Lecture 10: Upper Extremity Myology Flashcards
Pectoralis Major M.
What are the attachments?
Origin: Claviclular Head, Sheath of Rectus Abdominis, Clavical, Sternum
Insertion: Lateral Edge of the Intertubercular Groove of Humerus
(covers the long head of Biceps Brachii M)
Pectoralis Major M.
What are the major actions?
- Adduct and Medially Rotate Humerus
- Protract and Depress Scapula
- Clavicular Head: Flex Humerus
- Sternocostal Head: Extend Humerus from flexed state
Pectoralis Major M.
What is the innervation and blod supply?
Innervation: Lateral and Medial Pectoral Nerve
Blood Supply: Pectoral Branch of the Thoracoacromial Trunk
Pectoralis Minor M.
What are the attachments?
Origin: Medial aspect of Ribs 3-5
Insertion: Coracoid Process of the Scapula
Pectoralis Minor M.
What is the action?
Stabilizes the Scapula by holding it to thoracic wall
Pectoralis Minor M.
What is the innervation and blood supply?
Innervation: Medial Pectoral Nerve
(It gets pity innervated on the way to the Pectoralis Major M.)
Blood Supply: Pectoral Branch of the Throacoacromial Trunk
Subclavius M.
What are the attachments?
Origin: Upper border of 1st rib and 1st Costal Cartilage
Insertion: Inferior aspect of the Clavicle
Subclavius M.
What is the Action?
Depresses the Clavicle
Subclavius M.
What is the innervation and blood supply?
Innervation: Nerve to the Subclavius
Blood Supply: Clavicular Branch of the Thoracoacromial Trunk
Serratus Anterior M.
What are the attachments?
Origin: Lateral external surface of Ribs 1-8
Insertion: Anterior surface of medial border of scapula
Serratus Anterior M.
What are the actions?
- Protraction of the Scapula
* (Boxer’s Serratus Anterior Muscles are buff for this reason)* - Superior Rotation of the Glenoid Cavity
* (Pulls the medial border down towards the ribs - lateral end goes up)* - Stabalizes the Scapula by pulling it to the Thoracic Wall
Serratus Anterior M.
What is the innervation and blood supply?
Innervation: Long Thoracic Nerve
Blood Supply: Lateral Thoracic Artery
If the Serratus Anterior or Long Thoracic Nerve is damaged, what can it cause and what motion does this prevent?
“Winging” of the Scapula
- Scapula is no longer Stabalized against the Thoracic Wall
- Abduction of the Upper Extremity beyond the Horizontal Position
Deltoid Muscle
What are the Attachments?
Origin: Lateral Clavicle, Scapular Spine, and Acromion
Insertion: Deltoid Tuberosity of the Humerus
Deltoid Muscle
What are the actions?
Anterior Part: Flex and Medial Rotation of the Humerus
Middle Part/Whole Muscle: Abduction of the Humerus
Posterior Part: Extension of the Shoulder and Lateral Rotation of the Humerus
Deltoid Muscle
What is the innervation and blood supply?
Innervation: Axillary Nerve
Blood Supply: Posterior Circumflex Humeral Artery (main)
Deltoid Branch of Thoracoacromial Artery
Subscapularis Muscle
What are the attachments?
Orign: Medial Aspect Subscapular Fossa
Insertion: Lesser Tubercle of the Humerus
Subscapularis Muscle
What are its actions?
- Medial Rotation of the Humerus
- Adduction of the Humerus
- Holds humeral head in glenoid cavity
For the Subscapularis M.
What is the innervation and blood supply?
Innervation: Upper and Lower Subscapular Nerve
Blood Supply: Subscapular Artery
Supraspinatus Muscle
What are the attachments?
Origin: Supraspinous Fossa of the Scapula
Insertion: Greater Humeral Tubercle (running over the superior-most part of the Humerus)
Supraspinatus Muscle
What is the action?
- Abduction of the Humerus (along with deltoids)
- Holds Humeral Head in Glenoid Cavity
Supraspinatus Muscle
What is the innervation and blood supply?
Innervation: Suprascapular Nerve
Blood Supply: Suprascapular Artery
Infraspinatus Muscle
What are the attachments?
Origin: Infraspinous Fossa of Scapula
Insertion: Greater Tubercle of the Humerus
Infraspinatus Muscle
What is its action?
- Lateral Rotation of the Humerus
- Holds Humeral Head in Glenoid Cavity
Infraspinatus Musle
What is the innervation and blood supply?
Innervation: Suprascapular Nerve
Blood Supply: Suprascapular Artery and Circumflex Scapular Artery
(The Circumflex Scapular Artery comes around the lateral border of the scapula and heads superiorly and medially)
Teres Minor Muscle
What are the attachments?
Origin: Middle Part of Lateral Border of Scapula
Insertion: Greater Tubercle of Humerus
Teres Minor Muscle
What are its actions?
- Laterally Rotates Humerus
- Holds Humeral Head in Glenoid Cavity
Teres Minor Muscle
What is the innervation and blood supply?
Nerve: Axillary Nerve
Blood Supply: Circumflex Scapular Artery and Subscapular Artery
Teres Major Muscle
What are the attachments?
Origin: Posterior aspect of Inferior Angle of the Scapula
Insertion: Medial edge of Intertubercular groove
(Front of the Humerus)
Teres Major Muscle
What are the actions?
- Medial rotation of the Humerus
(Pulls the front of the Humerus medially)
- Adduction of the Humerus
Teres Major Muscle
What is the innervation and blood supply?
Innervation: Lower Subscapular Nerve
Blood Supply: Subscapular Artery and Circumflex Scapular Artery
What are the four rotator cuff muscles?
Supraspinatus M.
Infraspinatus M.
Teres Minor M.
Subscapularis M.
Triangular Space
What muscles make up the border?
What can be found within?
Borders: Teres Major, Teres Minor, Long Head of Triceps Brachii M.
Contains: Circumflex Scapular Artery and Vein
Quadrangular Space
What muscles make up the four borders?
What can be found within?
Borders: Long and Lateral Head of the Triceps Brachii M., Teres Major M. Teres Minor M.
Contains: Axillary Artery, Posterior Circumflex Humeral Artery, Posterior Circumflex Humeral Vein
(Contents are headed to the Deltoid Muscle, so if you remember the Deltoid M.’s nerve and artery, there you go)
Triangular Interval
What muscles make up its three borders?
What does it contain?
Borders: Long and Lateral Head of the Triceps Brachii, Teres Major M.
Contains: Deep Brachial Artery and Vein, Radial Nerve
What part of the Biceps Brachii M. covers the Pronator Teres M.?
The Bicipital Aponeurosis
Biceps Brachii Muscle
What are the attachments?
Origin: Long Head: Supraglenoid Tubercle of Scapula
Short Head: Coracoid Process of Scapula
Insertion: Radial Tuberosity and Antebrachial Fascia (bicipital aponeurosis)
The Biceps Brachii skips the Humerus entirely
Biceps Brachii Muscle
What are the actions?
- Flexes humerus and supinated forearm
- Supinates forearm
-
Short Head resists dislocation of shoulder
* Remember that these Muscles Flex/Extend the Joints they cross*
Biceps Brachii Muscle
What is the innervation and blood supply?
Innervation: Musculocutaneous Nerve
Blood Supply: Brachial Artery
Coracobrachialis Muscle
What are the attachments?
Origin: Coracoid Process of Scapula
Insertion: Medial Aspect of the Humeral Body
Coracobrachialis Muscle
What are the actions?
- Flexion of Shoulder
- Adduction of Shoulder
Coracobrachialis Muscle
What is the innervation and blood supply?
Innervation: Musculocutaneous Nerve
Blood Supply: Brachial Artery
Brachialis Muscle
What are the attachments?
Origin: Distal half of anterior aspect of Humerus
Insertion: Ulnar Tuberosity and Coranoid Process
Brachialis Muscle
What is the action?
Flexion of the Forearm (elbow joint)
The Bicep cannot flex a pronated Elbow. The Brachialis does that.
Brachialis Muscle
What is the innervation and blood supply?
Innervation: Musculocutaneous Nerve
Blood Supply: Radial Recurrent Artery
Triceps Brachii Muscle
Where are the attachments?
Origin: Long Head: Infraglenoid Tubercle of Scaupla
Lateral Head: Posterior aspect of Humerus (superior to radial groove)
Medial Head: Posterior aspect of Humerus (inferior to radial groove)
Insertion: Olecranon of Ulna and Antebrachial Fascia
Triceps Brachii Muscle
What is the action?
- Extend the Forearm
- Long Head resists dislocation of shoulder
Triceps Brachii Muscle
What is the innervation and blood supply?
Innervation: Radial Nerve
Blood Supply: Deep Brachial Artery
Anconeus Muscle
What are the attachments?
Origin: Lateral Humeral Epicondyle
Insertion: lateral aspect of Olecranon
(Even though it attaches to the Lateral Humeral Epicondyle like an extensor and exists entirely in the forearm, it’s considered a posterior compartment Brachial Muscle for this class. This may be because some people consider it to be a continuation of Triceps Brachii M.)
Anconeus Muscle
What is the action?
- Extends the forearm (elbow)
- Stabilizes elbow joint
Anconeus Muscle
What is the innervation and blood supply?
Innervation: Radial Nerve
Blood Supply: Deep Brachial Artery
Pronator Teres Muscle
What are the attachements?
Origin: Humeral Head: Medial Epicondyle of Humerus
Ulnar Head: Coranoid Process of Ulna
Insertion: Lateral aspect of the Radius
Pronator Teres Muscle
What is the action?
Pronate and Flex forearm (Elbow)
Pronator Teres Muscle
What is the innervation and blood supply?
Innervation: Median Nerve
Blood Supply: Ulnar Artery and Radial Artery
Flexor Carpi Radialis Muscle
What are the attachments?
Origin: Medial Humeral Epicondyle
Insertion: Base of 2nd Metacarpal on palmar aspect
Flexor Carpi Radialis Muscle
What are the actions?
- Flex forearm and hand
- Abduct the Wrist
Flexor Carpi Radialis Muslce
What is the innervation and blood supply?
Innervation: Median Nerve
Blood Supply: Ulnar Artery
Palmaris Longus Muscle
What are the attachments?
Origin: Medial Humeral Epicondyle
Insertion: Palmar Aponeurosis and Flexor Retinaculum
Palmaris Longus Muscle
What is the action?
- Flexes forearm and hand
- Tenses Palmar Aponeurosis
Palmaris Longus Muscle
What is the innervation and blood supply?
Innervation: Median Nerve
Blood Supply: Ulnar Artery