Muscular System Flashcards
What are the three types of muscles?
- Smooth - Walls of hollow organs (Stomach) - Involuntary
- Cardiac - Walls of the heart - Involuntary
- Skeletal - Attaches to the skeleton - Voluntary
How do bones attach to muscles?
Tendons
Tendons of Insertion
Attached to the more distal bone of a joint.
More mobile
Tendons of Origin
Attached to the proximal bone of a joint.
Less mobile
What are the two categories of the skeletal muscles?
- Slow-Twitch
2. Fast - Twitch
Slow-Twitch Muscle Fibers
Contract Slower
More Efficient
Used during aerobic metabolism when oxygen is readily available.
Fast-Twitch Muscle Fibers
Type 2A and 2X
Fatigue Quickly
More Powerful than Slow-Twitch
Myofibril
The portion of the muscle containing the thick (myosins) and thin (actin) contractile filaments.
A series of sarcomeres where the repeating pattern of the contractile proteins gives the striated appearance to skeletal muscle.
Myosin
Thick contractile protein in a myofibril.
Actin
Thin contractile protein in a myofibril.
Sarcomere
The basic functional unit of the myofibril containing the contractile proteins that generate skeletal muscle movements.
How does the muscle contract?
- Acetocolene is detected.
- Calcium is released.
- Actin binding sites exposed for myosin to attach.
- When ATP is plentiful the sites will bind easily and form a cross-bridge.
- Myosin pulls actin towards the center, sarcomere shortens.
- Several fibers stimulated at the same time then the muscle will contract.
Connective Tissue
Material between the cells of the body that gives the tissue form and strength.
What is the most abundant connective tissue?
Collagen
Collagen
Inextensibility and tensile strength.
What are the wave-like folds found in collagen called?
Crimps; when a fiber is pulled the crimp straightens and the it’s length increases.
Elastin
Found in extensible fibers and can stretch up to 150% of the original length before rupturing.
Tendons
Tough, chord-like tissues that connect muscles to bone.
Produces Movement
Ligaments
Attach bones to other bones.
Fascia
Superficial, deep, and intramuscular.
Know to be all the other connective tissue in the body.
Developing and isolating muscles to providing structural support.
Chronic Hypertrophy
Increase in:
- Myofibrils,
- Actin and myosin filaments
- Sarcoplasm
- Connective tissues
- Muscle protein synthesis
