Download Lecture Notes - Fullfrontalanatomy.com

Chapter 10
I.
Muscle Tissue
Student Notes
Overview of Muscle Tissue (p. 234).
A. In all its forms, muscle tissue makes up nearly half the body’s mass.
B. Functions of muscle tissue include movement, posture maintenance, joint stabilization, and generation of body heat.
C. Special functional characteristics separate muscle tissue from other tissues; special properties include contractility,
excitability, extensibility, and elasticity.
D. The three types of muscle tissue are skeletal, cardiac, and smooth; a cell in skeletal and smooth muscle tissue is called a
fiber.
II.
Skeletal Muscle (pp. 234–245, Figs. 10.1–10.9, and Table 10.1).
A. Basic features of skeletal muscle include connective tissue sheaths, fascicles, nerves, blood vessels, and attachment to
bones.
B. Every skeletal muscle is an organ.
C. The muscle ends of attachment are termed the origin and insertion; attachments also are direct (fleshy) or indirect.
D. Microscopic and functional anatomy of skeletal muscle tissue examines the structure and function of the skeletal muscle
fiber.
E. A skeletal muscle fiber is a single, very long cylindrical, multinucleate cell characterized by the presence of myofibrils
and sarcomeres; these striated cells are controlled voluntarily.
F.
The mechanism of contraction is explained by the sliding filament theory.
G. Muscle tissue can be stretched by the contraction of an opposing muscle. This is called muscle extension and should not
be confused with muscle elasticity.
H. Muscles attach to the skeleton at a near optimal length for generating the strongest pulling forces.
I.
Sarcomeres resist overextension due to the influence of titin and other myofibril proteins.
J.
Skeletal muscle contraction is regulated by two sets of intracellular tubules; sarcoplasmic reticulum is smooth
endoplasmic reticulum that stores calcium ions and T tubules are deep invaginations of the sarcolemma.
K. The three types of skeletal muscle fibers are slow oxidative fibers, fast glycolytic fibers, and fast oxidative fibers.
III.
Cardiac Muscle (pp. 245–247, Figs. 10.10–10.11).
A. Cardiac muscle is the muscle of the heart wall; the striated cells are branching chains with one or two nuclei and are
characterized by intercalated discs and involuntary contraction.
IV.
Smooth Muscle (pp. 247–249, Figs. 10.12–10.13).
A. Smooth muscle is located in the walls of hollow organs, such as the organs of the digestive tract and respiratory
structures; the uninucleate, spindle-shaped fibers lack striations and are involuntary.
V.
Disorders of Muscle Tissue (pp. 249–250).
A. Examples of disorders of skeletal muscle tissue are muscular dystrophy, myofascial pain syndrome, and fibromyalgia.
B. Smooth muscle disorders usually stem from external irritants.
C. Disorders of cardiac muscle tissue are the most common and there are three broad categories: coronary artery disease,
heart failure, and conducting system disorders. Chapter 18 covers this topic in detail.