1.
After a mini-exam, you and a couple of friends spend the weekend on the beach in St. Martin. At the end of the day, one of your friends complains of sunburn. His back is very red, warm, and painful to touch. What is the most likely cause of this erythema?
Correct Answer
C. Vasodilation of blood vessels in dermis
Explanation
The most likely cause of the erythema in this scenario is vasodilation of blood vessels in the dermis. Vasodilation refers to the widening of blood vessels, which allows for increased blood flow to a specific area. In the case of sunburn, prolonged exposure to the sun's ultraviolet rays can cause the blood vessels in the dermis to dilate, resulting in redness, warmth, and pain. This is a common physiological response to inflammation and is often seen in sunburn cases.
2.
Approximately 30-60 minutes after being bitten by a "bug", a 26-year-old man noticed a localized swelling and erythema in the affected area. The edema is most likely the result of:
Correct Answer
C. Increased vascular permeability
Explanation
The localized swelling and erythema observed after being bitten by a "bug" suggest an inflammatory response in the affected area. Increased vascular permeability is a characteristic of inflammation, where the blood vessels become more permeable, allowing fluid and immune cells to move into the tissues. This increased permeability leads to the accumulation of fluid in the area, resulting in edema. Therefore, increased vascular permeability is the most likely cause of the edema observed in this case.
3.
A pathology report notes that a granuloma was seen in the lung of your patient. The patient asks for a copy and explanation of this report. What should you say to best explain?
Correct Answer
D. An accumulation of WBCs that fight persistent bacterial infections
Explanation
Granuloma refers to an accumulation of white blood cells (WBCs) that are involved in fighting persistent bacterial infections. This explanation best describes the nature of a granuloma and its role in the body's immune response. It highlights the significance of the WBCs in combating bacterial infections and helps the patient understand the pathology report.
4.
A patient is scheduled to have a chronic abscess incised and drained. What would you expect a microscopic examination of the contents of the abscess to most likely show?
Correct Answer
E. An acute inflammatory infiltrate of PMNs
Explanation
A chronic abscess is characterized by a long-standing infection, which would result in an accumulation of neutrophils, also known as polymorphonuclear leukocytes (PMNs), at the site of infection. Therefore, a microscopic examination of the abscess would most likely show an acute inflammatory infiltrate of PMNs.
5.
An 8-year-old boy cuts his hand on a piece of glass. Two days later there is an open sore surrounded by swelling. His forearm is tender with red streaks extending towards the axilla. What is the most likely diagnosis?
Correct Answer
C. LympHangitis
Explanation
Lymphangitis-- is an inflammation of the lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is Streptococcus pyogenes (Group A strep). Lymphangitis is also sometimes called "blood poisoning".
Signs and symptoms include a deep reddening of the skin, warmth, lymphadenitis, and a raised border around the affected area. The person may also have chills and a high fever along with moderate pain and swelling. A person with lymphangitis should be hospitalized and closely monitored by medical professionals.
Thin red lines may be observed running along the course of the lymphatic vessels in the affected area, accompanied by painful enlargement of the nearby lymph nodes
6.
Which of the following would you expect to find in the alveoli in a patient with pneumococcal pneumonia of 24 hours duration?
Correct Answer
D. Suppurative inflammation
Explanation
suppurative refers to "pus" which is caused by Neutrophils.
Neutrophils are the first responders in infection.
7.
You order an erythrocyte sedimentation rate (ESR) in a chronically ill patient. The ESR is significantly elevated and is most likely associated with:
Correct Answer
C. Increased serum acute pHase reactants
Explanation
The ESR is governed by the balance between pro-sedimentation factors, mainly fibrinogen, and those factors resisting sedimentation, namely the negative charge of the erythrocytes (zeta potential). When an inflammatory process is present, the high proportion of fibrinogen in the blood causes red blood cells to stick to each other. The red cells form stacks called 'rouleaux,' which settle faster. Rouleaux formation can also occur in association with some lymphoproliferative disorders in which one or more immunoglobulin are secreted in high amounts
The ESR is increased by any cause or focus of inflammation. The ESR is increased in pregnancy or rheumatoid arthritis, and decreased in polycythemia, sickle cell anemia, hereditary spherocytosis, and congestive heart failure. The basal ESR is slightly higher in females
8.
A 72-y/o man develops gram-negative bacterial peritonitis resulting from colonic diverticulitis. The ensuing fever, macrophage activation, and B-cell mitogenicity are mediated by the induction of host cytokines including tumor necrosis factor (TNF) and IL-1.
What bacterial product activates these events?
Correct Answer
D. Lipopolysaccharide
Explanation
Lipopolysaccharide (LPS) is a component of the outer membrane of gram-negative bacteria. It is a potent activator of the immune system and can induce the production of pro-inflammatory cytokines such as tumor necrosis factor (TNF) and interleukin-1 (IL-1). In this case, the 72-year-old man developed gram-negative bacterial peritonitis, which means that the bacteria causing the infection were gram-negative. Therefore, it is likely that the presence of LPS from these bacteria activated the immune response, leading to fever, macrophage activation, and B-cell mitogenicity.
9.
A patient is being treated for tuberculosis. Caseating pulmonary granulomas were seen on microscopic examination of a lung biopsy. What is the usual outcome of a pulmonary granuloma after treatment?
Correct Answer
D. Scarring and calcification
Explanation
After treatment for tuberculosis, the usual outcome of a pulmonary granuloma is scarring and calcification. This occurs as a result of the immune response to the infection, where the body forms a granuloma to contain the bacteria. Over time, as the infection is treated and controlled, the granuloma undergoes fibrosis and calcification, leading to scarring in the lung tissue. This scarring helps to prevent further spread of the infection and can be seen on imaging studies such as X-rays or CT scans.
10.
A well-demarcated area of myocardium appears paler than surrounding tissue and microscopically consists of eosinophilic muscle fibers with only a few karyorrhectic and pyknotic nuclei remaining. Many polys are seen, especially at the margin of this area. What is the most likely age of this myocardial infarct?
Correct Answer
C. 2 days
Explanation
The most likely age of this myocardial infarct is 2 days. This is indicated by the presence of eosinophilic muscle fibers with only a few karyorrhectic and pyknotic nuclei remaining, as well as the presence of many polys at the margin of the area. These findings are consistent with the early stages of myocardial infarction, which typically occur within the first few days after the event.
11.
A 45-year-old woman has a lung biopsy because of a 1.0 cm lesion seen on a chest x-ray. Histologic examination reveals epithelioid macrophages and lymphocytes around a focus of caseous necrosis. What is the best explanation for this form of necrosis?
Correct Answer
A. Cell-mediated hypersensitivity
Explanation
Caseous necrosis is a form of cell death in which the tissue maintains a cheese-like appearance. The dead tissue appears as a soft and white proteinaceous dead cell mass.
Frequently, caseous necrosis is encountered in the foci of tuberculous infections. It can also be caused by syphilis and certain fungi.
A similar appearance can be associated with histoplasmosis, cryptococcosis, and coccidioidomycosis
12.
The chronic inflammation of a delayed hypersensitivity reaction is mediated by
Correct Answer
A. LympHokines
Explanation
Chronic inflammation in delayed hypersensitivity reactions is mediated by lymphokines. Lymphokines are small proteins released by activated T lymphocytes that regulate the immune response. They play a crucial role in recruiting and activating other immune cells, such as macrophages and neutrophils, to the site of inflammation. Lymphokines also enhance the production of other inflammatory mediators, such as cytokines, chemokines, and adhesion molecules, leading to the sustained inflammation seen in delayed hypersensitivity reactions.
13.
Which of the following events in acute inflammation occurs first?
Correct Answer
C. Hemostasis
Explanation
Vasodilation and its resulting increased blood flow causes the redness (RUBOR)
and increased heat (CALOR).
Increased permeability of the blood vessels results in an EXUDATION (leakage) of plasma proteins and fluid into the tissue (EDEMA),
which manifests itself as swelling (TUMOR).
Some of the released mediators such as bradykinin increase the sensitivity to pain (DOLOR).
The mediator molecules also alter the blood vessels to permit the migration of leukocytes, mainly neutrophils, outside of the blood vessels (EXTRAVASATION)
into the tissue. The neutrophils migrate along a chemotactic gradient created by the local cells to reach the site of injury. The loss of function (FUNCTIO LAESA)
is probably the result of a neurological reflex in response to pain.
14.
The suppurative response of inflammation is the result of:
Correct Answer
E. Release of hydrolases from neutropHils
Explanation
The suppurative response of inflammation is the result of the release of hydrolases from neutrophils. Hydrolases are enzymes that break down proteins, and their release from neutrophils leads to the breakdown of tissue and the formation of pus. This response is a part of the body's immune system and is triggered by infection or injury. The release of hydrolases helps to eliminate pathogens and damaged tissue, but it can also contribute to tissue damage and inflammation.