12 - Muscle structure / metabolism Flashcards
What is the diameter and length of skeletal muscle?
Diameter - 10-100 micrometer
Length - 1-40 millimeter
What is each muscle in an antagonist pair called?
Agonist
Synergist
Give some roles of skeletal muscles? e.g. posture
breathing, posture, locomotion, prehension, mastication, swallowing, vision, temperature regulation, food supply, venous return
What are the levels of organisation in muscle?
Muscle -> Fascicles (e.g. tendon) -> Fibres -> Fibrils -> Filaments
What are the stages of skeletal muscle fibre development?
Differentiation -> cell division -> cell fusion -> myotubes > cell growth (myofibres)
What are the components of a muscle cell? (8)
Basil Lamina, Plasmalemma, Nuclei, Myofibrils-myofilaments, Mitochondria, Glycogen/lipid
T Tubules, sarcoplasmic reticulum
What is the contractile apparatus of one sarcomere?
Z lines
actin filaments
myosin filaments
What are the components of actin? (thin filament)
Tropomyosin
Troponin complex
G actin
What is excitation–contraction (E-C) coupling
an action potential arrives to depolarize the cell membrane. this depolarization results in an increase in cytosolic calcium that is called a calcium transient. This increase in calcium activates calcium-sensitive contractile proteins that then use ATP to cause cell shortening.
Where does energy for E-C coupling come from?
With increasing importance: -Stored ATP • Stored ADP • Stored Creatine Phosphate (CP) • Anaerobic metabolism • Aerobic metabolism
give some functional sysems that may suffer primary damage in disease OR can be improved with exercise training
- Ion fluxes • Neuromuscular transmission • Excitation-contraction coupling • Oxidative phosphorylation • mRNA transport
What is a normal vs exercised CK level
Normal = 100IU Exercised = 250IU Diseased = 10,000IU
