Muscular System
A muscle ________ , also known as a muscle cell, contains a sarcolemma, sarcoplasm, myofilaments, and myofibrils.
Fiber
Activities requiring aerobic endurance are
characterized by sustained, low levels of activity
Transverse tubule
Tubes that form from sarcolemma that allow for electrical stimuli to reach deep into each fiber
Which of the following accurately lists the levels of organization within a muscle from largest to smallest?
muscle fiber, myofibril, myofilament
Which of the following areas of the human body are dominated by slow fibers?
back and calf muscles
Aponeurosis
Attaches muscle to muscle
Tendon
Attaches muscle to bone
Which of the following characteristics describes cardiac muscle?
Cardiac muscle cells are striated and branched with intercalated discs
The striated appearance of skeletal muscle results from myofilaments which are composed of proteins called
Cisternae placement
Which of the following statements about how skeletal muscles use and store energy is true?
During light activity, muscles generate energy through the aerobic breakdown of carbohydrates, lipids, or amino acids.
Skeletal muscle fibers differ from "typical cells" in that these muscle fibers
Have many nuclei
Which of the following parts of a sarcomere contain the protein actin only?
I band
Myofibrils
Made of bundles of myofilaments
A long, filamentous organelle found within muscle cells that has a banded appearance is called a
Myofibril
What structure divides the skeletal muscle into compartments and contains collagen fibers, elastic fibers, blood vessels, and nerves?
Perimysium
Curare is best known as the South American "poison arrow" toxin used for hunting. A synthetic form of curare is used routinely in emergency care to facilitate intubation. Curare specifically blocks acetylcholine (ACh) receptors. What is the result of administering curare to a skeletal muscle group?
Relaxation
The plasma membrane of the muscle cell is called the
Sarcolemma
The contractile unit of muscle is called a
Sarcomere
The skeletal muscles store calcium ions in the terminal cisternae of the
Sarcoplasmic reticulum
Which of the following statements best describes how muscles help maintain homeostasis?
Skeletal muscle contractions help maintain body temperature
A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more ________ in his or her leg muscles.
Slow fibers
Nonstriated, involuntary muscle is
Smooth
Structures filled with extracellular fluid, formed by the tunneling of the sarcolemma through the muscle fiber, are called
T tubules
Myosin
Thick myofilaments
Actin
Thin myofilaments
Sarcoplasm
The cytoplasm
Sarcolemma
The plasma membrane
What is the biochemical explanation for rigor mortis?
The sarcoplasmic reticulum is unable to remove calcium ions from the sarcoplasm.
Sarcomere
The smallest functional unit of skeletal muscle formed by repeats of myofilament arrangements
Sarcoplasmic Reticulum
The smooth endoplasmic reticulum; produces calcium needed for contraction
endomysium
The type of connective tissue that covers each muscle fiber
Epimysium
The type of connective tissue that covers the entire muscle
Perimysium
The type of connective tissue that divides the muscle into bundles
Which of the following statements regarding fast skeletal muscle fibers is true?
They are large in diameter, with relatively few mitochondria
