Cardiovascular System Flashcards
Embryonic origin of the left atrium
Trabeculated left atrium –> primitive atria Smooth part of left atrium –> smooth part of left atrium
Embryonic origin of the right atrium
Trabeculated right atrium –> primitive atria Smooth part of right atrium –> right horn of sinus venosus
Which embryonic aortic arch forms the adult aortic arch?
Left fourth
Which embryonic aortic arch forms the adult left pulmonary artery and ligamentum arteriosum?
Left sixth
Which embryonic aortic arch forms the adult right pulmonary artery?
Right sixth
Which embryonic aortic arch forms the adult right subclavian artery?
Right fourth
Describe the course of the recurrent laryngeal nerves?
The left recurrent laryngeal nerve loops under the aortic arch near the ligamentum arteriosum. The right recurrent laryngeal nerve loops under the right subclavian artery.
Which embryonic aortic arches forms the common carotid arteries and proximal internal carotid arteries?
Left and right third
Leads I and aVL
Lateral MI –> left circumflex
Leads V1-V4
Anterior MI –> left anterior descending
Leads V1-V4, V5-V6, I, aVL
Anterolateral MI –> left main
Leads II, III, aVF
Inferior MI –> posterior descending (85% branches from right coronary)
What increases the heart’s contractility?
Catecholamines –> ↑ inward Ca2+ current during phase 2 –> ↑ intracellular Ca2+ ↑ HR –> ↑ intracellular Ca2+ ↓ extracellular Na+ (↓ activity of Na+/Ca2+ pump) Digitalis –> inhibits Na+/K+ ATPase –> intracellular Na+ ↑ –> diminished gradient for Na+/Ca2+ pump –> ↑ intracellular Ca2+
What increases stroke volume?
↑ contractility ↑ preload ↓ afterload Anxiety, exercise (early), pregnancy
What decreases the heart’s contractility?
β1-blockade Heart failure with systolic dysfunction Acidosis Hypoxia/hypercapnea Non-dihydropyridine CCB Parasympathetic stimulation –> ↓ inward Ca2+ current –> ↓ intracellular Ca2+
What does S1 correspond to?
Closure of mitral and tricuspid valves
What does S2 correspond to?
Closure of aortic and pulmonary valves
What does S3 correspond to?
Rapid ventricular filling during early diastole a/w increased filling pressures –> mitral regurgitation, CHF, pregnancy
What does S4 correspond to?
Atrial kick in late diastole a/w high atrial pressures –> ventricular hypertrophy
What can cause prolonged QT interval?
Hypokalemia Hypomagnesemia Drugs (sotalol, risperidone, macrolides, chloroquine, protease inhibitors, quinidine, thiazides)
What decreases myocardial oxygen consumption?
↓ preload/end-diastolic volume ↓ BP (↓ afterload) ↓ HR ↓ contractility Nitrate + β-blocker greatly reduces myocardial oxygen consumption and is used to treat angina
Which congenital heart diseases results in early cyanosis (blue babies) and requires urgent surgical correction and/or maintenance of a PDA?
5 T’s: Truncus arteriosus Transposition of the great vessels Tricuspid atresia Tetrology of Fallot TAPVR (totally anomalous pulmonary venous return)
Congenital heart defect associated with DiGeorge syndrome (22q11 syndrome)?
Truncus arteriosus Tetralogy of Fallot
Congenital heart defect associated with Down Syndrome?
ASD VSD AV septal defect (endocardial cushion defect)
