1.
Dr. Moore
Which of the following are abundant in bone marrow stroma?
Correct Answer
E. MacropHages
Explanation
Macrophages are abundant in bone marrow stroma. Bone marrow stroma is a supportive connective tissue that provides a microenvironment for the development and maintenance of blood cells. Macrophages play a crucial role in the immune response and are involved in phagocytosis, antigen presentation, and cytokine production. They are present in high numbers in the bone marrow stroma, where they help regulate hematopoiesis and support the growth and differentiation of blood cells.
2.
Which of the following hematopoietic cells would you predict is the most numerous in bone marrow?
Correct Answer
A. OrthochromatopHilic erythroblast
Explanation
Orthochromatophilic erythroblasts are the final stage of erythropoiesis before the release of mature red blood cells into the bloodstream. They are highly specialized cells involved in the production of red blood cells. Since red blood cells are the most abundant type of blood cell in the body, it can be predicted that orthochromatophilic erythroblasts, which are directly involved in their production, would be the most numerous hematopoietic cells in the bone marrow.
3.
Dr. Royer
A 32-year-old male is hit by a drunk driver while walking home from work. He is placed in a cast to stabilize his leg while the fibular neck fracture heals. He returns for a follow-up visit 1 month after the cast is removed. You observe that the patient walks oddly and loudly as he enters the exam room. Which muscles are likely paralyzed, leading to footdrop in this patient?
Correct Answer
E. Extensor digitorum longus, extensor hallucis longus, tibialis anterior
Explanation
The patient is experiencing footdrop, which is characterized by the inability to dorsiflex the foot and toes. This suggests paralysis of the muscles responsible for dorsiflexion, which are the extensor digitorum longus, extensor hallucis longus, and tibialis anterior. These muscles are innervated by the deep peroneal nerve, which may have been damaged due to the injury or the cast placement. The other muscle options listed do not contribute to dorsiflexion and would not be responsible for the observed symptoms.
4.
An 80-year-old female suffers from degenerative disc disease. Her condition has worsened recently, leading to severe spinal stenosis between her L5-S1 vertebrae. What area of skin is most likely to present with pain and/or paresthesia as a result of the stenosis in this patient?
Correct Answer
A. Central dorsum and sole of foot
Explanation
The L5-S1 vertebrae are located in the lower back, and the nerves that exit at this level supply sensation to the central dorsum and sole of the foot. Therefore, if there is stenosis at this level, it is likely to compress these nerves, leading to pain and/or paresthesia in the central dorsum and sole of the foot.
5.
An individual may be predisposed to patellofemoral syndrome and patellar dislocation if they present with weakness of which structure?
Correct Answer
A. Vastus medialis muscle
Explanation
Weakness of the vastus medialis muscle can predispose an individual to patellofemoral syndrome and patellar dislocation. The vastus medialis muscle is responsible for stabilizing the patella (kneecap) and preventing it from moving laterally. If this muscle is weak, it can result in an imbalance in the forces acting on the patella, leading to malalignment and increased risk of patellofemoral syndrome and patellar dislocation. Strengthening exercises targeting the vastus medialis muscle are often recommended as part of the treatment and prevention of these conditions.
6.
Dr. Laville
A urine sample taken from a patient tested positive for blood. What further laboratory test would you perform to determine whether this patient is bleeding from muscle or other tissue?
Correct Answer
D. Haptoglobin
Explanation
Haptoglobin is a protein produced by the liver that binds to free hemoglobin in the blood. When there is bleeding from muscle or other tissues, free hemoglobin is released into the bloodstream. By measuring the levels of haptoglobin in the urine sample, it can be determined whether the patient is bleeding from muscle or other tissue. If the haptoglobin levels are low or absent, it suggests bleeding from muscle or other tissues, whereas normal or high levels indicate bleeding from other sources.
7.
A 47-year old female is brought to the emergency room with complaints of malaise, nausea, and vomiting. She admits that she has been drinking too much daily for the past three weeks. Which of the following enzymes would be raised in this patient?
Correct Answer
A. GGT
Explanation
GGT (gamma-glutamyl transferase) is an enzyme that is found primarily in the liver. It is commonly used as a marker of liver dysfunction or damage. In this patient, the history of excessive alcohol consumption suggests the possibility of alcoholic liver disease. GGT levels are known to be elevated in patients with alcohol-related liver injury, making it the most likely enzyme to be raised in this patient.
8.
Which of the following anticoagulants is used in the long term treatment of diseases which cause unnecessary blood clots?
Correct Answer
D. Warfarin
Explanation
Warfarin is used in the long-term treatment of diseases that cause unnecessary blood clots because it is an oral anticoagulant that inhibits the synthesis of vitamin K-dependent clotting factors in the liver. By doing so, it prevents the formation of blood clots and reduces the risk of thromboembolic events. Unlike other options listed, such as Heparin, Citrate, Oxalate, and EDTA, which may be used for short-term or specific purposes, Warfarin is commonly prescribed for the long-term management of conditions like deep vein thrombosis, atrial fibrillation, and pulmonary embolism.
9.
A 30-year-old woman presented to the emergency room with abdominal pain in the right upper quadrant. She also complained of vomiting after eating a fatty meal. Biochemical analyses revealed the following results:
This patient most likely has:
Blood Test
Results
Reference Range
Albumin
36g/L
35-45 g/L
Aspartate transaminase (AST)
45 IU/L
5-45 IU/L
Alanine transaminase (ALT)
38 IU/L
10-40 IU/L
Gamma-glutamyl transferase (GGT)
90 IU/L
10-55 IU/L
Alkaline phosphatase (ALP)
240 IU/L
40-110 IU/L
Correct Answer
A. Inflammation of the biliary tract due to gall bladder stones
Explanation
The patient's presentation of abdominal pain in the right upper quadrant, vomiting after eating a fatty meal, and elevated levels of alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) suggest inflammation of the biliary tract. The elevated ALP and GGT levels indicate cholestasis, which is commonly seen in biliary tract inflammation. The other liver enzymes, such as aspartate transaminase (AST) and alanine transaminase (ALT), are within the reference range, indicating that hepatocellular damage is not the primary cause. Gall bladder stones can cause obstruction of the biliary tract, leading to inflammation and the symptoms described by the patient.
10.
Dr. Smolanoff
A 35-year-old woman arrived at her doctor’s office concerned about her bluish skin color and was found to have a methemoglobin level of 20%. Which of the following could explain this high erythrocyte level of methemoglobin?
Correct Answer
D. Exposure to an oxidizing drug
Explanation
Exposure to an oxidizing drug could explain the high erythrocyte level of methemoglobin. Methemoglobin is a form of hemoglobin in which the iron molecule is oxidized, preventing it from binding oxygen effectively. Oxidizing drugs can cause this oxidation of hemoglobin, leading to an increase in methemoglobin levels. This can result in bluish skin color, known as cyanosis. Higher than normal levels of methemoglobin reductase would actually decrease methemoglobin levels, so it is not the correct answer. Nonspherocytic hemolytic anemia, carbon monoxide poisoning, and exposure to pentachlorophenol would not directly cause an increase in methemoglobin levels.
11.
Dr. Sloma
Immunodeficiencies can be caused by defects in the expression of many different molecules that contribute to both adaptive and innate immune responses. Failure to express which molecule would have no effect on the immune system’s ability to eliminate an extracellular bacterium?
Correct Answer
A. MHC class I
Explanation
The major histocompatibility complex (MHC) class I molecules are responsible for presenting intracellular antigens to cytotoxic T cells. They play a crucial role in the adaptive immune response. However, in the context of eliminating an extracellular bacterium, MHC class I molecules are not directly involved. Extracellular bacteria are typically eliminated by the innate immune response, which includes components such as surface-bound antibody molecules, toll-like receptors, and complement components. Therefore, failure to express MHC class I molecules would have no effect on the immune system's ability to eliminate an extracellular bacterium.
12.
I) Found in the tissues and bloodstream
II) Found at low levels in the blood as most are bound to Fc receptor
III) Found in secretions (saliva, tears)
IV) Found only on the surface of naïve B cells
V) Found only in the blood
VI) An efficient activator classical complement pathway
VII) An important neutralizer of pathogens in the gut
VIII) Efficient at triggering opsonization of pathogens
IX) Efficient at triggering mast cell degranulation
.
IgD can be described as:
Correct Answer
E. IV only
Explanation
IgD can be described as found only on the surface of naïve B cells. This means that IgD is exclusively present on the surface of B cells that have not yet encountered an antigen and undergone activation. It is not found in the tissues, bloodstream, secretions, or blood. It is also not involved in activating the classical complement pathway, neutralizing pathogens in the gut, triggering opsonization of pathogens, or triggering mast cell degranulation. Therefore, the correct answer is IV only.
13.
I) Found in the tissues and bloodstream
II) Found at low levels in the blood as most are bound to Fc receptor
III) Found in secretions (saliva, tears)
IV) Found only on the surface of naïve B cells
V) Found only in the blood
VI) An efficient activator classical complement pathway
VII) An important neutralizer of pathogens in the gut
VIII) Efficient at triggering opsonization of pathogens
IX) Efficient at triggering mast cell degranulation
IgA can be described as:
Correct Answer
A. III and VII
Explanation
IgA can be described as being found in secretions (saliva, tears) and being an important neutralizer of pathogens in the gut.
14.
Dr. Adebiyi
Microorganisms have developed ways and means of overcoming host defenses to cause disease. What factor is known to enable an organism to break down host intercellular tight junctions and facilitate the spread of the organism?
Correct Answer
C. Collagenase
Explanation
Collagenase is an enzyme produced by microorganisms that can break down the collagen, which is a major component of host tissues. By breaking down the collagen, the organism can disrupt the intercellular tight junctions between host cells, allowing it to spread and cause disease more easily. This enables the organism to overcome host defenses and facilitate its spread throughout the host's body.
15.
Dr. Arya
You are examining a peripheral blood smear from a patient with G6PD deficiency. Which of the following findings is most likely to be present on the smear associated with the patient’s clinical condition?
Correct Answer
E. Heinz bodies
Explanation
Heinz bodies are most likely to be present on the peripheral blood smear of a patient with G6PD deficiency. G6PD deficiency is an inherited condition that affects the red blood cells and leads to their destruction. Heinz bodies are denatured hemoglobin precipitates that form within the red blood cells due to oxidative stress. These bodies can be seen on a peripheral blood smear and are characteristic of G6PD deficiency.
16.
Dr. Beevers
A 29-year-old woman reports to her family physician complaining of generalized weakness, dizziness, and epigastric pain. Laboratory investigations are performed with the following results:
Hgb 8 g/dL (normal: 12-16)
Hct 27% (normal: 36-46)
Reticulocytes 0.2% (normal: 0.5-1.5)
MCV 75 fl (normal: 80-100)
MCH 22 pg/cell (normal: 25.4-34.6)
MCHC 29% (normal: 31-36)
Serum Ferritin Low
Serum Homocysteine Normal
The patient is started on an appropriate pharmacological agent to treat her hematopoietic disorder. Which of the following statements describes a pharmacodynamic characteristic of the drug that was most likely prescribed for this patient?
Correct Answer
D. Functions as the metal ion cofactor in heme
Explanation
The patient's laboratory results indicate a low hemoglobin (Hgb) level, low hematocrit (Hct), and low mean corpuscular volume (MCV), which are consistent with anemia. The low MCH and MCHC levels also suggest a microcytic hypochromic anemia, which is often caused by iron deficiency. The low serum ferritin level further supports the diagnosis of iron deficiency anemia. Iron is a crucial metal ion cofactor in the synthesis of heme, which is necessary for the production of hemoglobin. Therefore, the drug most likely prescribed for this patient functions as a metal ion cofactor in heme synthesis to treat her hematopoietic disorder.
17.
Dr. Larsen
In the archives of the genetic counseling clinic, you find an older case where one woman pointed to three possible fathers of her newborn child. Blood types of the people involved are given below. Which of the statements are most likely to be true?
Mother
A-Rh+
Child
B-Rh-
Potential 1
B-Rh+
Potential 2
O-Rh-
Potential 3
AB-Rh-
Correct Answer
C. Potential 1, 3 are equally likely
Explanation
Based on the blood types, both Potential 1 and Potential 3 could be the father of the child. The mother has blood type A-Rh+ and the child has blood type B-Rh-. This means that the child inherited the B antigen from one of the potential fathers. Potential 1 has blood type B-Rh+, which matches the child's blood type. Potential 3 has blood type AB-Rh-, which also matches the child's blood type since AB blood type can be formed by combining A and B antigens. Therefore, both Potential 1 and Potential 3 are equally likely to be the father of the child.
18.
Dr. Yin
Which of the following is a characteristic feature of the lymph nodes?
Correct Answer
D. Subcapsular sinus
Explanation
The subcapsular sinus is a characteristic feature of lymph nodes. It is a space located beneath the capsule of the lymph node, where lymphatic fluid flows through. It acts as a filter, allowing lymphocytes and other immune cells to enter the lymph node and encounter antigens that may be present in the lymph fluid. This helps initiate an immune response and is an important part of the lymphatic system's function in fighting infections and diseases.
19.
Which of the following statements characterizes the immune cells and organs?
Correct Answer
C. Periarterial lympHatic sheath (PALS) contains T cells
Explanation
The periarterial lymphatic sheath (PALS) contains T cells. This statement characterizes the immune cells and organs by describing the location of T cells within the lymphatic system. The PALS is a region of lymphoid tissue surrounding the central artery in the white pulp of the spleen, and it is primarily composed of T cells. This statement highlights the presence of T cells in a specific anatomical location, providing insight into the distribution and function of immune cells within the body.