Anatomy 7.1-7.3 Exam with Complete
Solutions
What are the functions of skeletal muscles? - ANS-1. produce movement
2. maintain body posture/position
3. Support soft tissues
4. Guard entrances and exits
5. Maintain body temperature
What are the 3 types of muscle tissue? - ANS-skeletal, smooth, cardiac
skeletal muscles - ANS-organs composed primarily of skeletal muscle tissue, but they
also contain connective tissues, nerves, and blood vessels
muscle tissue - ANS-Tissue made of cells capable of contracting
Skeletal Muscle Fibers - ANS-Located inside muscles, where they are organized into
bundles called fascicles (=fasciculi)
Fascicles - ANS-small bundle of muscle fibers
Perimysium - ANS-Connective tissue surrounding a fascicle. Portions of the perimysium
extend into the fascicle and merge with the endomysium.
Endomysium - ANS-A thin layer of areolar connective tissue that covers each muscle
fiber.
Epimysium - ANS-Connective tissue layer surrounding an individual muscle
Myofibers - ANS-Individual muscle cell or fiber; are long narrow cells that often span the
entire length or a muscle.
Sarcoplasm - ANS-The cytoplasm of a striated muscle fiber. Most of the sarcoplasm is
occupied by myofibrils.
Microfibrils - ANS-Cylindrical bundles of contractile proteins. Living muscle fibers usually
contain hundreds to thousands of myofibrils.
Sarcolemma - ANS-cell membrane of a muscle fiber
An extensible membrane enclosing the contractile substance of a muscle fiber.
, Striated - ANS-Marked with parallel bands; striped; Skeletal muscles fibers appear
striated.
Nuclei - ANS-Multinuclear; Skeletal muscle fibers are multinuclear. Each nucleus
regulates the metabolic needs of the surround sarcoplasm.
Sarcomeres - ANS-Unit of alternating light and dark striations between z lines.
Repeating subunits of a myofibril. Making up each sarcomere are several types of
proteins. Sarcomere is referred to as the smallest contractile unit of a muscle fiber.
Z Line - ANS-the lateral boundaries of a sarcomere.
Thin filaments - ANS-(myofilaments) extend from the Z lines to the center of a
sarcomere, where they partially overlap with the thick filaments.
Contraction - ANS-the thick filaments pull the thin filaments towars the center of the
sarcomeres. This movement causes the sarcomeres, myofibrils, and the muscle fiber all
to shorten.
M Line - ANS-made up of proteins that connect the central portions of each thick
filament to its neighbors (middle line)
I band - ANS-the light region between 2 successive A bands including the Z line
A band - ANS-dark area containing thick filaments
H zone - ANS-The region at the center of an A band of a sarcomere that is made up of
myosin only. The H zone gets shorter (and may disappear) during muscle contraction.
Tropomyosin - ANS-A helical protein that winds around actin helices in skeletal and
cardiac muscle cells to form the thin filament of the sarcomere. In the absence of Ca2+,
tropomyosin covers the myosin-binding sites on actin and prevents muscle contraction.
When calcium is present, a conformation change in tropomyosin occurs so that the
myosin-binding sites are exposed and muscle contraction can occur.
The dark bands in skeletal muscle that contribute to its striated appearance are known
as
A. A bands
B. Z bands
C. H bands
D. I bands - ANS-A
Skeletal muscle cells contain many
A. nuclei
B. mitochondria
Solutions
What are the functions of skeletal muscles? - ANS-1. produce movement
2. maintain body posture/position
3. Support soft tissues
4. Guard entrances and exits
5. Maintain body temperature
What are the 3 types of muscle tissue? - ANS-skeletal, smooth, cardiac
skeletal muscles - ANS-organs composed primarily of skeletal muscle tissue, but they
also contain connective tissues, nerves, and blood vessels
muscle tissue - ANS-Tissue made of cells capable of contracting
Skeletal Muscle Fibers - ANS-Located inside muscles, where they are organized into
bundles called fascicles (=fasciculi)
Fascicles - ANS-small bundle of muscle fibers
Perimysium - ANS-Connective tissue surrounding a fascicle. Portions of the perimysium
extend into the fascicle and merge with the endomysium.
Endomysium - ANS-A thin layer of areolar connective tissue that covers each muscle
fiber.
Epimysium - ANS-Connective tissue layer surrounding an individual muscle
Myofibers - ANS-Individual muscle cell or fiber; are long narrow cells that often span the
entire length or a muscle.
Sarcoplasm - ANS-The cytoplasm of a striated muscle fiber. Most of the sarcoplasm is
occupied by myofibrils.
Microfibrils - ANS-Cylindrical bundles of contractile proteins. Living muscle fibers usually
contain hundreds to thousands of myofibrils.
Sarcolemma - ANS-cell membrane of a muscle fiber
An extensible membrane enclosing the contractile substance of a muscle fiber.
, Striated - ANS-Marked with parallel bands; striped; Skeletal muscles fibers appear
striated.
Nuclei - ANS-Multinuclear; Skeletal muscle fibers are multinuclear. Each nucleus
regulates the metabolic needs of the surround sarcoplasm.
Sarcomeres - ANS-Unit of alternating light and dark striations between z lines.
Repeating subunits of a myofibril. Making up each sarcomere are several types of
proteins. Sarcomere is referred to as the smallest contractile unit of a muscle fiber.
Z Line - ANS-the lateral boundaries of a sarcomere.
Thin filaments - ANS-(myofilaments) extend from the Z lines to the center of a
sarcomere, where they partially overlap with the thick filaments.
Contraction - ANS-the thick filaments pull the thin filaments towars the center of the
sarcomeres. This movement causes the sarcomeres, myofibrils, and the muscle fiber all
to shorten.
M Line - ANS-made up of proteins that connect the central portions of each thick
filament to its neighbors (middle line)
I band - ANS-the light region between 2 successive A bands including the Z line
A band - ANS-dark area containing thick filaments
H zone - ANS-The region at the center of an A band of a sarcomere that is made up of
myosin only. The H zone gets shorter (and may disappear) during muscle contraction.
Tropomyosin - ANS-A helical protein that winds around actin helices in skeletal and
cardiac muscle cells to form the thin filament of the sarcomere. In the absence of Ca2+,
tropomyosin covers the myosin-binding sites on actin and prevents muscle contraction.
When calcium is present, a conformation change in tropomyosin occurs so that the
myosin-binding sites are exposed and muscle contraction can occur.
The dark bands in skeletal muscle that contribute to its striated appearance are known
as
A. A bands
B. Z bands
C. H bands
D. I bands - ANS-A
Skeletal muscle cells contain many
A. nuclei
B. mitochondria
