
types of learning that involve movement, such as learning to
tie shoelaces or to play the piano.
e.g., Field sobriety test- is set of 3 tests that include horizontal
gaze nystagmus (HGN), the walk-and-turn and the one-leg
stand tests.
-For one of the tests, to see if you are impaired; you would be
asked to walk heel to toe along a line or close your eyes and
touch your nose with your finger.
-When you are drunk, there is an impairment in the ability of
your cerebellum to produce smooth motor movements.
The Midbrain:
- Substantia Nigra (part of the Basal ganglia) – the nucleus from which dopamine neurons send
their axons to the striatum (Forebrain). - Involved in movement control (eye movements and fluid body movements) such as those
needed to hit a tennis ball or to skate gracefully and is important for coordination. - Damage of dopamine neurons in substantia nigra is associated with Parkinson’s Disease.
The Forebrain:
- The largest subdivision of the human brain, which controls complex
cognitive, emotional, sensory and motor functions.
The forebrain is the forward-most part of the brain; its
structures are:
* Thalamus
* Hypothalamus
* Pituitary gland
* Limbic system (comprises hippocampus, amygdala,
hypothalamus, parts of the thalamus)
* Basal Ganglia
Parts of the Forebrain: Thalamus
Thalamus - serves as a relay station
for incoming sensory information
Lateral Geniculate nucleus (LGN): relays
visual information to the visual area of the
cortex
Medial Geniculate nucleus (MGN): relates
auditory information to the auditory area
of the cortex
Parts of the Forebrain: Hypothalamus:
- Hypothalamus - important for
motivation, basic drives, and control
of the endocrine system - Important for motivated behaviors
necessary to survival, including eating,
drinking, sex, and maternal behavior. - Also critical for control of the endocrine,
or hormonal system.
Parts of the Forebrain: Pituitary Gland
- small structure located under the hypothalamus
- Works with hypothalamus to control a class of
chemical messengers in the body-hormones that
are important for growth, reproduction,
metabolism and stress reactions. - Produces releasing factors that control endocrine
glands, such as ovaries, testes, the thyroid and the
adrenal glands.
Parts of the Forebrain: The Limbic System
The Limbic System - involved in the regulation of
motivation, emotion, and learning and memory
- Comprises the hippocampus, amygdala, the
hypothalamus, parts of the thalamus, and
several other areas.
Parts of the Forebrain: The Basal Ganglia
The Basal Ganglia includes a group of nuclei (nuclei refers to a cluster of neurons in the CNS)
that work as a cohesive functional unit and include caudate nucleus and putamen (which
together form the striatum) as well as globus pallidus, substantia nigra, and nucleus
accumbens.
* As a group, basal ganglia play a role in aspects of cognition, and in regulating and
coordinating voluntary movement by exerting inhibitory effect on various motor systems.
* Nucleus accumbens - important for motivation, reward, and addiction. Dopamine release
in nucleus accumbens is associated with drug learning and in drug abuse.
Neocortex:
Visual, auditory, motor, sensory, and cognitive
Cerebral cortex:
-Frontal lobe (front of brain) - higher
intellectual thinking
-Prefrontal cortex - morality, mood,
planning
-Parietal lobe – sensory integration
-Occipital lobe (back of brain) – vision
-Temporal lobe (sides of brain) - recognizing
complex visual stimuli (like faces), memory
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Frontal Lobes function:
*Decision-making part of the brain responsible for
planning, problem solving, executive functioning,
and other thought processes
*Controls voluntary muscle movements
*Contains the motor cortex
Parietal Lobe functions:
- Receives sensory messages from the body
- Contains the somatosensory cortex
Temporal Lobe
- Processes auditory information, including language
- Contains Broca’s and Wernicke’s areas: key
language regions
Occipital Lobe:
- Processes visual information
Somatosensory Cortex
- Located behind the central fissure at the top of the brain in the parietal
lobe - Receives messages from skin senses all over the body
- Warmth and cold, touch, pain, and movement
Motor Cortex:
- Lies in the frontal lobe at the top of the brain
- Across the valley of the central fissure from the
somatosensory cortex - Neural impulses in the motor cortex are linked to
muscular responses throughout the body. - The right side of the brain controls the left side of
the body and vice versa, so injury to one side
affects movements on the opposite side.
Thinking, Language, and the Cortex
- Association areas are responsible for higher cognitive functions of problem
solving, planning, decision making. - Several interconnected regions of the brain are involved in these functions,
making up the information-processing system of our brain. - Parts of the parietal lobe, a section of the frontal lobe cortex, the hippocampus, a
portion of the limbic system, and the thalamus
Neuroplastcity
The brain’s ability to create new neural pathways as a result of experience or
following an injury.
e.g., Learning a new language such as French, involves creation of new neural
connections.
e.g., After brain injury such as stroke, part of the primary motor cortex in
frontal lobe important for moving leg is damaged, another part of the primary
motor cortex will take over function.
e.g., language area damaged in right hemisphere, left hemisphere part of brain
will take over function.
Brain Lateralization
- “The lateralization of brain function (or hemispheric
dominance) is the tendency for some neural functions or
cognitive processes to be specialized to one side of the brain
or the other.” - Language centers in most right-handed people are on the left
side of the brain - HOWEVER – in some left-handed people language centers are on
the right side (or on both sides!)
Left Brain or Right Brain?
- The left and right hemispheres have different
functional responsibilities, with some
overlap. - The left hemisphere controls the right side of the
body. - Relatively more involved in logical analysis,
language, and mathematical computation. - The right hemisphere controls the left side of the
body. - Usually superior in visual–spatial functions,
facial recognition, and emotional understanding
Handedness:
- Left-handedness is associated with a somewhat higher probability
of dyslexia, stuttering, migraines, and allergies. - Larger basal ganglia in left-handed individuals
- Plays a significant role in intentional motor control
- May explain left-handed individuals to be gifted athletes, artists,
and musicians.
CT Scan or CAT Scanning:
- During a CT scan, the patient lies on a
bed that slowly moves through the
gantry - the x-ray tube rotates around the
patient, shooting narrow beams of x-
rays through the body. - Instead of film, CT scanners use
special digital x-ray detectors, which
are located directly opposite the x-ray
source.
Magnetic Resonance Imaging (MRI)
- CT scans use X-rays to produce
images of the body - MRI uses powerful magnetic
fields and radio frequency pulses
to produce detailed pictures of
organs and other internal body
structures - Hydrogen protons (magnetic) are
randomly oriented (our body
contains lots of Water (H2O) - Exposure to magnetic field, aligns
orientation of H atoms - Radio frequency pulse applied,
axes of protons shifted puts in
elevated energy state - Pulse turned off, release energy
when spin back to orientation of
magnetic field - MRI sensors detect released
Functional Magnetic Resonance Imaging (fMRI)
Functional magnetic resonance imaging or functional
MRI (fMRI) measures brain activity by detecting
changes associated with blood flow. This technique
relies on the fact that cerebral blood flow and neuronal
activation are coupled. When an area of the brain is in
use, blood flow to that region also increases.
Evolutionary Psychology
- Evolution - the process of the development and divergence of
life (species) on this planet. - Evolutionary psychologists - study how the body and brain via
the interaction of our genes (video link) and the environment to
produce our thoughts and behaviours.
Evolution of Species Characteristics- Homologous traits
characteristics that are similar between species
and can be traced back to a common ancestor
Evolution of Species Characteristics- Analogous traits
characteristics that have evolved
independently in different species
Evolution of Species Characteristics- Convergent evolution
the development of similar physical
characteristics or behaviours in different species that do not share
a common ancestor (e.g., wings on birds and on bees)
Charles Darwin
-The father of evolution
His famous book On the
Origin of Species (1859)
described the theory of
evolution by the process
of natural selection.
Natural Selection
- Evolution by natural selection - animals with physical and
behavioural attributes well suited to their environment are more
likely to survive, reproduce, and pass on their traits to their
offspring - Fitness - an individual’s ability to successfully grow to maturity
and have offspring
Darwin made 4 important observations:
1) Animals were changing over time
2) Aspects of species that seem
different on the surface, such as a
human hand, a bat’s wing, and a
cat’s paw, had structural similarities
underneath
3) Selective breeding of captive animals leads to changes in the
appearance of the animal
4) Not all animals that are born will survive to maturity and be able
to reproduce
- Which of the following reflects the correct order for the structure of a neuron?
A) axon — cell body — terminal button — dendrite
B) terminal button — dendrite — cell body — axon
C) dendrite — cell body — axon — terminal button
D) cell body — dendrite — terminal button — axon
C) dendrite- cell body- axon- terminal button
- Which of the following is TRUE when a neuron is at rest?
A)Sodium and chloride are in higher concentration outside the cell; potassium and anions are in higher concentration inside the
cell.
B) Sodium and anions are in higher concentration outside the cell; potassium and chloride are in higher concentration inside the
cell.
C)Sodium and potassium are in higher concentration outside the cell; chloride and anions are in higher concentration inside the
cell.
D) Sodium, potassium, chloride, and anions are equally distributed outside and inside the cell.
A)Sodium and chloride are in higher concentration outside the cell; potassium and anions are in higher concentration inside the
cell.
3.The neurotransmitter associate with a reduction of arousal of the nervous system is
A)GABA.
B)glutamate.
C)serotonin.
D)dopamine.
A) GABA
4.Paige has a disorder that prevents her from paying attention or remaining vigilant on tasks.
Which neurotransmitter might be implicated in Paige’s disorder?
A)dopamine
B)norepinephrine
C)GABA
D)Serotonin
B) Norepinephrine
- is to most common inhibitory
neurotransmitter, as is to most common excitatory
neurotransmitter in
the brain.
A) GABA; glutamate
B) Serotonin; norepinephrine
C) Norepinephrine; serotonin
D) Glutamate; GABA
A) GABA; glutamate
- is to Parkinson’s disease and is to Huntington’s disease.
Question options:
A) Dopamine; glutamate
B) Acetylcholine; glutamate
C) Serotonin; norepinephrine
D) Glutamate; acetylcholine
A) Dopamine; glutamate
- This structure, which is part of the hindbrain, is involved in respiration, movement, waking, sleep, and
dreaming.
A) reticular formation
B) pons
C) cerebellum
D) medulla
B) pons
8.The substantia nigra, part of the , is important for the production of .
A)midbrain; dopamine
B)forebrain; dopamine
C)midbrain; serotonin
D)forebrain; serotonin
A) midbrain; dopamine
9.Messages from the eyes are relayed to the visual cortex through the
of the.
A)medial geniculate nucleus; hypothalamus
B)medial geniculate nucleus; thalamus
C)lateral geniculate nucleus; thalamus
D)lateral geniculate nucleus; striatum
C) lateral geniculate nucleus; thalamus
10.As you walk around the zoo, you notice that penguins and
dolphins both have fin-like structures, even though they are not
at all related. Which of the following is the best explanation for
this similarity?
A) Fins are an analogous characteristic.
B) Fins are a divergent characteristic.
C) Fins are a heterogeneous characteristic.
D) Fins are a homologous characteristic.
A) Fins are an analogous character
