Pectoral region, Anterior aspect of arm and shoulder joint Flashcards
Pectoralis major muscle
How many muscles are in the Pectoral region?
2 muscles
Pectoralis major muscle
What’s the origin of the Pectoralis major muscle?
Sternal → sternum 2-6 ribs
Clavicular → sternal half of clavicle
What’s the insertion of the Pectoralis major muscle?
Bicipital groove
What’s the function of the Pectoralis major muscle?
Adduction, Medial rotation, Flexion to shoulder joint. The shoulder joint is a spheroid joint that creates 3 movements.
What’s the nerve passing the Pectoralis major muscle?
Medial, lateral pectoral nerve
Pectoralis Minor muscle
What’s the origin of the Pectoralis Minor muscle?
3,4,5 ribs
What’s the insertion of the Pectoralis Minor muscle?
Corocoid process
What’s the function of the Pectoralis Minor muscle?
Pulls the shoulder towards the chest. If the shoulder is fixed the ribs are pushed towards the shoulder (forced inspiration/breathing)
What’s the nerve passing through the Pectoralis Minor muscle?
Medial pectoral nerve
What must be done to see the Pectoralis Minor muscle?
Dissect the Pectoralis major in half
Pectoralis minor muscle
Serratus Anterior Muscle
What’s the origin of the Serratus Anterior Muscle?
anterior and lateral aspect of 1-8 ribs
What’s the insertion of the Serratus Anterior Muscle?
Medial border, inferior angle of scapula
What’s the function of the Serratus Anterior Muscle?
Pulls the medial angle of the scapula towards the chest wall, turns the glenoid cavity upwards (hyper-abduction)
What’s the nerve passing the Serratus Anterior Muscle?
Long thoracic nerve
Serratus Anterior Muscle
Wing scapula
Explain the wing of scapula and how is it checked.
When the long thoracic nerve is damaged. Tell the patient to bend on the wall and if one is winged then the patient has a wing scapula which means that the scapula isn’t applied to the thorax wall.
Long and short head of bicep brachii muscle (superficial layer)
Brachialis muscle (deep layer)
Corocobrachialis muscle
Bicep brachii muscle
What’s the origin of the Bicep brachii muscle?
long head: supraglenoid tubercle
short head: corocoid processand pectoralis minor
What’s the insertion of the Bicep brachii muscle?
Radial tuberosity
What’s the function of the Bicep brachii muscle?
Supination of the forearm, flexion of the forearm, flexion the arm
What’s the nerve passing the Bicep brachii muscle?
muculocutaneous nerve
What’s the origin of the Corocobrachialis muscle?
corocoid process
What’s the insertion of the Corocobrachialis muscle?
Medial aspect of humerus
What’s the function of the Corocobrachialis muscle?
Adduction, Medial rotation, and flexion of the arm
What’s the nerve passing the Corocobrachialis muscle?
muculocutaneous nerve
What’s the origin of the Brachialis muscle?
Anterior aspect of humerus
What’s the insertion of the Brachialis muscle?
Coronoid process of ulna
What’s the function of the Brachialis muscle?
flexion to the forearm
What’s the nerve passing the Brachialis muscle?
muculocutaneous nerve
What muscles does the musculocutaneous nerve pass?
Corocobrachilais muscle, Bicep brachii muscle and Brachialis muscle
What type of nerve is the muculocutaneous nerve?
Mixed nerve (motor fibers and sensory fibers)
What does the muculocutaneous nerve pierce?
Corocobrachialis muscle
What happens when there is a musculocutaneous nerve palsy (doesnt work)?
Weakness of the elbow flexion(forearm) (due to brachialis and bicep brachii muscle)
Weakness of the forearm supination (due to bicep brachii muscle)
Numbness in the lateral aspect of the forearm
Why will there be only WEAKNESS of the forearm supination during musculocutaneous nerve palsy?
Only weakness, not loss because there’s another muscle called the supinator muscle.
