7: Musculo-neuro-vascular systems of arm and glenohumeral joint Flashcards
(118 cards)
1
Q
Anterior axio-appendicular muscles
A
1) pectoralis major
2) pectoralis minor
3) subclavius
4) serratus anterior
2
Q
Posterior axio-appendicular muscles
A
1) Trapezius
2) latissimus dorsi
3) levator scapulae
4) rhomboid minor and major
3
Q
Scapulohumeral muscles
A
Rotator cuff
Deltoid
Teres major
4
Q
Rotator cuff muscles are______ stabilizers of the glenohumeral joint
A
Active
5
Q
Origin of supraspinatus
A
Supraspinous fossa of scapula
6
Q
Insertion of supraspinatus
A
Greater tubercle of humerus (superior facet)
7
Q
Innervation of supraspinatus
A
Suprascapular nerve (C5,6) from superior trunk
8
Q
Actions of supraspinatus (2)
A
Abducts arm 0-15 degrees
Assists deltoid with abduction from 15-90 degrees
9
Q
Rotator cuff tear typically affects____ muscle
A
Supraspinatus
10
Q
Origin of infraspinatus
A
Infraspinous fossa of scapula
11
Q
Insertion of infraspinatus
A
Greater tubercle of humerus (middle facet)
12
Q
Innervation of infraspinatus
A
Suprascapular nerve (C5,6) from superior trunk
13
Q
Actions of intraspinatus (1)
A
Externally rotates arm at GH joint
14
Q
Origin of suprascapular nerve
A
C5, C6
15
Q
Course of suprascapular nerve
A
Arises from superior trunk of brachial plexus
Passes inferiorly through the scapular notch into the supraspinous fossa
Curves around the spine of the scapula entering the infraspinous fossa
16
Q
Structures innervated by suprascapular nerve
A
Supraspinatus
Infraspinatus
Glenohumeral joint
17
Q
Origin of teres minor
A
Infraspinous fossa
18
Q
Insertion of teres minor
A
Greater tubercle of humerus (inferior facet)
19
Q
Innervation of teres minor
A
Axillary nerve C5
20
Q
Actions of teres minor (2)
A
External rotation of humerus at GH joint
Adduction of the GH joint
21
Q
Origin of axillary nerve
A
Terminal branch of posterior cord (C5, C6)
22
Q
Course of axillary nerve
A
Passes laterally through quadrangular space reaching the posterior of the surgical neck
23
Q
Quadrangular space borders
A
Teres minor
Teres major
Surgical neck of humerus
Long head of triceps
24
Q
Structures innervated by axillary nerve
A
GH joint
Teres minor
Deltoid muscles
Skin of superolateralam
25
Origin of subscapularis
Subscapular fossa of scapula
26
Insertion of subscapularis
Lesser tubercle of humerus (anterior)
27
Innervation of subscapularis
Upper and lower subscapular nerves from posterior cord (C5,C6)
28
Actions of subscapularis (2)
Internal rotation of humerus at GH joint
Stabilizes GH joint
29
Subscapularis tendon tear results in.....
Weak internal rotation of the humerus
30
Origin of subscapular nerve
Posterior cord, upper: C5, lower: C6
31
Course of subscapular nerve
Upper: passes posteriorly to enter subscapularis directly
Lower: passes inferolaterally, deep to subscapular artery and vein
32
Structures innervated by subscapular nerve
Subscapularis (upper + lower)
Teres major (lower)
33
Acute tear
cause
Sudden powerful movement
34
Chronic tear cause
Tendon rubs against bone
35
Origin of deltoid (3)
Lateral 1/3 clavicle
Acromion
Lateral 1/3 spine of scapula
36
Insertion of deltoid
Deltoid tuberosity on humerus
37
Innervation of deltoid
Axillary nerve (C5,C6)
38
Actions of deltoid on glenohumeral joint
Anterior fibers: flexion
Middle fibers: abduction
Posterior fibers: extension
39
Origin of teres major
Inferior 1/3 of Medial border of scapula
40
Insertion of teres major
Medial lip of bicipital groove (intertuberclar sulcus)
41
Innervation of teres major
Lower subscapular nerve (C5,6)
42
Actions of teres major on glenohumeral joint
Internal rotation
Adduction
Extension
43
Causes of quadrangular space syndrome
Repeated injury and subsequent fibrosis can reduce the size of the quadrangular space
Leads to compression of the axillary nervev as it passes through the quadrangular space
44
Consequences of quadrangular space syndrome
Shoulder pain and paraesthesia in distribution of axillary nerve
Weakness of muscles innervated by axillary nerve
45
What is shoulder impingement?
During glenohumeral abduction, the supraspinatus tendon or its overlying subacromial bursa can be impinged between the head of the humerus and the inferior surface of the acromion.
46
Repeated shoulder impingement can lead to….
tendonitis or subacromial bursitis
47
What is painful arc syndrome?
Pain during shoulder abduction, within the 60-120° range. Usually follows shoulder impingement
48
Arterial blood supply to the glenohumeral joint
Anterior and posterior circumflex humeral arteries from the axillary artery
Suprascapular artery ( branch of thyrocervical trunk from subclavian)
49
Arterial blood supply to acromioclavicular joint
Suprascapular artery
Acromial branch of thoracoacromial artery, axillary artery
50
Arterial blood supply to supraspinous fossa
Suprascapular artery
51
Arterial blood supply to infraspinous fossa
Dorsal scapular, thoracodorsal and circumflex scapular arteries
52
Arterial blood supply to subscapular fossa (4)
Anastomosis between subscapular and thoracodorsal arteries with transverse cervical and dorsal scapular arteries
53
3 divisions of axillary vein
1) proximal to pectoralis minor
2) deep to pectoralis minor
3) distal, between lower border of pectoralis minor and lower border of teres major
54
Axillary vein is formed by union of...
Basilic vein and the brachial reins
55
Proximally the axillary vein receives....
The cephalic vein
56
Anterior compartment of arm
Biceps brachii
Brachialis
Coracobrachialis
57
Posterior compartment of arm
Triceps brachii
Anconeus
58
The two compartments of the arm are separated by..
Intermuscular septa
59
Origin of long head of biceps brachii
Supraglenoid tubercle
60
Origin of short head of biceps brachii
Coracoid process of scapula
61
Insertion of biceps brachii
Radial tuberosity
Bicipital adoneurosis and fascia of forearm
62
Innervation of biceps brachii
Musculocutaneous nerve (C5 -7)
63
Actions of biceps brachii (3 joints)
Flexes elbow joint
Supinates forearm via radioulnar joint
Weak GH flexor
Long head is a weak GH abductor when arm is externally rotated
Short head is a weak GH adductor
64
Long head of bicep passes...
Superiorly through bicipital groove
65
____ ligament forms a roof over the bicipital groove
Transverse humeral ligament
66
Long head of biceps inserts onto….
The supraglenoid tubercle
67
Origin of brachialis
Distal 1/2 of anterior surface of humerus
68
Insertion of brachialis
Ulnar tuberosity
69
Innervation of brachialis
Musculocutaneous nerve (C5-C7)
70
In 20% of people the brachialis recieves input from...
The radial nerve (C5, C6)
71
Brachialis lies deep to...
Biceps
72
Action of brachialis
Flexes elbow joint
73
Origin of coracobrachialis
Coracoid process of scapula
74
Insertion of coracobrachialis
Antero-medial aspect of humeral midshaft
75
Innervation of coracobrachialis
Musculocutaneous nerve (C5 -7)
76
Actions of coracobrachialis
Flexes arm at GH joint
Adducts arm at GH joint
Weak internal rotator of arm
77
Origin of musculocutaneous nerve
Lateral cord of brachial plexus (roots C5-7)
78
Course of musculocutaneous nerve
*Lies lateral to axillary artery
*Pierces and passes through coracobrachialis
*Descends between biceps and brachialis
* Emerges inferolateral at elbow and supplies elbow joint
79
What does the musculocutaneous nerve continue as
The lateral cutaneous nerve of the forearm
80
Structures innervated by musculocutaneous nerve
* muscles of anterior compartment of arm
* skin of lateral aspect of forearm
81
Origin of long head of triceps brachii
Infraglenoid tubercle
82
Origin of lateral head of triceps brachii
Posterior humerus (superior to radial groove)
83
Origin of medial head of triceps brachii
Posterior humerus (inferior to radial groove)
84
Insertion of triceps brachii
Olecranon process of ulna and fascia of forearm
85
Innervation of triceps brachii
Radial nerve (C6-C8)
86
Action of triceps brachii
Extends elbow joint
Long head is weak adductor and extensor of GH joint
87
Origin of anconeus
Lateral epicondyle of humerus
88
Insertion of anconeus
Lateral part of olecranon process of ulna Elbow joint capsule
89
Innervation of anconeus
Radial nerve (C7-T1)
90
Actions of anconeus
Extends elbow joint
Tenses elbow joint capsule so that it is not pinched by olecranon in olecranon fossa during elbow extension
91
Origin of radial nerve
Larger terminal branch of posterior cord form C5-T1
92
Course of radial nerve
*Lies posterior to axillary artery
* Passes through triangular interval and descends inferolaterally within the radial groove of the humerus
* Gives branches that supply triceps
* In ~20% of people it gives a branch to brachialis
93
What does the radial nerve continue as?
Posterior cutaneous nerve
94
Borders of triangular interval
Humeral shaft
Teres major
Long head of triceps
95
Contents of triangular interval
Radial nerve
Profunda brachii
96
Triangular interval syndrome
Weakness in muscles innervated by radial nerve and paraesthesia in sensory distribution of radial nerve
97
Radial nerve injury at axilla consequences (3)
Triceps denervated, weak or absent elbow extension
Wrist drop due to denervated wrist extensors
Loss of cutaneous sensation in the areas that the radial nerve normally supplies
98
Radial nerve injury at humeral mid shaft
Triceps still mostly functions
Wrist drop due to denervated wrist extensors
Loss of cutaneous sensation in the areas that the nerve normally supplies
99
Origin of lateral root of median nerve
Terminal branch of lateral cord (C6,C7)
100
Origin of medial root of median nerve
Terminal branch of medial cord ( C8,T1)
101
Course of median nerve
Lateral to axillary artery
Descends through arm adjacent to brachial artery
Crosses brachial artery from lateral to medial and lies medial to artery in cubital fossa
102
Structures innervated by median nerve
Muscles of anterior forearm compartment
Thenar half of palm of hand
Palmar skin
103
Origin of ulnar nerve
Larger terminal branch of medial cord (C8-T1)
104
Course of ulnar nerve
Descends medial arm
Passes posterior to medial epicondyle of humerus
Descends ulnar aspect of forearm to hand
105
Structures innervated by ulnar nerve (4)
Flexor carpi ulnaris
Ulnar half of flexor digitorum profundus
Intrinsic muscles of hand
Skin of hand medial to axial line of digit 4
106
What is the brachial artery?
The continuation of axillary artery past lower border of teres major
107
Position of brachial artery
Relatively superficial
Medial to biceps
Superficial to coracobrachialis/ brachialis
At elbow runs deep to biceps aponeurosis and divides into radial and ulnar arteries
108
Relations of brachial artery
Median nerve crosses anteriorly over artery
Ulnar nerve is posteromedial to artery
109
Branches of brachial artery (3)
Profunda brachii
Superior and inferior ulnar collateral arteries
Radial and ulnar arteries
110
Profunda
Deep
111
What does the profunda brachii supply?
Triceps and humerus
112
Course of profunda brachii
Profunda brachii passes between long and medial heads of triceps then courses inferolaterally through radial groove then terminates by dividing into radial and ulnar arteries
113
What does brachial vein do
Drains deoxygenated blood back towards the heart
114
Small veins around brachial artery
Venae comitantes
115
Course of basilic vein
Courses proximally along medial surface of superficial arm
About 1/2 way along arm, dives deep, piercing the brachial fascia
Basilic vein unites with brachial vein
At lower border of teres major vein becomes axillary vein
116
What region does cephalic vein drain?
Lateral superficial region of arm
117
Deltopectoral groove
Groove between deltoid anterior fibers and pectoralis major
118
Course of cephalic vein
At proximal deltopectoral groove, cephalic vein pierces through clave pectoral fascia and drains into axillary artery
