Pectoral Girdle and Shoulder Flashcards
(129 cards)
1
Q
What are the 4 anatomical regions of the upper limb?
A
- Shoulder (pectoral) 2. Arm 3. Forearm 4. Hand
2
Q
What are the 3 large joints in the UL?
A
Shoulder, elbow, wrist
3
Q
What are the 3 ‘spaces’ / neurovascular regions in the UL?
A
- Axilla (armpit) 2. Cubital fossa (anterior to elbow) 3. Carpal tunnel (wrist/hand)
4
Q
What region in the UL is often used in venepuncture?
A
Cubital fossa
5
Q
What is the most commonly dislocated joint in the body?
A
Shoulder
6
Q
What 2 bones does the ‘pectoral girdle’ refer to?
A
- Clavicle (collar bone)
- Scapula (shoulder blade)
7
Q
What does the pectoral girdle connect the upper limb to?
A
The thorax (axial skeleton)
- Clavicle attached to sternum (sternoclavicular joint)
- Scapula anchored to posterior chest wall by muscles and soft tissues
8
Q
What does the head of the humerus articulate with? What is this called?
A
Proximal part of the humerus articulates with a socket on the scapula called the glenoid fossa
9
Q
What is the joint between the glenoid fossa and the humerus called?
A
The glenohumeral joint
10
Q
How is the UL securely anchored to the thorax?
A
Via the glenohumeral joint
11
Q
What are the borders and angles of the anterior surface of the scapula?
A
- Superior border
- Medial border
- Lateral border
- Superior angle
- Inferior angle
12
Q
What is the coracoid process?
A
An attachment point on scapula for several muscles of the UL
Projects anteriorly
13
Q
When looking at the scapula from its anterior surface, does the coracoid process project anteriorly or posteriorly? Does the acromion project anteriorly or posteriorly?
A
Coracoid process –> anteriorly
Acromion –> posteriorly
14
Q
What is the subscapular fossa?
A
Anterior surface of scapula –> hollowed out middle bit
15
Q
Posterior view of scapula
A
16
Q
What feature majorly marks the posterior surface of the scapula?
A
Spine of scapula
17
Q
What is the spine of the scapula continuous with? What does it divide the posterior surface of the scapula into?
A
Acromion
Divides it into 2 regions: smaller region above and larger region below
18
Q
What is the region above the spine of the scapula called?
A
Supraspinous fossa (hollow)
19
Q
What is the region below the spine of the scapula called?
A
Infraspinous fossa
20
Q
Lateral view of scapula
A
21
Q
Anterior view of glenohumeral joint
A
(bones have been separated)
22
Q
What is the ‘anatomical neck’ of the humerus?
A
Separates the head of the humerus from tubercles
23
Q
Name the highlighted bony landmark
A
Glenoid fossa
24
Q
Name the highlighted bony landmark
A
Coricoid process
25
Name the highlighted bony landmark
Acromion
26
Which part of the humerus articulates with the glenoid fossa?
Head of humerus
27
How is the head of the humerus separated from the tubercles?
By the anatomical neck
28
What 2 tubercles are found on the proximal humerus?
Greater & lesser tubercles
29
Describe the greater tubercle
* Located laterally on humerus and has anterior and posterior surfaces
* Attachment site of 3 of the rotator cuff muscles
30
Name the highlighted bony landmark
Greater tubercle
31
Describe the lesser tubercle
* Anterior to greater tubercle (located more medially) with only an anterior surface
* Attachment site for last rotator cuff muscle
32
Name the highlighted bony landmark
Lesser tubercle
33
What is the 'surgical neck' of the humerus?
Region where head blends down to shaft of bone
34
Why is surgical neck an important landmark?
Is commonly fractured
35
Name the highlighted bony landmark
Spine of scapula
36
Name the highlighted bony landmark
Supraspinous fossa
37
Name it
Infraspinous fossa
38
Name
Anatomical neck
39
Name
Posterior aspect of greater tubercle
40
Posterior view of humerus
41
What type of joint is the shoulder joint? Is it a good fit?
Ball and socket joint but glenoid cavity is shallow so joint surfacesare poor fit --\> **'incongruent'**
42
What is it called in anatomy when joints aren't a good fit?
Incongruent
43
What is advantages to compromised stability of shoulder joint?
Increased range of movement
44
What features act to increase stability at shoulder joint?
1. Surronding muscles
2. Tendon of biceps
3. Glenoid labrum - a rim of cartilage around the edge of the glenoid which deepens the glenoid fossa (improves fit for humoral head)
45
What are the movements of the scapula?
1. Protraction (forward) --\> putting your arm out in front of you (e.g. pushing open a door)
2. Retraction (backward) --\> ‘squaring the shoulders’
3. Elevation (shrugging) and depression
4. Rotation --\> this moves the scapula so that the inferior angle is pointed either more medially or more laterally
46
Describe the origin and insertion of pectoralis major?
2 parts of pec major: clavicular and sternocostal parts
Clavicular part: originates from anterior surface of medial half of clavicle
Sternocostal part: originates from the anterior surface of sternum and the anterior aspects of the costal cartilages of ribs 1-6
Inserts: Both clavicular and sternocostal parts have **same** insertion point --\> inserts on the (bicipital groove and deltoid tuberosity of the) **humerus**
47
What movement does the pectoralis major allow?
Adduction and medial rotation of shoulder by pulling humerus
1. Flexion of humerus (e.g. throwing ball underhand)
2. Adduction of humerus (e.g. flapping arms)
3. Rotates humerus medially (e.g. arm wrestling)
Also keeps arm attached to trunk of body
48
What is the origin and insertion of the pectoralis minor?
Origin: ribs 3-5 (anterior surface)
Inserts: on coracoid process of scapula
I.e. ribs to shoulder
49
What movement does the pectoralis minor allow?
Stabilises the **scapula** and assists in **protraction** by contracting and pulling on attachment at coracoid process
50
Origin and insertion of serratus anterior?
Origin: Lateral surfaces of **ribs 1-8/9**
Inserts: Costal srufaces of medial border of **scapula**
51
What movement does serratus anterior allow?
PROTRACTOR of scapula --\> draws scapula forwards and lengthens upper limb (e.g. punching)
52
What are the muscles of the anterior pectoral girdle?
Pectoralis major and minor, serratus anterior
53
What is the axial skeleton?
The part of the skeleton that consists of the bones of the head and trunk of a vertebrate. In the human skeleton, it consists of 86 bones and is composed of six parts; the skull (22 bones), the ossicles of the middle ear, the hyoid bone, the rib cage, sternum and the vertebral column.
54
What do the muscles of the posterior pectoral girdle attach the bones of the pectoral girdle to?
The axial skeleton
55
What are the 2 layers of the muscles of the posterior pectoral girdle?
Superficial and deep layer
56
What muscles make up the superficial layer of the posterior pectoral girdle?
Trapezius and latissimus dorsi
N.B. Lat dorsi considered pectoral girdle muscle, although originates from the axial skeleton and inserts directly onto the humerus
57
What movement does the lat dorsi allow?
Adducts, medially rotates and extends the shoulder
58
Describe the direction of muscle fibres in the trapezius? How does this affect the movement of the scapula?
Fibres run in different directions: superior, middle and inferior fibres
When these fibres work independently they can move scapula in different directions: **elevate, retract or depress** scapula
59
Describe insertion of lat dorsi
Sweeps across lower back and inserts onto **anterior** aspect of **humerus** (posterior origin and anterior insertion)
60
What movement does lat dorsi allow?
Posterior origin and anterior insertion --\> extend arm, medially rotate and adduct arm
61
What muscles make up the deep layer of the posterior pectoral girdle?
Levator scapulae, rhomboid minor and rhomboid major (but the rhomboids work together)
62
What movement does levator scapulae cause when it contracts?
Levator scapulae contracts and elevates scapula towards neck
63
Insertion and origin of rhomboids?
Origin: thoracic vertebrae
Insertion: onto **medial** border of scapula
64
What movement do the rhomboids allow when they contract?
Pull medial border of scapula towards the vertebral column (**retraction**)
65
What bone does the anterior/posterior pectoral girdle muscles work on?
Scapula
66
What bone does the deltoid and teres major work on?
Shoulder
67
What do the deltoid and teres major connect?
Connect the humerus to the pectoral girdle
68
Where does the teres major originate and insert?
Origin: posterior scapula
Inserts: anteriorly on humerus
69
What movement does the teres major allow? What enables it to do this?
The orientation of the muscle (from posterior to anterior) allows it to **medially rotate** and **adduct** the shoulder (pulls humerus in towards body)
70
What is the largest muscle of the shoulder?
Deltoid
71
Describe location of deltoid muscle
Sits over shoulder joint
72
Origin and insertion of deltoid?
Origin: clavicle and spine of scapula
Inserts: on anterior humerus (deltoid tuberosity)
73
What is effect of of deltoid muscle when it contracts?
Pulls on deltoid tuberosity on humerus and pulls arm out laterally --\> **medially rotates and adducts** shoulder
Also contributes to flexion (anterior fibres) and extension (posterior fibres) of shoulder joint
Abduction --\> from 20-90 degrees
74
What is the rotator cuff?
a group of muscles and tendons that surround the shoulder joint --\> act to stabilise joint
75
Origin and insertion of rotator cuff muscles?
Origin: scapula
Insert: humerus
76
How many rotator cuff muscles are there? What are they?
4
1. Supraspinatus
2. Infraspinatus
3. Teres minor
4. Subscapularis
77
Name highlighted muscle (posterior view)
78
Where does supraspinatus muscle sit?
In supraspinous fossa (above spine of scapula from posterior view)
79
Describe location and insertion of supraspinatus
Muscle and tendon of supraspinatus travel from supraspinous fossa, travel underneath acromion and insert on top of the **greater tubercle** of humerus
80
What movement does supraspinatus muscle give when it contracts?
Gives first few degress of **abduction** (starts it off, approx 20 degrees)
81
After the first few degrees of abduction of arm, what muscle then takes over from supraspinatus?
Deltoid
82
Where is infraspinatus and teres minor found?
On posterior aspect of scapula
83
Which muscle is highlighted in blue? In yellow?
Blue: infraspinatus
Pink: teres minor
84
Origin and insertion of teres minor and infraspinatus?
Originate from posterior scapula and insert on greater tubercle of humerus
They act on shoulder joint in similar way due to similar orientation
85
What movement does teres minor and infraspinatus allow?
Laterally rotate shoulder
86
Where is subscapularis found?
On anterior aspect of scapula in subscapularis fossa
87
How is rotator clinically relevant?
Commonly injured - tendons can be torn or inflamed
88
Origin and insertion of subscapularis?
Origin: medial border and subscapular fossa
Insert: **LESSER** tubercle of humerus (different to others)
89
What movement does subscapularis allow when it contracts?
Adducts and medially rotates shoulder
90
What can injury/disease of shoulder cuff lead to?
Impaired movement, instability, pain
91
What are the main vessels of the upper limb?
Subclavian artery and vein
92
Describe path of subclavian vessels
Travel under clavicle (subclavian) and enter axilla (armpit)
93
What are subclavian vessels called once they enter axilla?
Axillary artery and vein
94
What branches does the axillary artery give off?
Anterior and posterior humeral circumflex artery
95
Is there a corresponding vein to circumflex humeral arteries?
NO - this area drained by **axillary** vein
96
What does the brachial plexus innervate?
Provides branches that innervate upper limb
97
Where are the terminal branches of the brachial plexus found?
In the axilla
98
What is the axillary nerve a branch of?
Is a terminal branch of the brachial plexus
99
Describe pathway of axillary nerve
Runs posteriorly, close to surgical neck of humerus
100
What does the axillary nerve supply?
Deltoid and teres minor
101
What is the cephalic vein? What does it drain into?
A major superficial vein that runs up lateral side of arm --\> once it enters the axilla it **drains into the axillary vein**
102
Where does cephalic vein lie?
Lies superficially between deltoid and pectoralis major in deltopectoral groove
103
What is osteomyelitis?
Bone infection
104
What is osteoarthritis?
Osteoarthritis is the most common form of arthritis. It occurs when the protective cartilage that cushions the ends of your bones wears down over time
105
What is tendonitis?
Inflammation of tendon
106
What is it called when muscle or tendon becomes trapped?
Impingement
107
Normal left shoulder X-ray. Find the:
* Medial, lateral, superior borders of scapula
* Acromion
* Coracoid process
* Glenoid fossa
* Greater tubercle
* Anatomical neck
* Surgical neck
There appears to be a gap due to tissues not showing up
108
What has been fractured here?
* Fracture at greater tubercle
109
What is problem with this shoulder joint?
Osteoarthritis of shoulder bone; outgrowths of bone called osteocytes, also get joint space narrowing
110
What is abnoramlity here?
* AC (clavicle and acromion) joint dislocation
* Normally in common with rupture of supporting ligament
111
Which bone is fractured? How do these fractures differ?
* Left --\> clavicle fracture
* Right --\> comminuted fracture
* Danger of piercing subclavian vessels
* Could cause ischaemia of upper limb
* Could cause life-threatening bleeding
* Danger of damaging brachial plexus
112
What joint is dislocated? Which direction has the dislocation occured?
Anterior dislocation of glenohumeral joint (humerus moves inferiorly and medially)
113
What is the most common problem of the rotator cuff?
The supraspinous tendon getting trapped (impinged) between the humeral head and the acromion and becoming inflamed
114
What is 'winged scapula'? What movement would a person with this conditon have trouble with?
A skeletal medical condition in which the shoulder blade protrudes from a person's back in an abnormal position
Would have trouble with protraction and getting arm about head (serratus anterior wouldn't be able to rotate scapula properly)
115
What is winged scapula caused by?
Injury to the **long thoracic nerve** which innervates the serratus anterior
116
If the long thoracic nerve is injured, how can it affect the serratus anterior?
Can paralyse it so cannot hold scapula on posterior chest wall anymore so medial border appears to lift off from ribs --\> 'winged scapula'
In picture --\> problem with right scapula
117
What is the brachial plexus?
Network of nerves that innervates the upper limb
118
Where does the brachial plexus originate?
From spinal cord
119
Where is the brachial plexus located?
In neck, travels under clavicle and into axilla
120
How many major branches does the brachial plexus give rise to?
5 --\> these provide motor and sensory innervation of upper limb
121
Branches of brachial plexus diagram
5 terminal branches:
1. Musculocutaneous
2. Axillary
3. Median
4. Radial
5. Ulnar
122
What are the 5 major branches of the brachial plexus?
1. Musculocutaneous
2. Axillary
3. Median
4. Radial
5. Ulnar
123
124
What is the glenohumeral joint?
BETWEEN SCAPULA AND HUMERUS
Joint between head of humerus and glenoid fossa on scapula
125
What muscles make up the posterior pectoral girdle?
Trapezius, lat dorsi, rhomboids, levator scapulae
126
What nerve innervates serratus anterior? What can damage to this nerve cause?
Long thoracic nerve
Can cause paralysis of scapula: winged scapula
127
What muscle starts abduction of arm/shoulder?
Supraspinatus
128
What is the quadrilateral/quadrangular spance?
The ‘gap’ that the axillary nerve and posterior circumflex humeral artery pass through to reach the posterior scapula region.
129
What forms the borders of the quadrilateral space?
Inferior: Teres major
Medial: long head of the bicep
Posterior: Teres minor
Anterior: Subscapularis
Lateral: Surgical neck of humerus
