UL1 - Muscles of the shoulder, arm & elbow Flashcards
1
Q
which of the following muscles is attached to the coracoid process?
A) brachialis
B) pectoralis minor
C) subclavius
D) pectoralis major
E) deltoid
A
B: pectoralis minor
2
Q
which of these muscles is innervated by the suprascapular nerve?
A) teres major
B) teres minor
C) rhomboid major
D) infraspinatus
E) latissimus dorsi
A
infraspinatus
3
Q
the insertion of the biceps brachii muscle is on which structure?
A
radial tuberosity
4
Q
what two structures pass through the quadrangular space?
A
axillary nerve
posterior circumflex humeral artery
5
Q
what are the muscles of the anterior axioappendicular group? (4)
A
pectoralis major
pectoralis minor
serratus anterior
subclavius
6
Q
what are the muscles of the posterior axioappendicular group? (5)
A
trapezius
latissimus dorsi
levator scapular
rhomboid major
rhomboid minor
7
Q
what are the muscles of the scapulohumeral group?
A
supraspinatus
infraspinatus
subscapularis
teres minor
teres major
deltoid
8
Q
what are the muscles of the anterior arm compartment? (3)
A
biceps brachii
coracobrachialis
brachialis
9
Q
what are the muscles of the posterior arm compartment? (2)
A
triceps brachii
anconeus
10
Q
what are the muscles of the rotator cuff muscle group?
A
supraspinatus
infraspinatus
subscapularis
teres minor
11
Q
origins and insertion of the pectoralis major?
A
ORIGIN - pectoralis major has two heads:
- clavicular head from medial 1/3 of clavicle
- sternoclavicular head from superior 6 costal cartilages & sternum
INSERTION on the lateral lip of the intertubercular sulcus/ bicipital groove of the humerus
12
Q
the pectoralis major consists of a clavicular head & sternocostal head? what are the actions of these heads individually? what happens when these heads work together?
A
sternocostal head contraction = shoulder extension
clavicular head = shoulder flexion
both = adduction & medial rotation of the shoulder
13
Q
action of the pectoralis major when both heads work together?
A
adduction & medial rotation of the shoulder
14
Q
innervation of the pectoralis major?
A
lateral & medial pectoral nerves
15
Q
origin and insertion of the pectoralis minor?
A
ORIGIN - anterior surface of 3-5th ribs
INSERTION - coracoid process of scapula
16
Q
action of the pectoralis minor?
A
depresses shoulder
stabilises scapula against thoracic wall
17
Q
innervation of pectoralis minor?
A
medial pectoral nerve
18
Q
origin & insertion of subclavius?
A
ORIGIN - junction of 1st costal cartilage of 1st rib
INSERTION - subclavian groove of clavicle
19
Q
action of subclavius?
A
depresses clavicle
stabilises clavicle at sternoclavicular joint
(not for large movements)
20
Q
innervation to subclavius?
A
nerve to subclavius - from the superior trunk of the brachial plexus
21
Q
origin and insertion of serratus anterior?
A
ORIGIN - anterior aspect of first 9 ribs
INSERTION - medial border of scapula
22
Q
action of serratus anterior?
A
protracts scapula & holds it against posterior thoracic wall
23
Q
innervation to serratus anterior?
A
long thoracic nerve
24
Q
what are the deep muscles of the posterior axioappendicular group?
A
levator scapulae
rhomboid major
rhomboid minor
25
what are the superficial muscles of the posterior axioappendicular group?
trapezius
larissimus dorsi
26
origin and insertion of the trapezius muscle?
ORIGIN - occipital bone, ligamentum nuchae, and spinous processes of C7–T12
INSERTION - lateral third of clavicle, acromion and spine of scapula
27
the trapezius muscle consists of three parts - what are they? what action are they each responsible for? what happens when they contract together?
descending - elevates scapula
transverse - retracts scapula
ascending - depresses scapula
together = forceful retraction & upwards rotation of scapula
28
action of the trapezius (all parts contracting together)?
forceful retraction & upwards rotation of scapula
29
innervation to trapezius muscle?
spinal accessory nerve
C3 & 4 cervical spinal nerves
30
what are the three parts of the trapezius muscle?
descending
ascending
transverse
(according to direction of fibres)
31
origin & insertion of latissimus dorsi?
ORIGIN - spinous processes of T7–T12, thoracolumbar fascia, iliac crest, and lower ribs
INSERTION - intertubercular sulcus of humerus
32
action of latissimus dorsi?
extension
adduction
medial rotation of humerus
33
innervation to latissimus dorsi?
thoracodorsal nerve from C6-8 nerve roots
34
what cervical vertebrae does the thoracodorsal nerve originate from? what muscle does it innervate?
C6-8 - innervates the latissimus dorsi
35
origin & insertion of the levator scapulae?
ORIGIN - transverse processes of C1–C4
INSERTION - medial border of scapula & superior angle
36
innervation of the levator scapulae?
dorsal scapular nerve (C5)
C3 & C4 cervical nerves
37
action of levator scapulae?
elevates scapula
38
origin & insertion of the rhomboid major?
ORIGIN - spinous processes of T2–T5
INSERTION - medial border of scapula
39
origin & insertion of the rhomboid minor?
ORIGIN - nuchal ligament and spinous processes of C7–T1
INSERTION - medial border of scapula
40
action of rhomboid major & minor?
retraction & downwards rotation of scapula
41
innervation to rhomboid major & minor?
dorsal scapula nerve (C4 & 5)
42
what common nerve innervates the deep muscles of the posterior axioappendicular group? what are its nerve roots?
dorsal scapular nerve - C4-5 nerve roots
43
what axioappendicular muscles insert on the intertubercular sulcus? (3)
pectoralis major - on the lateral lip
latissimus dorsi - on the floor
teres major - on the medial lip
("a lady between two majors")
44
which of the following muscles is NOT part of the anterior axioappendicular group?
a) Pectoralis Major
b) Pectoralis Minor
c) Subclavius
d) Levator Scapulae
D: levator scapulae
45
what is the primary action of the pectoralis minor?
a) Adduction of the humerus
b) Elevation of the ribs during forced inspiration
c) Depression and protraction of the scapula
d) Retraction of the scapula
C: depression & protraction of the scapula
46
which nerve is responsible for innervating the latissimus dorsi?
a) Thoracodorsal nerve
b) Lower subscapular nerve
c) Long thoracic nerve
d) Axillary nerve
A: thoracodorsal nerve (C6 & 8)
47
The trapezius is responsible for all the following actions EXCEPT:
a) Elevation of the scapula
b) Retraction of the scapula
c) Depression of the scapula
d) Medial rotation of the scapula
D: medial rotation of the scapula
48
TRUE/FALSE: the rhomboid major and minor are both innervated by the dorsal scapular nerve
TRUE
49
TRUE/FALSE: the trapezius is innervated by the accessory nerve (cranial nerve XI)
TRUE
50
Which of the following combinations of origin and insertion is correct for the levator scapulae?
a) Origin: Spinous processes of C7-T5, Insertion: Medial border of scapula
b) Origin: Transverse processes of C1-C4, Insertion: Superior angle & medial border of scapula
c) Origin: Clavicle, Insertion: Acromion process of scapula
d) Origin: Ribs 3-5, Insertion: Coracoid process of scapula
B: Origin: Transverse processes of C1-C4, Insertion: Superior angle & medial border of scapula
51
The pectoralis major has two heads. What is the correct pairing of origins for these heads?
a) Clavicular head: Anterior sternum, Sternocostal head: Medial clavicle
b) Clavicular head: Medial clavicle, Sternocostal head: Anterior sternum and first six costal cartilages
c) Clavicular head: Lateral clavicle, Sternocostal head: Ribs 3-5
d) Clavicular head: Acromion, Sternocostal head: Superior angle of scapula
B: Clavicular head: Medial clavicle
Sternocostal head: Anterior sternum and first six costal cartilages
52
which muscle can both protract and rotate the scapula upwards during overhead movements of the arm?
serratus anterior
53
the latissimus dorsi performs which combination of movements at the shoulder joint?
a) Flexion, abduction, lateral rotation
b) Extension, adduction, medial rotation
c) Flexion, adduction, medial rotation
d) Extension, abduction, lateral rotation
B: extension, adduction & medial rotation of the shoulder
54
when both the upper and lower fibres of the trapezius contract simultaneously, what is the resulting movement of the scapula?
forceful retraction & upwards rotation of the scapula
55
which muscle opposes the action of the rhomboids in scapular movement?
serratus anterior
(rhomboids retract the scapula, serratus anterior protracts it)
56
what movement occurs when the clavicular head of the pectoralis major contracts alone?
flexion of the shoulder joint
57
what would happen to scapular movements if the long thoracic nerve was damaged?
serratus anterior would be paralyzed - leads to winged scapula & impaired upward rotation and protraction of the scapula
58
which muscle is primarily responsible for initiating abduction of the arm at the shoulder joint?
a) Deltoid
b) Supraspinatus
c) Serratus anterior
d) Pectoralis major
B: supraspinatus
59
what is the main action of the serratus anterior?
a) Retracts and elevates the scapula
b) Protracts and rotates the scapula upward
c) Depresses and retracts the scapula
d) Stabilizes the scapula by downward rotation
B: protracts and rotates the scapula upward
60
which muscle retracts the scapula and rotates it downward?
a) Rhomboid major
b) Latissimus dorsi
c) Trapezius (middle fibres)
d) Pectoralis minor
A: rhomboid major
61
the pectoralis major muscle produces which of the following movements at the shoulder joint?
a) Extension, lateral rotation, and adduction
b) Flexion, medial rotation, and adduction
c) Abduction, flexion, and lateral rotation
d) Extension, medial rotation, and abduction
B: flexion, medial rotation, and adduction
62
what three muscles of the rotator cuff insert on the greater tubercle of the humerus? what is their common function?
supraspinatus
infraspinatus
teres minor
lateral rotation of shoulder joint
63
origin & insertion of the supraspinatus?
ORIGIN - supraspinous fossa of scapula
INSERTION - greater tubercle of humerus
64
actions of the supraspinatus?
initiates shoulder abduction - the first 15 degrees (deltoid takes over with the rest)
65
innervation of the supraspinatus?
suprascapular nerve
66
origin & insertion of the infraspinatus?
ORIGIN - infraspinous fossa
INSERTION - greater tubercle of the humerus
67
origin & insertion of the teres minor?
ORIGIN - middle part of lateral border of scapula
INSERTION - greater tubercle of humerus
68
innervation of the infraspinatus?
suprascapular nerve
69
innervation of the teres minor?
axillary nerve (one of the terminal branches passes out of the quadrangular space to supply Tminor)
70
actions of the infraspinatus?
lateral rotation of the shoulder
71
actions of the teres minor?
lateral rotation of the shoulder
72
what rotator cuff muscle inserts on the lesser tubercle of the humerus? what is its action?
subscapularis - from the subscapular fossa to the lesser tubercle
action - medial rotation of shoulder joint
73
innervation to subscapularis?
upper & lower/ superior & inferior subscapular nerves
74
origin and insertion of teres major?
ORIGIN - lateral border of scapula & inferior angle
INSERTION - medial lip of intertubercular sulcus
75
innervation to teres major?
lower/ inferior subscapular nerve
76
actions of the teres major?
extension
adduction
medial rotation of the shoulder
77
the deltoid muscle consists of three parts. what is the origin & insertion of these parts?
ORIGIN:
- anterior fibres = lateral third of clavicle
- middle fibres = acromion
- posterior fibres = spine of scapula
INSERTION - deltoid tuberosity of humerus
78
what are the three parts of the deltoid muscle?
anterior, middle, posterior
79
actions of the three different parts of the deltoid muscle?
anterior fibres - shoulder flexion & medial rotation
middle fibres - shoulder abduction
posterior fibres - shoulder extension & lateral rotation
80
what happens to the humerus during shoulder flexion?
humerus is pulled upwards
81
what action is performed when all three part of the deltoid muscle contract together?
powerful shoulder abduction - anterior and posterior fibres counteracting each other to stabilize movement
82
action of the anterior part of the deltoid muscle?
shoulder flexion & medial rotation
83
action of the posterior part of the deltoid muscle?
shoulder extension & lateral rotation
84
action of the middle part of the deltoid muscle?
shoulder abduction
85
innervation to the deltoid muscle?
axillary nerve - branches pass through quadrangular space to reach deltoid muscle
86
what separates the arm muscles into their anterior & posterior compartments?
intermuscular septum - derived from the brachial fascia
87
what nerve innervates all the muscles of anterior/ flexor compartment of the arm?
musculocutaneous nerve
88
what nerve innervates all the muscles of posterior/extensor compartment of the arm?
radial nerve
89
muscles of the same arm compartment share the same neurovascular supply. what is the clinical importance of this?
important for monitoring the spread of infection & haemorrhage
90
the biceps brachii has two heads - a long head & short head. origins of both? origin of the long head of the biceps brachii?
long head - supraglenoid tubercle of the scapula
short head - coracoid process of scapula
91
insertion point of the biceps brachii?
radial tuberosity & fascia of the forearm via the bicipital aponeurosis
92
actions of the biceps brachii at the shoulder joint?
flexion of shoulder
93
actions of the biceps brachii at the elbow joint?
supinates forearm - once supinated, flexes the elbow
94
origin & insertion of the coracobrachialis?
ORIGIN - coracoid process of the scapula
INSERTION - middle third of the medial humerus
95
actions of the coracobrachalis?
shoulder flexion & adduction
96
origin & insertion of the brachialis?
ORIGIN - distal half of the anterior humerus
INSERTION - ulnar tuberosity & coronoid process of the ulna
97
action of the brachialis?
elbow flexion
98
describe the course of the long head of the biceps brachii
originates from the supraglenoid tubercle of the scapula - through glenoid cavity & joint capsule of the glenohumeral joint
runs through bicipital groove & merges with short head to form one muscle belly - runs over elbow
inserts on radial tuberosity & gives off a tendon to insert via the bicipital aponeurosis
99
the triceps brachii consists of 3 heads - what are they? their origins?
long - infraglenoid tubercle of scapula
lateral - posterior humerus, superior to radial groove
medial - posterior humerus, inferior to radial groove
100
does the lateral head of the triceps brachii originate superior or inferior to the radial groove?
SUPERIOR
101
insertion point of the triceps brachii?
olecranon process of ulna
102
actions of the triceps brachii?
shoulder extension (via long head)
elbow extension
103
origin & insertion of the anconeus?
ORIGIN - lateral epicondyle of humerus
INSERTION - lateral olecranon and proximal ulna
104
actions of the anconeus?
stabilises elbow joint
helps with elbow extension
(small muscle)
