Joseph Miller, a 52-year-old farmer, presents to the local Emergency Department accompanied by his spouse. Joe is unable to speak but is able to acknowledge yes and no questions with noticeably painful head gestures. His wife Marjorie explains that Joe’s hand was cut badly while repairing a tractor attachment about nine days ago. The wound was quite deep and dirty, and Joe cleaned and bandaged it himself. Despite these measures, the wound became progressively more red, swollen, and painful. Three days ago, Joe began to experience muscle cramps, especially in the muscles around his jaw and neck. Eventually Joe began to have difficulty speaking and swallowing, at which point his wife insisted that he seek treatment.
At first glance, some might dismiss this as a simple wound infection. After all, Joe did not seek medical care for a rather deep and dirty wound, which creates perfect conditions for an infection. But remember that Joe has also experienced cramps, or muscle spasms—painful, involuntary muscle contractions. Is this a separate problem, unrelated to his wound, or are the two related?
1. In Joe’s case, which of the three types of muscle tissue would you expect to be affected?
a. Smooth muscle tissue
b. Skeletal muscle tissue
c. Cardiac muscle tissue
d. All three muscle tissue types would be affected.
2. Define the five common properties of muscle cells, and explain how each of these might be affected in Joe’s case.
Joe was examined by the nurse practitioner at the clinic. She notes that the wound is approximately 1 cm deep, and there is exposed muscle tissue with areas of apparent tissue death. In addition, Joseph’s head and neck muscles are in a continuous spasm, they resist passive flexion and extension, and there is increased tone in his muscles of mastication and muscles of facial expression
The findings from the physical exam lead us to think that there may be more to this story than a simple wound infection. The continuous spasm of the muscles of the head, neck, and face indicates something potentially more serious. Remember that the muscular system is responsible for vital functions such as breathing, so any disturbance in skeletal muscle homeostasis must be closely monitored.
1. Describe the structural components of the myofibril. What are the different proteins associated with the thick and thin myofilaments?
2. What would you expect the different regions of the sarcomeres to look like in the muscles of Joe’s jaw and neck?
a. The I band would increase in length as the sarcomere increased in length.
b. The A band and zone of overlap would increase in length as the sarcomere increased in length.
c. The I band would decrease in length as the sarcomere decreased in length.
d. The A band would decrease in length as the sarcomere decreased in length
Due to the progression of Joe’s symptoms, the nurse practitioner admits Joe to the hospital with a severe wound infection. She consults with a physician, and they prescribe immediate therapy with muscle-relaxing agents to try to lessen Joe’s muscle spasms. They also order tests to determine the cause of his illness and the best course of therapy.
Based on Joe’s recent medical history, the emergency room nurse practitioner diagnoses him with tetanus, a disease caused by the bacterium Clostridium tetani. C. tetani, which is a normal inhabitant of the soil, can easily contaminate dirty wounds, especially those due to farm implements, as with this case.
In the body, these bacteria produce a toxin called tetanospasmin. The toxin enters the central nervous system (the brain and spinal cord) where it blocks the mechanisms that inhibit motor neurons from firing when a muscle relaxes. With this inhibition removed, the neurons fire repeatedly and continually stimulate the muscle, causing painful and increasingly stronger muscle spasms. The masseter (jaw) muscles are often the first muscles involved, and it is the spasm of these muscles that gives rise to tetanus’ common name: lockjaw, also called trismus. The muscles of the face, neck, back, and proximal limbs are also commonly affected. The contraction of the facial musculature leads to a characteristic facial expression with a teeth-baring grin and raised eyebrows. Contraction of the back muscles may cause the back to arch posteriorly.
The worldwide incidence of tetanus is around one million cases per year. The mortality rate is nearly one hundred percent if no medical care is available. Fortunately, Joe is now in a hospital where his condition can be monitored and treated.
The most serious complication of tetanus is respiratory failure, which is usually due to spasms of the muscles around the throat. When respiratory failure develops, the only treatment is mechanical ventilation: inserting a tube into the trachea (windpipe) and having a machine breathe for the patient. Will Joe face this potentially deadly complication?
1. Why would repetitive stimulation from a motor neuron lead to a sustained muscle contraction? (Hint: Think about the processes of excitation-contraction coupling and relaxation.)
2. Which component of the neuromuscular junction is directly affected by the toxin produced by the tetanus organism?
a. The synaptic cleft
b. The axon terminals
c. The motor end plate
d. The sarcoplasmic reticulum
A potentially serious complication of tetanus is the destruction of the muscle fibers themselves, a condition known as rhabdomyolysis. The breakdown of muscle fibers releases myoglobin into the blood, which can put a strain on the kidneys and lead to a decline in their function.
Joe’s physician notes that his kidney function has declined. She suspects that this may be a result of this muscle fiber breakdown, because myoglobin was detected in Joe’s urine. She initiates immediate therapy for the kidney dysfunction and orders additional tests to look at the level of myoglobin in his blood. This is a setback for Joe’s recovery, and makes his prognosis more serious. Fortunately, his physician has discovered this complication early and has taken measures to protect his kidneys from the circulating myoglobin.
1. Joe’s skeletal muscles affected by the tetanus toxin would require an enormous amount of energy to continue to progress through repeated excitation-contraction coupling and relaxation cycles. (a) What is the role of myoglobin in muscle fiber energy production, and where is it normally found? (b) What would you expect to happen to the ATP level in Joe’s affected skeletal muscle fibers, given enough time?
2. Which of the following processes is/are used to regenerate ATP as it is consumed for energy during both muscle contraction and relaxation?
a. The creatine phosphate reaction in the cytosol
b. Glycolytic or anaerobic catabolism in the cytosol
c. Oxidative or aerobic catabolism in the mitochondria
d. Each of the above reactions is involved in ATP regeneration
Joe has now had eleven days of therapy with muscle-relaxing drugs, and is showing slow but steady improvement. He continues to have spasms in his neck and back, but they are less severe. . Joe’s physician feels that he should be able to go home soon, providing he continues to improve over the next few days.
Although he is still symptomatic, it seems as if Joe has avoided the most serious complication of tetanus: respiratory failure. However, even with improvement, he will still need to remain hospitalized for a few days to ensure that his body continues to respond to treatment.
1. If you were to do a myogram of Joe’s muscles while in spasm, what do you think it would show: isolated twitches, unfused tetanus, or fused tetanus? Why? Considering this, explain why this disease is called tetanus.
2. What would you expect to see and feel if you examined Joe’s affected skeletal muscles?
a. Flaccid or soft muscles with little muscle tone–hypotonia
b. Flaccid or soft muscles with abnormally high muscle tone–hypertonia
c. Rock hard muscles with little muscle tone–hypotonia
d. Rock hard muscles with abnormally high muscle tone—hypertonia
1. Describe the effects of disuse on Joe’s muscles if he was bedridden in the hospital for several months.
2. Damaged skeletal muscle fibers do not generally regenerate, because they are no longer capable of dividing by mitosis. Which of the following cells can assist in the repair of damaged skeletal muscle?
a. Fibroblasts
b. Satellite cells
c. Chondroblasts
d. Neurons
Sample Solution
The Bible: An Eternal Canon Distributed: 28th July, 2017 Last Edited: seventeenth August, 2017 Disclaimer: This article has been put together by an understudy. This isn't a case of the work composed by our expert exposition scholars. You can see tests of our expert work here. Any suppositions, discoveries, conclusions or proposals communicated in this material are those of the writers and don't really mirror the perspectives of UK Essays. When one thinks about the word Bible, it inspires pictures of disclosure at Sinai, brimming with lightning and thunder, where an awestruck country got the ten instructions. It summons pictures of Isaiah's taking off predictions, the anguish of Esther, and the valor of Daniel. Nonetheless, regardless of the history inside it, the Bible isn't a history book. One who turns the pages and peruses the antiquated words will discover guarantees of the prizes that anticipate the individuals who do great and the disciplines that come in the wake of malice. The Bible is a guide to living carefully; it gives exhortation and direction, comforts the oppressed and motivates the disheartened. It enlightens occasions and helps put them in context. It's anything but an old storybook and not only a book of law but instead an aggregation of the periods and individuals whose activities hold applicable exercises to be adapted, even a huge number of years after the fact. When they assembled and finished which books would be incorporated into the scriptural group, it was comprehended by the old Jewish experts that it was to be a guide for ages on the best way to live. A focal piece of Judaism is the investigation of Torah with a specific end goal to learn and stick to the laws and lifestyle that is normal by God, as it says in the book of Joshua "this book of the law will not withdraw out of your mouth, but rather you will reflect on it day and night, that you might be mindful so as to do as per all that is composed in it; for then you will advance prosperous, and afterward you will have great success"[1], implying that one who contemplated the Bible would gather from it what the right activity in their own life was and along these lines, would discover achievement. All things considered, while there were likely different books composed, and unquestionably there were numerous different prophets and predictions experienced, before the redaction of the scriptural ordinance started, not all things be deserving of unceasing consideration. A basis for incorporation was that each book picked by the antiquated Jewish experts was a choice which gave lessons, be they moral or good, that would be appropriate and pertinent for every future age, paying little respect to time and place. On the off chance that the Jewish experts did not feel that it would in any case be pertinent to be contemplated by who and what is to come, paying little respect to how intriguing it might have been, they did exclude it. The scriptural standard is intended to shape individuals. It is intelligent to trust that the Creator of the Universe furnished man with a set of principles, as it says God "insist[s] that His admirers satisfy strict norms of morals and morality"[2]. God, through His activities, showed the good and moral way that one should endeavor to copy. At the point when the old Jewish experts assembled the scriptural group, unmistakably they were including the books that displayed cases of upright and heavenly conduct that future ages should endeavor to copy. The scriptural group likewise attempts to bring individuals who read its old pages nearer to God. The books incorporated into the scriptural group were chosen with the aim that these immortal words would affect every single future age would at present make a structure for an association with God, even a large number of years after the fact. One more of the criteria for being incorporated into the book of scriptures was "that the works be made amid the time out of prophetic disclosure; that is, no later than the season of the working of the Second Temple in Jerusalem by the returned banishes from Babylonia"[3]. Books and predictions that rose after this cut-off date were excluded in the scriptural ordinance. It is hence that the Books of the Maccabees were not considered for scriptural incorporation, since they were composed after the time of prophetic disclosure had finished. A conclusion in the matter of why this was the cut-off date for incorporations is that it was trusted that no expansion would be on the heavenly level of the books initially incorporated into the book of scriptures. This is on the grounds that the period of awesome prescience had closed. There was additionally a sentiment of being post-scriptural Jews, which means they felt that regardless of how great a proposed new book for the Bible was, it didn't make a difference since the Bible was shut for new options. Notwithstanding, there is prove that as late as the second century CE there was a progressing banter about happening with respect to specific books that had initially been incorporated into the scriptural ordinance that a few rabbis accepted ought to be evacuated. This civil argument is shown in a Mishnah where the books Ecclesiastes and Song of Songs are talked about with the idea of one's hands getting to be sullied following contact with these blessed books.[4] A troublesome idea to comprehend, the embodiment of the thought is that if heavenly books make one's hands polluted, they would be taken care of all the more carefully, and the simple couple of transcribed duplicates available for use at the time would be shielded from an excess of utilization. An extra clarification for this thought, is that there was blessed bread that individuals would put alongside the sacred books, imagining that since both were viewed as heavenly it was a proper activity. Notwithstanding, it was discovered that rodents snacking on the sustenance would likewise bite on the parchments, in this manner harming them. In this way, the control was set up to anticipate harm to the books. The civil argument in regards to this administer as for Ecclesiastes and Song of Songs in this Mishnah is whether the two books specified render one's hands debased, which means are they viewed as heavenly like alternate books that incorporate the scriptural standard. The Mishnah expedites a few varying feelings the subject, and unmistakably while the two books stay in the Biblical Canon and are viewed as blessed like all the others, there was, eventually, a level headed discussion about whether they ought to have kept on being incorporated. It is clear that the old Jewish experts perceived the centrality of the scriptural standard to Judaism and took the undertaking of aggregating which books were fitting for consideration genuinely. Working with an understanding that the gathering of books they were assembling would be considered personally and completely for a large number of years, they settled on the choice that lone those books whose stories had appropriate exercises for future ages would be incorporated. Potential volumes that recounted times where no enduring life direction could be gathered were expelled. Materials that did not further one's association with God were likewise expelled, since a key segment of the scriptural ordinance is to convey people nearer to God and in addition to show people what God anticipates from them, morally and ethically, through God's activities in the book of scriptures. A last paradigm for incorporation in the scriptural group was the time in which an occasion happened. On the off chance that the book was composed after the time of disclosure had halted, it was naturally dismissed since the scriptural standard was shut to new increments that were not supernaturally enlivened. The antiquated Jewish specialists and their rabbinic beneficiaries did not buy in to the New Testament or the Koran since they didn't concur with the conviction that those books were of perfect motivation. In this manner, their criteria for consideration was proposed as an assurance against future man-made and human-roused works that possibly invalidated or repudiated the statutes of the Torah. In entirety, the antiquated Jewish specialists knew about the enormous obligation of gathering a group of books that would be applicable for who and what is to come and would hold solid the perfect of imitating God's routes with fealty and relentless devotion. Considering that, they built up definite criteria to take after to guarantee that even a large number of years after the fact, an individual could open these books to look in the wrinkled pages of time to uncover unceasing learning and astuteness of how one can change their experience of life today.>
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