The scapula is a flat, triangular bone located on the posterior aspect of the rib cage. It has three borders and three angles. Several muscles originate on the scapula, including the subscapularis, teres major, teres minor, and trapezius. The scapula acts to rotate the shoulder joint and stabilize the shoulder girdle.
2. The scapula is a
highly mobile bone
that is situated on
the posterior aspect
of the body
The Scapula
3. • The scapula is best
viewed from behind
• There are 2 scapulae one on
either side of the spinal
column
4. Each overlies the 2nd – 7 ribs The
scapula is a flat triangular-shaped bone
Anterior
View
5. Lateral
View
AnteriorPosterior
• The scapula is a flat triangular-shaped
bone
• It has a number of interesting projections best
viewed from the lateral aspect.
The scapula has two surfaces
6. The scapula has two surfaces
Anterior / Ventral surface Posterior / Dorsal Surface
7. The Dorsal surface of the Scapula is divided into
two regions by the spine of the Scapula
Scapular Spine Infraspinous Fossa Supraspinous Fossa
8. The scapula has 3 borders
Medial Border
Anterior View
Lateral Border Superior Border
9. The scapula has 3 angles
Superior Angle Inferior Angle
Anterior View
Lateral
10. The scapula has 3 lateral projections
Anterior View
Coracoid Process Spine
Acromion process
11. Summary of muscles that arise from the scapula
Biceps (both heads)
Coracobrachialis
Deltoid
Infraspinatus
Levator Scapulae
Latissimus Dorsi
Pectoralis Minor
Rhomboid Major
Rhomboid Minor
Serratus Anterior
Subscapularis
Supraspinatus
Triceps (Long Head)
Teres Major
Teres Minor
Trapezius
12. • Subscapularis arises from the whole of
the ventral surface of the Scapula
• It attaches to the Lesser Tuberosity of the Humerus
Subscapularis
Origin Subscapular fossa of scapula
Insertion Lesser tuberosity of humerus
Action Internal rotation and
adduction of the arm
Nerve Supply Upper and lower subscapular
nerves (C5, C6 and C7)
Blood Supply Subscapular artery
13. Biceps Brachii
Origin Short head: tip of coracoid process of
scapula; Long head: supraglenoid tubercle of
scapula
Insertion Tuberosity of radius and fascia of forearm via
bicipital aponeurosis
Action Supinates and flexes forearm
Nerve Supply
Musculocutaneous nerve (C5 and C6)
Blood Supply Muscular branches of brachial artery
14. Coracobrachialis
Origin
Tip of coracoid process of scapula
Insertion
Upper half of medial surface of
humerus
Action Flexes and adducts arm
Nerve Supply
Musculocutaneous nerve (C5, C6)
Blood Supply Muscular branches of brachial artery
15. Deltoid
Origin
Lateral third of clavicle,
acromion, and spine of scapula
Insertion Deltoid tuberosity of humerus
Action Anterior part: flexes and
internally rotates arm; Middle
part: abducts arm; Posterior part:
extends and externally
rotates arm
Nerve Supply Axillary nerve (C5 and C6)
Blood Supply Deltoid branch of thoracoacromial
artery
16. Infraspinatus
Origin Infraspinous fossa of scapula
Insertion
Middle facet on greater tuberosity of
humerus
Action Externally rotates arm
Nerve Supply
Suprascapular nerve (C5 and C6)
Blood Supply Suprascapular and circumflex
scapular arteries
17. Levator Scapulae
Origin
Posterior tubercles of transverse
processes of C1 - C4 vertebrae
Insertion
Superior part of medial border of
scapula
Action
Elevates scapula and tilts glenoid
inferiorly by rotating scapula
Nerve Supply
Dorsal scapular (C5) and cervical
(C3 and C4) nerves
Blood Supply Dorsal scapular artery
18. Latissimus Dorsi
Origin Spinous processes of inferior 6
thoracic vertebrae,
thoracolumbar fascia, iliac
crest, and inferior 3 or 4 ribs,
inferior angle of scapula
Insertion Floor of intertubercular groove
of humerus
Action Extends, adducts, and internally
rotates humerus; pulls body up
toward arms during climbing
Nerve Supply Thoracodorsal nerve (C6, C7,
and C8)
Blood Supply Thoracodorsal artery
19. Pectoralis Minor
Origin 3rd to 5th ribs near their costal
cartilages
Insertion
Medial border and superior
surface of coracoid process of
scapula
Action Stabilises scapula, pulls it
inferiorly and anteriorly against
thoracic wall
Nerve
Supply
Medial pectoral nerves; (C8 and
T1)
Blood
Supply
Pectoral branch of the
thoracoacromial trunk
20. Rhomboid Minor
Origin Nuchal ligament and spinous
processes of C7 and T1
vertebrae;
Insertion Medial border of scapula
adjacent to spine
Action
Retracts and rotates scapula
to move glenoid inferiorly;
fixes scapula to thoracic wall
Nerve
Supply
Dorsal scapular nerve ( C4
and C5)
Blood
Supply
Dorsal scapular artery
21. Rhomboid Major
Origin
Spinous processes of T2 - T5
vertebrae
Insertion Medial border of scapula
Action
Retracts and rotates scapula to
move glenoid inferiorly; fixes
scapula to thoracic wall
Nerve
Supply
Dorsal scapular nerve ( C4 and
C5)
Blood
Supply
Dorsal scapular artery
22. Serratus Anterior
Origin
Superolateral surfaces of upper 8
or 9 ribs at the side of chest
Insertion Medial border of scapula
Action Pulls scapula forward and
upward; abducts and rotates it;
stabilises medial border of
scapula
Nerve Supply Long thoracic nerve (C5, C6, C7)
Blood Supply Circumflex scapular artery
23. Supraspinatus
Origin Supraspinous fossa of scapula
Insertion
Superior facet on greater
tuberosity of humerus
Action Abduction of arm
Nerve
Supply
Suprascapular nerve (C4, C5
and C6)
Blood
Supply
Suprascapular artery
24. Triceps
Origin Long head: infraglenoid tubercle
of scapula; Lateral head:
posterior surface of humerus,
superior to radial groove; Medial
head: posterior surface of
humerus, inferior to radial
groove
Insertion Proximal end of olecranon
process of ulna and fascia of
forearm
Action Extends forearm
Nerve Supply Radial nerve (C6, C7 and C8)
Blood Supply Branches of deep brachial artery
25. Teres Major
Origin Dorsal surface of inferior
angle of scapula
Insertion
Medial lip of intertubercular
groove of humerus
Action Adducts and internally
rotates arm
Nerve
Supply
Lower subscapular nerve (C6
and C7)
Blood
Supply
Subscapular and circumflex
scapular arteries
26. Teres Minor
Origin Superior part of lateral border
of scapula
Insertion Inferior facet on greater
tuberosity of humerus
Action External rotation of the arm
Nerve
Supply
Axillary nerve (C5 and C6)
Blood
Supply
Subscapular and circumflex
scapular arteries
27. Trapezius
Origin Medial third of superior nuchal line;
external occipital protruberance,
nuchal ligament, and spinous
processes of C7 - T12 vertebrae
Insertion Lateral third of clavicle, acromion,
and spine of scapula
Action superior fibers elevate, middle fibers
retract, and inferior fibers depress
scapula
Nerve Supply Spinal root of accessory nerve (CN
XI) (motor) and cervical nerves (C3
and C4) (pain and proprioception)
Blood Supply Transverse cervical artery