L09 - Upper Limb Muscles Flashcards
Trapezius muscle origin?
External occipital protuberance; nuchal ligament; spinous processes of C7-T12 vertebrae
What are the superficial posterior axioappendicular muscles?
Trapezius
Latissimus dorsi
Trapezius insertion?
Inner aspect of Lateral third of clavicle; acromion and spine of scapula
Function of Trapezius?
Upper fibres elevate, middle fibres retract and lower fibres depress the scapula.
What are the deep posterior axioappendicular muscles?
Levator scapulae
Rhomboid major
Rhomboid minor
Origin of Levator scapulae?
Posterior tubercules of transverse processes of C1-C4 vertebrae
Insertion of Levator scapulae?
Medial border of scapula
superior to root of spine
Origin of Rhomboid minor?
Spinous process of C7 and T1 vertebrae, nuchal ligament
Origin of Rhomboid major?
Spinous process of T2 - T5 vertebrae
Insertion of Rhomboid minor and major?
Minor = Medial border of scapula (at medial end of scapula spine)
Major = Medial border of scapula from level of spine to inferiorly
Action of Levator scapulae, Rhomboid minor and Rhomboid major?
Levator scapulae = Elevate scapula
Rhomboid minor and major = Retract scapula
Function of Serratus anterior?
protracts & rotates scapula; holds scapula to body
Origin and insertion of Serratus anterior?
Origin = External surface of lateral parts of 1st to 8th ribs
Insertion = Converge into Anterior surface/ inferior angle of medial border of scapula
Explain which nerve is damaged and which muscle cannot function in ‘Winged Scapula’.
Injury to Long thoracic nerve
Arm cannot be completely abducted above the horizontal position because Serratus anterior is unable to rotate the glenoid cavity superiorly
Which muscles contract to rotate the scapula?
Serratus anterior + Trapezius
- Upper fibers of trapezius = rotate glenoid fossa superiorly
- Lower fibers of trapezius = rotate glenoid fossa of scapula inferiorly
- Lower fibers of serratus anterior = rotate inferior angle of scapula laterally
Origin and insertion of pectoralis minor?
Origin = 3rd to 5th rib near costal cartilage
Insertion = Coracoid process of scapula
Origin and insertion of Subclavius?
Origin = Between 1st rib and its costal cartilage
Insertion = Inferior surface of middle third of clavicles
Action of Pectoralis minor and Subclavius?
Both depress scapula
Pec minor = draw scapula inferiorly and anteriorly
Subclavius = Depresses scapula
What are the 9 muscles that move the arm at the shoulder joint?
Danny Likes Playing Super Sonic In The TV Cabin
Deltoid Latissimus dorsi Pectoralis major Subscapularis Supraspinatus Infraspinatus Teres minor Teres major Coracobrachialis
Generally speaking, where are the origins and insertions of muscles that move the arm at the shoulder joint?
- Origin: axial skeleton or pectoral girdle
* Insertion: humerus
Origin, insertion and function of Deltoid muscle?
Origin = Lateral 1/3 of calvicle, acromion and spine of scapula
Insertion = Deltoid Tuberosity of Humerus
Function: abducts arm beyond initial 15 degrees
Origin, insertion and function of Latissimus dorsi?
Origin = spinous process of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs
Insertion = Floor** of intertubercular groove of humerus
Function = adducts, medially rotates & extends arm
Insertion of Latissimus dorsi is lateral to which 2 other muscles’ insertion?
Lat. dorsi inserts at the FLOOR of intertubercular groove
Lateral to the FLOOR is Pectoralis major attachment
Medial to FLOOR is Teres major attachment
“Lady D lies between 2 majors”
Pectoralis major origin, insertion and function?
Origin:
Clavicular part = Anterior surface of medial half of clavicle;
Sternal part = sternum &superior 6 CC;
Abdominal part = aponeurosis of External oblique muscle
Insertion = Lateral lip of intertubercular groove of humerus
Function: adducts, flexes and medially rotates the arm
Muscles that form the rotator cuff? What are their collective and own functions?
Supraspinatus = ABduction (initial 15 degrees before Deltoid takes over)
Infraspinatus = Lateral rotation
Teres minor = Lateral rotation
Subscapularis = Medial rotation
Collectively hold the humeral head in the glenoid fossa of the scapula/ stabilize the shoulder joint
Origin and insertion of Supraspinatus?
Origin = Supraspinous fossa of scapula
Insertion = Superior facet of greater tubercule of humerus
Origin and insertion of Infraspinatus?
Origin = Infraspinous fossa of scapula
Insertion = Middle facet of greater tubercule of humerus
Origin and insertion of Teres minor?
Origin = Middle part of lateral border of scapula
Insertion = Inferior facet of greater tubercule of humerus
Origin and insertion of Subscapularis?
Origin = Subscapular fossa
Insertion = Lesser tubercule of humerus
Teres Major origin, insertion and function?
Origin = Posterior surface of inferior angle of scapula
Insertion = Medial lip of intertubercular groove of humerus
Function = Adduct, medially rotate and extends arm
Origin, insertion and function of Coracobrachialis?
Origin = Tip of coracoid process of scapula
Insertion = Middle third of medial surface of humerus
Function = Flex and adduct arm, resist dislocation of shoulder
What are the 2 groups of muscles of the arm?
Anterior group for Flexion of elbow joint
Posterior group for extension of elbow joint
2 groups separated physically by Medial and Lateral intermuscular septum
List the anterior flexor arm muscles and their own function?
- Coracobrachialis (flexes shoulder joint; does not cross elbow joint so doesn’t flex elbow)
- Biceps brachii (flexes elbow joint and is a strong supinator)
- Brachialis (flexes elbow joint)
Origin and Insertion of Biceps brachii?
Origin: Short head = tip of coracoid process; Long head = Supraglenoid tubercule of scapula
Insertion = Bicipital tuberosity of radius and fascia of forearm via Bicipital aponeurosis
Origin and insertion of Brachialis?
Origin = Distal half of anterior surface of humerus
Insertion = Coronoid process and tuberosity of ulna
List the posterior extensor arm muscles and their own function?
- Triceps brachii (extends the elbow joint)
2. Anconeus (considered part of the triceps brachii)
Origin and insertion of Triceps brachii?
3 heads:
a) Long head = infraglenoid tubercule of scapula
b) Lateral head = Posterior surface of humerus, Superior to radial groove
c) Medial head = Posterior surface of humerus, Inferior to radial groove (lies under lateral head)
Insertion: All 3 heads insert at Proximal olecranon of ulna and fascia of forearm
Origin and insertion of Anconeus?
Origin = Lateral epicondyle of humerus
Insertion = Lateral surface of olecranon and superior part of posterior surface of ulna
What are the 4 boundaries of the Quadrangular or quadrilateral space?
teres minor (superior),
surgical neck of humerus (lateral),
teres major (inferior),
long head of triceps brachii (medial
What passes through the Quadrangular space?
passageway for axillary nerve and posterior circumflex humeral artery and vein between the axilla and the dorsal scapular region
Boundaries of Triangular Space? What passes through it?
Long head of triceps brachii, teres major, teres minor
Circumflex scapular artery and vein pass through this gap
Boundaries of Triangular Interval? What passes through it?
long head of triceps, humeral shaft, teres major
Passageway between anterior and posterior compartments of the arm, and between the posterior compartment of the arm and the axilla.
Radial nerve, profunda brachii artery and associated veins course through this interval
What is the arrangement of muscles in the forearm?
Separated into flexor and extensor compartments by lateral intermuscular septum, radius, ulna and interosseous membrane
What are the layers in the anterior flexor group of the forearm?
Superficial, Intermediate and Deep layer
What are the muscles in the superficial layer of anterior flexor of forearm?
From lateral to medial:
- Pronator teres
- Flexor carpi radialis (FCR)
- Palmaris longus
- Flexor carpi ulnaris (FCU)
What are the origins and insertions of the superficial layer of anterior flexor of forearm?
Origin: All 4 muscles originate as common flexor tendon from medial epicondyle of humerus
Only Pronator teres doesn’t cross wrist
Insertion:
- Pronator teres (insertion: mid-shaft of radius)
- Flexor carpi radialis (insertion: bases of 2nd and 3rd metacarpals)
- Palmaris longus (Insertion: palmar aponeurosis & flexor retinaculum)
- Flexor carpi ulnaris (pisiform & base of 5th metacarpal)
Function of the superficial layer of anterior flexor of forearm?
- Pronator teres = Pronate and flexes forearm
- Flexor carpi radialis (FCR) = Flexes and abducts hand at wrist
- Palmaris longus = Flexes hand at wrist and tenses palmar aponeurosis
- Flexor carpi ulnaris (FCU) = Flexes and adducts hand at wrist
Origin, Insertion and Function of the Intermediate layer of Anterior flexor of forearm?
- Flexor digitorum superficialis
Origin = Medial epicondyle
Insertion = Shafts of middle phalanges of medial 4 fingers (not thumb), tendon splits into two slips at either side of middle phalanges
Function = Flexes middle phalanges at PIP of middle 4 fingers + proximal phalanges at MCP joints
List the muscles and their function in the Deep layer of anterior flexor of forearm?
- Flexor pollicis longus (FPL) = Flexes distal phalanx of Thumb
- Flexor digitorum profundus (FDP) = flex DIP joint
- Pronator quadratus = Pronates forearm, deep fibers bind radius and ulna together
Origin and Insertion of muscles of Deep layer of anterior flexor of forearm?
- Flexor digitorum profundus: origin = medial and anterior surfaces of ulna and interosseous membrane; Insert = Bases of distal phalanges of digit 2-5
- Flexor pollicis longus : origin = Anterior surface of radius and interosseous membrane; Insert = Base of distal phalanx of thumb
- Pronator quadratus: Origin = distal anterior surface of ulna; Insertion = Distal quarter of anterior radius
List all the muscles in the superficial layer of posterior extensors of forearm?
B ECRL ECRB ECU ED EDM
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor carpi ulnaris
- Extensor digitorum
- Extensor digiti minimi
List the functions of all the muscles in the superficial layer of posterior extensors of forearm?
- Brachioradialis = accesory flexor of elbow/ forearm (even though it’s in the extensor compartment)
- Extensor carpi radialis longus = extend and abduct wrist
- Extensor carpi radialis brevis = extend and abduct wrist
- Extensor carpi ulnaris = extend and ADDUCT wrist
- Extensor digitorum = Extend digit 2 -5
- Extensor digiti minimi = Extend digit 5
Origin and Insertion of the 6 superficial muscles of extensor of forearm?
All share origin at lateral supracondylar ridge and lateral epicondyle of humerus
- Brachioradialis = distal radius close to styloid process
- Extensor carpi radialis longus = dorsal aspect of base of 2nd metacarpal
- Extensor carpi radialis brevis = dorsal aspect of base of 3rd metacarpal
- Extensor carpi ulnaris = dorsal aspect of base of 5th metacarpal
- Extensor digitorum = extensor expansions of digits II - V
- Extensor digiti minimi = extensor expansion of digit V
List the muscles in the deep layer extensors of forearm?
S APL EPB EPL EI
Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis
Describe the insertion of extensor digitorum?
Lateral bands insert at base of distal phalanx
Central band insert at base of Middle phalanx
So extension of finger = extends both distal and middle phalanx
List the insertions of muscles in the deep layer extensors of forearm?
Supinator = wraps around and insert on the upper 1/3 of radius
Abductor pollicis longus = base of 1st metacarpal
Extensor pollicis brevis = proximal phalanx of thumb
Extensor pollicis longus = distal phalanx of thumb
Extensor indicis = extensor expansion of digit II
Which muscle tendons form the boundaries of the anatomical snuff box?
Radial border:
Abductor pollicis longus (most lateral/ radial)
Extensor pollicis brevis
Ulnar border:
Extensor pollicis longus
What are the 4 categories of muscles in the hand/ intrinsic muscles of the hand?
Thenar muscles (thumb), Hypothenar muscles (little finger), Lumbricals, Interosseous muscles
List the Thenar and Hypothenar muscles?
Thenar:
- Abductor pollicis brevis
- Flexor pollicis brevis
- Opponens pollicis
- Adductor pollicis
Hypothenar:
- Abductor digiti minimi
- Flexor digiti minimi
- Opponens digiti minimi
- Palmaris brevis
Origin and insertions of the thenar and hypothenar muscles?
All originate from carpal bones of the hand
Thenar:
- Abductor pollicis brevis = base of prox. phalanx
- Flexor pollicis brevis = base of prox. phalanx
- Opponens pollicis = shaft of 1st metacarpal
- Adductor pollicis = base of prox. phalanx
Hypothenar:
- Abductor digiti minimi = base of prox. 5th metacarpal
- Flexor digiti minimi = base of prox. 5th metacarpal
- Opponens digiti minimi = medial border of 5th metacarpal
- Palmaris brevis = subcutaneous muscle, puckers skin over hypothenar eminence to deepen palm
Origin, insertion and function of lumbricals?
Lumbricals: (act on digits II-V): Arise from the tendons of the flexor digitorum profundus and insert on the extensor expansions of digit 2 - 5
Function: Flex MCP, extend Interphalangeal joints of digit 2 - 5
Describe the innervation of the Thenar muscles?
Median nerve: Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis
Ulnar nerve: Adductor pollicis
Function of Thenar muscles?
All move the thumb:
- Abductor pollicis brevis = Adbuct thumb
- Flexor pollicis brevis = Flex thumb
- Opponens pollicis = Oppose thumb, draws 1st metacarpal medially to center of palm
- Adductor pollicis = Adduct thumb to lateral border of palm
Function of Hypothenar muscles (except Palmaris brevis)?
All move digit V
- Abductor digiti minimi = Abduction and assist in flexion of proximal phalanx
- Flexor digiti minimi = Flex proximal phalanx
- Opponens digiti minimi = Draws 5th metacarpal into opposion with thumb
What are the interosseous muscles of the hand and innervation?
Ulnar nerve
Dorsal Interossei (abduct) Palmar interossei (adduct)
Origin, insertion and function of Dorsal interossei?
Origin = Adjacent sides of 2 metacarpals
Insertion = Bases of proximal phalanges, extensor expansions of digit 2-4
Function = ABDUCT digit 2-4 + act with lumbricals to flex MCP and extend interphalangeal joints
Origin, insertion and function of Palmar interossei?
Origin = Palmar surfaces of digit 2,4,5 metacarpals
Insertion = bases of proximal phalanges, extensor expansions of digit 2,4,5
Function = ADDUCT digit 2,4,5 towards axial line + ct with lumbricals to flex MCP and extend interphalangeal joints
