Midterm 1 - Misc. Questions

Question 1

What is the correct definition of an ion?

Answer 1

An ion is an atom or molecule with a net electrical charge.

Question 2

What is true about proteins in terms of their composition?

Answer 2

Proteins are strings of amino acids.

Question 3

Where are proteins synthesized in eukaryotic cells?

Answer 3

Proteins are synthesized outside the nucleus in the ribosomes.

Question 4

What do microtubules do?

Answer 4

Microtubules are needed to transport vesicles within the cell.

Microtubules serve as tracks for motor proteins to transport vesicles (small sacs containing proteins) within the cell, facilitating communication and nutrient distribution essential for cellular function.

Question 5

What can be said about multicellular organisms?

Answer 5

Multicellular organisms are either made of all eukartyotic or all prokaryotic cells, but never both. Complex multicellular organims are made of eukaryotic cells.

Question 6

Cerebral Cortex, Hippocampus, Amygdala, Cerebellum

Unlike the brains of humans, which of the above structures is absent in the brains of other mammals like mice?

Answer 6

TRICK question - all these brain structures (Cerebral Cortex, Hippocampus, Amygdala, Cerebellum) are present in both mice and humans.

Question 7

What is the structure of the gene that encodes the voltage-gated sodium channel found in neurons?

Answer 7

The gene is a string of nucleic acids.

Question 8

What is the leak potassium channel found in neurons?

Answer 8

The leak potassium channel is a two-way door through which potassium can leave and enter the cell

Question 9

What is the function of the gene promoter for the leak potassium channel?

Answer 9

It regulates when and in which cells the leak potassium channel gene is read.

Gene promoters are sections of DNA that regulate gene expression. They are not the genes themselves.

Question 10

Of the following, which ion carries a negative charge when dissolved in water?

Sodium, Potassium, Calcium, Hydrogen

Answer 10

Trick question: NONE OF THE ABOVE!

Question 11

At its resting membrane potential, how is a neuron charged relative to the extracellular space?

Answer 11

The neuron is negatively charged relative to the extracellular space.

Question 12

What is the primary job of the voltage-gated potassium channel in neurons?

Answer 12

To quickly restore the resting membrane potential after an action potential.

Question 13

When the membrane potential of a neuron is exactly 0 mV during an action potential, what is true?

Answer 13

The concentration of sodium ions inside and outside the cell are equal.

Question 14

In a neuron sitting at rest (about -70 mV), how does the force of diffusion affect sodium ions moving into the axon at the peak of an action potential (about +40 mV)?

Answer 14

The force of diffusion encourages sodium ions to move into the axon at rest and out of the axon at the peak of an action potential.

Diffusion is driven by concentration gradients, and there is always 15 times more sodium outside a neuron than inside of it.

Question 15

Which of the following requires molecules of ATP to function?

Voltage-gated sodium channels, Leak potassium channels, Ionotropic receptors, Metabotropic receptors, Sodium-potassium pump

Answer 15

Sodium-potassium pump

Question 16

How is the density of sodium ions at the peak of an action potential?

Answer 16

At the peak of an action potential, the density of sodium ions is greater inside the cell than outside the cell.

Question 17

What does it mean when action potentials are described as “all or none”?

Answer 17

There is no such thing as a strong or weak action potential.

Question 18

What would most likely happen if you introduced a mutation that tripled the length of each segment of myelin sheath on an axon?

Answer 18

Action potentials would not propagate all the way down the myelinated axon.

Question 19

What triggers neurotransmitter release from the presynaptic membrane?

Answer 19

An influx of calcium ions into the axon terminal.

Question 20

What is true about every single glutamate receptor in the brain?

Answer 20

Every glutamate receptor is excitatory.

Question 21

Which process might mediate depolarization when neurotransmitters activate postsynaptic metabotropic receptors?

Answer 21

The closing of open potassium ion channels.

Question 22

What would happen to a neuron’s membrane potential if the concentration of potassium ions in the extracellular space was artificially increased?

Answer 22

Potassium ions would be less likely to leave through leak channels, so the membrane would depolarize.

Question 23

What is generally true about the autoreceptors expressed by neurons?

Answer 23

They are usually inhibitory.

Question 24

What is the correct order of the following from smallest to largest in size:

(1) Carbon atom
(2) Synaptic vesicle
(3) Voltage-gated sodium channel
(4) Neuropeptide
(5) Amino acid

Answer 24

1, 5, 4, 3, 2 (carbon atom, amino acid, neuropeptide, voltage-gated sodium channel, synaptic vesicle).

• A carbon atom is a single atom.
• A typical amino acid is about 20 atoms.
• A neuropeptide is short string of amino acids (about 600 atoms).
• Ion channels are proteins, which are long strings of amino acids (about 10,000 atoms).
• A synaptic vesicle can hold over 5000 neurotransmitters and has many proteins embedded in its membrane (about 100,000 atoms in total).

Question 25

When looking at a fixation point with an image flashed in your left periphery, what happens to the information from the right side of your left eye at the optic chiasm?

Answer 25

The information crosses over to the right hemisphere.

Question 26

In a split-brain patient, if an image is shown in their left periphery while staring at a fixation point, what would they be able to do?

Answer 26

They would be able to write what they saw with their left hand, which is controlled by the right hemisphere of the brain. However, they would not be able to verbally answer about what they saw, because the information processed in the right hemisphere cannot be communicated verbally.

Question 27

If a split-brain patient sees the word "fork" in their left periphery and "screwdriver" in their right periphery, what are they likely to verbally say and pick up with their left hand?

Answer 27

They would verbally answer "screwdriver" and pick up a "fork."

Question 28

Why would a split-brain patient who laughs at the word "laugh" make up a reason for laughing according to Gazzaniga’s Interpreter Theory?

Answer 28

The patient’s left hemisphere is creating a narrative to explain the behavior.

Question 29

Which of the following statements is false about Gazzaniga’s Interpreter Theory? - Consciousness is only located in the left hemisphere. - The function of consciousness is storytelling. - Free will is an illusion. - Human consciousness directly controls behaviour

Answer 29

Human consciousness directly controls behaviour Gazzaniga's Interpreter Theory believes that while human consciousness plays a role in decision-making and behavior, it does not directly control all behaviors, which are also influenced by unconscious processes, reflexes, and external factors.

Question 30

What term refers to Descartes' argument that our body exists in a physical realm while our mind exists in a separate immaterial realm?

Answer 30

Mind-body dualism.

Question 31

Which atoms or molecules primarily compose cells?

Answer 31

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.

Question 32

The cell membrane is similar to what structure and consists of what?

Answer 32

It is similar to a liposome and consists of a phospholipid bilayer.

Question 33

What is a liposome?

Answer 33

A liposome is a small, spherical vesicle made of phospholipid bilayers that encapsulates water-soluble substances. It protects and transports hydrophilic molecules (like drugs). It is commonly used in pharmaceuticals to improve drug solubility and reduce toxicity, as well as in cosmetics for ingredient delivery. It mimics cell membranes in structure but is artificial and lacks complex proteins.

Question 34

What is an important difference between prokaryotic and eukaryotic cells?

Answer 34

Prokaryotic cells have free-floating DNA, while eukaryotic cells have DNA contained in the nucleus.

Question 35

Which component of the cell is responsible for creating proteins?

Answer 35

Ribosome.

Question 36

What is an implication of Gazzaniga’s Interpreter Theory?

Answer 36

An implication of Gazzaniga's Interpreter Theory is that consciousness is localized in the right hemisphere.

Question 37

How can a sensory neuron differentially encode weak or strong sensory input?

Answer 37

By varying the amount of time between each action potential, the number of sodium ions that enter with each action potential, the time it takes for the action potential to travel along a section of axon, and the frequency of subthreshold depolarizations.

Question 38

If we replace all K+ leak channels with Na+ leak channels, what would the resting membrane potential be close to?

Answer 38

Approximately -40mV.

Question 39

What would most likely happen if action potentials were triggered simultaneously in the cell body and axon terminal of a neuron?

Answer 39

The action potentials would pass each other, propagating up to the cell body and down to the axon terminal.

Question 40

How are forces acting on chloride ions in a neuron with a higher concentration of chloride ions inside than outside at rest?

Answer 40

The diffusion force is pulling chloride into the cell, and the electrostatic force is pushing chloride out of the cell.

Question 41

What would happen if chloride leak channels were introduced to a neuron with a higher concentration of chloride inside?

Answer 41

The resting membrane potential will increase (become less negative).

Question 42

What do we expect to observe after a neuron at rest receives an EPSP that brings the membrane voltage to -60mV?

Answer 42

An influx of Na+ ions.

Question 43

What is true at 0mV during the depolarization phase of the action potential?

Answer 43

The diffusion and electrostatic forces acting on sodium ions are equal.

Question 44

What would likely occur if myelin sheath lengths between nodes of Ranvier were lengthened?

Answer 44

The action potential would be faster.

Question 45

What can be said about all ionotropic receptors?

Answer 45

They are strings of amino acids encoded by DNA.

Question 46

How could you artificially widen the action potential?

Answer 46

By infusing a voltage-gated K+ channel antagonist. Infusing a voltage-gated K+ channel antagonist prevents potassium channels from opening, which prolongs the duration of the action potential. This keeps the neuron depolarized longer, allowing for an extended period of excitability and potentially increasing the frequency of action potentials.

Question 47

What could a mutation that affects the DNA for the voltage-gated K+ channel do?

Answer 47

It could test two things: 1) whether the specific amino acids in the channel are important for allowing potassium (K+) to pass through, and 2) which types of cells actually have this voltage-gated K+ channel.

Question 48

How do autoreceptors affect neurotransmitter release at the presynaptic membrane?

Answer 48

Autoreceptors can reduce the chances of neurotransmitter release by causing the closure of potassium (K+) leak channels.

Question 49

Which correctly describes the sequence of events during an action potential?

Answer 49

Sodium channels open, sodium rushes in to depolarize the cell. Voltage-gated potassium channels then open, potassium rushes out and hyperpolarizes the cell.

Question 50

What are oligodendrocytes responsible for?

Answer 50

Oligodendrocytes are glial cells in the central nervous system responsible for myelinating multiple axons, providing essential metabolic support, regulating the extracellular environment, and assisting in repair after injury, thereby enhancing neuronal communication and overall brain function.

Question 51

Which brain region damage would explain an inability to identify objects by touch?

Answer 51

Damage to the somatosensory association cortex in the parietal lobe.

Question 52

Which type of nerve allows you to sense a dog's soft fur?

Answer 52

An afferent nerve from the peripheral nervous system.

Question 53

What symptoms are most likely following damage to the cerebellum?

Answer 53

Poor coordination, loss of balance, and jerky movements.

Question 54

What are the components of the midbrain?

Answer 54

The midbrain consists of the tectum, tegmentum

Question 55

What are the components of the hindbrain?

Answer 55

The hindbrain includes the medulla, pons, and cerebellum

Question 56

What are the components of the forebrain?

Answer 56

The forebrain is composed of the cerebral cortex (all 4 lobes), thalamus, hypothalamus, limbic system (including the amygdala and hippocampus), and basal ganglia.

Question 57

What does the medulla do?

Answer 57

Regulates vital autonomic functions such as heart rate, breathing, and blood pressure.

Question 58

What does the pons do?

Answer 58

Serves as a bridge between different parts of the brain and regulates sleep and arousal.

Question 59

What does the cerebellum do?

Answer 59

Coordinates voluntary movements, balance, and motor learning.

Question 60

What does the basal ganglia do?

Answer 60

Involved in the regulation of voluntary motor control and procedural learning.

Question 61

What does the tectum do?

Answer 61

Processes auditory and visual information and is involved in reflexive movements.

Question 62

What does the tegmentum do?

Answer 62

Plays a role in arousal and the modulation of motor functions.

Question 63

What does the hypothalamus do?

Answer 63

Regulates homeostasis, including temperature, hunger, and thirst, and controls the endocrine system.

Question 64

What does the thalamus do?

Answer 64

Acts as a relay station for sensory information, directing it to appropriate areas of the brain.

Question 65

What does the amygdala do?

Answer 65

Involved in emotion regulation, particularly fear and aggression.

Question 66

What does the hippocampus do?

Answer 66

Essential for memory formation and spatial navigation.

Question 67

What does the prefrontal cortex do?

Answer 67

Responsible for complex cognitive behavior, decision making, and social interactions.

Question 68

What does the frontal lobe do?

Answer 68

Controls voluntary movement, problem-solving, and planning.

Question 69

What does the parietal lobe do?

Answer 69

Processes sensory information related to touch, temperature, and pain.

Question 70

What does the temporal lobe do?

Answer 70

Involved in auditory processing and memory, as well as language comprehension.

Question 71

What does the occipital lobe do?

Answer 71

Primarily responsible for visual processing.

Question 72

What does the left hemisphere do?

Answer 72

The left hemisphere is primarily responsible for language processing, analytical thinking, and controlling the right side of the body.

Question 73

What does the right hemisphere do?

Answer 73

The right hemisphere is associated with spatial awareness, creativity, and controlling the left side of the body.

Question 74

Which fluid circulates around the central nervous system and peripheral nervous system?

Answer 74

Cerebrospinal fluid (CSF).

Question 75

What structure is responsible for producing cerebrospinal fluid?

Answer 75

Choroid plexus.

Question 76

Which membrane is closest to the brain?

Answer 76

Pia mater.

Question 77

What separates the rostral and caudal parts of the cerebral hemispheres?

Answer 77

Longitudinal fissure.

Question 78

Which part of the brain is involved in orienting to sound?

Answer 78

Inferior colliculi.

Question 79

What communicates signals to the body using axons?

Answer 79

The nervous system.

Question 80

Which neurotransmitter is involved in wakefulness and can be blocked by caffeine?

Answer 80

Adenosine.

Question 81

What is the role of the basal ganglia in movement?

Answer 81

It is involved in intentional movement, motivation, and reinforcement learning.

Question 82

What happens to a neuron’s membrane potential if it is influenced by chloride binding to a GABA receptor?

Answer 82

The membrane potential falls, becoming more negative.

Question 83

What effect do MAOIs (anti-depressants: monoamine oxidase inhibitors) have on neurotransmitter activity?

Answer 83

They inhibit the breakdown of monoamines.

Question 84

What does a direct antagonist do to a neurotransmitter receptor?

Answer 84

It blocks the receptor.

Question 85

What technique would best show brain activity during a cognitive task?

Answer 85

fMRI.

Question 86

What allows researchers to study the causal role of a brain area in behavior?

Answer 86

Manipulation techniques like optogenetics.

Question 87

What happens when a competitive agonist and a competitive antagonist are taken together?

Answer 87

The overall effect on dopamine activity cannot be determined without more information.

Question 88

What would allow for chronic recording of neural activity while stimulating an upstream region in the amygdala?

Answer 88

Using viral-mediated gene delivery to express calcium indicators in amygdala neurons.

Question 89

What is the choroid plexus?

Answer 89

The choroid plexus is a network of cells and blood vessels located within the ventricles of the brain. Its primary function is to produce cerebrospinal fluid (CSF), which cushions the brain and spinal cord, provides buoyancy, and helps remove waste products. The choroid plexus plays a crucial role in maintaining the homeostasis of the central nervous system by regulating the composition and volume of CSF.

Question 90

What does the reticular theory state?

Answer 90

The reticular theory states that the brain and nervous system are a single connected network

Question 91

Early in human development, neurons express transporters that concentrate chloride ions in the intracellular space (100x more than extracellular). Giving alcohol to an infant who is at the stage of development would most likely cause: dissociation, decreased anxiety, seizures, or hallucinations

Answer 91

Giving alcohol to an infant who is at the stage of development where neurons express transporters that concentrate chloride ions intracellularly would most likely cause seizures. This is because the high concentration of chloride ions in the intracellular space would lead to hyperpolarization of the neurons. Alcohol, which enhances inhibitory neurotransmission (specifically through GABA), could exacerbate this effect, potentially disrupting normal neuronal activity and leading to seizures.

Question 92

How can µ-opioid signaling be reduced?

Answer 92

By enhancing reuptake of µ-opioids to facilitate faster re-release, administering an inhibitor of the enzyme that degrades µ-opioids, blocking protein synthesis in the axon terminal, or blocking axonal transport.

Question 93

If you take too much Adderall and want to reduce its effects, what should you take? - An inhibitor of the dopamine degradation enzyme - A competitive partial agonist for post synaptic dopamine receptors - An antagonist for dopamine autoreceptors

Answer 93

An inhibitor of the dopamine degradation enzyme, a competitive partial agonist for post-synaptic dopamine receptors, or an antagonist for dopamine autoreceptors (A, B, and C). If someone has taken an excessive amount of Adderall and wants to mitigate its effects, they can use specific types of drugs to help counteract the overstimulation caused by Adderall, which primarily increases dopamine levels. An inhibitor of the dopamine degradation enzyme would prevent the breakdown of dopamine, maintaining its levels but potentially balancing the effects. A competitive partial agonist for post-synaptic dopamine receptors would partially activate these receptors, helping to modulate the excessive stimulation. Additionally, an antagonist for dopamine autoreceptors would block the feedback mechanism that usually reduces dopamine release, allowing for better regulation of dopamine signaling in the brain. Together, these options could help manage the adverse effects of too much Adderall.

Question 94

Which of the following drugs would not reduce serotonin activity at the post-synaptic membrane? - A direct antagonist for the post-synaptic 5-HT receptor - A competitive partial agonist for post-synaptic 5-HT receptors - A competitive partial agonist for pre-synaptic 5-HT autoreceptors - An indirect agonist for pre-synaptic 5-HT autoreceptors - A drug that blocks the enzyme that synthesizes 5-HT

Answer 94

A partial agonist for the pre-synaptic receptors affects how much serotonin is released, not the receiving side. Blocking the enzyme that produces serotonin stops new serotonin from being made but doesn’t lower activity where serotonin is already present.

Question 95

Define caudal

Answer 95

Refers to structures closer to the tail or lower part of the body. In the human body, this often means toward the bottom or the feet (inferior). Example: The sacrum is caudal to the lumbar spine.

Question 96

Define lateral

Answer 96

Refers to structures farther away from the midline of the body. Example: The ears are lateral to the eyes.

Question 97

Define distal

Answer 97

Describes a structure farther from the point of attachment to the body or from the trunk. Example: The fingers are distal to the elbow.

Question 98

Define rostral

Answer 98

Refers to structures closer to the front of the body or the head (anterior). Example: The forehead is rostral to the back of the head.

Question 99

Define medial

Answer 99

Refers to structures closer to the midline or center of the body. Example: The nose is medial to the eyes.

Question 100

Define proximal

Answer 100

Describes a structure closer to the point of attachment or the trunk. Example: The shoulder is proximal to the wrist.

Question 101

Define dorsal

Answer 101

Refers to the back side of the body or the top side in the case of the brain. Example: The spine is dorsal to the chest.

Question 102

Define ventral

Answer 102

Refers to the front or belly side of the body (or the underside in animals). Example: The abdomen is ventral to the spine.

Question 103

Define superior

Answer 103

Describes a structure above or higher than another part. Example: The head is superior to the chest.

Question 104

Define inferior

Answer 104

Refers to a structure below or lower than another part. Example: The feet are inferior to the knees.

Question 105

Define anterior

Answer 105

Refers to the front of the body or in front of another structure. Example: The chest is anterior to the spine.

Question 106

Define posterior

Answer 106

Describes a structure behind or toward the back of the body. Example: The shoulder blades are posterior to the ribs.

Question 107

Define midline

Answer 107

The midline is an imaginary line that runs vertically down the center of the body, dividing it into equal left and right halves. It serves as a reference point for describing anatomical directions, particularly when using terms like medial (closer to the midline) and lateral (farther from the midline). For example, the nose is medial because it is located near the midline, while the ears are lateral because they are farther from it.

Question 108

When is there a higher concentration of sodium ions than potassium ions inside a neuron?

Answer 108

NEVER! There is ALWAYS 30 times more potassium inside a neuron than outside of it, and there is always 15 times more sodium ions outside than in.