Chapter 11: Muscular System Flashcards
(170 cards)
1
Q
What are the 5 functions of the muscular system?
A
1) Stabilize body position. 2) Produce movement. 3) Regulate organ volume. 4) Move substances. 5) Produce heat.
2
Q
How many individual muscles are in the body?
A
700
3
Q
How do skeletal muscles produce movement?
A
They exert force on tendons which pull on bones or other structures. When a skeletal muscle contracts, it moves one of the articulating bones in a joint.
4
Q
What is the origin?
A
The attachment of the muscle’s tendon to a stationary bone.
5
Q
What is the insertion?
A
The attachment of the muscle’s other tendon to a movable bone.
6
Q
What is the belly?
A
The fleshy middle part of the muscle between the tendons.
7
Q
What is reverse muscle action (RMA)?
A
Muscle actions can be reversed during specific movements so the positions of the origin and the insertion are switched.
8
Q
What is the lever?
A
Rigid structure that can move around a fixed point (joint, fulcrum).
9
Q
What is the effort?
A
The force exerted by the muscular contraction that causes movement.
10
Q
What is the load?
A
The resistance that opposes the movement. Can be the weight of the body part being moved.
11
Q
What is mechanical advantage?
A
When the load is closer to the fulcrum, and the effort is farther from the fulcrum. A small effort is required to move a large load over a small distance.
12
Q
What is mechanical disadvantage?
A
When the effort is closer to the fulcrum, and the load is farther from the fulcrum. A large effort is required to move a small load but at a greater speed.
13
Q
First class lever.
A
Fulcrum is between the effort and the load. Can produce a mechanical advantage or disadvantage depending on whether the effort or load is closer to the fulcrum.
14
Q
First class lever example.
A
1) Scissors. 2) Head resting on vertebral column.
15
Q
Second class lever.
A
The load is between the fulcrum and the effort. Always produces a mechanical advantage. Produces the most force, but is uncommon in the human body.
16
Q
Second class lever example.
A
1) Wheelbarrow. 2) Standing up on toes.
17
Q
Third class lever.
A
The effort is between the fulcrum and the load. Always produces a mechanical disadvantage. Favours speed and range of motion over power. The most common lever in the human body.
18
Q
Third class lever example.
A
Elbow and biceps brachii with arm and forearm bones.
19
Q
How are muscle fibres arranged in a fascicle?
A
They are all parallel to one another.
20
Q
How much does a muscle fibre shorten when it contracts?
A
It shortens to 70% of its resting length.
21
Q
What can the length of a muscle fibre tell us?
A
The longer the fibre, the greater the range of motion.
22
Q
What can the cross-sectional area of a muscle tell us?
A
The more fibres per unit of cross-sectional area, the greater the power.
23
Q
What are the 5 patterns of fascicles?
A
1) Parallel. 2) Fusiform. 3) Circular. 4) Triangular. 5) Pennate.
24
Q
Parallel.
A
Fascicles are parallel to the longitudinal axis of the muscle. There are fewer and longer fascicles, generating a large range of motion with less power.
25
Fusiform.
Fascicles are nearly parallel to the longitudinal axis of the muscle, and are spindle-shaped.
26
Circular.
Fascicles are in concentric circular arrangements, and mostly form sphincter muscles.
27
Triangular.
Fascicles spread over a broad area and then converge at a thick central tendon.
28
Pennate.
Fascicles are short and feather-shaped, generating a small range of motion with lots of power. The tendon extends nearly the entire length of the muscle.
29
Unipennate.
Fascicles are arranged on only one side of the tendon.
30
Bipennate.
Fascicles are arranged on both sides of centrally positioned tendons.
31
Multipennate.
Fascicles attach obliquely from many directions to several tendons.
32
What is the prime mover?
The agonist muscle that contracts to cause movement.
33
What is the antagonist muscle?
The muscle that stretches and yields to the efforts of the prime mover.
34
How are unwanted movements prevented as the prime mover crosses intermediate joints?
Synergist muscles contract and stabilize these joints.
35
What are fixators?
Muscles that stabilize the origin of the prime mover, and steady the proximal end of a limb while movements are occurring at the distal end.
36
What is a compartment?
A group of skeletal muscles and their associated blood vessels and nerves that all have a common function.
37
Name the muscles of the head that produce facial expressions.
Occipitofrontalis, orbicularis oris, zygomaticus major, buccinator, orbicularis oculi.
38
What is the action of the occipitofrontalis?
It covers the scalp. The frontal belly of the muscle draws the scalp anteriorly to raise the eyebrows and wrinkle the forehead skin. The occipital belly of the muscle draws the scalp posteriorly.
39
What is the action of the orbicularis oris?
It covers the mouth, and it works to close and protrude the lips, and compress the lips against the teeth.
40
Which muscle is important for kissing and talking?
Orbicularis oris.
41
What is the action of the zygomaticus major?
It covers the mouth, and works to draw the angle of the mouth superiorly and laterally.
42
Which muscle is important for smiling?
Zygomaticus major.
43
What is the action of the buccinator?
It covers the mouth, and works to press the cheeks against the teeth and lips, keep food between teeth, and draw the corners of the mouth laterally.
44
Which muscle is important for whistling, blowing, sucking and chewing?
Buccinator.
45
What is the action of the orbicularis oculi?
It covers the orbits and eyebrows, and works to close the eyes.
46
Name the muscles of the mandible important for chewing and talking. Why are they called the muscles of mastication?
Masseter and temporalis. They move the mandible at the TMJ.
47
What is the action of the masseter?
It is the strongest muscle of mastication, and it works to elevate the mandible.
48
What is the action of the temporalis?
It works to elevate and retract the mandible.
49
What is the origin and insertion of the masseter?
Origin: maxilla and zygomatic arch. Insertion: angle and ramus of the mandible.
50
What is the origin and insertion of the temporalis?
Origin: temporal bone. Insertion: coronoid process and ramus of mandible.
51
Name the muscle of the neck that moves the head.
Sternocleidomastoid.
52
What is the origin and insertion of the sternocleidomastoid?
Origin: sternal head of manubrium and clavicular head of clavicle. Insertion: mastoid process of temporal bone and superior nuchal line of occipital bone.
53
What is the bilateral action of the sternocleidomastoid?
Flex cervical portion of vertebral column and extend head of atlanto-occipital joints.
54
What is the unilateral action of the sternocleidomastoid?
Laterally flex and rotate the neck and head.
55
What is the RMA of the sternocleidomastoid?
Elevate the sternum during forced inhalation.
56
Name the muscles of the abdomen.
Rectus abdominis, external oblique, internal oblique, transversus abdominis.
57
What is the action of the rectus abdominis?
Flex vertebral column and compress abdomen for defecation, urination, forced exhalation and childbirth.
58
What is the RMA of the rectus abdominis?
Flex pelvis.
59
What is the origin and insertion of the rectus abdominis?
Origin: pubic crest and symphysis. Insertion: cartilage of ribs 5-7 and xiphoid process.
60
What is the bilateral action of the external oblique?
Compress abdomen and flex vertebral column.
61
What is the unilateral action of the external oblique?
Laterally flex and rotate vertebral column.
62
What is the bilateral action of the internal oblique?
Compress abdomen and flex vertebral column.
63
What is the unilateral action of the internal oblique?
Laterally flex and rotate the vertebral column.
64
What is the action of the transversus abdominis?
Compress abdomen.
65
What is the insertion of the transversus abdominis?
Insertion: xiphoid process, lines alba and pubis.
66
Which muscles form the rectus sheaths?
The aponeuroses of the external oblique, the internal oblique, and the transversus abdominis?
67
What is the linea alba?
White tough and fibrous band that extends from xiphoid process of sternum to pubic symphysis.
68
Name the muscles of the thorax involved in breathing.
Diaphragm and intercostals.
69
What is the action of the diaphragm?
Increase the vertical dimension of the thoracic cavity for inhalation, and decrease it for exhalation.
70
What are the convex and concave surfaces of the diaphragm?
The convex surface is the superior surface of the diaphragm, and it forms the floor of the thoracic cavity. The concave surface is the inferior surface of the diaphragm, and it forms the roof of the abdominal cavity.
71
Describe the fibres of the 11 pairs of external intercostals.
Run in an oblique direction inferiorly and anteriorly from the rib above to the rib below.
72
Describe the fibres of the 11 pairs of internal intercostals.
Run at right angles to the external intercostals in an oblique direction inferiorly and posteriorly from the rib above to the rib below.
73
What is the action of the external intercostals?
Elevate ribs to increase anteroposterior and lateral dimensions of the thoracic cavity for inhalation, and depress the ribs for exhalation.
74
What is the action of the internal intercostals?
Draw adjacent ribs together to further decrease the anteroposterior and lateral dimensions of the thoracic cavity for exhalation.
75
Name the muscles of the thorax for pectoral girdle movement.
Pectoralis minor, serratus anterior, trapezius, levator scapulae, rhomboid major.
76
What is the action of the pectoralis minor?
It covers the anterior pectoral girdle, and works to abduct the scapula and rotate it downwards.
77
What is the RMA of the pectoralis minor?
Elevate ribs 3-5 during forced inhalation.
78
What is the action of the serratus anterior?
It covers the anterior pectoral girdle and is known as the boxer's muscle. It works to abduct the scapula and rotate it upwards.
79
What is the origin and insertion of the serratus anterior?
Origin: ribs 1-8. Insertion: inferior angle of scapula.
80
What is the RMA of the serratus anterior?
Elevate the ribs when the scapula is stabilized.
81
Which nerve innervates the serratus anterior?
Long thoracic nerve.
82
What is the origin and insertion of the trapezius?
Origin: superior nuchal line of occipital bone, ligamentum nuchae and spines of C7-T12. Insertion: clavicle and acromion and spine of scapula.
83
Which part of the pectoral girdle does the trapezius cover?
Posterior.
84
What is the action of the superior, middle and inferior fibres of the trapezius?
Superior: rotate scapula upward. Middle: adduct scapula. Inferior: depress and rotate scapula upward.
85
What is the action of the superior and inferior fibres of the trapezius?
Rotate scapula upward.
86
What is the RMA of the trapezius?
Superior fibres extend the head.
87
What is the action of the levator scapulae?
It covers the posterior pectoral girdle, and works to elevate and rotate scapula downwards.
88
What is the origin and insertion of levator scapulae?
Origin: transverse processes of C1-C4. Insertion: superior vertebral border of scapula.
89
What is the action of the rhomboid major?
It covers the posterior pectoral girdle, and works to elevate, adduct, stabilize and rotate the scapula downwards.
90
Name the muscles of the thorax and shoulder for humerus movement.
Pectoralis major, latissimus dorsi, deltoid, subscapularis, supraspinatus, infraspinatus, teres major, teres minor.
91
What is the action of the pectoralis major?
It is axial, and works to adduct and medially rotate arm at shoulder.
92
What is the origin and insertion of pectoralis major?
Origin: clavicle, sternum and costal cartilages of ribs 2-6. Insertion: greater tubercle and lateral lip of intertubercular sulcus of humerus.
93
What is the action of the latissimus dorsi?
It is axial, and works to extend, adduct and medially rotate the arm at the shoulder. It also works to draw the arm inferiorly and posteriorly.
94
What is the RMA of the latissimus dorsi?
Elevate vertebral column and torso.
95
What is the action of the lateral, anterior and posterior fibres of the deltoid.
It is scapular. Lateral: abduct arm at shoulder. Anterior: flex and medially rotate arm at shoulder. Posterior: extend and laterally rotate arm at shoulder.
96
What is the origin and insertion of the deltoid?
Origin: acromial extremity of clavicle, and acromion and spine of scapula. Insertion: deltoid tuberosity of humerus.
97
What is the action of the subscapularis?
It is scapular, and works to medially rotate arm at shoulder.
98
What is the action of the supraspinatus?
It is scapular, and works to assist deltoid in arm abduction.
99
What is the origin and insertion of the supraspinatus?
Origin: supraspinous fossa of scapula. Insertion: greater tubercle of humerus.
100
What is the action of the infraspinatus?
It is scapular, and works to laterally rotate arm at shoulder.
101
What is the action of the teres major?
It is scapular, and works to extend, adduct and medially rotate the arm at the shoulder.
102
What is the action of the teres minor?
It is scapular, and works to laterally rotate and extend arm at shoulder.
103
Name the muscles of the arm for radius and ulna movement.
Biceps brachii, brachialis, brachioradialis, triceps brachii, ancoenus, pronator teres, supinator.
104
What is the action of the biceps brachii?
It is a forearm flexor, and works to flex the forearm at the elbow, supinate the forearm at the radioulnar joints, and flex the arm at the shoulder.
105
What is the origin and insertion of the biceps brachii?
Origin: tubercle and coracoid process of scapula. Insertion: radial tuberosity of aponeurosis.
106
What is the action of the brachial?
It is a forearm flexor, and work to flex the forearm at the elbow.
107
What is the action of the brachioradialis?
It is a forearm flexor, and works to flex the forearm at the elbow, and supinate and pronate the forearm at the radioulnar joints to neutral position.
108
What is the action of the triceps brachii?
It is a forearm extensor, and works to extend forearm at elbow and arm at shoulder.
109
What is the origin and insertion of the triceps brachii?
Origin: infraglenoid tubercle and lateral and posterior humerus. Insertion: olecranon of ulna.
110
What is the action of the anconeus?
It is a forearm extensor, and works to extend forearm at elbow.
111
Which nerve innervates the anconeus?
Radial nerve.
112
What is the origin and insertion of the anconeus?
Origin: lateral epicondyle of humerus. Insertion: olecranon and superior ulna.
113
What is the action of the pronator teres?
It is a forearm pronator, and works to pronate forearm at radioulnar joints and weakly flex the forearm at the elbow.
114
What is the action of the supinator?
It is a forearm supinator, and works to supinate the forearm at the radioulnar joints.
115
Name the muscles of the forearm that move the wrist, hand, thumb and digits.
Flexor carpiradialis, palmaris longus, flexor carpiulnaris, flexor digitorum superficialis, extensor carpiradialis longus, extensor digitorum, extensor carpiulnaris.
116
What is the action of the flexor carpiradialis?
It is a superficial anterior flexor, and works to flex and abduct the hand at the wrist.
117
What is the origin and insertion of the flexor carpiradialis?
Origin: medial epicondyle of humerus. Insertion: metacarpals II and III.
118
What is the action of the palmaris longus?
It is a superficial anterior flexor, and works to weakly flex the hand at the wrist.
119
What is the action of the flexor carpiulnaris?
It is a superficial anterior flexor, and works to flex and adduct the hand at the wrist.
120
What is the origin and insertion of the flexor carpiulnaris?
Origin: medial epicondyle of humerus and superior posterior border of ulna. Insertion: pisiform, hamate and base of metacarpal V.
121
What is the action of the flexor digitorum superficialis?
It is a superior anterior flexor, and works to flex middle phalanx at proximal interphalangeal joint, flex proximal phalanx at metacarpophalangeal joint, and flex hand at wrist.
122
What is the origin and insertion of the flexor digitorum superficialis?
Origin: medial epicondyle of humerus, coronoid process of ulna, and ridge of radius. Insertion: middle phalanx of each finger.
123
What is the action of the extensor carpiradialis longus?
It is a superficial posterior extensor, and works to extend and abduct the hand at the wrist.
124
What is the action of the extensor digitorium?
It is a superficial posterior extensor, and works to extend distal and middle phalanges at interphalangeal joints, extend proximal phalanx at metacarpophalangeal joint, and extend hand at wrist.
125
What is the origin and insertion of the extensor digitorium?
Origin: lateral epicondyle of humerus. Insertion: distal and middle phalanges of each finger.
126
What is the action of the extensor carpiulnaris?
It is a superficial posterior extensor, and works to extend and adduct hand at wrist.
127
What is the origin and insertion of the extensor carpiulnaris?
Origin: lateral epicondyle of humerus and posterior ulna. Insertion: metacarpal V.
128
Name the muscles of the neck and back for vertebral column movement.
Erector spinae and scalenes.
129
What are the lateral, intermediate and medial muscle groups of the erector spinae?
Lateral: iliocastalis. Intermediate: longissimus. Medial: spinalis.
130
Which muscles are part of the iliocostalis muscle group?
Iliocostalis cervicis, thoracis, and lumborum.
131
What is the action of the iliocostalis muscles when working together?
Extend and maintain erect posture of vertebral column.
132
What is the action of the iliocostalis muscles when working singly?
Laterally flex vertebral column to the same side as the contracting muscle.
133
What is the action of the anterior scalene?
Elevate first ribs during sleep inhalation.
134
What is the action of the middle scalene?
Laterally flex and rotate cervical vertebrae.
135
What is the RMA of the middle scalene?
Flex cervical vertebrae.
136
What is the action of the posterior scalene?
Elevate second ribs during sleep inhalation.
137
What is the RMA of the posterior scalene?
Flex cervical vertebrae.
138
Name the muscles of the gluteal region for femur movement.
Iliopsoas, iliacus, gluteus maximus, gluteus medius, adductor longus, adductor magnus.
139
What is the action of the iliopsoas and iliacus?
Flex thigh at hip, laterally rotate the thigh, flex trunk at hip.
140
What is the origin and insertion of the iliopsoas and iliacus?
Origin: transverse processes and bodies of lumbar vertebrae. Insertion: lesser trochanter of femur with iliacus.
141
What is the action of the gluteus maximus?
Extend thigh at hip, and laterally rotate thigh.
142
What is the RMA of gluteus maximus?
Extend torso.
143
What is the origin and insertion of the gluteus maximus?
Origin: iliac crest, sacrum, coccyx, aponeurosis of sacrospinalis. Insertion: iliotibial tract of fascia lata and lines aspera.
144
What is the action of the gluteus medius?
Abduct thigh at hip and medially rotate thigh.
145
What is the action of the adductor longus?
Adduct and flex thigh at hip, and rotate thigh.
146
What is the RMA of the adductor longus?
Extend thigh.
147
What is the action of the adductor magnus?
Adduct thigh at hip and rotate thigh. Anterior part flexes thigh. Posterior part extends thigh.
148
Name the muscles of the thigh that move the femur, tibia and fibula.
Quadriceps femoris, sartorius, hamstrings.
149
What are the 4 heads of the quadriceps femoris?
Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius.
150
What is the function of the quadriceps femoris?
Anterior extensors. Extend leg at knee.
151
What is the action of the rectus femoris?
Flex thigh at hip.
152
What is the origin and insertion of the rectus femoris?
Origin: anterior inferior iliac spine. Insertion: patella and tibial tuberosity.
153
What is the origin and insertion of the vastus lateralis?
Origin: greater trochanter and linea aspera of femur. Insertion: patella and tibial tuberosity.
154
What is the origin and insertion of the vastus medialis?
Origin: linea aspera of femur. Insertion: patella and tibial tuberosity.
155
What is the origin and insertion of the vastus intermedius?
Origin: anterior and lateral femur. Insertion: patella and tibial tuberosity.
156
What is the action of the sartorius?
It is an anterior extensor, and works to weakly flex the leg at the knee, and weakly flex, abduct and laterally rotate thigh at hip.
157
What are the 3 muscles of the hamstrings?
Biceps femoris, semitendinosus, semimembranosus.
158
What is the action of the hamstrings?
They are the posterior extensors, and work to flex leg at knee and extend thigh at hip.
159
What is the origin and insertion of the biceps femoris?
Origin: ischial tuberosity and linea aspera of femur. Insertion: head of fibula and lateral condyle of tibia.
160
Name the muscles of the leg for foot and toe movements.
Tibialis anterior, extensor digitorum longus, fibularis longus, gastrocnemius, soleus, flexor digitorum longus.
161
What is the action of the tibialis anterior?
Covers the anterior leg, and works to dorsiflex foot at ankle and invert foot at intertarsal joint.
162
What is the origin and insertion of the tibialis anterior?
Origin: lateral condyle of tibia and interosseous membrane. Insertion: metatarsal I and first cuneiform.
163
What is the action of the extensor digitorum longus?
Covers the anterior leg, and works to dorsiflex foot at ankle and extend distal and middle phalanges at interphalangeal joints and proximal phalanx at metatarsophalangeal joint.
164
What is the origin and insertion of the extensor digitorum longus?
Origin: lateral condyle of tibia, anterior fibula and interosseous membrane. Insertion: middle and distal phalanges of toes II-V.
165
What is the action of the fibularis longus?
Covers the lateral leg, and works to plantar flex foot at ankle and evert foot at intertarsal joint.
166
What is the action of the gastrocnemius?
Covers the superficial posterior leg, and works to plantar flex foot at ankle and flex leg at knee.
167
What is the origin and insertion of the gastrocnemius?
Origin: lateral and medial condyles of femur and knee capsule. Insertion: calcaneus.
168
What is the action of the soleus?
Covers the superficial posterior leg, and works to plantar flex foot at ankle.
169
What is the action of the flexor digitorum longus?
Covers the deep posterior leg, and works to plantar flex foot at ankle, flex distal and middle phalanges at interphalangeal joints, and flex proximal phalanx of toes II-V at metatarsophalangeal joint.
170
What is the origin and insertion of the flexor digitorum longus?
Origin: posterior tibia. Insertion: distal phalanges of toes II-V.
