Chapter 10 A&P 1 practice questions
The term aponeurosis refers to a A. broad, flat, sheetlike tendon B. band of connective tissue that encloses entire groups of tendons C. connective tissue sheath that encloses several tendons D. thickened part of a muscle
broad, flat, sheetlike tendon
A sustained muscle contraction without partial relaxation between stimuli is called A. unfused (incomplete) tetanus B. fused (complete) tetanus C. recruitment D. recovery oxygen uptake
fused (complete) tetanus
The enzyme acetylcholinesterase causes A. ATP to break down to ADP B. acetylcholine to break down C. troponin to bind to tropomyosin D. breakdown of pyruvic acid to lactic acid
acetylcholine to break down
Myofibrils are composed primarily of a. actin and myosin b. troponin c. ATP d. tropomyosin
actin and myosin
The ______________________________________ is responsible for the striations of striated muscle. A. troponin-tropomyosin interaction B. hydrolysis of ATP C. position of H zones D. alternating of A bands and I bands
alternating of A bands and I bands
A muscle fascicle is surrounded by a. sarcomysium b. endomysium c. epimysium d. perimysium
perimysium
Muscles generate heat, stabilize the body positions and: A. line organs that open to the outside B. coordinate homeostatic functions for the body C. protect the body from invading organisms D. produce body movements
produce body movements
An increase in the number of active motor units in a muscle is called A. treppe B. peristalsis C. wave summation D. recruitment
recruitment
Calmodulin is involved in the contraction of: A. smooth muscle B. skeletal muscle C. striated muscle D. cardiac muscle
smooth muscle
When examined under a microscope, in which type of muscle tissue are myofibrils not apparent? a. skeletal muscle b. cardiac muscle c. atrophied muscle d. smooth muscle
smooth muscle
Which of the following does NOT have T-tubules? A. skeletal muscle B. smooth muscle C. striated muscle D. cardiac muscle
smooth muscle
Creatine phosphate A. breaks down ATP B. activates ATPase C. supplies energy for synthesis of ATP D. supplies energy to break ATP into ADP
supplies energy for synthesis of ATP
The following is a list of events in random order that occur in the contraction of skeletal muscle. Identify which of the subsequent letters represents the correct chronological order of these events. 1. Ca2+ binding to troponin 2. release of Ach at the neuromuscular junction 3. coming together of Z discs 4. depolarization of sarcolemma 5. myosin head attaching to myosin binding site on actin 6. depolarization of T-tubules
2, 4, 6, 1, 5, 3
For the initiation of an action potential that starts contraction in skeletal muscle fiber: A. Ach must bind to receptors on the motor end plate B. Ach must bind to the neurolemma of the somatic neuron C. acetylcholinesterase must break down Ach at the synapse D. K+ must flow into the neurolemma
Ach must bind to receptors on the motor end plate
Which of the following properties of muscle tissue is its ability to generate tension to do work? a. extensibility b. elasticity c. contractility d. excitability
contractility
Which type of muscle tissue is involuntary, slow in contracting, and able to regenerate considerably better than other types of muscle? A. skeletal muscle B. smooth muscle C. cardiac muscle D. striated muscle
smooth muscle
Cardiac muscle fibers are attached to one another at A. sarcomeres B. T-tubules C. intercalated discs D. A bands
intercalated discs
Muscle contraction is triggered by impulses carried over A. sensory neurons B. afferent neurons C. motor neurons D. myofibrils
motor neurons
A motor neuron and all the muscle fibers it stimulates form a A. motor end plate B. neuromuscular junction C. motor unit D. muscle
motor unit
If Ach is not released at the neuromuscular junction then: A. anaerobic respiration occurs B. aerobic respiration occurs C. acetylcholinesterase will be broken down D. muscle contraction will not happen
muscle contraction will not happen
In tetanus A. muscles wither away B. muscles undergo sustained contractions C. Ca2+ levels drop too low to sustain contractions D. muscles tire due to build up of ATP
muscles undergo sustained contractions
The elevated use of oxygen after exercise is called A. anaerobic respiration B. recovery oxygen uptake C. central fatigue D. asthma
recovery oxygen uptake
Excitability refers to the ability of a cell to a. return to its original length after stretching b. shorten c. assume a desired shape regardless of how much it has been stretched d. respond to a stimulus by producing an electrical signal
respond to a stimulus by producing an electrical signal
Elasticity refers to the ability of a muscle fiber to a. shorten b. stretch c. respond to a stimulus d. return to original shape after contracting or stretching
return to original shape after contracting or stretching
In an isometric contraction A. the muscle contracts but does not shorten B. the muscle moves the bone to reduce the angle of a joint C. the muscle increases in length during the contraction D. no energy is expended because nothing moves
the muscle contracts but does not shorten
When ATP attaches to the myosin head A. the head detaches from actin B. the head attaches to troponin C. Ca2+ reacts with the ATP D. actin and myosin both shorten
the myosin head detaches from actin
The binding of Ca2+ to __________________ starts the contraction cycle. A. tropomyosin B. ATP C. troponin D. sarcoplasmic reticulum
troponin
When calcium ion concentration in the sarcoplasm is low, the A. myosin stretches and the muscle relaxes B. actin detaches from the Z discs C. troponin-tropomyosin complex slides back over the myosin binding sites D. muscle cell membrane releases acetylcholine
troponin-tropomyosin complex slides back over the myosin binding sites
Which of the following links thin filaments to the sarcolemma? a. dystrophin b. myomesin c. titin d. myosin
dystrophin
Calcium ions move from the cytoplasm (sarcoplasm) into the sarcoplasmic reticulum because of the action of A. active transport pumps in the sarcoplasmic reticulum membrane B. ion diffusion channels in the sarcolemma C. myosin binding sites in the sarcoplasmic reticulum membrane D. acetylcholine receptors on the cell surface
active transport pumps in the sarcoplasmic reticulum membrane
The outermost layer of connective tissue surrounding a skeletal muscle is the A. epimysium B. perimysium C. endomysium D. sarcomysium
epimysium
In the liver, some of the lactic acid is converted to A. glycogen B. myoglobin C. ATP D. acetylcholinesterase
glycogen
Smooth muscle differs from skeletal because smooth muscle A. has dense bodies instead of Z discs B. is multi-nucleated C. is striated D. has a lot of sarcoplasmic reticulum
has dense bodies instead of Z discs
The motor end plate is part of a A. motor neuron B. skeletal muscle cell at the synapse C. cardiac muscle cell at the intercalated disc D. smooth muscle cell when two cells meet
skeletal muscle cell at the synapse
The sarcoplasmic reticulum a. is the cell membrane around each muscle fiber. b. stores Ca2+ when the fiber is at rest. c. opens to the outside through the sarcolemma. d. produces ATP for muscle contraction.
stores Ca2+ when the fiber is at rest.
When smooth muscles are stretched they contract, but within a short time the tension decreases. This is called A. passive contraction B. isotonic eccentric contraction C. stress-relaxation response D. incomplete tetanus
stress-relaxation response