Set 5 Flashcards
In the lower extremity, what are some of the clinical differences between peripheral vascular disease (PVD, also known as peripheral artery disease (PAD)) and deep venous thrombosis (DVT)?
PVD/PAD Athersclerosis of peripheral arteries Claudication (ischemia of the muscles with exercise aka angina of the legs) Decreased/absent peripheral pulses Foot may be cool to the touch Skin can become pale/shiny/hairless
DVT
Blood clot in a peripheral vein
Leg is warm (NOT cool)
Increased calf circumference
Moses sign (calf tenderness with compression)
Homan sign (calf pain with dorsiflexion of the ankle)
You have a patient who is experiencing progressive difficulty with swallowing liquids and solid food. Subsequently, the patient undergoes a barium swallow that reveals stenosis of the lower esophageal sphincter. What is the diagnosis associated with this barium swallow finding? What are some common causes of this diagnosis?
Achalasia (absence of relaxation)
“Bird’s beak” on barium swallow
Causes: most are idiopathic, can be secondary achalasia may arise from Chagas disease, or may also be caused by amyloidosis and sarcoidosis
Failure of relaxation of LES due to loss myenteric (Auerbach) plexus. High LES opening pressure and uncoordinated peristalsis -> progressive dysphagia to solids and liquids (vs. obstruction - solids only). Barium swallow shows dilated esophagus with an area of distal stenosis. Associated with an increased risk of esophageal squamous cell carcinoma
A 66-year-old man currently taking warfarin for atrial fibrillation is instructed to avoid food products that contain vitamin K to optimize anticoagulation. For what coagulation factors is vitamin K necessary?
II, VII, IX and X and protein C and S [*diSCo started in 1972]
Vit K is a cofactor for the gamma-carboxylation of glutamic acid residues on various proteins required for blood clotting & warfarin is a Vit K antagonist
A 22-year-old man suffers a stabbing injury to the chest. He has lost a lot of blood, and you are concerned that his cardiac output is low. What are the two equations for cardiac output?
CO = HR x SV
CO = rate of O2 consumption / (arterial O2 content - venous O2 content)
A 5-year-old boy is treated with mebendazole for a pinworm infection. Mebendazole acts on microtubules to inhibit the pinworms. What other medications act on microtubules? What syndrome demonstrates a defect in microtubule polymerization?
Microtubules Get Constructed Very Poorly Mebendazole (anti-helminthic) Griseofulvin (anti-fungal) Colchicine (anti-gout) Vincristine/vinblastine (anti-cancer) Paclitaxel (anti-cancer)
Chediak-Higashi syndrome - defect in lysosomal trafficking regulator gene (LYST). Microtubule dysfunction in phagosome-lysosome fusion, AR. Recurrent *pyogenic infections (staph and strep), *partial albinism, *peripheral neuropathy, progressive neurodegeneration, infiltrative lymphohistiocytosis, Giant granules in neutrophils and platelets, pancytopenia, mild coagulation defects.
Your 46-year-old male patient is asking your advice on whether to take a daily aspirin. How does taking an aspirin a day prevent platelet aggregation and myocardial infarction? Which two arachidonic acid products affect platelet aggregation?
Aspirin irreversibly inhibits cyclooxygenase (COX-1 and COX-2) by covalent acetylation, which decreases synthesis of both thromboxane A2 (TXA2) and prostaglandins. Increased bleeding time until new platelets are produced (7 days).
Thromboxane (TXA2) - increased platelet aggregation
Prostacyclin (PGI2) - decreased platelet aggregation
What is compartment syndrome, and how is it treated?
Injury to the leg - tissue swells and pressure within the fascial compartment increases
Treat w/ fasciotomy
Thiazolidinediones (TZDs) increase expression of one type of GLUT receptors—those in adipose tissue—as one of their antidiabetic actions. Which GLUT receptors would you expect to find on skeletal muscle and fat?
GLUT-4
Which GI ligaments match the following descriptions?
Separates the greater and lesser sacs
May be cut during surgery to access the lesser sac
2 ligaments that connect the spleen to other structures
Contains the portal triad
Connects liver to the anterior abdominal wall
Separates the greater and lesser sacs - Gastrohepatic, Gastrosplenic
May be cut during surgery to access the lesser sac - Gastrohepatic
2 ligaments that connect the spleen to other structures - Gastrosplenic, Splenorenal
Contains the portal triad - Hepatoduodenal
Connects liver to the anterior abdominal wall - Falciform
An 18-year-old woman has seasonal allergies. She complains that her eyes water and her nose runs constantly during the spring. Which cell type is responsible for her symptoms, and what drug inhibits these cells’ action? What WBCs descend from the myeloblast (granulocyte) lineage?
Mast cells - mediates allergic reactions in local tissues. Can bind the Fc portion of IgE to membrane, IgE cross-links upon antigen binding, causing degranulation, which releases histamine, heparin and eosinophil chemotactic factors. Involved in type I hypersensitivity reactions
Cromolyn sodium prevents mast cell degranulation (used for asthma prophylaxis)
(vs. Antihistamines block the downstream effects of histamine)
Granulocytes: neutrophils, eosinophils, basophils
Mast cells come from a different cell line (similar to basophils in terms of fn and appearance - mast cells found in mucosal surfaces and CT, basophils in the blood)
