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9 Sep 2018

Assume ionic concentrations in the nervous system of:

[K]_o = 4 mM

[K]_i= 155 mM

[Na]_o= 145 mM

[Na]_i= 12 mM

4. If the resting membrane of a neuron could only conduct Na, would the resting membrane potential (RMP) be the same as, or different from E_Na? Why? [2]

5. Calculate what the RMP would be for a neuron only permeable to Na. Does this ever occur in the nervous system? Explain your answer.

6. Explain in your own words why the membrane potential of a neuron is a negative value and always lies closer to E_K than to E_Na? [4]

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Patrina SchowalterLv2

10 Sep 2018

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Related questions

Assume ionic concentrations in the nervous system of:

[K]_o = 4 mM

[K]_i= 155 mM

[Na]_o= 145 mM

[Na]_i= 12 mM

7. Use the GHK equation (ignoring any contribution by Cl or the Na/K pump), and assume RT / zF = 58 mV, to calculate the RMP of a cell when the gK to gNa ratio is:

i) 10:1?

ii) 50:1?

iii) 100:1?

8. Which of the above permeability ratios most closely represents the membrane of a neuron at rest (assuming a cell at rest has an RMP of -70 mV)? Why? [2]

9. Which of the above permeability ratios most closely represents the membrane of a glia cell at rest? Why? [2]

1)What type of cell allows the immune system to respond morequickly if the same antigen is encountered a second time?

A)leukocytes

B)memory cells

C)macrophages

D)neutrophils

E)natual killer cells

2)why is the heart divided funtionally into two separate pumpsthat work in series?

A)because arteries carry blood away from the pump and veinsbring blood back to the pump

B)because blood decreases in pressure as it travels throughcirculation

C)because vessles in the vasculature keep blood moving in onedirection'

D)because there are four chambers to the heart

E)none of the above-the heart contracts in unison and is notdivided into two pumps

3)which of the following statements is correct?

A)Na+,K+, Ca2+ and Cl- are all more concentrated in theEXTRACELLULAR fluid

B)Na+, K+, Ca2+ and Cl- are all more concentrated in theEXTRACELLULAR fluid

C)Na+, Ca2+, and Cl- are all more concentrated in theEXTRACELLULAR fluid

D)K+, ca2+ are more concentrated in the EXTRACELLULAR fluid

E)K+, Ca2+ are more concentrated in the EXTRACELLULAR fluid

3)During skeletal muscle contraction:

A)the width of the H-zone decreases

B)the actin heads bind to myosin chain

C)ATP hydrolysis requires Ca2+ as a cofactor

D)tropomyosin changes conformation when Ca2+ binds

E)all of the above occur during skeletal muscle contraction

4)The rapid depolarization phase of myocardial contratile cellaction potential is due to the movement of which ion(s)?

A)Ca2+ flows into the cytosol

B)K+ flow out of the cytosol

C)Na+ flow into the cytosol

D)Ca2+ flow out of the cytosol

E)K+ flow into the cytosol

5)You are a physiology graduate student asked to study theeffect of ion permeability on the initiation of action potentials.You have isolated a cell with resting membrane potential of -70mVand have determined that the cell's threshold voltage is -55mV. Youthen change the cell to make it less permeable to K+ ions(Eions=-90mV)

With all ther condition staying the same, has cell's restingmembrane potential been DEPOLARIZED or HYPERPOLARIZED; and will thecell require a greater or smaller stimulus to reach threshold?

A)hyperpolarize; smaller

B)depolarize;greater

C)hyperpolarize;greater

D)depolarized; smaller

E)none of the above answers are possibe

6)Skeletal muscle cells are UNUSUAL in that they :

A)lack smooth endoplasmic reticulum

B)have no mitochondria

C)depend entirley on anaerobic respiration

D)have MULTIPLE nuclei

E)none of the baove are found in the skeletal muscle cells

7)What is the name for the autonomic nervous system synapses atthe neuroeffector?

A)electrical synapses

B)axon viscosities

C)bidirectional synapses

D)axon varicosities

E)light bulb synapse

8)Which cytokines are involvedin making cells resistant toviruses?

A)colony-stimulating actors

B)interferons

C)erythrpoietin

D)major histocompatibility complex

E)none of the above can make a cell resistant to a virus

9)If a person switiches from normal breathing to more shallowbreathing, whcih statement is true

A)tidal volume decreases

B)alveolar PO2 decreases

C)alveolar ventilation decreases

D)"a" and "b"

E)"a", "b', and "c"

10)Which scenerio supports hyperpolarization of pre-synapticcell?

A)allowing Cl- ions into the cell

B)allowing K+ ions to leave the cell

C)allowing Ca2+ ions into the cell

D)"a" and "b"

E)"a", "b", and "c"

11)The gap junctions in cardia muscle are part of specializedcell junctions that are localized to the__________.

A)transverse tubules

B)intercalated discs

C)Interdigitated fingers

D)desmosomes

E)high-end shppoinf malls

12)What role does myosin light chain kinase (MLCK) play insmooth muscle cell contraction?

A)dephosphorylates myosin

B)phosphorylates actin

C)phosphoylates myosin

D)dephosphorylates actin

E)both "a" and "c"Given that your forearm is 30cm long and yourbiceps inserts 2 cm away from your elbow joint, how much force mustyour biceps exert to hold up a 10kg weight?

A)0.67kg

B)6.0kg

C)20kg

d)150kg

e)600kg

erinbadger748

Physiology Psychology

1. The mind-body problem is a fundamental philosophical issue at the base of all cognitive/behavioral neuroscience research. Why? Discuss the mind-body problem and give an example of how it relates to an issue in cognitive/behavioral neuroscience. Explain.

2. Explain how an action potential occurs. Start with Glutamate release from the presynaptic neuron and end with neurotransmitter release from the postsynaptic neuron.

3. How does a neuron inhibit another neuron? Explain. {~1 paragraph}

4. Design a drug that would increase Dopamine (DA) and/or Norepinephrine (NE) levels and explain its mechanism of action (explain how it works to increase DA and/or NE). What kind of disorder could this drug be used to treat? What would be some side-effects you might expect from taking such a drug? Would there be any risks expected from long-term treatment? Explain.

5. Alzheimerâs dementia is a neurodegenerative disorder that results in severe cognitive impairment. Researchers hypothesize that Alzheimerâs is due to low Acetylcholine activity in the cerebral cortex. How could a researcher test this hypothesis? Justify your answer.

6. What is neural plasticity? Give an example and explain. [3-4 sentences]

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20. If a stroke patient has damage to their temporal lobe, along the ventral stream of visual processing, what type of disorder would the patient have? Describe the major symptoms and explain what the personâs behavior would be like. What did we learn about the function of the temporal lobe from studying these patients? Explain.

21. What is blindsight? Explain how studying patients with blindsight informed our understanding of the visual system.

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23. What is retrograde amnesia? What did we learn about long-term memory from studying patients with retrograde amnesia (e.g., patient KC)? Explain.

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27. Helen Fisherâs research delineated 3 stages of love in the brain. Explain, with an emphasis on the brain-behavior relationships.

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29. What are mirror neurons? Explain two pieces of evidence for the hypothesis that mirror neurons are the neural substrate for empathy and theory of mind in humans. Do we have evidence linking mirror neurons to autism? Explain.

30. What was the most interesting thing you learned in class this semester? Why did you find it interesting? Explain.

31. What is a circadian rhythm? Explain how light acts as a zeitgeber to control our sleep/wake circadian rhythms. If someone had trouble falling asleep (insomnia), what advice would you give them? Justify your answer.

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