Physiology CH 6 HW questions
Striated involuntary muscle tissue is classified as ________ muscle.
cardiac
Striated involuntary muscle tissue found in the heart is ________.
cardiac muscle
Which of these terms refers to the shape of a muscle?
deltoid
What is the function of creatine phosphate?
directly regenerates ATP from ADP within a muscle cell
Referring to the muscle attachment to bones, the __________ is the immovable attachment site.
origin
The point of muscle attachment to an immovable or less movable bone is known as the ________.
origin
Which term does NOT describe smooth muscle cells?
skeletal
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
Primary action of the adductor muscles
adduction
What term refers to a smooth, sustained contraction?
complete tetanus
The essential function of any muscle is to __________.
contract
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.
contractability
ALS (amyotrophic lateral sclerosis) is a disease that results in progressive paralysis. While the ultimate cause is unknown, __________ is the direct cause of the paralysis.
degeneration of motor neurons
Which layer of connective tissue surrounds each skeletal muscle fiber?
endomysium
Primary action of the erector spinae
extension
Which of these muscles is named for the arrangement of its fascicles?
external oblique
Muscles that are concerned with bracing actions are called __________.
fixators
Primary action of the rectus abdominis
flexion
Type of movement that decreases the angle of the joint
flexion
A smooth, sustained contraction, with no evidence of relaxation, is called ________.
fused, or complete, tetanus
Which of these characteristics applies only to cardiac muscle tissue?
intercalated discs
Type of movement that turns the sole of the foot medially
inversion
Consider the two types of muscle contractions described in this chapter; in __________ contractions, the muscle may shorten and movement may occur.
isotonic
Which of the following is a type isometric exercise in which muscles increase in size and strength?
lifting weights
Exercise throughout life helps muscles to retain both strength and __________.
mass
One neuron and all the skeletal muscles it stimulates is known as a ________.
motor unit
Which of the following refers to one neuron and all the skeletal muscle cells it stimulates?
motor unit
The anatomical term for a muscle cell, in skeletal and smooth muscle tissues, is __________.
muscle fiber
An inherited disease that causes muscles to degenerate and atrophy is known as ________.
muscular dystrophy
Which of these muscles is located on the ventral (anterior) side of the body?
pectoralis major
Type of movement that points the toes
plantar flexion
Considering the relationship between the biceps and the triceps, the biceps is the __________ whereas the triceps is the __________ as the elbow is flexed.
prime mover, antagonist
Which of the following is an example of an isometric contraction?
pushing against an immovable wall
What is key to offsetting the effects of aging on the muscular system?
regular exercise
What can older individuals do to increase muscle strength?
regularly use hand weights and practice leg lifts
What type of exercise causes increase in muscle size?
resistance exercise
The movement of a bone around its longitudinal axis
rotation
What term describes the rotation of a bone around its longitudinal axis?
rotation
The plasma membrane of a muscle cell is most usually termed a __________.
sarcolemma
What organelle wraps and surrounds the myofibril and stores calcium?
sarcoplasmic reticulum
Voluntary muscle tissue
skeletal muscle
The endomysium is a delicate connective tissue sheath that surrounds a/an __________.
skeletal muscle fiber
Muscle tissue that is multinucleate
skeletal muscle tissue
Muscle tissue that maintains posture, body position, and stabilizes joints
skeletal muscle tissue
Muscle tissue that activates arrector pili muscles to stand hairs on end
smooth muscle tissue
Muscle tissue that dilates and constricts the pupils of our eyes
smooth muscle tissue
Performs very slow, sometimes rhythmic, contractions
smooth muscle tissue
What must rush into a muscle cell to promote its depolarization?
sodium ions
Which of these muscles is located in the neck?
sternocleidomastoid
Type of movement that allows you to carry a soup bowl
supination
Which movement is associated with the hand but actually occurs in the forearm?
supination
The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________.
synaptic cleft
What term refers to a muscle that aids another muscle by producing the same the movement or reducing undesirable movements?
synergist
A sarcomere is
the contractile unit between two Z discs
A sarcomere is ________.
the contractile unit between two Z discs
The condition of skeletal muscle fatigue can be best explained by ________.
the inability of the muscle to contract even if it is being stimulated
Which one of the following is composed mostly of the protein myosin?
thick filaments
What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?
A bands and I bands
Which type of muscle tissue contracts most quickly upon stimulation?
Skeletal
What changes occur in the sarcomere during muscle contraction?
Z discs move closer together.
What is acetylcholine?
a neurotransmitter that stimulates skeletal muscle to contract
The mechanical force of contraction is generated by ________.
a sliding of thin filaments past thick filaments
Primary action of the deltoid
abduction
The movement of a limb away from the body midline
abduction
What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract?
acetylcholine
What initiates an action potential on a muscle cell?
acetylcholine binding to receptors on the sarcolemma within the neuromuscular junction
What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma?
action potential
The movement of a limb toward the body midline
adduction
Which movement is opposite to abduction?
adduction
What is covered by the endomysium?
an individual muscle cell
Which method of regenerating ATP during muscle contraction can produce lactic acid?
anaerobic glycolysis
Muscles that perform opposite actions to one another are termed ________.
antagonists
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
The muscle that facilitates flexion of the forearm is the __________.
biceps brachii
Although ATP provides the energy for muscle contraction, __________ must also be present for muscle fibers to slide properly during contraction.
calcium
What mineral is released within muscle cells to trigger contraction?
calcium
What type of muscle tissue is both striated and involuntary?
cardiac
Muscle tissue found only in the heart
cardiac muscle
What type of muscle tissue is both striated and involuntary?
cardiac muscle
There are three types of muscle tissue. Which of the following is classified as part of the muscular system?
all skeletal muscles
Which of these increases as muscles age?
amount of connective tissue in a muscle
Muscle tissue composed of branching cells and intercalated discs
cardiac muscle tissue
The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.
cross bridges
Skeletal muscle, as a whole, can generate different amounts of force, and different degrees of shortening, in response to stimuli. What is this concept called?
graded response
What term describes the ability of a muscle to vary its degree of shortening to generate the strength needed to lift a 5 lb weight, a 7 lb weight, and finally a 10 lb weight?
graded responses
Contractions in which muscles shorten and produce movement are known as ________.
isotonic contractions
Which chemical is produced during vigorous exercise when the supply of oxygen is limited or inadequate?
lactic acid
A motor neuron and all of the skeletal muscle fibers it stimulates are termed a ________.
motor unit
Amelie, a 29-year-old woman, complained to her doctor of being constantly fatigued and having difficulty swallowing. Her speech is slurred and her eyelids are droopy. Amelie most likely has __________.
myasthenia gravis
Which connective tissue bundles muscle fibers into fascicles?
perimysium
The plasma membrane of a skeletal muscle cell is called the ________.
sarcolemma
Creatine phosphate (CP) functions within the muscle cells by ________.
storing energy that will be transferred to ADP to resynthesize ATP as needed
The neurotransmitter __________ is vital to proper muscle functioning.
ACh
Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract?
Acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions into the cell.
Which of the following statements is NOT true regarding energy generation for muscle contraction? 1. Anaerobic glycolysis is not an energy source for muscle contraction. 2. At rest and during light exercise, ATP is regenerated almost entirely by metabolic pathways that use oxygen. 3. One of the pathways for ATP regeneration is direct phosphorylation of ADP by creatine phosphate. 4. Aerobic respiration refers to metabolic pathways that use oxygen.
Anaerobic glycolysis is not an energy source for muscle contraction.
What is the molecular basis of Duchenne's muscular dystrophy?
Muscle fibers lack a protein that helps to maintain the sarcolemma.
What happens to a muscle when the nerve supplying that muscle is cut?
Muscle paralysis and atrophy occur.
According to the sliding filament theory, how does muscle contraction occur?
Myosin heads form cross bridges and pull thin filaments, causing them to slide.
Which of the following statements is NOT true? 1. Tetanic contraction is normal and desirable, and is quite different from the pathologic condition of tetanus. 2. When a muscle is stimulated so rapidly that no evidence of relaxation is seen and the contractions are completely smooth and sustained, the muscle is said to be in tetanus or in tetanic contraction. 3. Tetanic contractions of muscles are smooth and prolonged muscle contractions, which can be slight or vigorous depending on what work has to be done. 4. Tetanic contraction of muscles refers to a disease that causes total, sustained contraction of muscles.
Tetanic contraction of muscles refers to a disease that causes total, sustained contraction of muscles.
