MSAK 1 - Muscles

Occipitalis

O: Lateral 2/3 of Highest/Supreme Nuchal Line & and mastoid process

I: Galea Aponeurotica

N: Facial (CN VII)

K: raises eyebrows, Scrunches scalp back

Frontalis

O: Galea Aponeurotica

I: Fascia & Skin superior to eye and nose

N: Facial (CN VII)

K: raises eyebrows, scrunches scalp forward

Temporalis

O: Temporal fossa

I: coronoid process & anterior ramus of mandible

N: trigeminal (CN V)

K: elevates and retracts mandible at temporomandibular joint

Masseter

O: Zygomatic arch

I: Angle and ramus of mandible

N: Trigeminal (CN V)

K: elevates and protracts mandible at temporomandibular joint

Zygomaticus Major

O: zygomatic bone

I: angle of mouth

N: facial VII

K: mouth corner up

Risorius

O: fascia over parotid gland superior to masseter

I: angle of mouth

N: facial VII

K: mouth angle lateral

Buccinator

O: Maxilla & mandible (outer surfaces of alveolar processes), TMJ OR fascia over parotid gland

I: Lips

N: facial VII

K: compression of cheeks against the teeth

Platysma

O: Subcutaneous fascia of superior chest

I: mandible & subcuntaneous fascia of lower face

N: Facial VII

K: moves skin of superior chest & neck, depresses and pulls lower lip laterally (side & down)

Sternocleidomastoid

O: manubrium of sternum & medial 1/3 of clavicle

I: mastoid process of temporal bone and lateral ½ spr nuchal line

N: spinal accessory nerve XI

K: lateral flexion of head (atlanto-occipital joint); lateral flexion of neck (spinal joints); contralateral rtn of head (atlanto-axial joint); contralateral rtn of neck (spinal joints); extension of head (atlanto-occipital jnt); extension of neck (spinal joints); flexion of lower neck (spinal joints); elevation of sternum and clavicle (forced inhalation)

Levator Scapulae

O: transverse processes of C1-4

I: Superior angle of scapula

N: cervical nerve and dorsal scapular nerve

K: elevates & medially rotates scapula; ipsilateral rotation of neck at spinal joints; extension of neck at spinal joints

Trapezius

O: upper: EOP, medial 1/3 of superior nuchal line, nuchal ligament and spinous process of C7; middle: spinous processes of T1-5; lower: spinous processes of T6-12

I: upper: lateral 1/3 clavicle, acromion; middle: acromion, spine of scapula; lower: tubercle at root of spine of scapula

N: spinal accessory XI

K: upper: elevate scapula, upward rotation of scapula, lateral flexion of head/neck, extension of neck; mid: retraction of scapula; lower: depression of scapula, upward rotation of scapula

Rhomboid

O: minor: C7-T1, major: T2-T5

I: medial border of scapula

N: dorsal scapular nerve

K: scapular retraction, elevation (weak), downward rotation (weak)

Deltoid

O: lateral 1/3 clavicle (anterior), acromion (lateral), spine of scapula (posterior)

I: Deltoid tuberosity of Humerus

N: Axillary nerve

K: abduction of Humerus (all fibres but esp medial); flexion and medial rotation (anterior); extension and lateral rotation (posterior)

Subclavius

O: rib 1, where it meets costocartilage

I: middle 1/3 of inferior surface of clavicle

N: depresses clavicle at sternoclavicular joint; elevates rib 1 at sternocostal & costospinal joints (forced inhalation); stabilises clavicle

K: subclavian nerve

Pectoralis Major

O: medial 1/3 clavicle, sternum, costal cartilage ribs 1-7

I: lateral lip of bicipital groove

N: Lateral and medial pectoral nerve

K: Flexion/Adduction/Horizontal adduction/medial rotation of arm at shoulder joint

Pectoralis Minor

O: Ribs 3-5, near costal cartilage joints

I: Coracoid process of scapula

N: Medial and lateral pectoral nerve

K: Depression, protraction, and medial rotation of scapula; elevation of ribs 3-5 if scapula is pinned (forced inhalation)

Serratus Anterior

O: ribs 1-9

I: anterior surface of medial border of scapula

N: Long thoracic nerve

K: protracts and medially rotates scapula at scapulocostal joint; protraction of scapula stabilises scapula against ribcage

Latissimus Dorsi

O: spinous processes of T7 to L5, posterior sacrum, posterior iliac crest

I: floor of bicipital groove of humerus

N: thoracodorsal nerve

K: medial rotation, adduction, extension of arm at shoulder joint; anteriorly tilts pelvis

Teres Major

O: Inferior 2/3 of lateral/axillary border of scapula

I: medial lip of bicipital groove

N: lower subscapularis nerve

K: medial rotation, adduction, extension of arm at shoulder joint

Superspinatus

O: supraspinous fossa

I: greater tubercle of humerus

N: suprascapular nerve

K: abduction of arm at shoulder joint (first 15 degrees)

Infraspinatus

O: infraspinous fossa

I: greater tubercle of humerus

N: suprascapular nerve

K: laterally rotate arm at shoulder joint

Teres Minor

O: superior 1/3 of lateral/axillary border of scapula

I: greater tubercle of humerus

N: axillary nerve

K: lateral rotation of arm at shoulder joint

Subscapularis

O: subscapular fossa

I: lesser tubercle of humerus

N: upper & lower subscapular nerve

K: medial rotation of arm at shoulder joint

Coracobrachialis

Triceps Brachii

Anconeus

Biceps Brachii

O: short head coracoid process; long head supraglenoid tubercle

I: radial tuberosity

N: musculocutaneous nerve

K: flexion of elbow; supination of forearm at elbow joint; flexion of arm at GH joint

Brachialis

O:

I:

N:

K:

Pronator Teres

Flexor Carpi Radialis

Palmaris Longus

Flexor Carpi Ulnaris

Palmaris Longus

Extensor Carpi Radialis Longus

Extensor Carpi Radialis Brevis

Extensor Digitorum

Extensor Digiti Minimi

Extensor Carpi Ulnaris

Supinator

Biceps Femoris

Semitendonosus

Semimembranosus

Rectus abdominus

External Obliques

Internal Obliques

Transverse Abdominus

Rectus Femoris