Anatomy~ Chapter 10

Three types of muscle tissue

Skeletal, Cardiac, Smooth.

Functions of muscle

Movement, Stability, Control of body openings and passages, Heat production.

Excitability (responsiveness)

The property of muscle to react to stimuli.

Contractility

The ability of muscle to shorten when stimulated.

Voluntary muscle

Muscle that can be consciously controlled, e.g., skeletal muscle.

Involuntary muscle

Muscle that cannot be consciously controlled, e.g., cardiac and smooth muscle.

Striated muscle

Muscle that has a patterned appearance due to the arrangement of myofilaments, e.g., skeletal and cardiac muscle.

Myofilaments

Contractile proteins within muscle fibers; includes thick myofilaments (myosin) and thin myofilaments (actin).

Sarcomere

The basic structural and functional unit of muscle, defined by the Z disc.

Neuromuscular junction

The synapse between a motor neuron and a muscle fiber, where neurotransmitters are released.

Myopathy

Diseases of muscle, including muscular dystrophy and myasthenia gravis.

Myosin

A thick myofilament that forms cross-bridges with actin during muscle contraction.

Actin

A thin myofilament involved in muscle contraction; exists in fibrous (F) and globular (G) forms.

Troponin

A regulatory protein that attaches to tropomyosin and binds calcium during muscle contraction.

Cardiac muscle characteristics

Striated, involuntary, typically mononucleated, with intercalated discs.

Smooth muscle characteristics

Non-striated, involuntary, fusiform shape, and can be categorized as multiunit or unitary.