A surprising amount of information can be gleaned about an individual just from one’s tissues. In this case, you have been assigned to shadow histopathologist Dr. Jonas Riehm as he attempts to identify the cause of death of 42-year-old Will Smithers. Mr. Smithers’s body was discovered sitting in his car near an alley several miles from his home. There was no obvious cause of death, necessitating an autopsy to determine if the death was from natural causes or foul play. However, due to a clerical error, the decedent’s body was released and interred before a proper autopsy could be performed, and an official cause of death was not established.
Fortunately, several tissue samples were taken before the interment and remain available for examination. Mr. Smithers’s family does not wish to have his body exhumed, so local law enforcement professionals have asked Dr. Riehm to examine the tissue samples in the hopes of determining his cause of death and whether or not an exhumation is needed. The following sections have been taken from the official report that Dr. Riehm sent to the local coroner’s office. You are to report to Dr. Riehm’s office with your anatomy and physiology textbook. He expects students to answer questions related to the work that he does in his histopathology laboratory.
Dr. Riehm enjoys teaching, and has a collection of microscope slides that he uses to introduce students to the fascinating universe of histology. He starts with the following definition: histology is the study of the normal structure of tissues. Although Dr. Riehm is an expert in the study of the diseases and abnormalities of tissues, histopathology, he is a firm believer that you must be able to recognize normal tissue before you can understand diseased tissue. He has set up four microscope stations for students to get familiar with how the microscopes function and to view slides of normal tissues.
- Each station has a microscope with a slide of one of the four primary tissue types. (a) Define tissue and organ, and then describe how each fits into the levels of body organization. (b) Describe what you would expect to observe on the epithelial tissue slide. What are the general functions of this tissue? (c) Describe what you would expect to see on the connective tissue slide. What are the general functions of this tissue? (d) Describe what you would expect to see on the muscle tissue slide. What are the general functions of this tissue? (e) Describe what you would expect to observe on the nervous tissue slide. What are the general functions of this tissue?
Satisfied that you are properly introduced to the concepts of normal tissue, Dr. Riehm begins to fill you in on the details of Mr. Smithers’s case, whose tissue samples have coincidentally arrived just in time for your shadowing visit. The first set of slides included an epithelium sample taken from Mr. Smithers’s forehead. The slide was taken from some oddly colored patches of skin that revealed some abnormal cells, specifically, squamous cell carcinoma. These cancerous cells were in the early stages of the disease and had not spread, or metastasized, to cause disease in other tissues. Dr. Riehm documented that while there was pathology noted in the epithelial slides provided, the squamous cell carcinoma, this was not the cause of Mr. Smithers’s death. Dr. Riehm continued to ask questions about epithelial tissues.
- Dr. Riehm has asked you to look at the epithelial tissue slide from the skin of Mr. Smithers’s forehead, and describe how the normal epithelium appeared. (a) Describe the difference between simple and stratified epithelium. Which type would you expect to see in Mr. Smithers’s tissue slide? (b) What are the different shapes that epithelial cells can assume in different epithelial tissues? Which cell shape would you expect to see in Mr. Smithers’s tissue slide; what type of specific epithelium is found in the skin? How would you describe the other two cell shapes? (c) Define what the basement membrane is and discuss the functions of its two components. (d)Which cellular junctions would you expect to find holding these cells to one another? (e) Describe where the apical, basal, and lateral surfaces of an epithelial cell are located.
Dr. Riehm began to review the next set of tissue samples, which included slides prepared from liver tissue and blood smears. He began with the slides taken from the liver and documented the following: the microscopic evaluation of the liver tissue is abnormal. Large deposits of adipose tissue can be seen interspersed throughout the normal structure of the liver tissue that is suggestive of hepatic lipidosis, or fatty liver. The most likely cause of hepatic lipidosis is excessive alcohol consumption, but this would need to be corroborated by further investigation outside the scope of this inquiry. For the record, he documented his findings of hepatic lipidosis. He then explained to you that these findings only indicate that the patient had tissue evidence of an unhealthy behavior, likely alcoholism, which could be a contributing factor in his cause of death but unlikely the cause itself. His family and friends would need to fill in the details about Mr. Smithers’s personal life. This wasn’t enough individually to warrant an exhumation of the body, nor was it enough to establish the cause of death as liver failure. He explained that this is a common histological finding in several long-standing illnesses, but in particular hepatitis, obstructive jaundice, and acute and chronic alcoholism with liver disease. This was still not enough to establish a cause of death but it was more information that would support an exhumation order by the state authorities. A review of Mr. Smithers’s medical history or a report from his personal physician would be helpful in determining the relevance of this finding.
Dr. Riehm moved on to Mr. Smithers’s peripheral blood smear slides. The erythrocytes appeared abnormally large, which provided more evidence that Mr. Smithers had done some significant damage to his body and tissues with alcohol consumption. Dr. Riehm documented his findings from the blood smear as abnormal, having found these large round erythrocytes called macrocytes. This condition called megaloblastic anemia leads to fewer normal cells, which limits the amount of oxygen and metabolic waste products that can be transported. This is a common finding in the peripheral blood smears of alcoholic patients with anemia. Many people suffering from alcohol dependence also have nutritional deficiencies, including poor intake of vitamin B12 and folate, both of which are critical for the normal development of erythrocytes in the bone marrow.
Dr. Riehm asked you to quickly finish your work on the connective tissue slides and take a look at the new set of cardiac muscle samples. Has he finally found something that could have caused Mr. Smithers’s death?
Dr. Riehm has been keeping you busy cataloging the slides that he has finished with while he prepares to review the slides of Mr. Smithers’s cardiac muscle tissue. Dr. Riehm described regions of necrosis, or dead tissue, as he explains, where cardiac muscle cells have died after being separated from the blood supply. This finding indicated that Mr. Smithers had a myocardial infarction or heart attack. Before you are able to even speculate “Was this the cause of Mr. Smithers’s death,” Dr. Riehm poses this question—are heart attacks always fatal, or in other words, can we determine from this slide that this event preceded and therefore caused Mr. Smithers’s death? People survive heart attacks, don’t they? Dr. Riehm would need to look at the slides more closely later in the day before he completed this portion of his report. He was not ready to sign off on myocardial infarction as the cause of death just yet.
Dr. Riehm reviewed the remaining slides in the set. He selected a blood vessel slide and discovered hypertrophy, or an enlargement of the smooth muscle, and damage to the endothelium lining the vessel walls. Both were signs of vascular disease, as was the finding of atherosclerosis, or plaque, which had probably clogged Mr. Smithers’s arteries and veins. All of these were pathological findings that supported a diagnosis of vascular disease. Vascular disease increases the likelihood of myocardial infarction. Mix the cardiovascular findings with fatty liver disease, anemia, and enough alcohol, and that could explain this man’s death. But it would still be speculation. All of these certainly could lead to a myocardial infarction, no doubt. There was evidence that a cardiac event had happened at some point in Mr. Smithers’s life. Like his fatty liver, these findings indicated that Mr. Smithers was unhealthy.
A review of Mr. Smithers’s medical history or a report from his personal physician would be helpful in determining the relevance of these finding. A pathologist would probably need to see the actual heart itself to make a cause of death by myocardial infarction determination. Dr. Riehm reminded you to get those slides filed away so we could move on to the last set of samples from Mr. Smithers’s brain tissue.
- Dr. Riehm suggested that you make flashcards of the following information: (a) briefly describe the structural characteristics and functions of skeletal muscle; (b) briefly describe the structural characteristics and functions of cardiac muscle; (c) briefly describe the structural characteristics and functions of smooth muscle; and (d) discuss the similarities and differences between the three different muscle tissue types.
Finally, being thorough, Dr. Riehm wanted to review his assessment of the cardiac tissue slides. Finding evidence of fibrous tissue interspersed among cardiac muscle cells indicated that the heart had tried to heal itself. Mr. Smithers would have had to have been alive long enough for scar tissue to form in his heart. The evidence from the cardiac tissue was consistent with an old myocardial infarction that Mr. Smithers survived. There was no evidence in the tissue samples to suggest that he had had an acute myocardial infarction. Dr. Riehm could only document what he observed in a small amount of cardiac tissue. Mr. Smithers could have had an acute and fatal myocardial infarction in a region of the heart from which no tissue samples were collected. For what he observed from the available tissue slide, however, a cardiac event as the cause of his death was unlikely. His report would undoubtedly leave more unanswered questions about the cause of Mr. Smithers’s death. A full gross examination of Mr. Smithers’s heart would be needed, which would obviously require that his body be exhumed.
- Dr. Riehm has found evidence of fibrosis in the cardiac muscle tissue slides, scattered throughout the dead cardiac muscle cells. This suggested that Mr. Smithers had survived that particular cardiac event. Which of the following statements is true with regard to how cardiac muscle tissue is repaired?
- Cardiac muscle cells are only capable of regeneration if the degree of damage is minimal. Extensive damage results in healing by fibrosis.
- Cardiac muscle cells are incapable of tissue regeneration because they are no longer capable of dividing by mitosis. Damaged cardiac tissue is replaced with scar tissue.
- Cardiac muscle cells differentiate into fibroblasts and regenerate functional cardiac tissue through the process of fibrosis.
- Fibroblasts secrete cardiac tissue ECM and once surrounded differentiate into mature cardiac muscle cells. This leads to regeneration of fully functional cardiac tissue.
WRAPPING UP THE CASE
Based on his findings, Dr. Riehm is fairly confident that the cause of Mr. Smithers’s death could not be determined based on an examination of tissue slides alone. Given the liver and vascular disease, he certainly wasn’t healthy, and a heart attack is a common outcome associated with both conditions. However, one question remains unanswered: the damage to the brain. This could have been the result of an accident or deliberate blunt force trauma. Mr. Smithers’s body would need a full autopsy to answer these questions. Tissue slides could provide details not seen with the naked eye but a close look at the body is required—this could be a criminal case. Mr. Smithers’s remains would need to help answer these questions. Due to the unknown cause of head trauma, Dr. Riehm recommends that Mr. Smithers’s body be exhumed so that it can be examined more closely. The details of the pathology will be available in the continuation of Mr. Smithers’s case (see Chapter 12).
Length: 750 – 1250 words
Structure: Include a title page and reference page in APA style. These do not count towards the minimal word amount for this assignment. Be sure to include an introduction and conclusion paragraph for the assignment.
References: Use the appropriate APA style in-text citations and references for all resources utilized to answer the questions. Include at least three (3) scholarly sources to support your claims.