muscle test Flashcards
Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for
contraction
Which of the following is a recognized function of skeletal muscle?
A) produce movement
B) maintain posture
C) maintain body temperature
D) guard body entrances and exits
At each end of the muscle, the collagen fibers of the epimysium, and each perimysium and endomysium, come together to form a
tendon
The dense layer of connective tissue that surrounds an entire skeletal muscle is the
epimysium
Nerves and blood vessels that service a muscle fiber are located in the connective tissues of its
endomysium
A fascicle is
a group of muscle fibers that are encased in the perimysium.
Put the following structures in order from superficial to deep:
epimysium, perimysium, fascicle, endomysium, muscle fiber and myofibril
Interactions between actin and myosin filaments of the sarcomere are responsible for
muscle contraction
In a sarcomere, thick filaments are linked laterally by proteins of the
M line.
The advantage of having many nuclei in a skeletal muscle fiber is
the ability to produce large amounts of the muscle proteins needed for growth and repair.
Skeletal muscle fibers are formed from embryonic cells called
myoblasts
The repeating unit of a skeletal muscle fiber is the
sarcomere
The plasma membrane of a skeletal muscle fiber is called the
sarcolemma.
Which of the following best describes the term sarcomere?
repeating unit of striated myofibrils
Muscle fibers differ from “typical cells” in that muscle fibers
have many nuclei.
Which of the following best describes the term sarcoplasmic reticulum?
storage and release site for calcium ions
Which of the following best describes the term Z line?
largely made of myosin molecules
The region of the sarcomere containing the thick filaments is the
A band.
Each thin filament consists of
two actin protein strands coiled helically around each other.
At rest, active sites on the actin are blocked by
tropomyosin molecules.
Which statement about the microscopic anatomy of skeletal muscle fibers is true?
A) Tubular extensions of the sarcolemma penetrate the fiber transversely.
B) Cross striations result from the lateral alignment of thick and thin filaments.
C) Each fiber has many nuclei.
D) Muscle fibers are continuous from tendon to tendon.
When a skeletal muscle fiber contracts,
A) the H bands and I bands get smaller.
B) the zones of overlap get larger.
C) the Z lines get closer together.
D) the width of the A band remains constant.
Each skeletal muscle fiber is controlled by a motor neuron at a single
neuromuscular junction.
After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as
rigor mortis.
Triggering of the muscle action potential occurs after
acetylcholine binds to chemically-gated channels in the end plate membrane.
In a______
muscle, the fascicles are concentrically arranged around an opening.
circular
The type of muscle whose functional characteristics most closely resemble those of its muscle fibers is the
_______muscle.
parallel
Muscles with fibers that run parallel to the long axis of the body are called
rectus.
Skeletal muscles in which the fascicles form a common angle with the tendon are muscles.
convergent
Which of the following is not one of the forms of fascicle organization?
perpendicular
____muscle fibers pull in different directions, permitting different actions depending on
stimulation.
Convergent
Most of the skeletal muscles in the body are
parallel muscles.
A lever consists of
a rigid structure and a fulcrum.
The most common lever systems in the body are those that have the applied force between the fulcrum and the load. These are called_____
third-class
Contracting the gastrocnemius muscles to elevate the body on the toes involves a______ lever.
second-class
Muscular walls of the thorax and abdomen are composed of
oblique and rectus muscles.
A muscle that flexes the spinal column is the
rectus abdominis.
Damage to which of the following muscles would interfere most with the ability to breathe?
intercostals
Excessive abdominopelvic pressure can cause
an inguinal and a diaphragmatic hernia.
Pam’s daughter is born cross-eyed. As she grows, the problem does not become any better.
Her physician suggests cutting an eye muscle to bring the eyes into a more normal position.
Which muscle will he cut?
medial rectus
Tom, a trumpet player, asks you which muscles he should develop in order to be a better trumpeter. What would you tell him?
the buccinator and orbicularis oris
Damage to the pectoralis major would interfere with a person’s ability to
adduct the humerus.
The pectoralis major muscle inserts on the greater tubercle of the humerus. When it con-tracts, it produces
flexion, medial rotation, and adduction.
Which of the following muscles does not have an action that is antagonistic to the action of the brachialis muscle?
brachioradialis
Which of the following is the insertion of the pectoralis major?
the greater tubercle of the humerus
Which of the following does not move the shoulder girdle?
deltoid
Muscles visible at the body surface are often called
superficials
Each of the following terms is used to describe the shape of a muscle, except:
pectinate
Muscles located close to the midline of the body may be called
medial
