anatomy & physiology ch 6

Place these structures of the skeletal muscle in order from largest to smallest: 1. fascicle 2. myofilament 3. muscle fiber (cell) 4. myofibril 5. sarcomere

1, 3, 4, 5, 2

T/F A muscle twitch results when the muscle is stimulated so rapidly that no evidence of relaxation is seen.

F

T/F An aponeurosis is a ropelike piece of muscle fascia that forms indirect connections to muscles of the leg.

F

T/F Cardiac and smooth muscle both have striations.

F

T/F Cardiac muscle fibers are relatively short, tapering cells within a single centrally located nucleus.

F

T/F Dorsiflexion and plantar flexion are synergistic actions.

F

T/F Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle.

F

T/F Smooth muscles activity generates heat to help maintain body temperature.

F

T/F Supination and pronation refer to up and down movements of the foot at the ankle.

F

T/F The deltoid is a prime mover of arm adduction

F

T/F The hamstring group inserts into the distal tibia.

F

T/F Thick filaments are made of a protein called actin.

F

T/F A sustained partial contraction of skeletal muscle is called muscle tone.

T

T/F Aerobic respiration requires the use of oxygen to generate ATP.

T

T/F All types of muscle have endomysium covering individual muscle cells.

T

T/F Biceps brachii, brachialis, and brachioradialis all cause arm flexion at the elbow joint.

T

T/F Muscle development in babies occurs in a cephalic/caudal direction.

T

T/F Oxygen debt promotes lactic acid accumulation on muscles from anaerobic cellular respiration.

T

T/F The deepest muscle of the abdominal wall is the transversus abdominis.

T

T/F The effect of the neurotransmitter on the muscle cell membrane is to temporarily modify its permeability of ions such as Na+ and K+.

T

T/F The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.

T

T/F The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.

T

T/F The striations seen in skeletal muscle are actually alternating A and I bands.

T

T/F 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.

T

When a skeletal muscle is fully contracted, the __________ are closer to the thick filaments.

Z discs

Acetylcholine is:

a neurotransmitter that stimulates skeletal muscle

The mechanical force of contraction is generated by:

a sliding of thin filaments past thick ones

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

Neurotransmitter substance released at motor end plates by the motor neuron

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

Enzyme that breaks down acetylcholine (ACh)

acetylcholinesterase

During skeletal muscle contraction, myosin heads attach to active sites of:

actin filaments

The movement opposite to abduction is:

adduction

A metabolic pathway that produces water, carbon dioxide, and ATP, and provides for a large amount of ATP per glucose because oxygen is used

aerobic respiration

The light and dark banding pattern send in striated muscle, like skeletal muscle, originate from:

alternating light and dark bands

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

Which of the following muscles are antagonists:

biceps brachii and triceps brachii

Which of the following muscles closes the jaw:

both masseter and temporalis

A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the:

buccinator

Chemical stored in the sarcoplasmic reticulum

calcium ions

Chemical that serves as the actual "go" signal for muscle contraction

calcium ions

Why are calcium ions necessary for skeletal muscle contraction:

calcium triggers the binding of myosin to actin

Muscle tissue composed of branching cells and intercalated discs

cardiac

Muscle tissue found only in the heart

cardiac

The arrangement of fascicles in orbicularis oris is __________.

circular

The movement that is commonly seen in a ball-in-socket joint, that includes a combination of flexion, extension, abduction, and adduction, is called __________.

circumduction

Which one of the following is the action of the orbicularis oris:

closes, purses, and protrudes the lips

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as __________.

contractility

Isometric contractions produce:

contractions

A reserve, high-energy compound used to convert ADP to ATP by the transfer of a high-energy phosphate group

creatine phosphate

The heads of the myosin myofilaments are called __________ when they link the thick and thin filaments together during skeletal muscle contraction.

cross bridges

Which one of the following muscles is involved in abduction of the arm at the shoulder joint:

deltoid

Which of these pathways is the fastest way to regenerate ATP during muscle activity:

direct phosphorylation of ADP by creatine phosphate

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

Type of movement that decreases the angle of the joint

flexion

Which of the following is NOT a function of the muscular system:

hematopoiesis

Paralysis of which of the following would make an individual unable to flex the hip:

iliopsoas

Which of the following muscles is NOT involved in dorsiflexion and/or plantar flexion of the foot:

iliopsoas

The condition of skeletal muscle fatigue can be best explained by:

insufficient intracellular quantities of ATP due to excessive consumption

The __________ muscle runs deep to the external oblique muscle.

internal oblique

Smooth muscle cells are:

involuntary

Contractions in which muscles do not produce movement or shortening are termed __________.

isometric

What is the main function of the quadriceps femoris group:

knee extension

Which one of the following does NOT compress the abdomen:

latissimus dorsi

Which one of the following is NOT a criteria 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

Which congenital muscle disease results from the degeneration and atrophy of muscles:

muscular dystrophy

Anaerobic glycolysis occurs without:

oxygen

Anaerobic glycolysis produces ATP in the absence of __________.

oxygen

A muscle located on the ventral (anterior) side of the body is the:

pectoralis major

The quadriceps femoris muscle group is composed of the three vastus muscles and the __________ muscle.

rectus femoris

Creatine phosphate (CP) functions within the muscle cells by:

storing energy that will be transferred to ADP to resynthesize ATP as needed

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

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 smooth, sustained contraction is called __________.

tetanus

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 filaments

A single, brief, jerky muscle contraction is termed:

twitch

The muscle referred to as the "smiling" muscle because it raised the corners of the mouth upward is the __________.

zygomaticus

The __________ zone of a sarcomere contains no actin filaments while the skeletal muscle is at rest (noncontractile state).

H

The plasma membrane of a skeletal muscle cell is called the:

sarcolemma

The plasma membrane of skeletal muscle cells is called __________.

sarcolemma

Which of the following can actually shorten during a muscle contraction:

sarcomeres

An elaborate and specialized network of membranes in skeletal muscle cells that function in calcium storage is the:

sarcoplasmic reticulum

Which of these muscles is NOT located in the head:

sartorius

What is the origin of the deltoid muscle:

scapular spine and clavicle

Muscle tissue that is multinucleate

skeletal

Muscle tissue that maintains posture, body position, and stabilizes joints

skeletal

Striated, voluntary, multinucleate muscle is classified as __________ muscle.

skeletal

Voluntary muscle tissue

skeletal

Which type of muscle tissue responds the fastest to stimulations to contract:

skeletal

Voluntary muscle tissue is;

skeletal muscle

Muscle tissue that activates arrector pili muscles which stand hairs on end

smooth

Muscle tissue that forms valves to regulate the passage of substances through internal body openings

smooth

Performs very slow, sometimes rhythmic, contractions

smooth