KAAP309 Lecture Notes - Lecture 6: Endoplasmic Reticulum, T-Tubule, Myocyte

• School: University of Delaware
• Department: Kinesiology & Appl Physiology
• Course: KAAP309
• Professor: Rose William

Document Summary

Sarcomere=part of one striated muscle cell = from one. Dark where thick filaments are lined up together, light where there aren"t thick filaments. Why do dark bands maintain length and light bands get shorter when muscle contracts? (compared to both bands getting shorter, or just dark bands getting shorter, neither of which happens to any significant degree. ) Actin & myosin major components of thin & thick filaments. T tubule function conduct voltage impulse from sarcolemma into depths. Voltage sensor proteins in t-tubule line up with ca-release proteins in sr. E-c coupling = events from nerve impulse arriving at muscle cell to generation of force. Cross bridge cycle: see marieb & hoehn 9th ed. , fig. Steps in fig 9. 12 repeat in a cycle many (dozens of) times in a single brief muscle twitch, because the ca stays high for 10 ms or more, while steps of fig. 9. 12 are much faster (0. 06 millisecond according to mann (http://www. unmc. edu/physiology/mann/mann14. html.