BIOL 1119- Final Exam Guide - Comprehensive Notes for the exam ( 158 pages long!)

• School: Northeastern University
• Department: Biology
• Course: BIOL 1119
• Professor: Christopher Richardson

Document Summary

Mechanical junctions tightly join myocytes desmosomes: weld- like mechanical junctions between cardiocytes: enables the cells to pull on each other without pulling apart during contraction. Increase afterload decreases sv: amount of tension in ventricular myocardium before it contracts. The more a muscle is stretched, the better the overlap between filaments and the stronger the contraction. Frank-starling law of heart: sv edv. Ventricles eject as much blood as they receive: more they are stretched, the stronger the contraction. Contractility: contraction force for a given preload, sympathetic nervous system and chemicals affect contractility, the parasympathetic system via the vagus nerve has no significant effect on strength of ventricular contraction because it does not innervate the myocardium. Afterload: pressure in arteries above semilunar valves opposes opening of valves. Any restricting of arterial circulation increases afterload (lung disease, atherosclerosis, etc. : continuous increases in afterload causes hypertrophy of ventricular myocardium, may lead to weakening and failing of ventricles.