10. Muscles

Muscle contraction around joints

01:26

Practice this topic

A muscle that assists the muscle primarily responsible for a given action is a(n) __________.

True or False: if false, choose the answer that best corrects the statement.

A fixator works to stabilize the insertion of the antagonist.

The genioglossus is the primary muscle involved sticking out your tongue. The styloglossus is responsible for pulling the tongue back in, making it a(n) _______ for sticking out your tongue?

The soleus, gastrocnemius, and the tibialis anterior are all major muscles of the lower leg. The gastrocnemius and the soleus are both located in the posterior region of the calf, while the tibialis anterior is located in the anterior region of the lower leg. Based only on this information, which statement do you think is most likely true?

The major abductor muscle of the upper arm is the __________.

1635

The prime mover for flexion of the thigh is the __________ muscle.

1742

The __________ assists the triceps brachii in forearm extension.

1286

__________ are muscles that oppose or reverse a particular movement.

The extensor digitorum muscle is an example of a __________ muscle.

1197

The prime movers of back extension are the __________.

1391

The __________ is the prime mover of dorsiflexion of the foot.

2050

The prime mover of arm extension is the __________.

A muscle that assists an agonist by causing a like movement or by stabilizing a joint over which an agonist acts is a(n) a. antagonist, b. prime mover, c. synergist, d. agonist.

377

Multiple Choice More than one choice may apply. Doing the pincer grasp is an________movement. a. extending b. abducting c. adducting d. opposing

203

The hamstring and quadriceps muscle groups are antagonists of each other, and each group is a prime mover in its own right. What action does each muscle group perform?

422

Name three muscles or muscle groups used as sites for intramuscular injections. Which is most often used in babies?

284

While jogging, Mr. Ahmadi was forced to jump out of the way of a speeding car. He heard a snapping sound that was immediately followed by pain in his right lower calf. A gap was visible between his swollen calf and his heel, and he was unable to plantar flex that foot. What do you think happened?

319

Why does a convergent muscle exhibit more versatility when contracting than does a parallel muscle?

202

Why can a pennate muscle generate more tension than can a parallel muscle of the same size?

209

Why is it difficult to lift a heavy object when the elbow is at full extension?

168

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

d. The buccinator muscle pulls the cheeks in, producing sucking movements.

160

Which eye muscle passes through the trochlea and turns the eye inferiorly and laterally?

a. Lateral rectus muscle

b. Inferior rectus muscle

c. Inferior oblique muscle

d. Superior oblique muscle

185

Which function is being fulfilled by a muscle that holds a bone steady during movement?

a. Antagonist

b. Synergist

c. Supinator

d. Fixator

181

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

a. The main action of the zygomaticus major and minor muscles is to pull the corners of the mouth up to produce smiling.

148

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

c. The rhomboid major and minor muscles retract the scapula.

144

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

d. The deltoid muscle is a main abductor of the forearm.

139

Match the muscle with its main action:

______Biceps brachii muscle

______Pronator teres muscle

______Extensor digitorum muscle

______Brachialis muscle

______Triceps brachii muscle

______Flexor carpi radialis musclea.

a. Extends fingers and hand

b. Supinates forearm

c. Flexes hand

d. Extends forearm

e. Pronates forearm

f. Flexes forearm

124

Match the muscle with its main action:

_____Sternocleidomastoid muscle

_____Transversus abdominis muscle

_____Internal oblique muscle

_____Rectus abdominis muscle

_____Splenius capitis muscle

_____Quadratus lumborum musclea.

a. Laterally flexes the trunk

b. Flexes the trunk

c. Compresses the abdominal cavity

d. Extends the vertebral column

e. Flexes the head

f. Extends the head

177

Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

a. The pectoralis major and coracobrachialis muscles are antagonists.

145

Predict the location and function of the flexor digitorum profundus muscle based only on its name.

163

Why do the three parts of the trapezius muscle have three different actions?

259

Explain why strengthening the levator ani muscle may help improve bladder and bowel continence (voluntary control over urination and defecation).

155

Mr. Bell presents with the inability to move certain muscles on one side of his face. You ask him to make various facial expressions and find that on his right side he is unable to purse his lips, pull in his cheeks, elevate his upper lip, and smirk. What muscles is Mr. Bell unable to contract?

Ms. Cho presents with muscle pain in the area around her anterior neck and superior chest. She explains that she has had a respiratory infection over the past 2 weeks that made it hard for her to breathe. What is likely causing her muscle soreness? (Hint: Remember that the origin and insertion of some muscles can switch and that one likely has to breathe more deeply with a respiratory infection.)

139

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. A property of all muscle cells is elasticity, which means that the tissue is able to stretch.

156

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The common function of all types of muscle tissue is to generate tension.

152