Muscle Flashcards
Muscle makes up ______ of mass in humans
30-50%
What are the two types of striated muscle
Skeletal and cardiac
What is the non striated muscle type
Smooth
What is the only voluntary muscle type
Skeletal
Where is the site of most ANS innervation and function
Smooth muscle
What is the order of how a muscle is packed?
Muscle-fascicles-fibers(myocyte)-sarcomeres
Long, thin cell with multiple nuclei and many myofibrils
Muscle fiber (myocytes)
What is the muscle cytoplasm
Sarcoplasm, lots of mitochondria
What does each myofibril consist of
Many sarcomeres surrounded by the sarcoplasmic reticulum and T tubule system
Highly organized contractile and structural proteins
Sarcomeres
What muscle type does not have sarcomeres
Smooth
Thick and thin filaments
Contractile proteins
Thick filament
Myosin
What does myosin consist of
- intertwined heavy chains with globular heads
- heads bind actin and have ATPase activity
What is the makeup of actin
2 strands of F actin in a helix
What is F actin made of
Many G actin molecules
Where are hte myosin binding sites
Actin
Double stranded helix around actin. Covers the myosin binding site
Tropomyosin, regulatory
What is bound to tropomyosin
Troponin complex
Troponin T (TnT)
Binds the complex to tropomyosin
Troponin I (TnI)
- inhibitory
- holds tropomyosin in the myosin binding site
Troponin C (TnC0
Binds calcium, uncovers myosin binding site
Connect sarcomeres to sarcolemma and ECM
Dystrophin
What is the most common mutation that causes muscular dystrophy
Mutations in dystrophin