Week 5 Muscular System Flashcards
The I band within a skeletal muscle fiber is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
B) Label B
The A band within a myofibril is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
A) Label A
The H zone, located within the A band, lacks thin filaments and is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
D) Label D
The myofilament composed of actin is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
C) Label C
The epimysium is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
A) Label A
The perimysium wraps a fascicle of muscle cells and is represented by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
C) Label C
The muscle fiber (cell) is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
B) Label B
The endomysium that wraps individual muscle fibers is indicated by \_\_\_\_\_\_\_\_. A) Label A B) Label B C) Label C D) Label D
D) Label D
Striated involuntary muscle tissue is classified as \_\_\_\_\_\_\_\_ muscle. A) skeletal B) cardiac C) smooth D) either smooth or skeletal
B) cardiac
Which term does not describe smooth muscle cells? A) Visceral B) Nonstriated C) Skeletal D) Involuntary
C) Skeletal
What organelle wraps and surrounds the myofibril and stores calcium? A) Cross bridge B) Sarcomere C) Sarcolemma D) Sarcoplasmic reticulum
D) Sarcoplasmic reticulum
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as \_\_\_\_\_\_\_\_. A) elasticity B) irritability C) contractility D) extensibility
C) contractility
One neuron and all the skeletal muscles it stimulates is known as a \_\_\_\_\_\_\_\_. A) sarcoplasmic reticulum B) motor unit C) synaptic cleft D) neuromuscular junction
B) motor unit
The heads of the myosin myofilaments are called ________ when they link the thick and thin
filaments together during skeletal muscle contraction.
A) neuromuscular junctions
B) synapses
C) cross bridges
D) motor units
C) cross bridges
What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma? A) Neuromuscular junction B) Action potential C) Neurotransmitter D) Acetylcholine
B) Action potential
According to the sliding filament theory, how does muscle contraction occur?
A) Myosin heads form cross bridges and pull thin filaments, causing them to slide.
B) Both thick and thin filaments shorten as the muscle contracts.
C) A bands bunch up and shorten as myosin heads attach to thin filaments.
D) Myosin heads attach and detach from thin filaments, causing thin filaments to shorten
A) Myosin heads form cross bridges and pull thin filaments, causing them to slide.
The method that regenerates the most ATP during muscle activity is \_\_\_\_\_\_\_\_. A) direct phosphorylation B) aerobic pathway C) anaerobic pathway D) lactic acid pathway
B) aerobic pathway
A smooth, sustained contraction, with no evidence of relaxation, is called \_\_\_\_\_\_\_\_. A) fused, or complete, tetanus B) a twitch C) unfused, or incomplete, tetanus D) summing of contractions
A) fused, or complete, tetanus
Leaning against an immovable wall while waiting for a bus is a type of \_\_\_\_\_\_\_\_. A) isotonic contraction B) twitch C) isometric contraction D) resistance exercise
C) isometric contraction
The point of muscle attachment to an immovable or less movable bone is known as the \_\_\_\_\_\_\_\_. A) innervation B) action C) insertion D) origin
D) origin
Lead poisoning can cause a condition known as wrist drop in which the wrist is pronated or \_\_\_\_\_\_\_\_. A) the palms face posteriorly B) the palms face medially C) the palms face anteriorly D) the elbow flex
A) the palms face posteriorly
The arrangement of fascicles in orbicularis oris is \_\_\_\_\_\_\_\_. A) circular B) convergent C) pennate D) fusiform
A) circular
Which facial muscle is considered the "smiling" muscle since it raises the corners of the mouth? A) Orbicularis oris B) Frontalis C) Orbicularis oculi D) Zygomaticus
D) Zygomaticus
The prime mover of arm abduction is the \_\_\_\_\_\_\_\_ muscle. A) trapezius B) deltoid C) triceps brachii D) biceps brachii
B) deltoid
Jason injured his hamstring muscle group during football practice. He will be unable to perform \_\_\_\_\_\_\_\_. A) thigh extension and knee flexion B) dorsiflexion C) thigh abduction and adduction D) leg rotation and plantar flexion
A) thigh extension and knee flexion
An inherited disease that causes muscles to degenerate and atrophy is known as \_\_\_\_\_\_\_\_. A) torticollis B) muscular dystrophy C) cystic fibrosis D) myasthenia gravis
B) muscular dystrophy
Striated involuntary muscle tissue found in the heart is \_\_\_\_\_\_\_\_. A) smooth muscle B) skeletal muscle C) dense regular D) cardiac muscle E) dense irregular
D) cardiac muscle
What is covered by the endomysium? A) Fascicles of muscle cells B) An entire muscle C) An individual muscle cell D) Myofibrils E) Smooth muscle only
C) An individual muscle cell
The type of muscle tissue pictured in Figure 6.3 is \_\_\_\_\_\_\_\_. A) skeletal muscle B) voluntary C) striated D) found only in the heart E) smooth muscle
E) smooth muscle
The plasma membrane of a skeletal muscle cell is called the \_\_\_\_\_\_\_\_. A) sarcolemma B) sarcomere C) myofilament D) sarcoplasm E) sarcoplasmic reticulum
A) sarcolemma
What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue? A) Sarcoplasm and sarcolemma B) Thick filaments and myosin heads C) A bands and I bands D) H zones and M lines E) Z discs and H zones
C) A bands and I bands
Which type of filament is anchored to the Z disc within a myofibril? A) Thin filaments B) H zone C) Thick filaments D) Myosin filaments E) Cross bridges
A) Thin filaments
Which of the following is not a function of the muscular system? A) Production of movement B) Maintenance of posture C) Stabilization of joints D) Generation of heat E) Blood cell formation
E) Blood cell formation
A sarcomere is ________.
A) the nonfunctional unit of skeletal muscle
B) the contractile unit between two Z discs
C) the area between two intercalated discs
D) the wavy lines on the cell, as seen in a microscope
E) a compartment in a myofilament
B) the contractile unit between two Z discs
Which of the following is composed mostly of the protein myosin? A) Thick filaments B) Thin filaments C) All myofilaments D) Z discs E) Light bands
A) Thick filaments
What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract? A) Potassium ions B) Actin C) Sodium ions D) Neurotransmitter E) Myosin heads
D) Neurotransmitter