Question

A Case Study of the Muscular System

The purpose of this assignment is to assess your ability to communicate effectively, think critically, and understand quantitative information. This assignment also gives you the opportunity to work through a potential real-life scenario in the medical field.

Obtain all data for the patients to answer the questions, fill out the tables, and produce graphs. You will be submitting answers (typed), tables, and graphs. Your words must be your own, do not just write one paragraph for everyone to turn-in. Graphs must be properly labelled. All sources used, including textbook, must be referenced at the end of your paper. You should turn-in a unique typed assignment that includes the following:

·         The answers to questions 1 through 20 (includes tables 1, 2, 3, and graphs)

·         Write an alphabetized list of all sources referenced in your answers in proper APA format.

Part I

You are a volunteer in a California medical office of Dr. Williams. Dr. Williams specializes in rare neuromuscular and musculoskeletal disorders. You’re also a grad student and working with Dr. Williams has allowed you to gain first-hand experience with some of the material that you’re learning in your human physiology course.

Today a group of high school students is coming for a tour and Dr. Williams has asked you to prepare some information about muscles to present to the students, such as the neuromuscular junction (NMJ), skeletal muscle contraction, and issues that can arise when signaling between neurons and muscles does not happen as it is supposed to.

Questions [Critical Thinking and Communication]

1. Write a summary paragraph to explain the action of muscles to high school students as Dr. Williams instructed.

Part II – Joyce Snyder

After the high school group finishes their tour, Dr. Williams sees two patients.

Joyce Snyder is a biochemist working for a bio-warfare lab at a university. She is working on a project using sarin as a model substance. Suddenly, while working, the lab alarms go off and Joyce accidentally knocks a vial of sarin over and a bit of the liquid splashes onto her arm between her gloves and lab coat.

She suddenly starts to feel dizzy, her heart starts pounding harder than ever, and she has shortness of breath. She feels incredibly sluggish and tries to get to the exit. As she approaches the lab door, her muscles cramp and she falls down and hits her head, knocking her unconscious. Her colleagues from across the hall happen to see her fall and call for help. Joyce is given oxygen and taken to the nearby hospital.

Joyce is admitted to the hospital and Dr. Williams examines her. Joyce is unconscious but seems to be experiencing some paralysis, so Dr. Williams orders blood work. The results are listed in Table 1 below, the top line represents her initial readings; the following three rows are for subsequent time points. You must work with your team members to interpret all clinical values.

Dr. Williams looks over the results and knows from Joyce ’s colleague that she is a bioweapons biochemist. Dr. Williams figures out that Joyce has been working on synthesizing a new sarin-like biochemical weapon and suspects she has a type of poisoning that is like that of sarin.

Questions [Critical Thinking]

2. What symptoms is Joyce experiencing?

3. What is the role of AChE in the NMJ?

4. Examine Table 1 below. Fill-in the normal range of values for each of the variables in the last (blank) row.

Table 1. Lab values for Joyce Snyder. (Serum)

Time Point	BP	Temp. (°F)	Hemat. (%)	Glucose (mg/dL)	Na+ (mEq/L)	K+ (mEq/L)	AChE Activity (% of normal)	Thyroxine (pmol/L)	Serum Triiodothyronine (FT3) (pg/dL)	Antibodies for Ach Receptors
1	105/65	99.4 °F	37.5%	88 mg/dL	139 mEq/L	3.8 mEq/L	44%	9.1       pmol/L	112 pg/dL	none
2	108/70	100.1 °F	38.0%	100 mg/dL	135 mEq/L	5.0 mEq/L	42%	8.5 pmol/L	100 pg/dL	none
3	130/92	98.0 °F	36.2%	95 mg/dL	132 mEq/L	5.2 mEq/L	50%	10.0 pmol/L	150 pg/dL	none
4	115/85	99.2 °F	36.9%	80 mg/dL	144 mEq/L	3.5 mEq/L	88%	12.0 pmol/L	82 pg/dL	none
Normal Values

Questions [Critical Thinking and Communication and Quantitative]

5. Which of Joyce ’s levels are abnormal and at what time point?

6. What is the mechanism of action of sarin or a sarin-like chemical?

7. How would exposure to a sarin-like poison affect the amounts of Na⁺ going into the muscle cell? Explain why.

8. How would exposure to a sarin or sarin-like chemical affect Ca2⁺ levels inside the sarcoplasmic reticulum? Why?

9. How do these altered Ca2⁺ levels affect the position of the actin and myosin filaments? Why/how?

10. What needs to happen to Joyce’s post-synaptic membrane to remedy her paralysis? Physiologically what do we need more of, and where?

Part V

21. Write an alphabetized list of all sources referenced in your answers in proper APA format!!!

Answer 1

1. The muscular action can be described as the movement relative to the joint achieved when the action potential arrives at axon terminal triggers the release of Ach from the synaptic vesicle at the synaptic cleft which binds to receptors on post synaptic muscle cells to trigger muscle contraction. In most bodily movements are contraction of group of muscles and these terms are used to describe the role of each muscle involved are agonists, or prime movers, are responsible for the bulk of the action, antagonist, synergist etc.,

2. Joyce experience fatigue, acute vertigo, muscle cramps, palpitation, shortness of breath, paralysis and unconciousness.

3. Ach is a neurotransmitter or chemical messenger that propagate nerve impulses across the neuromuscular junction between a nerve and a muscle. It binds to the AchR on the sarcolemma of musce cell and triggers the opening of sodium channels resulting in the rapid entry of sodium into the muscle cell resulting in spreading of depolarization.

Table is not clear for question 4 & 5.

6. Sarin acts class of chemical weapons called G-series nerve agents which is a potent inhibitor of acetylcholinesterase. It is an enzyme crucial for degradation of the neurotransmitter acetylcholine in the synaptic cleft.