Anatomy of the shoulder Flashcards
- which bones are involved in the movement of the shoulder [3]?
- movements of the shoulder include a combination of movements from which joints [4]?
- which bones are involved in the movement of the shoulder [3]?
- clavicle
- scapula
- humerus - movements of the shoulder include a combination of movements from which joints [4]?
- sternoclavicular joint
- acromiclavicular joint
- glenohumeral joint
- scapulothrocic joint
which of the following is the only articulation between upper limb and axial skeleton?
- sternoclavicular joint
- acromiclavicular joint
- glenohumeral joint
- scapulothrocic joint
ssternoclavicular joint
Sternoclavicular joint:
What is the type of joint? [1]
Which structure is present for shock absorption? [1]
Which type of movement does the joint permit? [1] ?
joint type: synovial, saddle joint
shock absoption: articular disc
movements: around 60 degrees when elevate scapula
is the sternoclavicular joint easy / hard to break? why [2]
is the sternoclavicular joint easy / hard to break? why [2]
- hard to break [1]
- ligaments arround sternoclavicular joint are extremely strong [1]
(is often alongside other fractures)
which structures would be affected by a posterior fractture to sternoclavicular joint? [5]
- common carotid artery
- vagus nerve
- brachiocephalic vein
- trachea
- oesophagus
therefore v serious have posterior break !
what happens to your shoulder when your clavicle fractures? [1]
- shoulder will drop (bc wont act as a strut any more to keep shoulder in place)
If you break your clavicle, which structures act and cause different movements of the clavicle? [3]
What do u need to help bring bones back together to heal? [1]
- Sternocleidomastoid muscle: pulls medial aspect of clavicle up
- Pectoralis major muscle pulls arm and clavicle medially
- Gravity will pull down
- need an internal fixation
Acromioclavicular joint?
Which joint is present? [1]
What type of movement does this allow? [1]
which bones does this joint connection? [2]
what type of joint is the acromioclavicular joint? [2]
- synovial [1]; plane joint [1]
- gliding movement [1]
what is a connection between? [1]
- acromonion of scapula
- clavicle
what is a typical trauma mechanism on for breaking the acromioclavicular joint? [1]
- force that depresses the pectoral girdle (e.g. falling off bike / contact sports)
label these xox
which of these labels are joining points for muscles? [3]
which of these labels are joining points for muscles? [3]
- coracoid process
- supraspinous fossa
- infraspinous fossa
glenohumeral joint:
What is the type of joint? [2}
Which movements does this joint permit? [5]
Joint:
- synovial [1]; ball & socket [1]
Movements:
- flexion-extension
- abduction
- adduction
- rotation
- circumduction
what are two prominent structures / features of the the glenohumeral joint? [2]
Why is this clinically significant [1]
what are two prominent features of the glenohumeral joint?
glenoid cavity accomodates approx/ 1/3 of the humeral head: means that should can have wider range of movement
inferior joint capusule is lax. allows elevate above head. but means is much weaker than superior portion
what is most common type of dislocation of the glenohumeral joint? [1]
What type of movements cause ^ [3}
what is most common type of dislocation of the glenohumeral joint? [1]
- anterior dislocation
what type of movements cause ^ [3}
- abduction
- external rotation
- external extension
which nerve can be effected glenohumeral dislocation? [1]
which muscle does this nerve particularly effect if damaged? [1]
axillary nerve
deltoid muscle
Which structures deepen the shallow glenoid fossa? [2]
what is the shallow glenoid fossa deepened by? [2]
- glenoid labrum (fibrocart. ring that surrounds articular surface). helps deepen the socket and support the joint
- long head of the biceps - attaches to superior aspect of labrum
whats a SLAP tear?
SLAP tear: when superior aspect of labrum pulls away from glenoid fossa
Scapulotharacic joint
What is the type of joint [1]?
Which movements does this joint allow? [3]
not a true joint articulation between scapula and thoracic wall
movements:
- elevation & depression
- protraction & retraction
- rotation - important in abduction
what is the scapula-humeral rthym?
First 30 degrees of shoulder elevation involves a “setting phase”:
- the movement is largely glenohumeral.
- scapulothoracic movement is small and inconsistent.
And after the first 30 degrees of shoulder elevation:
- The glenohumeral and scapulothoracic joints move simultaneously.
- Overall 2:1 ratio of glenohumeral to scapulothoracic movement.
(e.g. when the arm is abducted 180 degrees, 60 degrees by rotation of the scapula & 120 degrees occurs by rotation of the humerus at the glenohumeral joint)
which part of the humerus is most likely to break? [1]
surgical head !
label A-E
A: acromioclavicular joint
B: corocoid process
C: clavicle
D: acromion
E: glenoid fossa
trapezius - where found?
where does it run? [3]
what are the three different fibre parts? [3] what movements do they cause [3]
trapezius
runs from occipital bone to bottom of thoracic vertebral. attaches to spine of scapula and clavicle
three parts
- descending fibres / suprior fibres = elevate (shrug shoulders)
- middle fibres = retract scapula
- ascending / inferior fibres = depress scapula
which nerve is the trapezuius innervated by? [1]
why is this special?
accessry nerve (CNXI) special bc all other muscles are innervated from brachial plexus
latissimus dorsi
Movements of the latissimus dorsi? [3]
runs from lower thoracic vertebra onto the lumbar vertebra & iliac crest. runs from iliac crest to anterior aspect of the humerus
movements:
- extend, adduct and medially rotate the shoulder
teres major
Movements of the teres major? [3]
runs from:
- inferior angle of scapula to anterior aspect of humerus
movements:
- extend, adduct and medially rotate the shoulder
where do the the rhomboids and levator scapulae run from?
which movements do they cause?
rhomboids
medial aspect of scapula to upper thoracic vertebra. muscle fibres cause retraction of scapula
- *levator scapulae:**
- neck to superior aspect of scapular
- elevates scapula
Serratus anterior
Where is the serratus anterior found? [1]
What movement does the serratus anterior permit? [1]
Which nerve supplies the serratus anterior? [1]
originates from medial border of the scapula, wraps around thorax to insert on the ribs
Movement:
* protraction of scapula when throwing a punch boxers muscle
Nerve:
long thoracic nerve
Why is the long thoracic nerve easy to damage? [1]
Runs anterior to the muscle [1]
pectoralis major and minor:
where do they run?
movements?
innervation?
pectoralis major:
most superficial: runs from humerus to medial aspect of clavicle, sternum and ribs
two heads: clavicular head & sternocostal head
movment: adduct, flex and medial rotates the shoulder (hugging muscle!)
- *pectoralis minor:**
- corocoid process to upper ribs
- not much movement - stabilises the stable joint
both innervated by pectoral nerves
fyi pec major
deltoid muscle
What are the three heads of the deltoid muscle? [3]
What movements do each head permit? [3]
Which nerve innervates the deltoid muscle? [1]
Heads:
* anterior : flexion of arm
* posterior: extension of arm
* middle abduction of arm: major one
Innervation
* axillary nerve
Rotator cuff musles
What are names of the different rotator cuff muscles [4]
What rotator cuff muscles are located posterioly? [3]
Which rotator cuff is found anteriorly? [1]
- surround the glenohumeral joint and stabilise the joint
- deep !
Posterior:
* supraspinatus muscle: superior to scapula spine
* infraspinatus muscle: inferior to scapula spine
* teres minor: inferior to infraspinatus
Anterior:
subscapualris muscle
What are the movements that each of the following permit?
supraspinatus muscle [1]
infraspinatus muscle [1]
teres minor [1]
subscapularis muscle [1]
Supraspinatus muscle: first 10 degrees of abduction
Infraspinatus muscle: external rotation
Teres minor: external rotation
Subscapularis muscle: internal rotation
rotator cuff muscles:
which muscles attach to greater tubercle?
which muscles attach to lesser tubercle?
- *greater tubercle:**
- teres minor
- supraspinatus muscle
- infraspinatus muscle:
- *lesser tubercle**
- subscapularis
Which muscle initates the first 10 degrees of abduction? [1]
supraspinatus
what does rotator cuff tear occur from ?
what can it cause?
tearing of the supraspinatous tendon - causes the los of initial 10 degrees od abduction
muscles of the arm:
anterior compartment is innervated by?
posterior compartment is innervated by?
muscles of the arm:
anterior compartment is innervated by musculocutaneous nerve = flexion
posterior compartment is innervated by radial nerve = extension
what are the three muscles found in anterior compartment of upper arm? what do they do?where do they run to?
biceps brachii - two heads:
i) one from corocoid process, distally to elbow (short head)
ii) superior border of glenoid fossa, superiorly to elbow
flex shoulder
- *coracobrachialis**: corocoid process to humerus
- flex shoulder
brachialis: mid shaft of humerus to elbow
which is the main muscle of posterior compartment of upper arm?
- what movement does it cause to shoulder?
- what are the three different heads?
posteior compartment extends the shoulder
triceps brachii:
three heads:
- *-medial head & lateral head:** humerus to elbow (olecranon process)
- *-long head**: inferior head of glenoid fossa - olecranon. this is the main one that causes extension of should
Which of the following is the glenoid labrum?
A
B
C
D
E
Which of the following is the glenoid labrum?
A
B
C
D
E
Which of the following is the acromion?
A
B
C
D
E
Which of the following is the acromion?
A
B
C
D
E
Which of the following is the scapula?
A
B
C
D
E
Which of the following is the scapula?
A
B
C
D
E
Which of the following is the supraspinatus muscle?
A
B
C
D
E
Which of the following is the supraspinatus muscle?
A
B
C
D
E
Which of the following is the glenoid labrum
A
B
C
D
E
Which of the following is the glenoid labrum
A
B
C
D
E
Which of the following is the glenoid cavity
A
B
C
D
E
Which of the following is the glenoid cavity
A
B
C
D
E
What is muscle D? [1]
What is bone E? [1]
D: supraspinatus
E: Acromion
Which of the following is the articular capsule
A
B
C
D
E
Which of the following is the articular capsule
A
B
C
D
E
Which of the following is the articular capsule
A
B
C
D
E
Which of the following is the articular capsule
A
B
C
D
E
