Anatomy Muscle Test
cardiac muscle tissue
-Muscle tissue found only in the heart. -Muscle tissue composed of branching cells and intercalated discs.
skeletal muscle tissue
-Muscle tissue that is multinucleate. -Muscle tissue that maintains posture, body position, and stabilizes joints. -Voluntary muscle tissue.
smooth muscle tissue
-Performs very slow, sometimes rhythmic, contractions. -Muscle tissue that activates arrector pili muscles to stand hairs on end. -Muscle tissue that forms valves to regulate the passage of substances through internal body openings.
abduction
-The movement of a limb away from the body midline -Primary action of the deltoid
adduction
-The movement of a limb toward the body midline
supination
-Type of movement that allows you to carry a soup bowl
flexion
-Type of movement that decreases the angle of the joint
inversion
-Type of movement that turns the sole of the foot medially
Hyaline cartilage
The most abundant skeletal cartilage.
rotation
The movement of a bone around its longitudinal axis
All types of muscle have endomysium covering individual muscle cells.
True
Cardiac and skeletal muscle both possess striations
True
The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.
True
When a skeletal muscle is fully contracted, the ________ are closer to the thick filaments.
Z discs
What changes occur in the sarcomere during muscle contraction?
Z discs move closer together.
Acetylcholine is ________.
a neurotransmitter that stimulates skeletal muscle
The mechanical force of contraction is generated by ________.
a sliding of thin filaments past thick filaments
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
Which neurotransmitter is released by motor neurons at the neuromuscular junction?
acetylcholine
Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract?
acetylcholine (ACh) causes temporary permeability to sodium
What initiates an action potential on a muscle cell?
acetylcholine binding to receptors on the sarcolemma within the neuromuscular junction
During skeletal muscle contraction, myosin heads attach to binding sites associated with ________.
actin filaments
The movement opposite to abduction is ________.
adduction
There are three types of muscle tissue. Which of the following is classified as part of the muscular system?
all skeletal muscles
Endomysium covers ________.
an individual muscle cell
Muscles that perform opposite actions to one another are termed ________.
antagonists
Neurotransmitters are released upon stimulation from a nerve impulse by the ________.
axon terminals of the motor neuron
ALS (amyotrophic lateral sclerosis) is a disease that destroys nerve cells that control skeletal muscle activity. Without neural stimulation, skeletal muscles eventually waste away and mobility is impossible. In other words, skeletal muscles __________
become atrophied
In order to excite a muscle cell, acetycholine must ________
bind to receptors in the sarcolemma of the muscle cell
What mineral is released within muscle cells to trigger contraction?
calcium
Why are calcium ions necessary for skeletal muscle contraction?
calcium triggers the binding of myosin to actin
Striated involuntary muscle tissue is classified as ________ muscle.
cardiac
Striated involuntary muscle tissue found in the heart is ________.
cardiac muscle
What type of muscle tissue is both striated and involuntary?
cardiac muscle
The arrangement of fascicles in orbicularis oris is ________.
circular
What term refers to a smooth, sustained contraction?
complete tetanus
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.
contractility
The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.
cross bridges
Which of these terms refers to the shape of a muscle?
deltoid
What is the function of creatine phosphat
directly regenerates ATP from ADP within a muscle cell
Which layer of connective tissue surrounds each skeletal muscle fiber?
endomysium
Which of these muscles is named for the arrangement of its fascicles?
external oblique
A muscle twitch results when the muscle is stimulated so rapidly that no evidence of relaxation is seen.
false
Bundles of muscle fibers are known as aponeuroses.
false
Isometric contractions produce movement when filaments slide past one another and the muscle shortens.
false
The fastest mechanism for producing ATP is aerobic respiration.
false
Thick filaments are made of a protein called actin.
false
A smooth, sustained contraction is called ________.
fused, or complete, tetanus
Anaerobic glycolysis requires ________ to make ATP
glucose
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
Which of the following is NOT a function of the muscular system?
hematopoiesis
The condition of skeletal muscle fatigue can be best explained by ________.
insufficient intracellular quantities of ATP due to excessive consumption
Which of these characteristics applies only to cardiac muscle tissue?
intercalated discs
Smooth muscle cells are ________.
involuntary
Contractions in which muscles shorten and produce movement are known as ________.
isotonic contractions
What metabolic waste accumulates in muscle with excessive exertion?
lactic acid
Which chemical is produced during vigorous exercise when the supply of oxygen is limited or inadequate?
lactic acid
Which one of the following is NOT a criterion generally used in naming muscles?
method of attachment of the muscle to bone
A motor neuron and all of the skeletal muscle fibers it stimulates are termed a ________.
motor unit
One neuron and all the skeletal muscles it stimulates is known as a ________
motor unit
The least movable point of muscle attachment to a bone is termed its ________.
origin
The point of muscle attachment to an immovable or less movable bone is known as the ________.
origin
Anaerobic glycolysis occurs without ________.
oxygen
Which connective tissue bundles muscle fibers into fascicles?
perimysium
Which of the following is an example of an isometric contraction?
pushing against an immovable wall
What type of exercise causes increase in muscle size?
resistance exercise
extension
rimary action of the erector spinae
What term describes the rotation of a bone around its longitudinal axis?
rotation
The plasma membrane of a skeletal muscle cell is called the ________
sarcolemma
Which of the following can actually shorten during a muscle contraction?
sarcomere
An elaborate and specialized network of membranes in skeletal muscle cells that function in calcium storage is the ________.
sarcoplasmic reticulum
The ________ is an organelle that wraps and surrounds the myofibril and stores calcium.
sarcoplasmic reticulum
Which type of muscle tissue contracts most quickly upon stimulation?
skeletal
Creatine phosphate (CP) functions within the muscle cells by ________.
storing energy that will be transferred to ADP to resynthesize ATP as needed
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
The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction 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 muscle group that works with and assists the action of a prime mover is a(n) ________.
synergist only
The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike ________
tendons; aponeuroses
A muscle inserts on which of the following?
the bone that moves when the muscle contracts
A sarcomere is ________.
the contractile unit between two Z discs
A skeletal muscle twitch differs from a tetanic contraction in that ________.
the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous
Which one of the following is composed of myosin protein?
thick filament
Cross bridges are created when myosin heads bind to ________.
thin filaments
Abduction and adduction are antagonistic actions.
true
Aerobic respiration requires the use of oxygen to generate ATP.
true
Aerobic, or endurance, exercise involves jogging or biking.
true
The effect of the neurotransmitter on the muscle cell membrane is to temporarily modify its permeability of ions such as Na+ and K+.
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
When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands move closer together but do not diminish in length.
true
The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?
A myosin head bound to actin
Chondrocytes
Cartilage producing cells.
Elastic cartilage
Contain stretchy elastic fibers and can withstand repeated bending.
A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.
False
Fibrocartilage
Has parallel rows of chondrocytes alternating with thick collagen fibers.
extracellular matrix (ECM)
Jelly-like ground substance and fibers found.
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.
