Muscle Structure Function Flashcards
3 types of muscle tissue
Skeletal
Smooth
Cardiac
Fascia
Layers of dense connective tissue which surround and separate each muscle
What gives rise to tendons?
Fascia extending beyond the ends of the muscle
Aponeuroses
Broad sheets of connective tissue which sometimes joins muscles together
Where is the perimysium?
Extends inwards from the epimysium and surrounds bundles of skeletal muscle fibres
What is each muscle cells covered by?
The endomysium - A connective tissue layer
Sarcolemma
Cell membrane of a muscle fibre
Sarcoplasm
The cytoplasm of a muscle cell
What does the sarcoplasm contain?
Mitochondria and nuclei
Parallel myofibrils
What do thick filaments contain?
Protein myosin
What do thin filaments contain?
Protein actin
Troponin & Tropomyosin
What are myofibrils made up of?
Sarcomeres
What are I bands made up of?
Actin filaments
What are A bands made up of?
Overlapping thick and thin filaments
What does the H zone consist of?
Myosin filaments only
What does the M line consist of?
Proteins which hold the myosin filaments in place
What activates muscle contraction when the fibre is stimulated?
Sarcoplasmic reticulum and T tubules
How is a synapse created?
Each skeletal muscle fibre is functionally connected to the axon of a motor neuron
Neuromuscular junction
A synapse between a motor neuron and a muscle fibre it regulates
What exerts the pulling force in skeletal muscle contraction?
The binding of myosin to actin
What causes the shortening of a muscle fibre?
Actin and myosin filaments overlapping as they slide past each other
Actin
Globular protein arranged in twisted filaments
Contains myosin binding sites
What 2 proteins are associated with the surface of actin molecules?
Troponin and tropomyosin
