Muscular System Flashcards
Functions of Muscle
Movement, Stability, control openings, heat production(85%), glycemic control
Characteristics of muscle
Excitability, conductivity, contractility, extensibility, elasticity
Types of muscle tissue
Smooth/Involuntary, Cardiac, Skeletal/Voluntary
Smooth/Involuntary Muscle characteristics
uninucleated, fusiform shape, no striation, slow sustained contraction
Cardiac Muscle characteristics
Uninucleated, branched cells, striations, interclated discs, autorhythmic
Skeletal/Voluntary Characteristics
Multinicleated, long cells, striations, respond to nerve stimulation
Myofiber
Skeletal muscle cell
Sarcolemma
Cell membrane of muscle cell
Sarcoplasmic Reticulum
Endoplasmoc Reticulum of muscle cell
Terminal Cisterns
End savs on sarcoplasmic reticulum
Transverse tubules
Inavginstions of sarcolemma
Componets of muscle
Largest to Smallest
- Muscle
- Fasicles
- Muscle fiber
- Myofibrils
- Myofilaments
Sarcomere Componets
Actin filaments (Thin) Myosin filaments (Thick) Dystrophin: Links actin go sarcolemma Troponin tropomyosin complex: Cover active sites on actin Z disc
Muscle Coverings (Smallest to Largest)
- Sarcolemma
- Endomysium
- Permysium
- Epimysium
Sarcolemma(Covering functions)
Cell membrane to muscle fiber
Endomysium
Areolar connective, surrounds myofiber
Perimysium
Dense irregular connective, covers fasicles
Epimysium
Dense irregular comnective, covers all muscle till tendon
A band
Dark; myosin overlaps myosin/actin filaments
H bands
Middle of A, ONLY myosin filament
I band
Light, ONLY actin
Z line
Attachment point for actin filaments, marks sarcomere
Motor unit
- One somatic nerve fiber and all myofibers innervated by that nerve
- Somatic nerve fires and stimulates all myofibers
- Strength of contraction depends on how many units called