week 3 mcq Flashcards
n the myofibril the thin filament is organized around a rod-like core protein called titin. actin. G actin. nebulin. myosin.
nebulin
Fast fibers
- have low resistance to fatigue.
- rely on aerobic metabolism.
- have many mitochondria.
- have twitches with a very brief contraction phase.
- have low resistance to fatigue and quick twitches.
-have low resistance to fatigue and quick twitches.
During anaerobic glycolysis, ATP is produced. pyruvic acid is produced. oxygen is not consumed. carbohydrate is metabolized. All of the answers are correct.
all the answers are correct
The type of contraction where the tension is less than the load is called isometric contraction. isotonic eccentric contraction. isotonic concentric contraction. isometric concentric contraction. isometric eccentric contraction.
isotonic eccentric contraction.
thin filaments are mostly made of the protein actin. titin. myosin. tropomyosin. nebulin.
actin
Which of the following become connected by myosin cross-bridges during muscle contraction? thin filaments and thick filaments thick filaments and titin filaments z disks and actin filaments thick filaments and t-tubules thin filaments and t-tubules
thin filaments and thick filaments
Which of the following is not a function of smooth muscle tissue?
- altering the diameter of the respiratory passageways
- elevating hairs on the arm
- forcing blood from the heart into the major arteries
- moving food materials along the digestive tract
- forcing urine out of the urinary tract
forcing blood from the heart into the major arteries
Which of the following is not characteristic of smooth muscle?
- The striations are due to the orderly arrangement of actin and myosin.
- Neurons that innervate smooth muscles are under involuntary control.
- Smooth muscle cells are uninucleate.
- Smooth muscles do not contain sarcomeres.
- The thin filaments of smooth muscle fibers are attached to dense bodies
The striations are due to the orderly arrangement of actin and myosin.
Match the level of organization with the structure that surrounds it: Level of organization: skeletal muscle, muscle fascicle, muscle fiber, myofibril Surrounding structure: endomysium, epimysium, perimysium, sarcoplasmic reticulum.
- skeletal muscle>epimysium; muscle fascicle>perimysium; muscle fiber>endomysium; myofibril> sarcoplasmic reticulum
- skeletal muscle>sarcoplasmic reticulum; muscle fascicle>epimysium; muscle fiber>perimysium; myofibril>endomysium
- skeletal muscle>endomysium; muscle fascicle>epimysium; muscle fiber>perimysium; myofibril> sarcoplasmic reticulum
- skeletal muscle>endomysium; muscle fascicle>perimysium; muscle fiber>sarcoplasmic reticulum; myofibril>epimysium
- skeletal muscle>epimysium; muscle fascicle>endomysium; muscle fiber>perimysium; myofibril> sarcoplasmic reticulum
skeletal muscle>epimysium; muscle fascicle>perimysium; muscle fiber>endomysium; myofibril> sarcoplasmic reticulum
Which of the following is a recognized function of skeletal muscle? produce movement maintain posture maintain body temperature guard body entrances and exits All of the answers are correct.
all of the answers are correct
Muscles that position or stabilize an organ are called externus. superficialis. intrinsic. extrinsic. oblique.
extrinsic
\_\_\_\_\_\_\_\_ muscle fibers pull in different directions, permitting different actions depending on stimulation. Convergent Parallel Straight Pennate Circular
convergant
Damage to the pectoralis major would interfere with a person's ability to extend the forearm. abduct the humerus. flexion of the humerus. elevate the scapula. rotate the elbow.
flexion of the humerus.
Which of the following originates on the medial epicondyle of the humerus? flexor carpi radialis flexor carpi ulnaris palmaris longus pronator teres All of the answers are correct.
All of the answers are correct.
Jill suffers a severe cut that severs the tendon that attaches the insertion of the flexor carpi ulnaris. As a result of this injury, what action is difficult for her to perform? flex her forearm flex her elbow flex her ulna flex and adduct her hand flex her shoulder
flex and adduct her hand
Give the origins of the heads of the triceps brachii.
- lateral surface of the humerus, infraglenoid tubercle of scapula, posterior surface of the humerus
- lateral surface of the humerus, medial surface of the humerus, posterior surface of the humerus
- lateral surface of the humerus, anterior surface of the humerus, posterior surface of the humerus
- all on olecranon of ulna
- coracoid process of scapula, supraglenoid tubercle of scapula, anterior surface of humerus
lateral surface of the humerus, infraglenoid tubercle of scapula, posterior surface of the humerus
Which quadriceps femoris muscle is not visible from the superficial anterior thigh? (Figure vastus lateralis vastus medialis vastus intermedius rectus femoris biceps femoris
vastus intermedius
The long strap-like muscle on the anterior thigh is the \_\_\_\_\_\_\_\_ muscle. gracilis rectus femoris iliotibial tract adductor longus sartorius
sartorius
The adductor brevis has its origin on the ilium. pubis. sacrum. iliac crest. linea aspera.
pubis
The only knee flexor that originates superior to the acetabulum is the biceps femoris. gracilis. sartorius. iliopsoas. semimembranosus
sartorius
Skeletal muscle fibers are formed from embryonic cells called sarcomeres. myofibrils. myoblasts. fascicles. myomeres.
myoblasts
Which of the following best describes the term sarcomere?
- protein that accounts for elasticity of resting muscle
- repeating unit of striated myofibrils
- storage site for calcium ions
- thin filaments are anchored here
- largely made of myosin molecules
-repeating unit of striated myofibrils
Which of the following describes the action of the serratus anterior?
- adducts the arm
- adducts and flexes the humerus
- protracts the shoulder, abducts and medially rotates the scapula
- medial rotation of the humerus
- lateral rotation of the humerus
-protracts the shoulder, abducts and medially rotates the scapula
Which of the following is the insertion of the pectoralis major? the vertebral border near the spine the greater tubercle of the humerus the mastoid region of the skull the occipital bone of the skull the clavicle and scapula
the greater tubercle of the humerus
The whole deltoid muscle \_\_\_\_\_\_\_\_ the humerus. abducts flexes pronates rotates inverts
abducts
Muscles of the rotator cuff include all of the following except the supraspinatus. infraspinatus. subscapularis. teres minor. rhomboid.
rhomboid.
Muscles with fibers that run perpendicular to the long axis of the body are called lateralis. transversus. rectus. oblique. medialis.
transversus.
Detachment of myosin cross-bridges occurs during the contraction phase. relaxation phase. stimulus phase. latent period. isotonic period.
relaxation phase.
Which of the following types of muscle fibers are best adapted for prolonged contraction such as standing all day? uninucleated fibers striated fibers fast fibers slow fibers intermediate fibers
slow fibers
In the myofibril the protein that possesses the active site for myosin heads to bind is called titin. actin. G actin. nebulin. myosin.
G actin
Which of the following allows muscles to return to their original shape during relaxation?
- gravity
- opposing muscle contractions
- elastic forces
- myosin binding
- gravity, opposing muscle contractions, and elastic forces
-gravity, opposing muscle contractions, and elastic forces
In a sarcomere, the central portion of thick filaments are linked laterally by proteins of the Z line. M line. H band. A band. I band.
m line
A muscle that dorsiflexes the foot is the tibialis anterior. tibialis posterior. peroneus brevis. soleus. gastrocnemius.
tibialis anterior.
Which of these muscles produces lateral rotation at the hip? gluteus maximus piriformis obturator externus obturator internus All of the answers are correct.
All of the answers are correct.
The band of collagen fibers that laterally braces the knee is the linea alba. tensor fasciae latae. linea aspera. iliotibial tract. piriformis.
iliotibial tract.
The insertion of the flexor hallucis longus is
- above the femoral condyles.
- the superior surface of the distal phalanx of the great toe.
- the inferior surface of the distal phalanx of the great toe.
- the lateral condyle of the tibia and anterior surface of the fibula.
- the posterior surface of the medial condyle of the tibia.
-the inferior surface of the distal phalanx of the great toe.
Which of the following is not characteristic of smooth muscle?
- The striations are due to the orderly arrangement of actin and myosin.
- Neurons that innervate smooth muscles are under involuntary control.
- Smooth muscle cells are uninucleate.
- Smooth muscles do not contain sarcomeres.
- The thin filaments of smooth muscle fibers are attached to dense bodies.
-The striations are due to the orderly arrangement of actin and myosin.
The muscle that adducts the thumb is the adductor pollicis. abductor pollicis. extensor digitorum. flexor digitorum profundus. flexor pollicis longus.
adductor pollicis.
The powerful abductor muscle of the upper arm is the supraspinatus. subscapularis. deltoid. coracobrachialis. teres major.
deltoid.
The \_\_\_\_\_\_\_\_ extends the neck. spinalis thoracis splenius capitis trapezius splenius splenius cervicis
trapezius
Which of the following are members of the hamstring group?
- biceps femoris and rectus femoris
- semimembranosus, semitendinosus, and gastrocnemius
- biceps femoris, semitendinosus, and semimembranosus
- adductor longus and adductor magnus
- gluteus maximus and rectus femoris
-biceps femoris, semitendinosus, and semimembranosus
If you bruised your gluteus maximus, you would expect to experience discomfort when
flexing your hip.
extending your hip.
abducting your hip.
laterally rotating your hip.
extending and laterally rotating the hip.
extending and laterally rotating the hip.
The advantage of having many nuclei in a skeletal muscle fiber is the ability to
- contract much more forcefully. - produce more ATP with little oxygen. - store extra DNA for metabolism. - produce large amounts of muscle proteins. - produce nutrients for muscle contraction.
-produce large amounts of muscle proteins.
The ability of smooth muscle to function over a wide range of lengths is called elasticity. contractility. extensibility. plasticity. variability.
plasticity.
The most important factor in decreasing the intracellular concentration of calcium ion after contraction is
- active transport of calcium across the sarcolemma.
- active transport of calcium into the sarcoplasmic reticulum.
- active transport of calcium into the synaptic cleft.
- diffusion of calcium out of the cell.
- diffusion of calcium into the sarcoplasmic reticulum.
-active transport of calcium into the synaptic cleft.
the complex of a transverse tubule and two adjacent terminal cisternae is known as a trimer. triad. triptych. trisome. trilogy.
triad
The structural theory that explains how a muscle fiber contracts is called the \_\_\_\_\_\_\_\_ theory. sliding filament excitation-contraction coupling neuromuscular muscle contraction action-myosin interaction
sliding filament
Synaptic vesicles contain neurotransmitters that are released by \_\_\_\_\_\_\_\_ when the action potential arrives. endocytosis apoptosis exocytosis hydrolysis sodium
exocytosis
How would an elevated level of thyroid hormone in the body affect skeletal muscles?
- It would stimulate atrophy.
- It would stimulate hypertrophy.
- It would stimulate energy use and heat production.
- It would decrease heat production by muscle tissue.
- It would cause an increase in muscle mass.
-It would stimulate energy use and heat production.
In a convergent muscle, fascicles converge on a common attachment site that may be a slender band of collagen fibers known as a(n) retinaculum. raphe. aponeurosis. orbicularis. ligament.
raphe
A resting muscle generates most of its ATP by hydrolysis of creatine phosphate. anaerobic respiration. aerobic metabolism of fatty acids. glycogenolysis. the tricarboxylic acid cycle.
aerobic metabolism of fatty acids.
The area in the center of the A band that contains no thin filaments is the Z line. M line. H band. I band. zone of overlap.
H band
Active sites on the actin become available for binding after actin binds to troponin. troponin binds to tropomyosin. calcium binds to troponin. calcium binds to tropomyosin. myosin binds to troponin.
calcium binds to tropomyosin.
Put the following events of the neuromuscular junction in the order in which they occur. 1. Action potential is propagated in the sarcolemma. 2. Acetylcholine binds to ligand gated sodium channels. 3. Action potential arrives at the neuromuscular junction. 4. Vesicles full of acetylcholine are stored at the axon terminal. 5. Acetylcholine is released into the synaptic cleft. 4,3,5,2,1 4,3,5,1,2 4,5,3,2,1 4,3,1,5,2 4,1,3,2,5
4,3,5,2,1
Physical evidence that supports the sliding filament theory of muscle contraction includes
- constant distance between Z lines during contraction.
- decreased width of the H band during contraction.
- increased width of the I band during contraction.
- decreased width of the A band during contraction.
- the I band + H band distance is constant during contraction.
-decreased width of the H band during contraction.
