Pectoral & Upper Limb Muscles Flashcards
Pectoralis major
Origin
- Clavicular head: Medial one half of the clavicle
- Sternocostal head: Sternum, & Costal cartilage 1-7
Pectoralis major
Insertion
Lateral lip of the intertubercular sulcus of humerus
Pectoralis major
Action
- Medially rotates the humerus
- Flexes the humerus
- ** Adducts the humerus
Pectoralis major
Innervation & blood supply
Innervation: Medial and lateral pectoral nerves
(from C8-T1 and C5-C7 of brachial plexus, respectively)
Blood supply: Pectoral branch of the thoracoacromial artery
Pectoralis minor
Origin
Ribs 3-5
near costal cartilage
Pectoralis minor
Insertion
Coracoid process of the scapula
Pectoralis minor
Action
- Anteriorly tilts and depresses the scapula
2. Elevates ribs for deep inspiration
Pectoralis minor
Innervation and blood supply
Innervation: Medial pectoral nerve (from C8-T1 of brachial plexus)
Blood supply: Pectoral branch of the thoracoacromial artery
Subclavius
Origin
Rib 1
Subclavius
insertion
Clavicle
Subclavius
Action
- Depresses the clavicle
- Stabilizes the sternoclavicular joint
Subclavius
Innervation and blood supply
Innervation: Nerve to subclavius
Blood supply: Clavicular branch of the thoracoacromial artery
Serratus anterior
Origin
Medial border of the scapula (anterior surface)
Serratus anterior
Insertion
Ribs 1-9, lateral parts
Serratus anterior
Action
- Protects and rotates the scapula
- Holds scapula against thoracic wall
(esp. when reaching anteriorly)
Serratus anterior
Innervation and blood supply
Innervation: Long thoracic nerve (brachial plexus)
Blood supply: Lateral thoracic artery
Subscapularis
Origin
Subscapular fossa
Subscapularis
Insertion
Lesser tubercle of the humerus
Subscapularis
Action
Medially rotates the humerus
Subscapularis
Innervation & blood supply
Innervation: upper and lower subscapular nerves (C5 and C6 of brachial plexus, respectively)
Blood supply: subscapular artery
Coracobrachialis
Origin
Coracoid process of the scapula
Coracobrachialis
Insertion
Medial side of the shaft of the humerus
Coracobrachialis
Action
Adducts and flexes the humerus
Coracobrachialis
Innervation and blood supply
Innervation: Musculocutaneous nerve (ventral rami of C5, C6)
Blood supply: Muscular branches of brachial artery
Biceps brachii
Origin
Long head: Supraglenoid tubercle of the scapula
Short head: Coracoid process of the scapula
Biceps brachii
Insertion
- Radial tuberosity and antebrachial fascia
Connects via bicipital aponeurosis
Biceps brachii
Action
Supinates and flexes the forearm
- POWERFUL
Biceps brachii
Innervation and blood supply
Innervation: Musculocutaneous nerve (c5,c6)
Blood supply: muscular branches of brachial artery
Brachialis
Origin
Anterior aspect of the humerus
Brachialis
Insertion
Tuberosity of the ulna
Brachialis
Action
Flexes the forearm
Brachialis
Innervation and blood supply
Innervation: Musculocutaneous nerve (ventral rami of C5, C6)
Blood supply: Muscular branches of brachial artery
Joints of the upper limb
- Acromioclavicular (AC) joint (gliding)
- Glenohumeral (shoulder) joint (ball & socket)
- Elbow (humeroulnar) Joint (Hinge)
- Superior and inferior radioulnar joints (pivot)
- Radiocarpal (wrist) joint (Condyloid)
- Metacarpophalangeal joint (Condyloid)
- Proximal interphalageal joint (hinge)
- Distal interphalageal joint (hinge)
Winged Scapula
When a patient extends arm, medial border of scapula is visible through skin when long thoracic nerve is damaged
- Serratus anterior cannot hold scapula to thoracic wall
Types of shoulder disocations
These are all glenohumeral joint dislocations
- Subcoracoid dislocation
- Subglenoid dislocation
- Subclavicular dislocation
What are the rotator cuff muscles?
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
Deltoid
Origin
- Clavicular part: Lateral 1/3 of the clavicle
- Acromial part: Acromion process of scapula
- Spinal part: Spine of scapula
Deltoid
Insertion
Deltoid tuberosity of the humerus
Deltoid
Action
Clavicular part: Flexes, internally rotates
Acromial part: Abducts the humerus
Spinal part: Extends and externally rotates the humerus
Deltoid
Innervation and Blood Supply
Innervation: Axillary nerve (brachial plexus)
Blood supply: Posterior Circumflex Humeral Artery
Brachioradialis
Origin
Lateral supracondylar ridge of the humerus
Brachioradialis
Insertion
Styloid process of the radius
Brachioradialis
Action
- Flexes elbow from mid-prone position
“The drinking muscle”
Brachioradialis
Innervation and Blood Supply
Innervation: Radial nerve
Blood supply: Radial recurrent artery
Triceps brachii
Origin
Long head: Infraglenoid tubercle of the scapula
Medial/Lateral head: Posterior surface of the humerus
Triceps brachii
Insertion
Olecranon process of the ulna
Triceps brachii
Action
Extends the forearm
Long head: Extends & adducts the arm
Triceps brachii
Innervation & Blood supply
Innervation: Radial nerve (C6, C7, C8)
Blood supply: Deep brachial artery
Carpal bones
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
- Hamate
- Capitate
- Trapezoid
- Trapezium
Anterior forearm muscles (superficial)
From lateral to medial:
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
Pass-Fail-Pass-Fail
Anterior forearm muscles (superficial)
Innervation
Median nerve
EXCEPT for flexor carpi ulnaris (which is ulnar nerve)
Anterior forearm muscles (intermediate) & Innervation
- Flexor digitorum superficialis (travels through carpal tunnel to palm)
Innervation: Median nerve
Anterior forearm muscles (deep group)
- Flexor digitorum profundus (travels through carpal tunnel to palm)
- Flexor pollicis longus (travels through carpal tunnel to palm)
- Pronator quadratus
Anterior forearm muscles (deep group)
Innervations
- Flexor digitorum profundus: Medial part is ulnar neve, Lateral part: median nerve
- Flexor pollicis longus: Median nerve
- Pronator quadratus: Median nerve
- Flex DIP usually
Posterior forearm muscles (superficial group)
- Extensor carpi radialis longus
- Extensor carpi radialis brevus
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
Posterior forearm muscles (deep group)
- Abductor pollicis longus (acts on thumb)
- Extensor pollicis brevis (acts on thumb)
- Extensor pollicis longus (acts on thumb)
- Extensor indicis
- Supinator
ABLEs
Thenar eminence muscles (thumb)
- Abductor pollicis
- Flexor pollicis brevis
- Opponens pollicis
Palmar aponeurosis (what is it? Location?)
Deep fascia, longitudinal fibrous sheaths from digits 2-5
- Connects to palmaris longus tendon
Adductor pollicis
- Origin
- Insertion
- Action
- Innervation
NOT part of thenar eminence
- Transverse head is from shaft of metacarpal 3, Oblique head is from capitate bone, bases of metacarpals 2-3
- Base of proximal phalynx of thumb
- Adducts thumb
- Ulnar nerve (deep branch)
Hypothenar eminience muscles (little finger)
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
Lumbrical muscle
- Origin
- Insertion
- Action
- Innervation
- Tendons of flexor digitorum profundus
- Lateral sides of the dorsal digital expansions of the tendons of extensor digitorum muscles
- Flexes MCP joint, Extends DIP and PIP joint
- Innervation: 1-2 are median nerve (lateral side); 3-4 are ulnar nerve
Dorsal interosseus muscles
- Origins
- Insertions
- Actions
- Innervations
There are 4 of them
- Origins: Between digits 1&2, 2&3, 3&4, 4&5
- Insertions: lateral side of digit 2, 3; medial side of digit 3,4
- Actions: abducts digits 2-4 away from axis of middle finger, Flex MCP joints, Help extend PIP and DIP joints
- Innervation: Ulnar nerve
Palmar interosseus muscles
- Origins
- Insertions
- Actions
- Innervations
There are 3 of them
- Origins: Medial side of metacarpal 2, Lateral side of metacarpal 4, Lateral side of metacarpal 5
- Insertions: Medial side of digit 2, lateral side of digit 4, lateral side of digit 5
- Actions: ADducts digits 2-4 towards the axis of middle finger, Flex MCP joints, Help extend PIP and DIP joints
- Innervation: Ulnar nerve
Function of Acromioclavicular joint
Doesn’t normally move (helps lift arm over head), can be affected by muscles when AC is broken
Function of radioulnar joints
Participate in supination and pronation of forearm
Pronator teres
Origin
- Medial epicondyle/ supraepicondylar ridge of the humerus
- medial side of the coraNoid process
Pronator teres
Insertion
Lateral midshaft of radius
Pronator teres
Action
Pronates AND flexes the forearm
Pronator teres
Innervation
Median nerve
Pronator teres
Blood supply
Ulnar artery
Flexor carpi radialis
Origin
Medial epicondyle of the humerus
Flexor carpi radialis
Insertion
Base of metacarpals 2-3
Flexor carpi radialis
Action
Flexes AND abducts the wrist
Flexor carpi radialis
Innervation
Median nerve
Flexor carpi radialis
Blood supply
Ulnar artery
Palmaris longus
Origin
Medial epicondyle of the humerus
Palmaris longus
Insertion
Palmar aponeurosis
Palmaris longus
Innervation
Median nerve
Palmaris longus action
Flexes the wrist
Palmaris longus
Blood supply
Ulnar artery
Flexor carpi ulnaris
Origin
Medial epicondyle of humerus
Flexor carpi ulnaris
Insertion
Pisiform bone
Base of metacarpal 5
Flexor carpi ulnaris
Action
Flexes and ADucts wrist
Flexor carpi ulnaris
Innervation
Ulnar nerve
Flexor carpi ulnaris
Blood supply
Ulnar artery
Flexor digitorum superficialis
Origin
Medial epicondyle of the humerus
& oblique line of the radius
Flexor digitorum superficialis
Insertion
Middle phalanges of digits 2-5
Flexor digitorum superficialis
Action
Flexes PIP of digits 2-5
Flexor digitorum superficialis
Innervation
Median nerve
Flexor digitorum superficialis
Blood supply
Ulnar artery
Flexor digitorum profundus
Origin
Anterior and medial surface of the ulna and interosseous membrane
Flexor digitorum profundus
Insertion
Distal phalanges of digits 2-5