Biology 362 Knowledge Inventory (Quiz) #3 done june 2015

26 Jun Biology 362 Knowledge Inventory (Quiz) #3 done june 2015

Question
Neurobiology

Biology 362

Knowledge Inventory (Quiz) #3

INSTRUCTIONS: Please read and refer to readings designated for this week to answer the questions below.

1. Intraneuronal communication can be defined as___________________.

A) chemical signaling between neurons

B) signals within an individual neuron

C)signals shared electrically (through gap junctions) among several neurons

D)electrical (ion-based) signaling between neurons

2. Invertebrate animals such as octopus or squid are ideal for studying the nervous system because _____________________.

A) the nervous system is not obstructed by bone

B) they live in salt water

C)they are somewhat intelligent and have fast reflexes

D)they have relatively large neurons

3. An EPSP is more likely to bring a neuron to threshold for firing an action potential than an IPSP is because _______________________.

A) IPSPs activate calcium channels and do not lead to changes in the membrane potential

B) EPSPs activate sodium channels and cause sodium influx into a neuron

C)EPSPs inactivate sodium channels and cause sodium efflux out of a neuron

D)IPSPs inactivate sodium channels and cause sodium influx into a neuron

4. Using the steps identified below, place the steps of neuron function in the correct order. I. action potential is initiated at the axon hillock

II. synaptic vesicles fuse with the membrane of the axon terminal

III.membrane potential change at the dendrite of the postsynaptic neuron

IV. action potential travels along the axon of the postsynaptic neuron

V. neurotransmitter is released into the synaptic cleft

A) II, V, I, II, IV

B) III, I, IV, II, V

C)III, IV, I, V, II

D)V, IV, I, III, II

5. At resting membrane potential, the concentration of sodium is higher ____________ the neuron and the concentration of potassium is higher ___________ the neuron.

A) outside; inside

B) inside; outside

C) inside; inside

D) outside; outside

6. Many channels associated with the sense of touch are _____________________ channels.

A) nonspecific

B) ligand-gated

C) mechanically-gated

D) calcium

E) voltage-gated

7. Using the image above, identify the location during an action potential when sodium will have the highest intracellular (inside the cell) concentration.

A) site 1

B) site 3

C) site 5

D) site 6

8. If a stimulus opens a sodium channel in a neuron membrane, the membrane potential will become

_____________________.

A) repolarized

B) hyperpolarized

C) less negative

D) less positive

E) decremented

9. The action potential generated at the axon terminal is ________________ as the action potential generated at the axon hillock and they look _________.

A) the same one; very different

B) not the same; very different

C) the same one; similar

D) not the same one; identical

10. When the intensity of a stimulus increases, action potentials _______________.

A) increase in frequency

B) increase in number

C) increase in size (amplitude)

D) increase in duration

E) Both A and B

11. Electrophysiological recordings can be made with microelectrodes without damaging individual neurons because microelectrodes __________________.

A) have tips as small as about 10-6 meters (a micron)

B) are made of biopolymers

C) do not penetrate the cell

D) are coated with an anesthetic

12. What membrane change would occur when the positive pole of a battery that is inserted into the cytoplasm (intracellular component) of a neuron is switched on and a microelectrode is being used to record membrane potential changes? The membrane potential will __________.

A) not change

B) become hyperpolarized

C) become refractory

D) become less negative

E) become more negative

13. When using a stimulator to inject current into a neuron, the membrane potential change is expected to __________________________.

A) vary proportionately with the intensity of the stimulus

B) have the same amplitude for all stimulus intensity levels

C) become less responsive to the stimulus current over time

D) vary inversely with the intensity of the stimulus

14. An action potential will be generated if stimulation ___________________.

A)causes the membrane potential at the axon hillock to reach threshold for firing an action potential

B) activates dendrites of the neuron

C) is positive current

D) is negative current

E) inactivates sodium channels at the axon hillock

15. Action potentials are ultimately propagated to the __________________.

A) axon terminal

B) synapse

C) postsynaptic membrane of the target neuron

D) axon hillock

E) soma of the postsynaptic neuron

16. Where in a neuron will you definitely find voltage-gated ion channels?

A) dendrites

B) mitochondria

C) cell soma

D) nucleus

E) axon hillock

17. The property of “All -or-none” responsiveness in a neuron is most closely linked with which of the following neural functions?

A) reaching firing threshold

B) summating membrane potentials over space

C) summating membrane potentials over time

D) entry of calcium ions into the axon terminal

18. At equilibrium and at resting membrane potential (Vrest), what prevents sodium ions from entering into the intracellular compartment?

A) ion channels for sodium are closed

B) sodium ion channels open at more positive membrane potential than Vrest

C) potassium is freely flowing through the sodium channels

D) both A and B

E) both B and C

19. At the maximum amplitude of an action potential, potassium ions are free to exit the cell membrane due to ____________________________.

A) opening sodium channels

B) closing calcium channels

C) blocked voltage-gated sodium channels

D) open voltage-gated potassium channels

20. When potassium ions leave the intracellular space near the maximum height of an action potential,

they will ___________ then ______________ the neuronal cell membrane.

A) repolarize; hyperpolarize

B) repolarize; depolarize

C) repolarize; bind to receptors on

D) bind to receptors on; hyperpolarize

E) hyperpolarize; repolarize

21. What determines the absolute refractory period?

A) open and activated sodium channels

B) open and inactivated sodium channels

C) inactivated calcium channels

D) both A and B

E) both A and C

22. Multiple presynaptic neurons that stimulate a postsynaptic neuron simultaneously might result in an action potential through ____________ (name a process) in the postsynaptic neuron.

A) inhibition

B) spatial summation

C) closing sodium channels

D) saltatory conduction

E) vesicular fusion

23. During the repolarization phase, potassium ions are re-distributing and moving toward their equilibrium potential at _________ mV.

A) -70

B) +30

C) -90

D) -30

E) 0

24. Fusion of synaptic vesicles with the presynaptic membrane in the presynaptic neuron is dependent on all of the following EXCEPT ____________.

A) neurotransmitter transport down to the axon terminal

B) neurotransmitter attachment to the receptor of the postsynaptic neuron

C) action potential propagation in the presynaptic neuron

D) voltage-gated calcium channels in the presynaptic membrane

E) membrane potential depolarization in the presynaptic terminal

25. Saltatory conduction occurs because __________________.

A) myelin is a good conductor of ions

B) voltage-gated sodium channels are concentrated at the nodes of Ranvier

C) myelin has many sodium and potassium channels to facilitate action potential generation

D) voltage-gated potassium channels are concentrated at the nodes of Ranvier

E) both B and D