Anatomy: Chapter 6 Exam Review
What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?
A bands and I bands
Leaning against an immovable wall while waiting for a bus is a type of ________.
Isometric contraction
One neuron and all the skeletal muscles it stimulates is known as a ________.
Motor unit
An elderly man fell down his stairs and was diagnosed with an injury to his tibialis anterior muscle. Evaluate the following actions to determine how his mobility will be impaired in the coming weeks.
Moving the foot down while walking
The state of continuous partial muscle contractions is known as ________.
Muscle tone
Which organelle stores calcium in muscle fibers?
Sarcoplasmic reticulum
What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract?
The neurotransmitter ACh or Acetylcholine
Which type of filament is anchored to the Z disc within a myofibril?
Thin filaments
A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.
True
Abduction and adduction are antagonistic actions.
True
All muscles have at least two attachments: the origin and the insertion.
True
Cardiac and skeletal muscle both possess striations.
True
Cardiac muscle fibers are joined by special gap junctions called intercalated discs; these discs allow heart activity to be closely coordinated.
True
The deepest muscle of the abdominal wall is the transversus abdominis.
True
The deltoid muscle is a common site for intramuscular injections.
True
The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.
True
The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.
True
The striations seen in skeletal muscle are actually alternating dark A and light I bands.
True
What is covered by the endomysium?
an individual muscle cell
What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone?
atrophy
Neurotransmitters are released upon stimulation from a nerve impulse from the ________.
axon terminals of the motor neuron
Which of the following muscles are antagonists?
biceps brachii and triceps brachii
Which of the following is not> a function of the muscular system?
blood cell formation
Like the biceps brachii muscle, which muscle is a prime mover in elbow flexion?
brachialis
A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the ________.
buccinator
Striated involuntary muscle tissue is classified as ________ muscle.
cardiac
Striated involuntary muscle tissue found in the heart is ________.
cardiac muscle
The arrangement of fascicles in orbicularis oris is ________.
circular
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.
contractility
The prime mover of arm abduction is the ________ muscle.
deltoid
According to the sliding filament theory, how does muscle contraction occur?
myosin heads form cross bridges and pull thin filaments, causing them to slide
The point of muscle attachment to an immovable or less movable bone is known as the ________.
origin
Which of these muscles is located on the ventral (anterior) side of the body?
pectoralis major
Which muscle helps compress the abdominal contents during defecation or childbirth
rectus abdominis
The plasma membrane of a skeletal muscle cell is called the ________.
sarcolemma
What organelle wraps and surrounds the myofibril and stores calcium?
sarcoplasmic reticulum
Which term does >not describe smooth muscle cells?
skeletal
The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________.
synaptic cleft
Which of the following muscles acts as a synergist to the masseter and closes the jaw?
temporalis
A sarcomere is ________.
the contractile unit between two Z discs
Which of the following is composed mostly of the protein myosin?
thick filaments
Jason injured his hamstring muscle group during football practice. He will be unable to perform ________.
thigh extension, knee flexion
Which of these muscles is the prime mover of elbow extension?
triceps brachii
Which facial muscle is considered the "smiling" muscle since it raises the corners of the mouth?
zygomaticus
Isometric contractions produce movement when filaments slide past one another and the muscle shortens.
False
Muscles will hypertrophy if they are not used continually.
False
Smooth muscle cells produce movement of the body and generate heat.
False
Supination and pronation refer to up and down movements of the foot at the ankle.
False
The deltoid is a prime mover of arm adduction.
False
Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle.
False This is false. The tibialis posterior muscle works towards plantar flexion.
Which muscle forms the curved calf of the posterior leg?
Gastrocnemius
While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called ________.
abduction
Sandra is playing the piano for her recital. Which muscle is not involved in the movement of her hands and/or fingers?
extensor digitorum longus
Which movement is antagonistic to extension?
flexion
A smooth, sustained contraction, with no evidence of relaxation, is called
fused or complete tetanus
Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus?
hamstring group
What is the main function of the quadriceps group?
knee extension
Which of the following consists of two large, flat muscles that cover the lower back?
latissimus dorsi
Which of the following is a type isometric exercise in which muscles increase in size and strength?
lifting weights/pushing against a wall
Which one of the following is not a criterion generally used in naming muscles?
method of attachment of the muscle to bone
An inherited disease that causes muscles to degenerate and atrophy is known as ________.
muscular dystrophy
