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.