Page 1 Flashcards
What results from the contraction and relaxation of muscles?
Motion results from alternating contraction and relaxation of muscles.
What is the prime function of muscle?
The prime function of muscle is changing chemical energy into mechanical energy to perform work.
What are the properties of muscular tissues?
- Electrical excitability: responds to stimuli by producing action potentials.
- Contractility: ability to generate tension to do work.
- Extensibility: ability to be extended or stretched.
- Elasticity: ability to return to original shape after contraction or extension.
What characterizes skeletal muscle tissue?
Skeletal muscle tissue is primarily attached to bones, striated, and voluntary.
What is fascia?
Fascia lines the body wall and limbs, surrounds and supports muscles, allows free movement, carries nerves and blood vessels, and fills space between muscles.
What are tendons?
Tendons are rope-like extensions of connective tissue that attach the muscle to bone or other muscle.
What is an aponeurosis?
Aponeurosis is a wide and flat extension of connective tissue that attaches the muscle to bone or to other muscles.
What are somatic motor neurons?
Somatic motor neurons provide the nerve impulses that stimulate skeletal muscle to contract.
What are satellite cells?
Satellite cells are myoblasts that persist after birth.
What is the sarcolemma?
The sarcolemma is the muscle fiber’s plasma membrane surrounding the sarcoplasm.
What are myofibrils?
Myofibrils are the contractile elements of skeletal muscle.
What is myosin?
Myosin is a contractile protein that makes up the thick filament and generates force during muscle contractions.
What is actin?
Actin is a contractile protein that is the main component of the thin filament.
What is tropomyosin?
Tropomyosin is a regulatory protein that covers myosin binding sites on actin molecules when a skeletal muscle fiber is relaxed.
What is troponin?
Troponin is a regulatory protein that helps switch the muscle contraction process on and off.
What are structural proteins in muscle tissue?
Structural proteins keep thick and thin filaments together, including titin, alpha-actinin, myomesin, nebulin, and dystrophin.
What is the sarcoplasmic reticulum?
The sarcoplasmic reticulum surrounds each myofibril.
What are sarcomeres?
Sarcomeres are compartments within myofibrils that contain thick and thin filaments.
What are Z discs?
Z discs are narrow, plate-shaped regions of dense material that separate one sarcomere from the next.
What is the A band?
The A band is the dark middle part of the sarcomere that extends the entire length of thick filaments.
What is the I band?
The I band is a lighter, less dense area of the sarcomere that contains thin filaments but no thick filaments.
What is the H zone?
The H zone is a narrow region in the center of each A band that contains thick filaments but no thin filaments.
What is the M line?
The M line is the region in the center of the H zone that contains proteins holding thick filaments together.
What characterizes cardiac muscle tissue?
Cardiac muscle tissue forms the wall of the heart, is striated, and involuntary.
How do cardiac muscle fibers connect?
Cardiac muscle fibers connect through intercalated discs, which contain desmosomes and gap junctions.
How long does cardiac muscle tissue remain contracted compared to skeletal muscle?
Cardiac muscle tissue remains contracted 10 to 15 times longer than skeletal muscle tissue.
What stimulates cardiac muscle tissue to contract?
Cardiac muscle tissue contracts when stimulated by its own auto rhythmic fibers.
What type of respiration does cardiac muscle depend on?
Cardiac muscle depends greatly on aerobic respiration to generate ATP.
Where is smooth muscle tissue located?
Smooth muscle tissue is located primarily in internal organs and is non-striated and involuntary.
