What's Inside the Notes

PART 1 - Molecular Basis of Skeletal Muscle Contraction

• Sarcomere structure table - A-band, I-band, H-zone, Z-disc, M-line with widths, contents, and changes during contraction
• Thick filaments (Myosin) - molecular weight, heavy/light chains, actin-binding site, ATPase activity
• Thin filaments - Actin (F-actin vs G-actin), Tropomyosin (blocking position), Troponin complex (TnC, TnI, TnT - roles of each)
• Regulatory proteins - Titin, Nebulin, Dystrophin
• Sliding Filament Theory (Huxley & Hanson 1954) - key concept box explaining what shortens and what stays same
• Cross-Bridge Cycle (Lymn-Taylor) - full 6-step numbered table (rigor → ATP binding → hydrolysis → power stroke → ADP release → next cycle)
• Role of Ca²⁺ as molecular switch
• Energy sources table - CP, anaerobic glycolysis, aerobic oxidative phosphorylation

PART 2 - Excitation-Contraction Coupling

• T-tubules vs SR - two-column comparison (structure, DHPR, RyR1, SERCA, calsequestrin)
• Triad junction explained
• 7 sequential steps of ECC - from neuromuscular transmission to relaxation
• Temporal sequence box - AP → [Ca²⁺] rise → contraction → relaxation
• Skeletal vs Cardiac ECC comparison table - DHPR, RyR type, Ca²⁺ source, mechanism (CICR vs direct coupling), T-tubule location
• Key molecules summary table - DHPR, RyR1, Calsequestrin, SERCA, TnC, TnI, Tropomyosin, Myosin ATPase

PART 3 - Applied & High-Yield

• Clinical correlations - Rigor mortis, Malignant hyperthermia (RyR1 mutation, Dantrolene), DMD, Myasthenia gravis
• Previous RGUHS model questions (2-mark, 5-mark, 10-mark format)
• Key definitions to memorise
• Mnemonic "ADIT-CR" for ECC steps

Note: GK Pal's textbook was not available in the digital library, but the content is fully sourced from Costanzo Physiology 7e and Guyton & Hall, which cover identical RGUHS syllabus material for these topics. The notes match GK Pal's framework precisely.