Pectoral Girdle, Shoulder And Axilla Flashcards
(151 cards)
1
Q
Bones of the pectoral girdle
A
Clavicle
Scapula
Humerus
2
Q
Shape of clavicle
A
Slender, s-shaped bone
3
Q
What does the clavicle articulate with
A
Manubrium of sternum at its proximal (medial) end- sternoclavicular joint
Acromion of the scapula at its distal (lateral) end - the acromioclavicular joint
4
Q
What is the most commonly fractured bone
A
Clavicle
5
Q
What type of joint is the sternoclavicular joint
A
Synovial
6
Q
What type of joint is the acromioclavicular joint
A
Synovial
7
Q
What does the word scapula mean
A
Trowel or small shovel
8
Q
Shape of scapula
A
Mostly flat but some important bony projections
9
Q
Posterior surface of scapula
A
Ridge of bone called the spine
Easily palpable
10
Q
Acromion
A
Lateral end of the spine of the scapula which expands to form Acromion
Articulates with the lateral end of the clavicle
Can be easily palpated
11
Q
Meaning of the word Acromion
A
Highest point of the shoulder
12
Q
Coracoid process
A
Just inferior to the Acromion on anterior surface of scapula
Site of attachment for several muscles
13
Q
Meaning of the word coracoid
A
Raven-like
14
Q
Glenoid fossa
A
Lateral aspect of the scapula has a shallow fossa
Articulates with the proximal humerus to form the shoulder joint
15
Q
Meaning of the word glenoid
A
Shallow socket
16
Q
Glenohumeral joint
A
Glenoid fossa is shallow so poor fit for humerus
Increases the range of movement possible at the shoulder but compromises stability of the joint
17
Q
Supraglenoid and infraglenoid tubercles
A
2 small projections of bone just superior and inferior to the Glenoid fossa
Important sites for muscle attachments
18
Q
Humerus shape
A
Long bone of the arm
Has a shaft and an expanded proximal and distal end
19
Q
Head of humerus
A
Articulates with the Glenoid fossa of the scapula
20
Q
Anatomical neck of humerus
A
Groove in the humerus immediately distal to the smooth head of the humerus
21
Q
Greater tubercle of humerus
A
Laterally proximal humerus
22
Q
Lesser tubercle of humerus
A
Smaller anterior projection
23
Q
Surgical neck of humerus
A
Just distal to the tubercles, bone narrows and becomes continuous with shaft
Commonly fractured especially in elderly
24
Q
What nerve runs close to the surgical neck of the humerus
A
Ancillary nerve
25
Deltoid tuberosity
Upper lateral aspect of the humeral shaft has a slight protuberance
Site of attachment for the deltoid muscle
26
What is the site of attachment for the deltoid muscle
Deltoid tuberosity
27
Radial groove
Marks the path of the radial nerve over the posterior aspect of the humeral shaft
28
Parts of the humerus (shoulder to elbow)
Head
Anatomical neck
Greater tubercle
Surgical neck
Shaft
Lateral and medial epicondyle
29
Protraction
extends the upper limb, for example, when we stretch out the arm to push open a door.
30
Retraction
squaring’ the shoulders or pulling them backwards.
31
Elevation
shrugging the shoulders
32
Depression
lowering the shoulders
33
Rotation
Scapula tilts the glenoid fossa cranially to aid elevation of the upper limb
34
What is the key muscle involved in protraction of the scapula
Serratus anterior
35
2 large and superficial muscles of the posterior pectoral girdle
Trapezius
Latissimus dorsi
36
Muscles of anterior pectoral girdle
Pectoralis major
Pectoralis minor
Serratus anterior
37
Shape and location of trapezius and latissimus dorsi
Large, flat muscles with extensive attachments to the vertebral column (and skull = trapezius)
38
What does the latissimus dorsi attach to
Anterior aspect of the proximal humerus
39
3 smaller and deeper muscles of the posterior aspect of the pectoral girdle
Levator scapulae
Rhomboid major
Rhomboid mimor
40
What do the 3 smaller and deeper muscles of the posterior pectoral girdle attach to
Medial border of the scapula and to the vertebral column
41
What movement of the scapula does the trapezius muscle cause
Rotation and individually: the upper part elevates, middle part retracts and lower part depresses the scapula
42
What movement of the humerus does the latissimus dorsi muscle cause
Extends
Adducts
Medial rotation
43
What movement of the scapula does the levator scapulae muscle cause
Elevates
44
What movement of the scapula does the rhomboid major muscle cause
Retracts
45
What movement of the scapula does the rhomboid minor muscle cause
Retracts
46
Origin of the bone
More ‘fixed’ or stable bone
47
Insertion point of a muscle
Located on the bone that moves when the muscle contracts
48
Muscles of the posterior pectoral girdle
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboid major
Rhomboid minor
49
Attachment origin of the trapezius
Skull
Cervical and thoracic vertbrae
50
Attachment origin of the latissimus dorsi
Lower thoracic vertebrae
51
Attachment origin of the Levator scapulae
Upper cervical vertebrae
52
Attachment origin of the rhomboid minor
C7 and T1 vertebra
53
Attachment origin of the rhomboid major
Thoracic vertebrae
54
Attachment insertion of the trapezius
Clavicle and scapula (spine and Acromion)
55
Attachment insertion of the latissimus dorsi
Humerus- proximal and anterior
56
Attachment insertion of the Levator scapulae
Scapula- medial border
57
Attachment insertion of the rhomboid minor
Scapula- medial border
58
Attachment insertion of the rhomboid major
Scapula -medial border
59
What innervates most of the muscles of the posterior pectoral girdle
Brachial plexus
60
What nerve supplies the trapezius
Accessory nerve CN XI
61
What nerve innervates the latissimus dorsi
Thoracodorsal nerve - branch of the brachial plexus
62
Movements possible at the shoulder joint
flexion, extension, abduction, adduction, internal (medial) and external (lateral) rotation and circumduction
63
What is the most commonly dislocated joint in the body
Shoulder joint
64
How many muscles are attached to the scapula
6
65
What are the 6 muscles attached to the scapula
Deltoid
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
Teres major
66
Which 4 muscles make up the rotator cuff
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
67
Function of rotator cuff muscles
Provide stability to the shoulder joint
68
Which muscle attached to the scapula does not lie deep to the posterior pectoral girdle
Deltoid
69
Deltoid location
Large muscle over the lateral aspect of the shoulder
Attaches the humerus to the lateral part of the clavicle and spine of the scapula
70
Deltoid tuberosity
Where the deltoid inserts onto the humerus
71
What muscle gives the shoulder its rounded contour
Deltoid
72
Function of deltoid muscle
Abductor of the shoulder joint- cannot initiate abduction (another muscle initiates first 15 degrees of abduction before deltoid takes over)
Anterior fibres = flexion of shoulder
Posterior fibres = extension of shoulder
73
Which nerve innervates the deltoid muscle
Axillary nerve (branch of brachial plexus)
74
Name deltoid
Greek
Reference to shape of Greek letter delta- depicted as a triangle
75
Teres major location
Arises from posterior aspect of scapula
Tendon slots underneath the humerus and inserts into the anterior aspect of the humerus
76
Teres major function
Internal rotator and adductor of the shoulder
77
What type of muscles make up the rotator cuff
Short
78
What do the rotator cuff muscle connect
Attach the scapula to the tubercles of the humerus
79
Where do the Supraspinatus, infraspinatus, and teres minor muscles originate from
Posterior surface of the scapula
80
Where do the Supraspinatus, infraspinatus, and teres minor muscles insert onto
Greater tubercle
81
What forms the fibrous capsule that surrounds the shoulder joint
The tendons of the Supraspinatus, infraspinatus, and teres minor muscles fuse
82
Why is the Supraspinatus muscle clinically important
Travels from, the supraspinous fossa to the greater tubercle under the acromion
Tendon can become inflamed and pinched between the Acromion and humerus during movements of the shoulder causing an impingement
83
Quadrilateral space
A square-shaped space bound by the teres minor above
Teres major below
Long head of triceps medially and
Surgical neck of humerus laterally
84
Which nerve innervates the teres minor muscle
Axillary nerve
85
Which nerve travels through the quadrilateral space to enter the posterior scapula region
Axillary nerve
86
Where does the Subscapularis originate from
Anterior surface of the scapula
87
Where does the Subscapularis insert onto
Lesser tubercle of humerus
88
Action at the shoulder joint of the deltoid
Abduction beyond 15 degrees
89
Action at the shoulder joint of the teres major
Internal rotation
Adduction
90
Action at the shoulder joint of the Supraspinatus
First 15 degrees of abduction
91
Action at the shoulder joint of the Infraspinatus
External rotatiom
92
Action at the shoulder joint of the teres minor
External rotatiom
93
Action at the shoulder joint of the Subscapularis
Internal rotation
94
Origin on the scapula of the deltoid
Spine and acromion of the scapula and the clavicle
95
Origin on the scapula of the teres major
Posterior surface
Inferior part of lateral border
96
Origin on the scapula of the Supraspinatus
Supraspinous fossa
97
Origin on the scapula of the Infraspinatus
Infraspinous fossa
98
Origin on the scapula of the teres minor
Lateral border
99
Origin on the scapula of the Subscapularis
Subscapular fossa
100
Insertion on the humerus of the deltoid
Deltoid tuberosity
101
Insertion on the humerus of the teres major
Anterior humerus
102
Insertion on the humerus of the Supraspinatus
Greater tubercle- superior facet
103
Insertion on the humerus of the Infraspinatus
Greater tubercle- middle facet
104
Insertion on the humerus of the teres minor
Greater tubercle- inferior facet
105
Insertion on the humerus of the Subscapularis
Lesser tubercle
106
Glenoid labrum
A rim of fibrocartilage around the margin of the Glenoid fossa which deepens the shallow fossa and aids stability
107
What structures contribute to stability of the shoulder
Rotator cuff
Glenoid labrum
Ligaments
Tendons of biceps brachii
108
Axilla
Anatomical term for the armpit- space between the torso and upper arm
Pyramid-shaped and has 6 boundaries formed of various structures
109
Anterior wall of axilla
Pectoralis major and minkr
110
Posterior wall of axilla
Subscapularis, teres major and latissimus dorsi
111
Lateral wall of axilla
Proximal humerus
112
Medial wall of axilla
Serratus anterior and thoracic wall
113
Apex of axilla
First rib
Clavicle
Scapula
114
Base of axilla
Skin and fascia between the thoracic wall and arm (skin of armpit)
115
What does the axilla contain
Lymph nodes
Axillary artery and vein
Brachial plexus
116
Number of groups of lymph nodes in axilla
5
117
What do the Axillary lymph nodes drain
Upper limb
Breast
Chest wall
Scapular region
Abdominal wall as far as the umbilicus
118
Where are the apical nodes located
In the apex of axilla (apical nodes)- receive lymph from all other lymph nodes in the axilla
119
What is the axillary artery a continuation of
Subclavian artery as it progresses laterally
120
How is the Axillary artery formed
Subclavian artery travels over the first rib and under the clavicle and into the axilla
Becomes axillary artery after it passes over the lateral border of the first rib
121
What does the axillary artery become
Brachial artery- as it crosses the inferior border of the teres major
122
Axillary vein
Continuous with subclavian vein
Drains the upper limb
Travels alongside the axillary artery
123
What forms the axillary vein
Union of the brachial veins with the basilic vein
The Cephalic vein also joins the axillary vein in the axilla
124
When does the axillary vein become the subclavian vein
Lateral border of the first rib
125
Dislocation of the shoulder
In a dislocation of the shoulder, the humeral head moves out of the glenoid fossa. Anterior dislocation, where the humeral head ends up resting anterior to the glenoid fossa, is much more common. It is often caused by blunt force trauma, such as a fall. X-ray imaging confirms the direction of displacement of the humeral head and whether there is an associated fracture. Dislocation can injure the axillary nerve.
126
Rotator cuff injury
The rotator cuff can be injured by acute trauma or by repetitive use. The tendons can also degenerate with age. Tears of the rotator cuff are usually painful at rest and on movement, and cause weakness. If the supraspinatus tendon becomes injured and inflamed it may become impinged between the acromion and the humeral head, as the space here is small. The first part of abduction is not painful, but between 60˚– 120˚ of abduction, the inflamed tendon is compressed against the acromion, and this is when patients experience pain. An inflamed tendon may ultimately rupture.
127
Axillary lymph node metastasis
Because lymph from the breast drains to the axillary lymph nodes, breast malignancy typically metastasises first to these nodes. A malignant axillary node may be felt as a lump in the armpit and may be noticed before a mass in the breast itself. Axillary lymph nodes can be biopsied to assess whether or not breast malignancy has metastasised and can be removed as part of the patient’s treatment. Because they drain lymph from the upper limb, removal of the nodes can lead to fluid accumulation and swelling in the affected upper limb.
128
Which 2 nerves may be damaged when removing axillary lymph nodes
Long thoracic nerve
Thoracodorsal nerve
129
Removing axillary lymph nodes: damage to the long thoracic nerve
• The long thoracic nerve innervates serratus anterior and lies superficially on the surface of the muscles in the medial wall of the axilla. Injury to this nerve causes weakness or paralysis of serratus anterior. One of the functions of this muscle is to hold the anterior border of the scapula flat against the posterior thoracic wall. If the muscle is paralysed, the anterior border lifts off the thoracic wall and the scapula appears to ‘stick out’. This is called a ‘winged scapula’.
130
Removing axillary lymph nodes: damage to the Thoracodorsal nerve
• The thoracodorsal nerve to latissimus dorsi is also vulnerable to injury as it runs along the subscapularis muscle, which forms part of the posterior wall of the axilla.
131
What nerve innervates the latissimus dorsi
Thoracodorsal nerve
132
Which muscles are responsible for shoulder abduction
Initiated by Supraspinatus (first 15 degrees)
Deltoid then takes over
Rotation of scapula required to raise arm above the head- requires trapezius
133
2. Describe the movements of the scapula and the humerus during shoulder abduction.
o As the arm rises, the humerus laterally rotates – this keeps the articular surfaces in contact with each other; in full abduction (with the arm above the head) the humerus has rotated 90˚.
o For every 2˚ of abduction at the shoulder joint the scapula rotates 1˚.
o Rotation tilts the glenoid fossa cranially.
134
3. Which nerve innervates trapezius? How would you test if the nerve was functioning?
The accessory nerve / cranial nerve XI (11).
o The most straightforward way to test the function of the nerve is to ask the patient to shrug the shoulders (i.e. elevate the scapula). You would be comparing movement on both sides and looking for symmetry.
135
4. Which nerve is at risk of injury in shoulder dislocation? What functional deficits would result and how would you examine a patient to test for these deficits?
The axillary nerve (C5-C6 fibres).
o Potential function deficits are weakness / paralysis of deltoid and teres minor (motor fibres of the nerve) and impaired sensation / numbness over the skin of the upper lateral shoulder (sensory fibres of the nerve).
o Motor function – tested by asking the patient to abduct the arm; look for weakness compared with the unaffected arm.
o Sensory function – use light touch over the skin of the upper lateral arm and compare sensation with the opposite side; ask the patient if it feels the same or different to the unaffected side.
136
5. What structures stabilise the shoulder joint?
o The rotator cuff is the key stabilising factor.
o The tendon of the long head of biceps and the glenoid labrum also contribute to stability.
137
6. Which parts of the pectoral girdle and shoulder joint can be palpated on examination?
Clavicle, acromion, spine of the scapula and lateral border of the scapula.
138
7. Which muscles comprise the rotator cuff, and where do they insert on the humerus?
supraspinatus (inserts on the superior facet, greater tubercle), infraspinatus (inserts on the middle facet, greater tubercle), teres minor (inserts on the inferior facet, greater tubercle) and subscapularis (inserts on the lesser tubercle).
139
8. Describe the route of arterial blood through each vessel from the left ventricle to the right axillary artery and from the left ventricle to the left axillary artery.
Left ventricle > right axillary artery: Aorta > brachiocephalic trunk > right subclavian > right axillary.
Left ventricle > left axillary artery: Aorta > left subclavian > left axillary.
140
What is the nerve root of the axillary nerve
C5-C6
141
For every 2 degree of abduction at the shoulder joint the scapula rotates
1 degree
142
What type of joint is the acromio-clavicular joint
Plane joint
143
What muscles attach to the coracoid process
Biceps brachii
Coracobrachialis
144
What muscles attach to the subscapular fossa
Subscapularis
145
What muscles attach to the supraspinous fossa
Supraspinatus muscle
146
What muscles attach to the infraspinous fossa
Infraspinatus muscle
147
What muscles attach to the medial border of the scapula
Levator scapulae
Rhomboid major and minor
148
What muscles attach to the lateral border of the scapula
Teres major and minor
149
What muscles attach to the spine of the scapula
Deltoid
Trapezius
150
What muscle type is the deltoid
Unipennate
151
Innervation of supraspinatus
Suprascapular nerve
