Download Lab 4 part 2 Shoulder 3

Lab 4 – 3.2: Shoulder
Deltoid
•
Origin: spine of scapula, acromion, anterior lateral 1/3 clavicle
•
Insertion: Deltoid tuberosity (humerus)
•
Innervation: Axillary Nerve (C5,C6)
•
Function: abduction of arm
Deltoid (cont)
• Note: posterior humeral circumflex artery supplies deltoid
Supraspinatus
•
Origin: supraspinous fossa
•
Insertion: Greater tubercle of the humerus (superior surface)
•
Innervation: Suprascapular nerve (C5,C6)
•
Function: abduction of arm at glenohumeral joint
Greater tubercle
Supraspinatus (cut)
• Note:
– Superior transverse scapular ligament
– Suprascapular Nerve (inferior to ligament)
– Suprascapular artery (superior to ligament)
Suprascapular Artery
• Right Subclavian artery  thyrocervical trunk  suprascapular artery
• Supplies suprascapular muscle and glenohumeral joint
Greater tubercle
Infraspinatus
•
Origin: medial 2/3 of intraspinous fossa
•
Insertion: Greater tubercle of the humerus (middle posterior surface)
•
Innervation: Suprascapular nerve (C5,C6)
•
Function: lateral rotation of arm at glenohumeral joint
Greater tubercle
Circumflex scapular Artery
• Branch from suprascapular artery – supplies infraspinatus muscle and
glenohumeral joint
Greater tubercle
Suprascapular Vein
• Drains posterior
scapular region
Greater tubercle
Teres Minor Muscle
•Origin: lateral border of the
scapula
•Insertion: greater tubercle of
the humerus
•Innervation: Axillary nerve
•Function: Rotator Cuff Muscle
lateral rotation of the arm at the
glenohumeral joint
Teres Major Muscle
Origin: Scapula (inferior
angle and lateral border)
Insertion: humerus (medial
lip of the intertubercular
sulcus)
Innervation: lower
subscapular nerve
Function:
• medial rotation of arm
• extension of the arm
• Adduction of the arm
Long head of the triceps brachii
Origin: scapula (infraglenoid
tubercle)
Insertion: olecranon of ulna
Innervation: Radial nerve
Function:
• extension of the forearm
• Accessory adductor/extensor
of the arm
Serratus anterior
Origin: lateral surface of ribs
1-9
Insertion: scapula (medial
border)
Innervation: long thoracic
nerve
Function:
• Abduction of the scapula
• Medial rotation of
scapula
• Keeps medial border and
inferior angle of scapula
opposed to thoracic wall
Pectoralis Major
•
Origin:
– medial clavicle
– sternum, costal cartilages 17,
– aponeurosis of external
abdominal oblique muscle
•
Insertion: intertubercular sulcus
of humerus (lateral lip)
•
Innervation:
– Lateral pectoral nerve (C5-7)
– Medial pectoral nerve (C8T1)
•
Function: Adduction, medial
rotation, and flexion of humerus
(shoulder joint)
*active during forced inspiration
Pectoralis Minor
Origin: ribs 3-5
Insertion: Coracoid process
of scapula
Innervation: Medial
pectoral nerves
Function: Depresses tip of
shoulder; protracts scapula
Active during forced
inspiration
Deltopectoral Triangle
• Also known as “clavipectoral” triangle
• Bordered by pectoralis major muscle, deltoid
muscle, and clavicle
• Passageway for cephalic vein
Greater tubercle
Axillary Vein
 Drainage: Pectoral, shoulder,
and scapular regions
Axillary Nerve
• Motor
• Innervates the deltoid
muscle
Latissimus Dorsi
• Origin: Spinous processes of
TVII through LV and sacrum,
iliac crest, ribs X–XII
• Insertion: Humerus (floor of
intertubercular sulcus)
• Innervation: Thoracodorsal
nerve (C6–C8)
Latissimus Dorsi
• Function: Extends, adducts, and medially rotates humerus
Quadrangular Space
Location: Shoulder (posterior
scapular region)
Boundaries:
• Superior boundary: Inferior
margin of teres minor
• Lateral boundary: Surgical
neck of the humerus
• Inferior boundary: Superior
margin of teres major
• Medial boundary: Lateral
margin of the long head of
the triceps brachii
Function:
• Passageway for posterior
circumflex humeral artery
and vein and axillary nerve
Quadrangular space
Triangular Space
Location: shoulder (posterior)
Boundaries:
• Superior boundary: inferior
teres minor muscle
• Inferior boundary: superior
teres major muscle
• Lateral boundary: medial long
head of triceps brachii muscle
Function:
• Passageway for circumflex
scapular artery and vein
Deltoid
Axillary Nerve
Supraspinatus
Infraspinatus
Teres Minor Muscle
Teres Major Muscle
Long head of the triceps brachii
Serratus anterior
Pectoralis Major
Pectoralis Minor
Latissimus Dorsi
Arteries and Nerves
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