Pectoral and scapular region Flashcards
What are the 4 muscles in the anterior chest?
- Subclavius
- Pectoralis Major
- Pectoralis Minor
- Serratus anterior
What does the Subclavius move?
Moves the clavicle
What innervates the subclavius?
Nerve to subclavius
What is the origin and insertion of the subclavius?
- Origin is at the first 1st costal cartilage
- Inserts into the lower border of the clavicle
What is the function of the subclavius?
Stabilises/ depresses the clavicle
What moves the humerus?
Pectoralis Major
What innervates the pectoralis major?
The median and Lateral pectoral nerves
What are the two heads of the pectoralis major?
-Clavicular head
- Sternocostal head
Where does the clavicular head of the pectoralis major attach?
On the medial third of the clavicle
Where does the sternocostal head of the pectoralis major?
Attaches to the upper six ribs
Where do the pectoralis major muscle heads converge?
Both head come down and converge on the lateral lip of the intertubercular sulcus of the humerus
Describe the function of the pectoralis major?
- Powerful adductor of the glenohumeral joint
- Clavicular head can also aid in shoulder flexion
- In a flexed position, the lower fibres of the pectoralis major (sternocostal head) can also extend the shoulder (only as far as the anatomical position)
What does the pectoralis minor move?
The scapula
What innervates the pectoralis minor?
Medial Pectoral Nerve
What is the origin of the pectoralis minor?
The 3rd, 4th and 5th ribs
What is the insertion of the pectoralis minor
Into the coracoid process of the scapula
What is the function of pectoralis minor?
To stabilise the scapula as the elbow and shoulder move around
What does the serratus anterior move?
The scapula
What innervates the serratus anterior?
Long thoracic nerve
What is the origin of the serratus anterior?
Upper nine ribs
What is the insertion of the serratus anterior?
Wraps around the body wall and inserts onto the medial border of the scapula
What is the function of the serratus anterior?
Protracts
Prevents winging
Scapular rotation
Describe the arterial supply of the pectoral regions
- Suprascapular artery
- Dorsal scapular artery
- Subscapular artery
Describe the venous drainage of the pectoral regions
Drainage into the subclavian or axillary veins
What are the 3 extrinsic back muscles?
- Latissimus Dorsi
-Trapezius - Rhomboids
What does the latissimus dorsi move?
Moves the humerus
What innervates the latissimus Dorsi
Thoracodorsal Nerve
What is the origin of the latissimus dorsi?
Attaches to spinous processes of T8-T12 via the Thoracolumbar fascia
What is the insertion of the latissimus dorsi?
Inserts into the floor of the intertubercular sulcus between the 2 lips
What is the function of the latissimus dorsi?
-Extends
- Abducts
- Medially rotates
What does the trapezius move?
The scapula
What innervates the trapezius?
The spinal accessory nerve roots C4 C5
Only muscle of the upper limb not innervated by brachial plexus
What is the origin of the trapezius?
To the base of the skull at external occipital protuberance, nuchal ligament and spinous processes of C7 - T12
Where is the insertion of the Trapezius?
The acromion, spine of the scapula and clavicle
What is the function of the trapezius?
- Superior part elevates scapula
- Middle part retracts scapula
- Inferior part depresses scapula
What do the rhomboids move?
Scapula
What innervates the rhomboids?
