Anatomy of the Shoulder Region Flashcards
Skeletal components of the Shoulder Region
- C..
- S…
- Both referred to as the … …
- H…
- 2 joints:
- … joint
- … joint
- Clavicle
-
Scapula
- Both referred to as the Pectoral Girdle
- Humerus
- 2 joints:
- Glenohumeral joint
- Acromioclavicular joint
The humerus has 2 tubercles- - what are they?
- What sits between these tubercle?
- The Greater tubercle and the Lesser tubercle
- The intertubercular sulcus/bicipital groove sits between them
Where is the intertubercular sulcus/bicipital groove?
Sits between greater and lesser tubercle of the humerus
Necks of the Humerus
- What are the necks called?
- Anatomical neck
- Surgical neck - more prone to fracture
Distal Region of the Humerus
- At the distal end, we have the medial and lateral …
- The … is the larger of the two and extends more distally.
- The ulnar nerve passes in a groove on the posterior aspect of the … …where it is palpable.
- At the distal end, we have the medial and lateral epicondyles
- The medial is the larger of the two and extends more distally. The ulnar nerve passes in a groove on the posterior aspect of the medial epicondyle where it is palpable.
The Glenohumeral joint is a … type of joint - between the … and …
The Glenohumeral joint is a ball and socket type of joint - between the head of humerus and the glenoid fossa
The Acromioclavicular joint is a … type of joint - between the … and …
The Acromioclavicular joint is a synovial plane type of joint - between the acromion and clavicle
- can become dislocated
Ligaments of the shoulder region
- Stabilize/support the shoulder region - Very strong
- Acromioclavicular, Coracoclavicular, Coracoacromial, Glenohumeral (superior, middle, inferior)
- Attachments are in the name
- Stabilize/support the shoulder region - Very strong
- Acromioclavicular, Coracoclavicular, Coracoacromial, Glenohumeral (superior, middle, inferior)
- Attachments are in the name
Coracoclavicular ligament
- Two parts - composed of the … and … ligaments
- Major … ligament
- Two parts - composed of the trapezoid and conoid ligaments
- Major stabilizing ligament
Coracoacromial ligament
- Forms …
- Provides support for … of …
- Prevents superior …
- Forms arch
- Provides support for head of humerus
- Prevents superior dislocation
The … ligament - Running between the acromion and coracoid process of the scapula it forms the coraco-acromial arch. This structure overlies the shoulder joint, preventing superior … of the humeral head.
The Coracoacromial ligament - Running between the acromion and coracoid process of the scapula it forms the coraco-acromial arch. This structure overlies the shoulder joint, preventing superior dislocation of the humeral head.
Glenohumeral joint
- Highly mobile … joint
- Articulation between head of humerus and glenoid fossa
- Allows for:
- A…/…
- F…/…
- C…
- L../… rotation
- Highly mobile ball and socket joint
- Articulation between head of humerus and glenoid fossa
- Allows for:
- Abduction/Adduction
- Flexion/Extension
- Circumduction
- Lateral/Medial rotation
Abduction of the arm
- Performed by … muscle
- Origin: Spine of … + a.. + c..
- Insert: … tuberosity
- Supplied by … nerve
- … fibres:
- Extension + lateral rotation
- … fibres:
- Flexion + medial rotation
- Performed by deltoid muscle
- Origin: Spine of scapula + acromion + clavicle
- Insert: Deltoid tuberosity
- Supplied by axillary nerve
-
Posterior fibres:
- Extension + lateral rotation
-
Anterior fibres:
- Flexion + medial rotation
Adduction of the arm
- Performed by what 2 muscles?
- Performed by latissimus dorsi, pectoralis major
What muscle is this?
Latissimus dorsi
What muscle is this?
Pectoralis major
Abduction/adduction of the arm
- … joint accommodates parts of movement
- Rotation of … increases range of movement
- Glenohumeral joint accommodates parts of movement
- Rotation of scapula increases range of movement
Rotation of scapula increases range of movement - means i can lift arm above head - what muscles allow rotation of scapula?
- Trapezius (upper fibres and middle fibres) and Serratus anterior
Adduction of arm (from above head down to side of body) is mainly about gravity - however … scapulae and … contract which brings the scapula back towards the midline
Adduction of arm (from above head down to side of body) is mainly about gravity - however levator scapulae and rhomboids contract which brings the scapula back towards the midline
Overview of Abduction/Adduction of Arm
- Abduction of arm (to 90 degrees - horizontal) - … muscle
- Abduction of arm (above head) - … of scapula via upper / lower fibres trapezius and serratus anterior
- Adduction (arm back down from above head) - gravity and levator … and … contracting to bring scapula back to midline
- Abduction of arm (to 90 degrees - horizontal) - deltoid muscle
- Abduction of arm (above head) - rotation of scapula via upper / lower fibres trapezius and serratus anterior
- Adduction (arm back down from above head) - gravity and levator scapulae and rhomboids contracting to bring scapula back to midline
Flexion of the arm (upper)
- At … joint
- … brachii, c… and … fibres of … flex the upper arm
- At glenohumeral joint
-
Biceps brachii, coracobrachialis and anterior fibres of deltoid flex the upper arm
- note - brachialis flexes the forearm
-
Biceps brachii, coracobrachialis and anterior fibres of deltoid flex the upper arm
Biceps brachii
- Biceps brachii is one of the three muscles found in the … compartment of the arm.
- It gets its name from its two heads, each of which has a separate origin.
- The long head originates from the … tubercle of scapula, while the short head shares its origin with the coracobrachialis muscle at the coracoid process of …
- Biceps brachii is one of the three muscles found in the anterior compartment of the arm.
- It gets its name from its two heads, each of which has a separate origin.
- The long head originates from the supraglenoid tubercle of scapula, while the short head shares its origin with the coracobrachialis muscle at the coracoid process of scapula.
Coracobrachialis
- Coracobrachialis is the most medial muscle in the … compartment of the arm.
- Its attachments at the … process of the scapula and the anterior surface of the shaft of humerus make coracobrachialis a strong adductor of the arm.
- Additionally, this muscle is also a weak … of the arm at the shoulder joint.
- Coracobrachialis is the most medial muscle in the anterior compartment of the arm.
- Its attachments at the coracoid process of the scapula and the anterior surface of the shaft of humerus make coracobrachialis a strong adductor of the arm.
- Additionally, this muscle is also a weak flexor of the arm at the shoulder joint.
Brachialis does not act at the glenohumeral joint, it is a flexor of the …
forearm
Extension of arm - (upper)
- Muscles which extend the upper arm - … brachii, … fibres of deltoid and … dorsi
- Triceps brachii, posterior fibres of deltoid and latissimus dorsi
Triceps brachii
- Triceps brachii is a large muscle found in the posterior (…) compartment of the arm.
- It consists of three distinct muscle bellies (heads) each of which has a different origin but share the same insertion point.
- The long head arises from the … tubercle of scapula
- The … head from the posterior surface of the humerus (inferior to radial groove)
- The … head originates from the posterior surface of the humerus (superior to radial groove).
- All three heads join to form a single tendon, which inserts onto the … of ulna and fascia of the forearm.
- Triceps brachii is a large muscle found in the posterior (extensor) compartment of the arm.
- It consists of three distinct muscle bellies (heads) each of which has a different origin but share the same insertion point.
- The long head arises from the infraglenoid tubercle of scapula
- The medial head from the posterior surface of the humerus (inferior to radial groove) - extend the forearm
- The lateral head originates from the posterior surface of the humerus (superior to radial groove). - extend the forearm
- All three heads join to form a single tendon, which inserts onto the olecranon of ulna and fascia of the forearm.
What head of the triceps brachii extends the arm? (upper arm - not forearm)
Long head of triceps (lateral and medial head extend the forearm)
Which heads of the triceps brachii extend the forearm? (not the upper arm)
Medial and lateral head of triceps extend forearm (long head = upper arm)
All three heads of the triceps brachii muscle join to form a single tendon, which inserts onto the … of ulna and fascia of the forearm.
All three heads of the triceps brachii muscle join to form a single tendon, which inserts onto the olecranon of ulna and fascia of the forearm.
Glenohumeral joint stability
- … humeral head
- … glenoid fossa
- … structure
- Most frequently … joint
- Anterior … common
- (Humeral head descends inferiorly and ends up anterior)
- Large humeral head
-
Shallow glenoid fossa
- Unstable structure
- Most frequently dislocated joint
- Anterior dislocation common
- (Humeral head descends inferiorly and ends up anterior)
Is the Glenohumeral joint stable?
no - unstable structure (large humeral head, shallow glenoid fossa - most frequently dislocated joint
What is the most frequently dislocated joint?
Glenohumeral joint
Factors increasing stability of the Glenohumeral joint
- Coracoacromial …
- Glenohumeral …
- Deepening of glenoid fossa by glenoid …
- … heads of biceps (above) and triceps (below)
- Tendons of … cuff muscles
- Coracoacromial arch
- Glenohumeral ligaments
- Deepening of glenoid fossa by glenoid labrum
- Long heads of biceps (above) and triceps (below)
- Tendons of rotator cuff muscles
Factors increasing stability of the Glenohumeral joint
- … arch
- Glenohumeral ligaments
- … of glenoid fossa by glenoid labrum
- Long heads of … (above) and … (below)
- … of rotator cuff muscles
- Coracoacromial arch
- Glenohumeral ligaments
- Deepening of glenoid fossa by glenoid labrum
- Long heads of biceps (above) and triceps (below)
- Tendons of rotator cuff muscles
Coracoacromial arch
- The acromion, together with the coracoacromial … and the coracoid process, form the coracoacromial arch
- Prevents superior … of the humerus
- The acromion, together with the coracoacromial ligament and the coracoid process, form the coracoacromial arch
- Prevents superior dislocation of the humerus