BIO10004 Week 4.2 Muscles 1

Flashcards reviewing the key concepts of muscle tissue, including skeletal, cardiac, and smooth muscle, their functions, organization, and contraction mechanisms.

What are the three types of muscle tissue?

Skeletal muscle, cardiac muscle, and smooth muscle.

What are the four common properties of muscle tissue?

Excitability, contractility, extensibility, and elasticity.

List the functions of skeletal muscle.

Producing movement, maintaining posture, supporting soft tissues, guarding entrances/exits, maintaining body temperature, and storing nutrients.

What are the three layers of connective tissue in skeletal muscle?

Epimysium, perimysium, and endomysium.

What is the function of the epimysium?

Surrounds the entire muscle and separates it from surrounding tissues.

What is the function of the perimysium?

Surrounds muscle fiber bundles (fascicles).

What is the function of the endomysium?

Surrounds individual muscle cells (muscle fibers).

What is a tendon?

A bundle of collagen fibers that attaches skeletal muscles to bones.

What is an aponeurosis?

A sheet of collagen fibers that attaches skeletal muscles to bones.

Why do skeletal muscles have extensive vascular networks?

They deliver oxygen and nutrients and remove metabolic wastes.

How do skeletal muscles contract?

They are stimulated by the central nervous system.

How do skeletal muscle fibers develop?

Fusion of embryonic cells called myoblasts.

Name the 2 types of myofilaments.

Actin and Myosin.

Name the bands of a sarcomere.

I band, A band, H band (M line).

What happens during the sliding filament theory of muscle contraction?

H bands and I bands narrow, zones of overlap widen, Z lines move closer together, and the width of A band remains constant.

What is the neuromuscular junction (NMJ)?

Synapse between a motor neuron and a skeletal muscle fiber.

What neurotransmitter is released at the neuromuscular junction?

Acetylcholine (ACh).

What are the characteristics of cardiac muscle tissue?

Found only in the heart, striated like skeletal muscle, and connected by intercalated discs.

Where is smooth muscle tissue found?

Sheaths around organs and blood vessels; found in integumentary, cardiovascular, respiratory, digestive, urinary, and reproductive systems.

What are the functional characteristics of smooth muscle tissue?

Excitation-contraction coupling, length-tension relationships, control of contractions, and smooth muscle tone.

What is plasticity in the context of smooth muscle?

The ability to function over a wide range of lengths.

What is smooth muscle tone?

Normal background level of activity in smooth muscle.