Anatomy Block 1 Muscles

Trapezius Origin

occipital protuberence and spinous processes of cervical and thoracic vertebrae

Trapezius Insertion

spine and acromion process of scapula

Trapezius Innervation

Accessory nerve (CN XI)

trapezius action

elevates, depresses, retracts scapula, stabilizes shoulder in the upper limb "shrugs"

trapezius blood supply

transverse cervical artery (thyrocervical trunk of subclavian artery)

latissimus dorsi origin

Thoracolumbar Aponeurosis

latissimus dorsi insertion

floor of intertubercular groove of humerus

latissimus dorsi innervation

thoracodorsal nerve

latissimus dorsi action

extends

latissimus dorsi blood supply

thoracodorsal artery

levator scapulae origin

transverse processes of C1-C4

levator scapulae insertion

superior angle of scapula

levator scapulae action

elevates scapula

levator scapulae innervation

dorsal scapular nerve

levator scapulae blood supply

dorsal scapular artery

rhomboideus major origin

spinous processes of T1-T4

rhomboideous minor origin

spinous processes of C6

rhomboideous major and minor insertion

medial border of scapula

Rhomboideous (major and minor) action

elevates and retracts the scapula; stabilizes and braces shoulder

Rhomboideous (major and minor) innervation

dorsal scapular nerve

Rhomboideous (major and minor) blood supply

dorsal scapular artery (deep branch of transverse cervical artery)

Splenious Capitis Origin

nuchal ligament

splenious capitis insertion

mastoid process; occipital

splenious capitis innervation

dorsal primary rami of spinal nerve

splenious capitis action

extends

splenious cervicis origin

spinous process T3-T6

splenious cervicis insertion

transverse process C1-C2

splenous cervicis action

extends and rotates cervical spine

splenious cervicis innervation

dorsal primary rami of spinal nerve (segmental)

what is the action if the splenius cervicis and splenius capitits act alone

laterally flex and rotate head to the same side

what is the action if the splenius cervicis and splenius capitis act together

extend the head and neck

erector spine action

chief extensor of spine. found on either side of the vertebral column

erector spine 3 muscles in group

illiocostalis

illiocostalis insertion

Posterior Ribs & Cervical Transverse Processes

Longissmius insertion

extends to transverse processes and ribs

spinalis insertion

spinous process to spinous process

erector spinae action unilaterally

flex spinal column

erector spinae action bilaterally

extend head and vertebral column

erector spinae innervation

innervated segmentally by dorsal primary rami

pectoralis major origin

medial 1/2 of clavicle

pectoralis major insertion

lateral lip of bicipital (interburcular) groove of humerus

pectoralis major action

adducts and rotates arm medially

pectoralis major innervation

lateral and medial pectoral nerve

pectoralis major blood supply

thoracoacromial artery, lateral thoracic artery

pectoralis minor origin

ribs 3-5

pectoralis minor insertion

coracoid process of scapula

pectoralis minor action

protracts scapula rotates glenoid inferiorly, elevates ribs

pectoralis minor innervation

medial pectoral nerve

pectoralis minor blood supply

thoracoacromial artery

serratus anterior origin

ribs 1-9

serratus anterior insertion

anterior and medial border of the scapula

serratus anterior action

protracts the scapulae in pushing and forward-reaching movements; rotates the inferior angle of the scapula laterally turning the glenoid cavity superiorly when arm is raised above the head

serratus anterior innervation

long thoracic nerve

serratus anterior blood supply

lateral thoracic artery

subscapularis origin

subscapular fossa

subscapularis insertion

lesser tubercle of humerus

subscapularis action

medial rotation of humers/shoulder

subscapularis innervation

upper and lower subscapular nerve

subscapularis blood supply

subscapular artery

supraspinatus origin

supraspinous fossa

suprasinatus insertion

greater tubercle

supraspinatus action

initiates abduction to 15 degrees

supraspinatus innervation

suprascapular nerve

supraspinatus blood supply

suprascapular artery

infraspinatus origin

infraspinous fossa

infraspinatus insertion

greater tubercle

infraspinatus action

lateral rotation

infraspinatus innervation

suprascapular nerve

infraspinatus blood supply

suprascapular artery

teres minor origin

lateral border of scapula

teres minor insertion

greater tubercle

teres minor action

lateral rotation

teres minor innervation

axillary nerve

teres minor blood supply

posterior circumflex humeral, scapular circumflex

teres major origin

inferior angle of scapula

teres major insertion

medial lip of intertubercular groove

teres major action

adducts and medially rotates humerus

teres major blood supply

subscapular and scapular circumflex artery

deltoideus origin

lateral third of clavicle

deltoideus insertion

deltoid tuberosity on humerus

deltoideus action

intermediate fibers abduct humerus to 90

deltoideus innervation

axillary nerve

deltoideus blood supply

anterior and posterior circumflex humeral arteries

biceps brachii origin

long head: supraglenoid tubercle short head: coracoid process

biceps brachii insertion

radial tuberosity and antebrachial fascia

biceps brachii action

flexes and supinates the forearm; long head also flexes and abducts humerus

biceps brachii innervation

musculocutaneous nerve

biceps brachii blood supply

brachial artery

coracobrachialis origin

coracoid process

coracobrachialis insertion

medial surface of the humeral shaft

coracobrachialis action

flexes arm; weakly adducts the arm when it is abducted

coracobrachialis innervation

musculocutaneous nerve

coracobrachialis blood supply

brachial artery

brachialis origin

distal shaft of anterior surface of the humerus

brachialis insertion

tuberosity of the ulna and anterior surface of the corocoid process

brachialis action

powerful flexor of the forearm

brachialis innervation

musculocutaneous nerve

brachialis blood supply

brachial artery

triceps brachii origin

long head: infraglenoid tubercle of scapula lateral head: humeral shaft

triceps brachii insertion

olecranon process