Lecture Notes on the Muscle System

These flashcards cover key concepts from Chapter 09 of the Muscle System, including muscle types, structures, functions, and related disorders.

What are the three types of muscle tissue in the muscular system?

Skeletal muscle, cardiac muscle, and smooth muscle.

How is skeletal muscle characterized?

Skeletal muscle is attached to bones, is voluntary, and is composed of over 600 muscles, functioning under conscious control.

What distinguishes cardiac muscle?

Cardiac muscle makes up the heart wall, is involuntary, and responsible for pumping blood.

Describe smooth muscle. Where is it found?

Smooth muscle is involuntary, found in the walls of internal organs, such as the digestive tract.

What are the connective tissue coverings of muscles?

Fascia, tendon, and aponeurosis cover skeletal muscles.

What is compartment syndrome?

It is a condition with fluid accumulation, increasing pressure in compartments of muscles, leading to pain and deficiency of oxygen and nutrients.

What is the structure of a skeletal muscle fiber?

Skeletal muscle fibers are multinucleated and include structures like sarcolemma, sarcoplasm, and myofibrils.

What is the sliding filament model in muscle contraction?

It explains that during contraction, actin and myosin filaments slide past each other, shortening the sarcomeres.

What neurotransmitter initiates skeletal muscle contraction?

Acetylcholine (ACh) stimulates contraction by binding to receptors on the motor end plate.

What are fast-twitch and slow-twitch muscle fibers?

Fast-twitch (Type II) fibers are geared for rapid contractions and quick energy, while slow-twitch (Type I) fibers are fatigue-resistant and rely on aerobic metabolism.

Define muscular hypertrophy. How is it achieved?

Hypertrophy is the enlargement of skeletal muscle due to exercise that stimulates slow-twitch fibers and increases mitochondria and capillaries.

What is the difference between isotonic and isometric contractions?

Isotonic contractions change muscle length, while isometric contractions produce tension without changing length.

Explain the term 'motor unit'.

A motor unit consists of a motor neuron and all the muscle fibers it controls.

What is muscle fatigue?

Muscle fatigue is the inability to contract muscle, commonly influenced by decreased blood flow and ion imbalances.

What are the major functions of smooth muscle?

Smooth muscle controls involuntary movements in internal organs, such as peristalsis in the digestive tract.

How does the heart muscle differ from skeletal muscle?

Cardiac muscle has intercalated discs, is striated, and contracts in a synchronized manner as a unit.

What are the characteristics of skeletal, smooth, and cardiac muscles?

Skeletal muscle is voluntary and striated; smooth muscle is involuntary and lacks striations; cardiac muscle is involuntary and striated.