anatomy chap 10

What are the three types of muscle tissue?

Skeletal, Cardiac, and Smooth.

What is the primary function of skeletal muscle?

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

What stimulates skeletal muscles?

Somatic motor neurons.

What is the structural unit of a muscle fiber called?

Sarcomere.

What are the thick and thin filaments in a sarcomere?

Thin filaments are composed of Actin, and thick filaments are composed of Myosin.

What is the role of calcium ions in muscle contraction?

Ca++ ions bind to troponin, causing tropomyosin to expose binding sites for myosin on actin.

What is the sliding filament model?

It describes how thin filaments slide past thick filaments during muscle contraction.

During which type of contraction does muscle length change?

Isotonic contractions.

What happens during isometric contractions?

Muscle length does not change because the load exceeds the tension the muscle can generate.

What occurs during wave summation?

Excitation-contraction coupling effects of successive motor neuron signaling add together.

What is hypertrophy in muscle fibers?

Increase in muscle size due to an increase in the number of FG fibers.

What is atrophy in muscle fibers?

Reduction in muscle mass due to disuse.

What type of muscle tissue is found only in the heart?

Cardiac muscle tissue.

What structural features are characteristic of cardiac muscle tissue?

Intercalated discs, gap junctions, and desmosomes.

Where is smooth muscle tissue typically found?

Around organs in the digestive, respiratory, reproductive tracts, and in the iris of the eye.