Marieb Main Ch 9 Muscle Tissue

What are the three types of muscle tissue?

Skeletal, Cardiac, and Smooth muscle tissue.

What type of muscle tissue is striated and voluntary?

Skeletal muscle tissue.

Where is cardiac muscle tissue located?

Only in the heart.

What is the main function of skeletal muscle?

Movement of bones or fluids, maintaining posture, stabilizing joints, and heat generation.

What are the connective tissue sheaths of skeletal muscle?

Epimysium, Perimysium, and Endomysium.

What is the smallest contractile unit of a muscle fiber?

Sarcomere.

What is the role of calcium ions in muscle contraction?

Ca2+ binds to troponin, causing tropomyosin to move and allowing myosin heads to attach to actin.

What is the sliding filament model of contraction?

Myosin heads bind to actin, detach, and bind again to slide the thin filaments towards the M line.

What is a motor unit?

A motor neuron and all the muscle fibers it supplies.

What are the three phases of a muscle twitch?

Latent period, Period of contraction, Period of relaxation.

What is muscle fatigue?

Physiological inability to contract, often due to ionic imbalances or prolonged exercise.

What is muscular dystrophy?

A group of inherited muscle-destroying diseases that cause muscle fibers to atrophy.

What is the difference between single-unit and multiunit smooth muscle?

Single-unit smooth muscle contracts rhythmically as a unit; multiunit smooth muscle does not.

What condition is characterized by the immune system attacking the neuromuscular junction?

Myasthenia gravis.

What is the purpose of the acetylcholine (ACh) at the neuromuscular junction?

It binds to receptors on the sarcolemma, initiating muscle contraction.

What happens in the cross bridge cycle during muscle contraction?

Myosin heads attach to actin, pull the thin filaments, detach, and are then recocked by ATP.