Question

QUESTION 22

1. A neuron receives two neurotransmitter signals in a row from a single neuron. Each causes a graded potential that would by itself be insufficient to trigger an action potential, but the combined effect of the two graded potentials is sufficient to trigger an AP. This is an example of:

   		temporal summation
   		spatial summation
   		summed twitches
   		graded potential synergy

1 points   

QUESTION 23

1. The resting membrane potential is negative because:

   		there are more positively charged proteins in the interstitial fluid
   		there are more negatively charged proteins in the interstitial fluid
   		there are more positively charged proteins in the intracellular fluid
   		there are more negatively charged proteins in the intracellular fluid

1 points   

QUESTION 24

1. Novocaine works by:

   		blocking myelin in pain-sensing neurons
   		blocking voltage-gated Na+ channels in pain-sensing neurons
   		blocking voltage-gated K+ channels in pain-sensing neurons
   		blocking voltage-gated Ca+ channels in pain-sensing neurons

1 points   

QUESTION 25

1. The cells in your inner ear that allow you to respond to sound are called hair cells. When sound waves cause movement of fluid in the inner ear, it bends little hair-like protrusions on the cell causing ion channels in the cell to open. What type of ion channels are these?

   		Voltage-gated channels
   		Leak channels
   		Mechanically-gated channels
   		Chemically-gated channels

1 points   

QUESTION 26

1. Which of the following stimuli could trigger the opening of a voltage-gated channel?

   		a chemical signal
   		any of these could trigger the opening of a voltage-gated channel
   		a change in the cellâ s membrane potential
   		physical force on the cell

1. In an action potential, the falling phase is caused by:

   		K+ entering the cell
   		K+ leaving the cell
   		Na+ entering the cell
   		Na+ leaving the cell

1 points   

QUESTION 30

1. Drugs taken to treat psychiatric conditions often have many side effects. This is because:

   		They primarily target amine neurotransmitters, which have diverse effects and have the ability to activate multiple receptors
   		They work by blocking sodium channels, which are present on all neurons
   		They work by causing IPSPs in multiple subtypes of neurons
   		They target neurotransmitters which can also act as hormones

1 points   

QUESTION 31

1. If you were to increase the concentration of Na+ outside a cell while maintaining other ion concentrations as they were, what would happen to the cell's membrane potential?

   		The membrane potential would become more negative.
   		The membrane potential would become more positive.
   		The membrane potential would be unaffected.
   		The answer depends on the thermodynamic potential.

1 points   

QUESTION 32

1. The amount of neurotransmitter release from an axon terminal is dependent on:

   		the distance between the presynaptic and postsynaptic cells
   		the size of the action potentials
   		the amount of Ca+ in the interstitial fluid
   		the frequency of action potentials

1 points   

QUESTION 33

1. If voltage-gated calcium channels in an axon terminal were blocked:

   		enzymes on the post-synaptic cell would be unable to break down the neurontransmitter signal
   		neurotransmitter produced in the cell body could not be transported to the axon terminal
   		the neuron would be unable to generate an action potential
   		the neuron would be unable to release neurotransmitter
   		the neuron would be unable to recycle neurotransmitter

1 points   

QUESTION 34

1. When potassium channels in the plasma membrane of a neuron open,

   		K+ enters the cell, and the cell depolarizes
   		K+ leaves the cell, and the cell depolarizes
   		K+ enters the cell, and the cell hyperpolarizes
   		K+ leaves the cell, and the cell hyperpolarizes

1 points   

QUESTION 35

1. The cells in your nose that allow you to respond to odorants (chemicals that cause smells) have ion channels that open when receptors on the cell surface bind to the odorant. What type of ion channels are these?

   		Voltage-gated channels
   		Leak channels
   		Mechanically-gated channels
   		Chemically-gated channels

1 points   

QUESTION 36

1. If voltage-gated sodium channels in the cell body of a neuron were blocked:

   		An action potential could be generated, but it would take a long time to return to the resting membrane potential
   		neurotransmitter produced in the cell body could not be transported to the axon terminal
   		the neuron would be unable to generate an action potential
   		the neuron would be unable to release neurotransmitter
   		the neuron would be unable to recycle neurotransmitter

1 points   

QUESTION 37

1. A neuron receives a neurotransmitter from neuron A and within a few milliseconds, receives another from neuron B. Each signal causes a graded potential that would by itself be insufficient to trigger an action potential, but the combined effect of the two graded potentials is sufficient to trigger an action potential. This is an example of:

   		temporal summation
   		spatial summation
   		summed twitches
   		graded potential synergy

1 points   

QUESTION 38

1. The drug nitroglycerine is taken to treat chest pain associated with impaired blood flow to the heart (angina). In the body, nitroglycerine is rapidly converted to the neurotransmitter nitric oxide; this has the effect of:

   		Blocking transmission of pain signals to the brain
   		Relaxing smooth muscle in blood vessels, restoring blood flow to the heart
   		Constricting smooth muscle in blood vessels, lowering blood pressure
   		Breaking down blood clots

1 points   

QUESTION 39

1. How does an action potential spread from one Node of Ranvier to the next?

   		K+ ions flowing out of the cell diffuse over the cell surface, depolarizing the next Node of Ranvier
   		positive charge flows through the cytoplasm in the axon, depolarizing the next Node of Ranvier
   		A new action potential must be initiated in each Node of Ranvier
   		Signals spread among Nodes of Ranvier using gap junctions

1 points   

QUESTION 40

1. Which of the following is not a type of neurotransmitter?

   		Biogenic amines
   		Amino acids
   		Steroids
   		Gases
   		Acetylcholine

Answer 1