Module 6: The Skeletal Muscle System Flashcards
(128 cards)
1
Q
Where are the origins typically found in the limbs?
A
Proximal to the trunk.
2
Q
Where are the insertions typically found in the limbs?
A
Distal to the trunk.
3
Q
Where are origins typically found in the trunk of the body?
A
Medial to the midline.
4
Q
Where are insertions typically found in the trunk?
A
Lateral from the midline.
5
Q
Origin
A
The point at which a muscle’s tendon attaches to the more stationary bone.
6
Q
Insertion
A
The point at which a muscle’s tendon attaches to the more moveable bone.
7
Q
Belly
A
The largest part of the muscle, which actually contains the muscle cells.
8
Q
How does the motion of skeletal muscles typically work?
A
Skeletal muscles usually work as partners opposite of each other. When the first partner contracts, the second relaxes, and movement in one direction is caused. Movement in the other direction requires a reversal of these roles.
9
Q
Synergists
A
Muscles working together to create the same movement.
10
Q
Prime mover/agonist
A
A muscle more important in the motion of a synergist group.
11
Q
Antagonist
A
A muscle that works opposite of another muscle. Ex: The triceps is the antagonist of the biceps.
12
Q
Fulcrum
A
A fixed point on which a lever rotates.
13
Q
Why do muscles tend to work as levers?
A
They can only contract, meaning they cannot lengthen on their own. Thus, muscles pull and cannot push. A muscle creates a pull on a lever made out of bone to achieve movement.
14
Q
Effort
A
The force applied to a lever.
15
Q
Resistance
A
The weight applied to a lever.
16
Q
Name the position of the resistance, effort, and fulcrum in a first-class lever.
A
The fulcrum is between the effort and the resistance.
17
Q
Name the position of the resistance, effort, and fulcrum in a second-class lever.
A
The resistance is between the effort and the fulcrum.
18
Q
Name the position of the resistance, effort, and fulcrum in a third-class lever.
A
The effort is between the fulcrum and the resistance.
19
Q
Name a real-world example of a first class lever.
A
A seesaw.
20
Q
Name a real-world example of a second-class lever.
A
A wheelbarrow.
21
Q
Name a real-world example of a third-class lever.
A
A shovel.
22
Q
Name an anatomical example of a first class lever.
A
The posterior neck muscles which tilt the head up. The muscles pull down on the back of the head, the joint between the skull and C1 is the fulcrum, and the head is the resistance.
23
Q
Name an anatomical example of a second-class lever.
A
In the foot, when standing on your tiptoes, the calf muscles pull on the heel. The ball of the foot acts as the fulcrum, and using this lever, the calf muscles can lift the entire weight of the body.
24
Q
Name an anatomical example of a third-class lever.
A
The forearm. The biceps pull on the radius, the elbow acts as the fulcrum, and the object in the hand is lifted.
25
Which type of lever moves the resistance the least?
A second-class lever.
26
Which type of lever requires the least amount of effort?
A first-class lever.
27
Which type of lever requires the greatest force?
A third-class lever, although this lever can move the resistance much farther than the other types.
28
What are the seven characteristics that play a role in the naming of a muscle?
1) Muscle size. 2) Muscle shape. 3) Location of the muscle. 4) Orientation of the muscle's fascicles. 5) Muscle origin and insertion. 6) Number of heads (origins) on the muscle. 7) Muscle function.
29
Superficial skeletal muscles
The muscles on the surface of the skeletal muscle system.
30
What muscle is the prime mover of the group of muscles that rotate and flex the head?
The sternocleidomastoid.
31
Describe the motion that ensues from the contraction of a sternocleidomastoid muscle.
This muscle comes in pairs on opposite sides of the neck, and when one muscle contracts, the head rotates so that the chin moves over towards to opposite side of the contracted muscle.
32
What is unique about the muscles of facial expression?
They insert into the skin or connective tissue of the face.
33
What two muscles make up the occipitofrontalis?
The frontalis and occipitalis.
34
What is the function of the frontalis?
It elevates the eyebrows and wrinkles the forehead.
35
What is the function of the orbicularis oculi?
It circles the orbit and is used to close the eye, as in winking.
36
What is the function of the orbicularis oris?
It surrounds the lips and purses them. It is often nicknamed the "kissing muscle."
37
What is the function of the buccinator?
This is the cheek muscle, and it can compress the cheek and make rapid changes in the volume of the oral cavity.
38
What is the function of the zygomaticus major?
It elevates and draws the corner of the mouth laterally.
39
What is the function of the zygomaticus minor?
It elevates the upper lip.
40
When smiling, what two muscles are used?
The zygomaticus major and the zygomaticus minor.
41
What is the function of the platysma?
It pulls the corners of the mouth down into a frown.
42
Where do wrinkles form in relation to the contraction of muscles on the face?
They form in the dermis at right angles to the contraction of the muscles.
43
Mastication
The process of chewing.
44
What is the function of the temporalis?
It elevates the mandible powerfully and can be used to retract the mandible.
45
What is the function of the masseter?
It elevates the mandible and protracts (pushes forward) the mandible.
46
What is the function of the lateral pterygoid?
It depresses (lowers) the mandible and is used to open the mouth.
47
What is the function of the medial pterygoid?
It elevates the mandible in order to close the mouth.
48
What three muscles elevate the mandible?
The temporalis, the masseter, and the medial pterygoid.
49
What is the function of the anterior muscle fascicles of the deltoid?
They flex the arm. (The arm is straight up and pointing forward.)
50
What is the function of the lateral fascicles of the deltoid muscle?
They abduct the arm. (They bring the arm straight out away from the body.)
51
What is the function of the posterior fascicles of the deltoid muscle?
They extend the arm. (They bring it from a flexed position back to the anatomical position.)
52
What is the function of the pectoralis major muscle?
It adducts, flexes, and medially rotates the arm.
53
What does adduction do to the arm?
It brings the outstretched arm back to anatomical position.
54
What does flexion do to the arm?
It puts the arm in a pointing-straight-ahead position.
55
What does medial rotation do to the arm?
It twists the arm toward the trunk.
56
What is the function of the pectoralis minor?
It elevates the ribs, as in a deep breath, and depresses the scapula, as in pulling down on something above your head.
57
What is the function of the major muscles of the abdomen?
They flex and rotate the vertebral column, compress the abdomen, and are useful in urination, vomiting, defecation, and childbirth.
58
Linea alba
"White line" that is a band of connective tissue that binds all of the abdominal muscles.
59
What is the main job of the transversus abdominis?
It compresses the abdomen.
60
What is the function of the trapezius?
It extends the head and elevates, depresses, and retract the scapula. Also known as the "shoulder-shrugging" muscle.
61
What is the function of the latissimus dorsi?
It works opposite the deltoid to adduct the arm. (It brings an arm that is pointing sideways from the trunk back to anatomical position.) It also medially rotates and extends the arm.
62
Where is the insertion of the latissimus dorsi?
On the inside of the humerus, originating in the vertebral column, which makes it a medial rotator.
63
What is the function of the teres major?
It works with the latissimus dorsi to adduct, extend, and medially rotate the arm. It also inserts on the inside of the humerus.
64
What is the function of the rhomboideus major and minor and the levator scapulae?
These muscles work together to move the scapula and provide a wide range of motion for the shoulder.
65
What is the function of the triceps brachii?
It extends the forearm at the elbow.
66
Why must the ball of the humerus be held in its socket with muscle tension?
The socket is shallow, and since additional ligaments would reduce the range of motion of the joint, muscle tension is used to hold it in instead.
67
What are the four muscles that cause muscle tension in the shoulder joint? (The rotator cuff muscles)
Supraspinatus, infraspinatus, teres minor, and subscapularis.
68
What is the function of the rotator cuff muscles? Also, what are some other names for the cuff?
They provide joint security. Also known as the rotocuff or the musculotendinous cuff.
69
What is the function of the brachioradialis?
It aids the biceps brachii in flexing the forearm.
70
What is the function of the pronator teres?
It pronates the forearm at the elbow, turning the forearm to a palms-down movement.
71
What is the function of the pronator quadratus?
It aids the pronator teres in pronation.
72
What is the function of the supinator?
It supinates the forearm (turns the palm upward).
73
Why is it easier to open a jar left-handed?
To open a lid, one must supinate the left forearm or pronate the right forearm. Since the biceps brachii aids the supinator, supination is a stronger action than pronation. Thus, the left hand exerts a more powerful force.
74
What is the function of the flexor carpi radialis?
It flexes and abducts the hand.
75
What is the function of the flexor carpi ulnaris?
It flexes the hand and acts as the antagonist of the flexor carpi radialis by adducting the hand.
76
What is the function of the palmaris longus?
It flexes the hand.
77
Why can't the palmaris longus abduct or adduct the hand?
It is between the two flexor carpi muscles and inserts straight into the middle of the palm.
78
What is the function of the flexor digitorum superficialis?
It flexes both the wrist and the four fingers to which it inserts.
79
What is the function of the flexor digitorum profundus?
It aids the flexor digitorum superficialis in its function.
80
What is the function of the extensor carpi radialis longus?
It extends and abduct the hand.
81
What is the function of the extensor carpi radialis brevis?
It extends and abducts the hand.
82
What is the function of the extensor carpi ulnaris?
It extends the hand.
83
What two muscles is the extensor carpi ulnaris an antagonist to, and why?
The extensor carpi radialus longus and the extensor carpi radialis brevis. Those two muscles abduct, but the extensor carpi ulnaris adducts the hand.
84
What side of the forearm are the hand adductors?
The medial side.
85
What side of the forearm are the hand abductors on?
The lateral side.
86
What is the function of the extensor digitorum?
It extends the hand and the four fingers to which it inserts.
87
What is the antagonist of the flexor digitorum superficialis?
The extensor digitorum.
88
Extensor retinaculum
A bracelet of dense regular connective tissue that winds around the wrist and covers the extensor tendons.
89
What is the purpose of the extensor retinaculum?
It holds the tendons down as the muscles work. If not for this structure, the extensor tendons would bow outward when the extensors contracted.
90
What two muscles flex the forearm, and what are their antagonists?
The biceps brachii and brachioradialis. Their antagonist is the extensor triceps brachii.
91
What two muscles supinate the forearm, and what are their antagonists?
The biceps brachii and the supinator. The pronators produce the opposite motion, so that is the pronator teres and the pronator quadratus.
92
Where do hands get their strength?
The extrinsic hand muscles.
93
Extrinsic hand muscles
Muscles in the forearm that create movement in the hands.
94
Where do the hands get their delicate ability?
The intrinsic hand muscles.
95
Intrinsic hand muscles
Muscles in the hand that produce movement in the hand.
96
What is the function of the gluteus maximus?
It extends, abducts, and laterally rotates the thigh.
97
What is the function of the gluteus medius?
It abducts and medially rotates the thigh.
98
Why do health practitioners inject medicine into the gluteus medius for an intramuscular injection?
The gluteus medius is far from the sciatic nerve, a major nerve in the buttocks that can be injured by the needle.
99
What is the function of the gluteus minimus?
It abducts and medially rotates the thigh.
100
Which three muscles compose the hamstring muscle group?
The biceps femoris, the semimembranosus, and the semitendinosus.
101
What is the main job of the hamstring muscle group?
They flex the leg and extend the thigh.
102
What is the function of the iliopsoas?
It flexes the thigh.
103
What two muscles compose the iliopsoas?
The iliacus and psoas major.
104
Where does the iliopsoas originate?
The iliopsoas originates in the posterior abdominal wall on the lumbar vertebrae and ilium.
105
Where does the iliopsoas insert?
It inserts into a process on the proximal end of the femur.
106
What muscles make up the quadriceps femoris?
The rectus femoris, the vastus lateralis, the vastus intermedius, and the vastus medialis.
107
Where does the quadriceps femoris insert?
A process on the tibia.
108
What is the function of the quadriceps femoris?
It extends the leg.
109
What is the function of the sartorius?
It flexes and laterally rotates the thigh and flexes the leg.
110
What two muscles work together to adduct the thigh and laterally rotate the thigh?
The adductor longus and the adductor magnus.
111
What is the relationship between the adductor longus and the adductor magnus?
They work together to adduct and laterally rotate the thigh, but they are antagonists in flexion and extension. Adductor longus: Flexes. Adductor magnus: Extends.
112
What is the function of the gracilis?
It adducts the thigh and flexes the leg.
113
List the muscles involved in flexing the thigh and their antagonists (the extensors).
The thigh flexors are the tensor fasciae latae, rectus femoris, sartorius, iliopsoas, and adductor longus. The antagonists are the extensors: gluteus maximum, semitendinosus, semimembranosus, biceps femoris, and adductor magnus.
114
List the muscles involved in abducting the thigh and list their antagonists (the adductors).
The thigh abductors are gluteus maximus, gluteus medius, gluteus minimus, and tensor fasciae latae. Their antagonists are the adductors: adductor longus, adductor magnus, and gracilis.
115
List the muscles involved in medially rotating the thigh and list their antagonists (the lateral rotators).
The muscles that medially rotate the thigh are tensor fasciae latae, gluteus medius, and gluteus minimus. The antagonists are those that laterally rotate the thigh: gluteus maximus, adductor longus, and adductor magnus.
116
What two muscles form the calf?
The gastrocnemius and the soleus.
117
What is the function of the gastrocnemius?
It plantarflexes the foot and flexes the leg.
118
What is the function of the soleus?
It plantarflexes the foot.
119
Where do the gastrocnemius and soleus muscles insert?
They insert into the calcaneus (heel bone) via the calcaneal tendon (the Achilles tendon).
120
What is the function of the tibialis anterior?
Dorsiflexion and inversion of the foot.
121
What is the function of the peroneus longus (also known as fibularis longus?
Eversion and plantarflexion of the foot.
122
What is the function of the peroneus brevis (also called the fibularis brevis)?
Eversion and plantarflexion of the foot.
123
What is the function of the flexor digitorum longus?
It flexes the four lateral toes.
124
What is the function of the extensor digitorum longus?
It extends the four lateral toes.
125
What is the antagonist of the flexor digitorum longus?
The extensor digitorum longus.
126
What is the function of the extensor hallucis longus?
It dorsiflexes and inverts the foot, as well as extends the big toe.
127
What muscle is the peroneus tertius (also known as the fibularis tertius) essentially a part of?
The extensor digitorum longus.
128
Patellar ligament
The ligament struck by a practitioner to test reflexes. It extends from the patella.
