BIPN 105 Lecture Notes - Lecture 7: Cardiac Muscle, Afterload, Sarcomere

• School: UCSD
• Department: Bioinformatics
• Course: BIPN 105
• Professor: Catalina Reyes Gonzalez

Document Summary

Cardiac muscle contraction: phases of cardiac muscle contraction. Isometric: maintain length of muscle; changes in tension. Isotonic: maintain tension; changes in length of muscle. Skeletal vs. cardiac muscle tension: active tension: tension generated during contraction. Depends on contractile properties of the muscle (myosin and actin forming cross bridges: passive tension: depends on elastic elements of muscle. Before contraction, how much tension is generated: total tension: active tension + passive tension, heart vs. skeletal, sarcomere length for cardiac muscle is shorter, so pt curve shifted left, cardiac muscle is less compliant/elastic. Little bit of stretch increases passive tension a lot: both pt and at start to the left of the curve, creating a straight total tension curve. Indicates that as you stretch cardiac muscle, tension increases in almost a linear fashion, so cardiac muscle can generate more tension and force of contraction will increase (to a physiological limit). Intrinsic property of the heart (depends on nothing outside of the heart)