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