Muscle tissue enables the body to move, pump blood, and move materials through internal organs and passageways. This lesson introduces the three types of muscle tissue, explains properties they share, and compares their microscopic organization and roles.
Muscle is one of the body's four primary tissue types. The three muscle tissue types are skeletal muscle, cardiac muscle, and smooth muscle. Although they differ in structure and function, all share important abilities.
All flashcards
What is an action potential in muscle tissue?
An electrical signal produced by a change in a muscle cell membrane's electrical state; it travels along the membrane.
What is the role of actin and myosin in contraction?
Myosin pulls on actin to generate force and, in many circumstances, shorten muscle.
How does calcium support contraction in smooth muscle?
Calcium activates enzymes that then activate myosin heads, enabling contraction.
What distinguishes a cardiac muscle fiber from a skeletal muscle fiber?
A cardiac fiber usually has one or two nuclei and connects physically and electrically with other cardiac fibers. A skeletal muscle fiber is multinucleated.
What do contractility, extensibility, and elasticity mean?
Contractility is the ability to generate force and shorten; extensibility is the ability to stretch; elasticity is the ability to recoil toward the original length.
Quiz questions
What are the three types of muscle tissue?Answer: Skeletal muscle, cardiac muscle, and smooth muscle.
What does excitability describe in muscle tissue?Answer: The ability of a cell membrane to respond to a stimulus by changing its electrical state.
How do troponin and tropomyosin contribute to contraction in skeletal and cardiac muscle?Answer: Calcium interacts with these regulatory proteins, exposing actin-binding sites for myosin.
A muscle is stretched and then recoils toward its original length. Which property does this demonstrate?Answer: Elasticity.
Why can cardiac muscle fibers help the heart contract as a coordinated unit?Answer: They are physically and electrically connected, allowing coordinated activity across the tissue.
Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.