Muscles of the Upper Extremities Flashcards
(119 cards)
1
Q
How many muscles keep the scapula attached to the skeleton of the thorax?
A
six, grouped into an anterior and posterior group
2
Q
Why does the scapula need to be stabilized?
A
Does not directly attach to the skeleton
must be steady by muscle action to be the origin of the muscles that move the humerous
3
Q
True or false: the muscles of scapular stabilization move the scapula to decrease ROM of the humerous to avoid injury
A
False: the muscles of scapular stabilization move the scapula to increase the ROM of the humerous
4
Q
How is the scapula stabilized?
A
muscles steady the scapula by producing forces that pull it in opposite directions (antagonize each other)
5
Q
What muscles are in the anterior group of muscles that stabilize the scapula?
A
subclavius
pectoralis minor
serratus anterior
6
Q
What muscles are in the posterior group of muscles that stabilize the scapula?
A
trapezius
levator scapulae
rhomboid major
rhomboid minor
7
Q
What are the movements of the scapula?
A
- elevation: shrugging shoulders
- depression:pulling down
- abduction:moving laterally + anteriorly (punching)
- adduction: moving medially + posteriorly (pulling down)
- upward rotation: inferior angle moves laterally (raising arms)
- downward rotation: inferior angle moves medially (lowering raised arms)
8
Q
Describe the subclavius
A
- a small, cylindrical muscle under the clavicle
- part of the anterior group of muscles that stabilize the scapula
9
Q
Where is the origin/insertion of the subclavius?
A
Origin: the first rib
Insertion: the clavicle (acromial end)
10
Q
What is the action(s) of the subclavius?
A
- depresses + moves the clavicle anteriorly
- steadies the clavicle
11
Q
Describe the pectoralis minor
A
- part of the anterior group of muscles that stabilize the scapula
- deep to the pectoralis major
- auxillary muscles for inspiration
12
Q
Where does the pectoralis minor originate?
A
may vary:
- 2-5th rib
- 3-5th rib
- or the 2-4th rib
13
Q
Where does the pectoralis minor insert?
A
coracoid process of the scapula
14
Q
What are the action(s) of the pectoralis minor?
A
abduction + downward rotation of the scapula
RMA: elevates the ribs
15
Q
Describe the serratus anterior
A
- part of the anterior group of muscles that stabilize the scapula
- fan shaped, extended between the ribs + the scapula
- antagonist to the rhomboids
16
Q
Where does the serratus anterior originate?
A
1-8 or 1-9 ribs
17
Q
Where does the serratus anterior insert?
A
medial border + inferior angle of the scapula
18
Q
What are the actions of the serratus anterior?
A
- abduction + upward rotation of the scapula
- RMA: elevates the rubs when the scapula is fixed
19
Q
Describe the trapezius mucles
A
- part of the posterior group of muscles that stabilize the scapula
- flat, wide triangular muscle that forms a diamond shape resembling a trapezoid
- extends from the skull + vertebral column medially to the pectoral girdle laterally
- most superficial of back muscles
20
Q
Where does the trapezius muscle originate?
A
superior nuchal line, ligamentum nuchae, spinous processes of C7 to T12
21
Q
Where does the trapezius muscle insert?
A
spine of scapula, acromion, clavicle
22
Q
What are the directions of the muscle fibers of the trapezius muscle?
A
superior, inferior, lateral
23
Q
What are the actions of the superior fibers of the trapezius muscle?
A
upward rotation of the scapula
24
Q
What are the actions of the lateral fibers of the trapezius muscle?
A
adduction of the scapula (pulling shoulders back)
25
What are the actions of the inferior fibers of the trapezius muscle?
depression
| downward rotation of the scapula
26
What are the actions of the trapezius muscle?
```
upward rotation
adduction
depression
downward rotation
extension of the head
```
27
How does the trapezius muscle stabilize the scapula?
the superior and inferior fibers acting together
28
Describe the Levator scapulae
- part of the posterior group of muscles that stabilize the scapula
- deep to the SCM and trapezius
29
Where does the levator scapulae originate?
transverse processes C1-C4
30
Where does the levator scapulae insert?
super angle and upper vertebral border of the scapula
31
Which muscle is superior, the rhomboid major or rhomboid minor?
the rhomboid minor is superior
| the rhomboid major is inferior
32
Where does the rhomboid minor originate?
spinous processes of C7 to T1
33
Where does the rhomboid major originate?
spinous processes of T2 to T5
34
Are the rhomboid muscles one muscle or two?
considered one muscle but there is a clear anatomical separation
35
Where does the rhomboid minor insert?
same place as rhomboid major: medial border of the scapula
36
Where does the rhomboid major insert?
same place as the rhomboid minor: medial border of the scapula
37
What are the actions of the rhomboid muscles?
- elevation of the scapula
- adduction of the scapula
- retraction of the scapula
- stabilizes the scapula in conjunction with the serratus anterior
38
Describe the rhomboid muscles
- part of the posterior group of muscles that stabilize the scapula
- antagonist to the serratus anterior
- two muscles considered one
39
Describe the pectoralis major
- forms the anterior fold of the thorax
| - fan-shaped, large, thick muscle
40
Where does the pectoralis major originate?
clavicle, sternum, costal cartilages 2-6
41
Where does the pectoralis major insert?
lateral lip of the intertubercular sulcus
42
What are the actions of the pectoralis major?
hugging: flexion, medial rotation, adduction
RMA: elevates the ribs in forced inspirawtion when the humerous is fixed
43
Describe the latissimus dorsi
- widest muscle of the back
| - forms most of the posterior fold of the axilla
44
Where does the latissimus dorsi insert?
intertubercular sulcus of the humerous
45
Where does the latissimus dorsi originate?
- spinous processes of T7 TO L5
- sacral crest
- iliac crest
- ribs 9-12
46
What are the actions of the latissimus dorsi?
- pulling something out of your back pocket: extension, adduction, medial rotation
- RMA:elevates the vertebral column + torso (pull ups)
47
Describe the deltoid muscle
- forms the round contour of the shoulder
- originates from three different points
- three fascicles act differently on the humerous
48
Where does the deltoid muscle insert?
deltoid tuberosity of the humerous
49
Where do the anterior fibers of the deltoid muscle originate? What is their action?
originate: acromial extremity of the clavicle
action: flexion + medial rotation
50
Where do the lateral fibers of the deltoid muscle originate? What is their action?
originate: acromion
action: abduction
51
Where do the posterior fibers of the deltoid muscle originate? What are their actions?
originate: spine of scapula
action: extension + lateral rotation
52
What is the alternative name of the rotator cuff muscles?
musculotendinous cuff
53
What muscles are included in the rotator cuff?
supraspinatus
infraspinatus
teres minor
subscapularis
54
What is the point of the rotator cuff?What does it do?
- to pull the head of the humerous into the glenoid fossa
- their tendons fuse to form a complete circle around the joint
- strengthen + stabilize the joint
55
Which muscles of the rotator cuff rotate the humerous?
infraspinatus, teres minior, subscapularis
56
What muscle of the rotator cuff does not rotate the humerous?
supraspinatus
57
true or false: the rotator cuff muscles are rarely injured
false: rotator cuff is commonly injured
58
Which muscle of the rotator cuff is most injured? Why?
supraspinatus because its tendon is compressed during abduction
59
What is one of the most common causes of shoulder pain and dysfunction, particularly in athetes?
inpingement syndrome
60
What causes inpingement syndrome?
repetitive movement of the arm over the head continuously pinches the tendon of the supraspinatus with the acromion, the tendon become inflamed and painful
61
What happens to the tendon of the supraspinatus with inpingement syndrome?
becomes inflamed and painful
injured tendon may degenerate near the attachment to the humerous, may tear away from bone causing rotator cuff injury
62
What sports are the athletes most commonly at risk for inpingement syndrome?
- baseball
- racquet sports
- volleyball
- swimming
- weight lifting
63
Where does the coracobrachialis originate?
coracoid process
64
Where does the coracobrachiallis insert?
middle medial surface of humerous
65
What are the actions of the coracobrachiallis?
flexion and adduction of the arm
66
How are the muscles that move the forearm divided
| ?
into flexors, extensors, pronators and supinators
67
What muscles are the flexors of the muscles of the arm that move the forearm?
- biceps brachii
- brachialis
- brachioradialis
68
What muscles are the extensors of the muscles of the arm that move the forearm?
- triceps brachiaa
| - anconeous
69
What muscles are the supinators of the muscles of the arm that move the forearm?
- biceps brachii
| - supinator
70
What muscles are the pronators of the muscles of the arm that move the forearm?
pronator teres
| pronator quadratus
71
Describe the biceps brachii
- palpable superficial muscle in the anterior of the arm
- acts on both the shoulder and elbow joints
- consists of a long head and a short head
72
Where does the long head of the biceps brachii originate?
supraglenoid tubercle
73
Where does the short head of the biceps brachii originate?
coracoid process of the scapula
74
Where does the biceps brachii insert?
radial tuberosity
75
What are the actions of the biceps brachii
flexion of the arm and forearm
| supination of the forearm
76
Describe the brachialis
- deep the the biceps brachii
| - most powerful flexor at the elbow joint
77
Which muscle is the most powerful flexor at the elbow joint?
brachialis
78
where does the brachialis originate?
anterior surface of the humerous
79
where does the brachialis insert?
ulnar tuberosity
80
what are the actions of the brachialis?
flexion of the forearm
81
Where does the brachioradialis originate?
lateral distal end of the humerous
82
Where does the brachioradialis insert?
styloid process of the radius
83
What are the actions of the brachioradialis?
flexion of the forearm
| brings supination and pronation to neutral position
84
Describe the triceps brachii
- superficial
- most powerful extensor at the elbow
- acts on both thee shoulder and elbow joints
- consists of three heads
85
What are the three heads of the triceps brachii?
long head
medial head
lateral head
86
Where does the long head of the triceps brachii originate?
infraglenoid tubercle
87
Where does the medial head of the triceps brachii originate?
posterior surface of the humerous
88
Where does the lateral head of the triceps brachii originate?
posterior surface of the humerous
89
Where does the triceps brachii insert?
the three heads join to insert in the olecranon
90
What are the actions of the triceps brachii?
extension. it is an extensor muscle at the shoulder and elbow joints
91
Describe the anconeus muscle
a small postero-lateral muscle
92
Where does the anconeus originate?
lateral epicondyle of the humerous
93
Where does the anconeus muscle insert?
olecranon of the ulna
94
What are the actions of the anconeus?
extension of the forearm
95
Where does the pronator teres originate?
- medial epicondyle of the humerous
| - coranoid process of the ulna
96
Where does the pronator teres insert?
mid-lateral surface of the radius
97
What are the actions of the pronator teres?
pronation of the forearm
98
Describe the pronator quadratus
deep muscle extended across the distal ends of the radius and ulna
99
Where does the pronator quadratus originate?
distal end of ulna
100
Where does the pronator quadraus insert?
distal end of radius
101
What are the actions of the pronator quadratus?
pronation of the forearm
102
Where does the supinator muscle originate?
lateral epicondyle of the humerous
103
Where does the supinator muscle insert?
lateral proximal surface of the radius
104
What are the actions of the supinator muscle?
supinator of the forearm
105
What is a compartment?
used to encase muscles that will support each other increasing strength
106
What are the flexor muscles of the superficial compartment of muscles that move the hand and fingers?
- flexor carpi radialis (FCR)
- palmaris longus (absent in 10%)
- flexor carpi ulnaris (FCU)
- flexor digitorum superficialis (FDS)
107
Where do the superficial compartment of muscles that move the hand and fingers originate?
medial epicondyle of the humerous
108
Where do the superficial compartment of muscles that move the hand and fingers insert?
carpal, metacarpal, and phlangeal bones
109
What are the actions of the superficial compartment of muscles that move the hand and fingers?
flexion of the hand + fingers
110
What are the extensor muscles of the superficial compartment of muscles that move the hand and digits?
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digiti minimi
- extensor carpi ulnaris
111
Where do the superficial compartment of muscles that move the hand and digits originate?
posterior surface of the radius, ulna, interosseus membrane
112
Where do the superficial compartment of muscles that move the hand and digits insert?
thumb + index finger
113
What are the actions of superficial compartment of muscles that move the hand and digits?
aduct and extend the thumb
| extend the index
114
What is the extensor retinaculum?
- located over the dorsal surface of the carpal bones
- the thin and long tendons of the extensor muscles pass deep to it
- less prominent than the flexor retinaculum
115
What is the flexor retinaculum?
- located over the palmar surface of the carpal bones
| - the long and thin tendons of the flexor muscles together with the median nerve pass deep to it along the carpal tunnel
116
Describe the intrinsic muscles of the hand
- produce weak but very complex and precise movements of the fingers
- origin and insertion located in the hand
- divided into thenar, hypothenar and midpalmar compartments
117
Describe the thenar eminence. What does it include?
-moves the thumb
-includes:
abductor pollicis brevis
opponens pollicis
flexor pollicis brevis
adductor pollicis
118
Describe the hypothenar eminence. What does it include?
-move the pinkie
-includes:
adductor digiti minimi
flexor digiti minimi
opponens digiti minimi
119
Describe the midpalmar eminence. What does it include?
lumbricals
palmar interossei
dorsal interossei
