physiological systems 0

Q1.  The table below shows the current recorded from patch clamp experiments on potassium channels in cultured rabbit lacrimal gland cells at different stimulating membrane potentials.

Current (pA)

Membrane potentials (mV)

1.9

60

0.95

50

0.05

40

-0.9

30

-1.85

20

-2.8

10

-3.8

0

-4.8

-10

-5.7

-20

-6.65

-30

-7.6

-40

-8.6

-50

 

Draw an I – V curve. (8 marks)

Calculate the reversal potential. (2 marks)

Calculate the conductance of this ion channel. (6 marks)

 

 

 

 

 

Q2. A human red blood cell has a membrane surface area of about 81µm2 and a membrane thickness of about 110 Aº. If the concentration of urea in the extracellular fluid is 1.6mM, and its intracellular concentration is 0.8mM, calculate the flux of urea in µmoles/sec across the red blood cell membrane. Assume that the diffusion coefficient of urea is 1 x 10-8 cm2/sec. (10 marks)

 

Q3. During the course of a neurosurgical procedure a drug is applied to the surface of the brain in order to inhibit the activity of a group of neurons that lie 3mm below the surface. Approximately how long will it take the drug to diffuse from the surface to those neurons?  Assume the diffusion coefficient of the drug in brain tissue is         3 x 10-4 cm2/sec. (6 marks)

 

Q4. Calculate the membrane potential (Vm) of a cell, given the following resistances and equilibrium potentials. Need to show all calculations. (12 marks)

EK = – 94mV, RK = 0.5 x 106 Ω, ENa = 66mV, RNa = 0.5 x 106 Ω

 

Q5. If EK = -92 mV and VM = -72 mV what will be the direction and magnitude of the ECDF? (4 marks)

 

Q6. If ENa = 66 mV and VM = -52 mV what will be the direction and magnitude of the ECDF? (4 marks)

 

Q7. Draw an I-V plot for two different non-voltage dependent ionic currents IA and IB under the following conditions:

·       When the conductance (g) is the same (2pS) for both ions A and B, but equilibrium potentials (-70mV for A, -50mV for B respectively) are different. Label the axes. (5 marks)

·       When the equilibrium potentials for both are the same            (-40mV) but they have different conductance’s (2pS for A, 4pS for B respectively). Label the axes. (5 marks)

 

Q8. A cell has a membrane potential of – 68 mV with the concentration of an ion [X+] inside (135mM) and concentration outside (8mM). What will be the direction and magnitude of the ECDF? (8 marks)

 

Q9. Consider a situation where K+ ion has an intracellular fluid (ICF) concentration of 320 mM and an extracellular fluid (ECF) concentration of 35 mM.  What will be the direction and magnitude of the ECDF acting on K+ at Vm = – 82 mV? (8 marks)

 

Q10. If ICF (K+) ion concentration is 165 mM, what ECF (K+) concentration is required for the condition of no net passive flux of K+ across the membrane at Vm = – 66 mV ? (6 marks)

 

 

 

 

Q11. What is the Donnan Effect? Two solutions are separated by a membrane permeable to sodium and chloride ions. The concentrations on side 1 are  sodium = 100 mM and proteins = 100mM and the concentrations on side 2 are sodium = 100 mM and      chloride = 100 mM.  At steady state approximate the concentrations of the different species and describe the different forces contributing to this steady state. (10 marks)

 

Q12. The concentration of carbon at 1 mm into the surface of the titanium slab is 0.25 kg/m3 and at 3 mm the concentration is 0.68 kg/m3. The temperature of the carburizing environment is 925 degrees Celsius, and the rate at which carbon is entering this 2 mm thick region is 1.27 x 10-9 kg/(m2s). What is the diffusion coefficient for this particular treatment? (6 marks)

 

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tjx companies inc stocks analysis 2

TJX Companies inc stocks analysis.

Analysis of stock prices throughout the year with an emphasis on events triggering significant changes in stock value.

Write a paper 400 words about the company stocks and make a bullet points in 3 slides about it.

The major events to include in paper are:

a.28 May 2019:

TJ Maxx announced a tough quarter and posted lower than expected earnings and revenue based on the daily price change of the company.

b. 1st August 2019:

U.S. stocks dropped after president trump wrote on twitter that the administration would be imposing 10% tariffs on Chinese imports. If we see the previous day was -0.76 and on Friday decreases more about -3.6 percent.

c. 17 Oct 2019:

tjx stocks close at high price o 60.49$ find why

Note:

Easy level of writing and English

write from perspective of international student

 

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Are spin doctors always a negative presence in politics?

Write an essay about the question above: are spin doctors always a negative presence in politics?
Critically assess the questions and provide empirical examples. Pull out key arguments and discuss within the context of the question. Answer the question with an argument, analysis, evidence and examples. The essay needs to be a maximum of 2,000 words and minimum 1,900.

Patient Is A 24 Year Old Female

 800 WORDS 

 Patient is a 24-year-old female administrative assistant who comes to the emergency department with a chief complaint of severe right-sided headache. She states that this is the sixth time in the last 2 months she has had this headache. She says the headaches last 2–3 days and have impacted her ability to concentrate at work. She complains of nausea and has vomited three times in the last 3 hours. She states, “the light hurts my eyes.” She rates her pain as a 10/10 at this time. Ibuprofen and acetaminophen ease her symptoms somewhat but do not totally relieve them. No other current complaints.

In your Case Study Analysis related to the scenario provided, explain the following: Both the neurological and musculoskeletal pathophysiologic processes that would account for the patient presenting these symptoms. Any racial/ethnic variables that may impact physiological functioning. How these processes interact to affect the patient.

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