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ANATOMY
Medicine Made Simple
, Pectoral Region, Breast and Scapular region
Pectoral region
Muscle Origin Insertion Nerve supply Action
Pectoralis Clavicle – ant. Surface Bicipital groove – Medial & lateral Adduction, med.
major medial part lateral lip pectoral nerves rotation & flexion of
Manubrium (bilaminar tendon) shoulder joint
Sternum ant.
Upper 6 costal surface clavicular head-
Cartilage flexion of arm at
External oblique shoulder
aponeurosis
Pectoralis 3,4,5 ribs Coracoid process Medial pectoral Protraction,
minor (Medial side) nerve depression and lateral
rotation of the
scapula
Serratus Upper 8 ribs Scapula medial Long thoracic Entire muscle
anterior border – entire nerve protracts scapula &
length holds it against ribs.
Rotates scapula
laterally
Muscle origin Insertion innervation Action
Deltoid Anterior border Deltoid tuberosity Axillary nerve Abduction
(has a of lateral 1/3rd of Flexion and medial
multipennate clavicle rotation- Anterior fibers
part) Acromion Extension and lateral
Spine of scapula rotation of pos. fibers
Clinical
Paralysis of Serratus anterior causes ‘winging’ of the Scapula
- Medial border of scapula – unduly prominent
- Arm can’t be abducted beyond 90
Pec. Major testing (Pec. Major is the only muscle of the upper limb to be supplied by all 5 segments
of brachial plexus)
- Clavicular head - attempt to lift a heavy table
- flex arm to a 90 against resistance
- sternocostal head – try to depress a heavy table
- extend the flexed arm against resistance
press fists against each other
1
ANATOMY
Medicine Made Simple
, Pectoral Region, Breast and Scapular region
Pectoral region
Muscle Origin Insertion Nerve supply Action
Pectoralis Clavicle – ant. Surface Bicipital groove – Medial & lateral Adduction, med.
major medial part lateral lip pectoral nerves rotation & flexion of
Manubrium (bilaminar tendon) shoulder joint
Sternum ant.
Upper 6 costal surface clavicular head-
Cartilage flexion of arm at
External oblique shoulder
aponeurosis
Pectoralis 3,4,5 ribs Coracoid process Medial pectoral Protraction,
minor (Medial side) nerve depression and lateral
rotation of the
scapula
Serratus Upper 8 ribs Scapula medial Long thoracic Entire muscle
anterior border – entire nerve protracts scapula &
length holds it against ribs.
Rotates scapula
laterally
Muscle origin Insertion innervation Action
Deltoid Anterior border Deltoid tuberosity Axillary nerve Abduction
(has a of lateral 1/3rd of Flexion and medial
multipennate clavicle rotation- Anterior fibers
part) Acromion Extension and lateral
Spine of scapula rotation of pos. fibers
Clinical
Paralysis of Serratus anterior causes ‘winging’ of the Scapula
- Medial border of scapula – unduly prominent
- Arm can’t be abducted beyond 90
Pec. Major testing (Pec. Major is the only muscle of the upper limb to be supplied by all 5 segments
of brachial plexus)
- Clavicular head - attempt to lift a heavy table
- flex arm to a 90 against resistance
- sternocostal head – try to depress a heavy table
- extend the flexed arm against resistance
press fists against each other
1
