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