Rubbernecking
I Heart Biochemistry
Cells?
I Heart Drugs
Patent pending
Heart Skipped a Beat
Erythropoeiesis
100
An 8-year-old boy presents with a hoarse voice due to compression of a nerve that loops inferior to and then passes posterior to this structure before ascending to the larynx.
What is the aortic arch?
100
Deficiency of this enzyme impairs maturation of HDL by preventing esterification of surface cholesterol.
What is LCAT?
100
Phosphorylation of this regulatory protein by PKA allows increased calcium uptake into the sarcoplasmic reticulum.
What is phospholamban?
100
This class of drugs lowers serum cholesterol, resulting in a downstream upregulation of SREBP cleavage in normal hepatocytes.
What are statins?
100
Anterosuperior displacement of the aorticopulmonary septum during development results in this cyanotic congenital heart defect.
What is Tetralogy of Fallot?
100
A patient receives a drug that primarily acts on fast Na+ sodium channels, leading to a prolonged PR interval, which corresponds to this phase of the cardiac action potential.
What is phase 0 depolarization?
100
From about ages 5 to 20, these bones are the primary site of RBC production.
What are the long bones?
200
A patient has mild right hemidiaphragm elevation with no loss of sensation to the mandibular region or the skin over the right ear, likely due to a lesion to in this spinal nerve root.
What is C2?
200
Decreased oxygen delivery to myocardial tissue causes increased reliance on this substrate, resulting in lactate accumulation and a decrease in pH.
What is glucose?
200
A histological cross-section of a bronchus shows pseudostratified ciliated epitheleum, hyaline cartilage, smooth muscle, and elastic fibers but an absence of this cytochrome P-450-containing cell type.
What is a club cell?
200
A patient receives a cholesterol-lowering therapy that targets NPC1L1 within this portion of the small intestine, preventing absorption of dietary and biliary cholesterol, making it a good synergistic add on to statin therapy.
What is the jejunum?
200
Parasympathetic ganglia supplying the heart are derived from these migratory embryologic cells.
What are neural crest cells?
200
The completion of this ECG wave most closely corresponds to the end of ventricular systole.
What is the T wave?
200
This progenitor cell enters circulation and takes about 1 to 2 days to fully mature.
What is a reticulocyte?
300
As it enters the thorax, the phrenic nerve passes immediately anterior to a muscle that attaches to this rib.
What is the first rib?
300
This endogenous purine nucleoside accumulates during myocardial ischemia and helps protect the heart from reperfusion injury.
What is adenosine?
300
Vascular smooth muscle cells lack a troponin complex and instead rely on Ca²⁺/CaM activation of this kinase to phosphorylate its target and allow myosin to interact with actin.
What is myosin light chain kinase (MLCK)?
300
This Vaughan-Williams class primarily prolongs ventricular repolarization through potassium channel blockade, increasing the risk of Torsades de Pointes.
What is class III?
300
During cardiovascular development, most of this vessel regresses, while its contralateral counterpart contributes to the descending aorta.
What is the right dorsal aorta?
300
This type of AV block shows up on ECG as a constant PR interval, regular rhythm, but an absent QRS complex every fourth beat.
What is second-degree, Mobitz type II?
300
An MCV greater than 100 fL accompanied by elevated methylmalonic acid may indicate deficiency of this vitamin necessary for regeneration of the cofactor required for thymidine triphosphate synthesis.
What is vitamin B12?
400
This nerve lies posterior to the common corotid artery within the carotid sheath.
What is the vagus nerve (CN X)?
400
Deficiency of ApoE would most directly impair hepatic clearance of remnants derived from this ApoB-48-containing lipoprotein.
What is chylomicron?
400
Despite representing only a small fraction of airway epithelial cells, dysfunction of this cell type contributes significantly to the pathogenesis of cystic fibrosis due to its high expression of CFTR.
What are pulmonary ionocytes?
400
This antiarrhythmic is used to treat atrial fibrillation by enhancing vagal tone but carries the risk of atrial tachycardia and AV node block.
What is digoxin?
400
Failure of fusion of the endocardial cushions, aorticopulmonary septum, and muscular interventricular septum result in this developmental heart defect.
What is a membranous ventricular septal defect?
400
An elevated ST segment in leads V3-V4 may indicate ischemia in this region of the heart.
What is anteroapical?
400
This stage of erythropoiesis is characterized by simultaneous basophilic RNA staining and increasing eosinophilia from hemoglobin accumulation.
What is a polychromatic erythroblast?
500
Baroreceptors within this structure detect changes in blood pressure and can be found at the base of the internal carotid artery.
What is the carotid sinus?
500
Despite normal LCAT function, a patient exhibits decreased LCAT activation, likely due to a deficiency or defect in this lipoprotein.
What is ApoA-I?
500
(Nor)epinephrine increases cardiac contractility by activating this Gs-coupled receptor, resulting in increased cAMP and PKA activity.
What is β-1 adrenergic receptor?
500
Gemfibrozil accelerates triglyceride and VLDL clearance by activating this nuclear receptor, resulting in decreased ApoC-III expression and increased free fatty acid uptake by tissues.
What is PPARα?
500
The conus arteriosus of the adult heart is derived from this embryologic structure involved in cardiac dextral looping.
What is the bulbus cordis?
500
What is atrial fibrillation?
500
Absence of this growth factor would lead to the inability of nearly all committed cell lines to progress from their respective colony-forming units.
What is interleukin-3?
600
Anesthetizing this branch of CN X would impair sensory innervation to the laryngeal inlet while preserving function of most intrinsic laryngeal muscles.
What is the internal branch of the superior laryngeal nerve?
600
Inhibition of HMG-CoA reductase decreases synthesis of this 30-carbon molecule formed by condensation of two farnesyl pyrophosphate molecules.
What is squalene?
600
Binding of Ca²⁺ to this intracellular regulatory protein contributes to negative feedback of CICR by promoting Ca²⁺-dependent inactivation of L-type Ca²⁺ channels.
What is calmodulin?
600
A patient treated with niacin develops worsening gout. The increase in HDL observed with this therapy is primarily due to decreased hepatic catabolism of this apolipoprotein.
What is ApoA-I?
600
The remnants of this embryologic structure can be observed in the adult as fibrous cord within the free edge of the falciform ligament.
What is the left umbilical vein?
600
ECG shows an elevated ST segments in leads II, III, and aVF, leading you to suspect ischemia in this major vessel.
What is the right coronary artery?
600
A patient with untreated celiac disease develops macrocytic anemia because deficiency of this vitamin impairs conversion of dUMP to dTMP in developing erythroblasts.
What is folate (B9)?
700
This vessel travels with the internal branch of the superior laryngeal nerve through the thyrohyoid membrane.
What is the superior laryngeal artery?
700
Accumulation of long-chain fatty acyl-CoA contributes to decreased hexokinase activity and impaired glucose utilization. Chronic elevation of blood glucose would be detected clinically by measuring this glycated protein.
What is HbA1C?
700
Mechanosensors within type I alveolar cells activate this surfactant-stimulating G protein coupled receptor within type II alveolar cells.
What is P2Y2 receptor?
700
This class of drugs should be taken one hour or more or four hours or more after other medications and is contraindicated in patients with complete biliary obstruction.
What are bile acid sequestrants?
700
The distal portion of this pharyngeal arch artery derivative forms the ductus arteriosus.
What is the left 6th pharyngeal arch artery?
700
ECG shows a prolonged QT interval compared to baseline following administration of an antiarrhythmic drug that primarily acts on this phase of the ventricular action potential.
What is phase 3 repolarization?
700
Stabilization of this nucleus-binding factor upregulated production of erythropeoietin.
What is HIF-1α?
800
Impairment to the only tensor muscle of the larynx would result in an inability to move this synovial joint and an inability to produce higher-pitched sounds.
What is the crycothyroid joint?
800
A neonate presents with syndactyly, microcephaly, and multiple internal organ malformations, resulting from a defect in this terminal enzyme of de novo cholesterol synthesis.
What is 7-dehydrocholesterol reductase (DHCR7)?
800
Endothelial dysfunction within vascular structures could lead to rolonged vasoconstriction due to imaired CaM activation of this enzyme that catalyzes the oxidation of L-arginine.
What is endothelial nitric oxide synthase (eNOS)?
800
This drug that's commonly used to treat homozygous familial hypercholesterolemia that blocks microsomal triglyceride transfer protein can increase risk of severe hepatoxicity.
What is lomitapide?
800
This adult cardiovascular structure arises from the anastomotic network of vitelline veins.
What is the portal vein?
800
An ECG showing a predominantly positive QRS complex in lead I and a predominantly isoelectric aVF would be expected to have a QRS vector in this direction in aVR.
What is a negative QRS vector?
800
Hypoxia-responsive fibroblast-like cells within this renal compartment serve as the primary source of erythropoietin in adults.
What is the interstitial parenchyma?