Shoulder Anatomy Flashcards
(37 cards)
subscapularis origin, insertion, innervation, and action
origin: subscapular fossa
insertion: lesser tuberosity of humerus
nerve supply: upper and lower subscapular nerves
action: medial rotation of humerus
deltoid nerve supply
axillary nerve C5 and C6
Joints of shoulder region
what are the borders of the quadrangular space and what are its contents?
Borders-
medial- long head of triceps
lateral- humeral shaft
superior
contents: axillary and posterior humeral circumflex artery (deep brachial artery)
Features of the glenohumeral joint
Features: • Stability: NOT STABLE: Head of humerus is 3 times larger than glenoid cavity, Capsule is redundant.
Few ligamentous support: (glenoid labrum • coracohumeral)
- Main support: muscles around the joint (ROTATOR CUFF)
- Wide range of movement
What are the borders and contents of triangular interval?
superior border: teres major
lateral border: lateral head of tricep
medial border: long head tricep
contains: radial nerve
deep profunda brachial artery
Nerves of shoulder region
- Axillary nerve (main)
- Radial nerve (beginning)
- Ulna nerve (beginning)
- Median nerve (beginning)
- Musculocutaneous nerve
Bones of shoulder region
- scapula (shoulder blade)
- clavicle (collarbone)
- humerus (upper arm bone)
spaces in shoulder region
quadrangular space
triangular space
triangular interval
suprascapular foramen
infraspinatus origin, insertion, innervation and action
origin: infraspinous fossa
insertion: greater tuberosity of humerus
innervated by suprscapular nerve
action: lateral rotation of humerus
What structure does the axillary arise from, what’s it course, and what does it innervate?
- Terminal branch of the brachial plexus.
- From posterior cord
- From ventral rami of C5 and C6.
- Course: passes posteriorly, through the quadrangular space, inferior to shoulder joint, where it is vulnerable to damage during shoulder dislocations
The branches:
-Muscular branches to the deltoid and teres minor muscles - Articular branch to the shoulder joint. - Upper lateral cutaneous nerve of arm supplies the skin over the superior part of the lateral aspect of the arm.
Explain axillary artery
- continuation of subclavian artery
- divided into 3 by pectoralis minor
What are the borders and contents of the triangular space?
Borders
Superior: lower border of teres minor
Lateral: long head of triceps
Inferior: teres major
Contents: subscapular circumflex artery
Branches of axillary artery
1st part:
-Highest or superior thoracic artery.
2nd part:
-thoracoacromial artery immediately divides into terminal branches. (Clavicular • Acromial • Deltoid • Pectoral)
lateral thoracic artery.
3rd part
subscapular artery
anterior circumflex humeral
posterior circumflex humeral
Some Times Life Seems A Pain
Ligaments of shoulder joint
Ligaments
• Glenohumeral Ligaments
- Superior -Middle -Inferior •
Coraco-acromial Ligament
• Coraco-clavicular Ligaments
-Trapezoid -conoid
- Transverse Humeral Ligament
- Coraco-humeral
- Acromio-clavicular
teres minor origin, insertion, nerve supply, action
origin: lateral border of scapula
insertion: greater tuberosity of humerus
nerve supply: axillary nerve
action: lateral rotation of humerus
deltoid insertion
deltoid tuberosity of humerus
review landmarks of humerus, scapula, and clavicle
humerus: anatomical neck, surgical neck, greater tuberosity, intertubuclar groove between, lesser tuberosity
clavicle: lateral end angle of clavicle, medial aspect
3rd part of axillary artery branch
- subscapular artery.
- anterior circumflex humeral artery
- posterior circumflex humeral artery
3rd part of axillary artery supply
Anteriorly: pectoralis major, medial root of the median nerve
Posteriorly: subscapularis, latissimus dorsi, the teres major, axillary, radial nerves.
• Laterally: coracobrachialis, biceps, humerus, lateral root of the median nerve, musculocutaneous nerves •
Medially: • ulnar nerve, axillary vein, the medial cutaneous nerve of the arm
Blood supply of shoulder region
- Subclavian artery
- Axillary artery- Thoracoacromial artery
- Brachial artery
teres major origin, insertion, innervation, and action
origin: lateral border of scapula
insertion: bicipital groove of humerus
nerve supply: lower subscapular nerve
action: extension, adduction, and medial rotation of humerus
relations of shoulder joint (borders)
anterior
posterior
superior
inferior
anterior: subscapularis, deltoid
posterior: infraspinatus. teres minor
superior: supraspinatus, subacromial bursa, coracoacromial ligament, deltoid muscle
inferior: axillary nerve, posterior cirucumflex artery, long head of triceps, muscle
Explain the 2nd part of axillary artery and what it supplies?
Anteriorly: skin, pectoralis minor, and pectoralis major
Posteriorly: posterior cord of the brachial plexus, subscapularis muscle, shoulder joint
Laterally: lateral cord of the brachial plexus
Medially: The medial cord of the brachial plexus, the axillary vein
