QUESTION 58
A medical student is watching a presentation on Budd-Chiari syndrome, which is due to thrombosis of major hepatic veins. During the presentation, a pathologist shows a slide with a microscopic image of the liver. Changes consistent with which of the following processes would be present around the central veins?
A. Acute congestion
B. Chronic congestion
C. Acute hyperemia
D. Chronic hyperemia
Answer for Question 58
Answer: A (acute congestion)
Explanation: thrombosis of major hepatic veins should present acutely as there is greatly reduced ability for blood to exit the liver, effectively blocking its flow. With obstruction of venous outflow from the liver, blood will back up into the central veins, which is a passive process, and hence congestion. Given that it happened suddenly, it is an acute process. So, the appropriate process would be acute congestion. Hyperemia is an active process, such as occurs with vasodilation during acute inflammation. Chronic hyperemia would essentially never occur, because it would require an active process to constantly stimulate dilation of the vessels.
QUESTION 59
During their rotation in the emergency room, on one day, a medical student saw a patient with prominent swelling of their left upper extremity and a light red-pink discoloration and a patient with prominent swelling of both lower extremities and a dark red-blue discoloration. Of the following, the concentration of which compound accounts for the color difference?
A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Carbon monoxide
E. Methemoglobin
Answer for Question 59
Answer: B (Oxygen)
Explanation: in hyperemia, patients have an active process that causes dilation of blood vessels (e.g., acute inflammation). Because of the dilation of the blood vessels, the vessels become filled with oxygenated blood, which imparts a lighter red-pink coloration to the tissue. In congestion, patients have a passive process that causes dilation of blood vessels (e.g., failure of the heart leading to back-up in the venous system). The blood that accumulates is deoxygenated blood, which will impart a dark red blue discoloration to the tissue.
QUESTION 60
A 64-year-old male with congestive heart failure due to end-stage systemic hypertension presents to his primary care physician. Physical examination reveals rales and pitting edema of the lower extremities. Of the following, which mechanism was most responsible for his physical findings?
A. Increased hydrostatic pressure
B. Decreased hydrostatic pressure
C. Increased plasma osmotic pressure
D. Decreased plasma osmotic pressure
Answer for Question 60
Answer: A (increased hydrostatic pressure)
Explanation: with congestive heart failure, failure of the ventricles to be able to effectively pump blood leads to congestion within the venous systems (i.e., systemic venous system with failure of the right side of the heart and pulmonary venous system with failure of the left side of the heart). An increased amount of blood in the veins will distend the vessel, thereby increasing the hydrostatic pressure, which will promote the leakage of fluid from the vessel into the surrounding tissue and hence, edema.
QUESTION 61
A 34-year-old pregnant female is brought to the emergency room by her husband because she suddenly became short of breath and developed chest pain. A spiral CT scan reveals a peripherally located thromboembolus in the lower lobe of her left lung. Physical examination revealed that the left thigh and calf had a greater diameter than the right thigh and calf. Of the following, which mechanism was responsible for the physical examination findings?
A. Increased hydrostatic pressure
B. Decreased hydrostatic pressure
C. Increased plasma osmotic pressure
D. Decreased plasma osmotic pressure
Answer for Question 61
Answer: A (increased hydrostatic pressure)
Explanation: a pulmonary thromboembolus is a complication of a venous thrombosis, most commonly of the deep veins in the lower extremities. Because of the thrombosis of the vein, blood will pool in the venous system distal to the thrombosis as it cannot go around the site of blockage. An increased amount of blood in the veins will distend the vessel, thereby increasing the hydrostatic pressure, which will promote the leakage of fluid from the vessel into the surrounding tissue and hence, edema of the lower extremities, which would appear on physical examination as an increased girth of the affected extremity.
QUESTION 62
A 41-year-old alcoholic male presents to an acute care clinic complaining that his stomach has been getting larger lately. Physical examination reveals a fluid wave, consistent with ascites. Of the following, which two mechanisms are most responsible for his physical examination findings?
A. Increased hydrostatic pressure; increased plasma osmotic pressure
B. Increased hydrostatic pressure; decreased plasma osmotic pressure
C. Decreased hydrostatic pressure; increased plasma osmotic pressure
D. Decreased hydrostatic pressure; decreased plasma osmotic pressure
Answer for Question 62
Answer: B (increased hydrostatic pressure; decreased plasma osmotic pressure)
Explanation: a certain proportion of alcoholics develop cirrhosis of the liver and patients with cirrhosis of the liver can develop ascites (accumulation of watery fluid in the abdominal cavity). The scarring of the liver associated with cirrhosis causes some degree of obstruction of venous blood flow through the liver, which contributes to increased hydrostatic pressure, leading to edema. In addition, the liver produces albumin, which is the main protein in the blood and hence, the largest contributor to the plasma osmotic pressure. Damage to the liver leads to a decreased production of albumin and thus, decreased plasma osmotic pressure, leading to edema.
QUESTION 63
A 42-year-old female is presenting to her general surgeon for a visit after having undergone a partial mastectomy and lymph node dissection of the right breast for the treatment of invasive ductal carcinoma. The surgeon notes during physical examination and as reported by the patient that her right arm and forearm are swollen. Of the following, which is the most likely mechanism responsible for this physical examination finding?
A. Increased hydrostatic pressure
B. Decreased hydrostatic pressure
C. Increased plasma osmotic pressure
D. Decreased plasma osmotic pressure
E. Localized sodium retention
F. Lymphatic obstruction
Answer for Question 63
Answer: F (lymphatic obstruction)
Explanation: with a lymph node dissection, the flow of lymph can be disrupted; as lymph serves to return fluid to the heart that does not make its way back into the venous vasculature, obstruction of lymphatic flow will cause edema, which could produce enlargement of the right upper extremity. While it could be argued that increased hydrostatic pressure due to loss of veins and thereby resultant obstruction of venous flow, which would lead to edema, could result, during the surgery, preservation of the vasculature as best as possible could occur, whereas, a lymph node dissection, by its nature, would be damaging to the lymphatic system. Current techniques very greatly minimize the risk of such occurrences (i.e., lymphatic obstruction post surgery); however, understanding the complication and its mechanism is still useful.
QUESTION 64
During a wrestling competition, an amateur wrestler, while dead-lifting 300 lbs, develops tiny pinpoint red dots on his eyelids. Of the following, which would be the best descriptive term to use for these lesions?
A. Hemorrhage
B. Purpura
C. Ecchymoses
D. Bruising
E. Petechiae
Answer for Question 64
Answer: E (petechiae)
Explanation: various terms are used to describe hemorrhages in the skin and mucous membranes. These terms are based upon the size. Pinpoint hemorrhages (1-2 mm) are referred to as petechiae. Purpura are larger (3-5 mm) and can be raised (i.e., palpable). Ecchymoses are even large (1-2 cm or more). A hemorrhage is a non-specific term that applies to all three. Bruising is another term for ecchymosis.