Skeletal Muscle Groups Ready or not, here we go!

A. Muscles of Facial Expression 1. Frontalis A: elevates eyebrows O: occipital bone I: skin of eyebrow 2. Occipitalis A: pulls scalp posterior O: mastoid process of occipital bone I: galea aponeurotica

3. Orbicularis oculi 4. Orbicularis oris A: closes eyelid O: frontal & maxillary bones I: skin around eyelid 4. Orbicularis oris A: closes lips Kissing, speaking O: facia surrounding lips I: corners of mouth

5. Zygomaticus Major/Minor A: Retracts & elevates corners of mouth smiling O: zygomatic bone I: corner of mouth/upper lip 6. Buccinator- “kissing muscle” A: compresses cheeks Sucking, whistling, blowing O: mandible & maxillary bones I: orbicularis oris

7. Depressor anguli oris A: Depresses corner of mouth O: Anterolateral surface of mandibular body I: Skin at corner of mouth

Muscles of Facial Expression

B. Muscles of Mastication 1. Masseter- strongest jaw muscle A: elevates the mandible Closes mouth O: zygomatic arch I: mandibular ramus 2. Temporalis A: elevates mandible O: temporal bone I: coronoid process of mandible

Muscles of Mastication

C. Muscles of the Neck 1. Platysma 2. Sternocleidomastoid A. Depresses mandible, tenses neck O: Upper thorax between cartilage of 2nd rib & acromion process I: Mandible & skin of cheek 2. Sternocleidomastoid A: flexes head, turns head side to side O: clavicle & manubrium I: mastoid process of temporal bone

3. Omohyoid 4. Sternohyoid A. Depresses hyoid & larynx O: Central tendon attaches to clavicle & 1st rib I: 2 bellies: Superior- hyoid bone Inferior- superior margin of scapula 4. Sternohyoid A: Depresses hyoid & larynx O: Clavicle & manubrium I: Hyoid bone

Muscles of the Neck

Quiz Tomorrow! Head & Neck Muscles

D. Muscles of the Pectoral Girdle 1. Trapezius A: extends head & elevates scapula Look up & shrugs shoulders O: occipital bone & thoracic & cervical vertebrae I: clavicle & scapula 2. Serratus Anterior A: Abduction, upward rotation, protracts shoulder O: Anterior & superior margins of ribs 1-9 I: Anterior surface of medial border of scapula

3. Rhomboid Major/Minor 4. Pectoralis Minor A: Adduction, downward rotation O: Major: Spinus processes of upper thoracic vertebra Minor: Spinus processes of cervical vertebrae I: Vertebral border of scapula 4. Pectoralis Minor A: elevates ribs (breathing) & depresses shoulders O: ribs 3-5 I: coracoid process of scapula

E. Muscles of the Shoulder & Upper Arms 1. Pectoralis Major A: adducts & flexes humerus, rotates arms medially O: clavicle, sternum, & costal cartilage I: greater tubercle of humerus 2. Deltoid A: abducts humerus O: clavicle & scapula I: deltoid tuberosity of humerus

(Rotator Cuff Muscles) 3. Supraspinatus A: Abduction, stabilization O: Supraspinous fossa of scapula I: Greater tubercle of humerus 4. Infraspinatus A: Adduction, outward rotation O: Infraspinous fossa of scapula

(Rotator Cuff Muscles) 5. Teres Minor A: Adduction, outward rotation O: Inferior angle of scapula I: Medial lip of intertubercular groove of humerus 6. Subscapularis A: Adduction, inward rotation O: Subscapular fossa of scapula I: Lesser tubercle of humerus

7. Teres Major 8. Latissimus Dorsi A: Adduct, inward rotation, extension O: Inferior angle of scapula I: Medial lip of intertubercular groove of humerus 8. Latissimus Dorsi A: extends, adducts, & rotates arms medially O: spines of T7-sacrum, iliac crest, & ribs 9-12 I: intertubercular groove of humerus

9. Biceps Brachii- “two heads” A: flexes arm @ elbow, supinates forearm O: scapula I: radial tuberosity 10. Triceps Brachii- “three heads” A: extends arm (antagonist to biceps brachii) O: scapula & humerus I: olecranon process of ulna

11. Coracobrachialis A: Adduction, flexion O: Coracoid process I: Medial margin of shaft of humerus

F. Muscles of the Forearm 1. Brachioradialis A: flexes arm @ elbow, supinates forearm O: lateral epicondyle of humerus I: styloid process of radius 2. Brachialis A: Flexion O: Anterior distal surface of the humerus I: Tuberosity of ulna

(mentioned previously) 3. Biceps Brachii A: Flexion, supination O: scapula I: radial tuberosity 4. Triceps Brachii A: extends arm O: scapula & humerus I: olecranon process of ulna

G. Muscles of the Hand & Wrist 1. Flexor Carpi Radialis A: Flexion & abducts wrist & hand O: Medial epicondyle of humerus I: Base of 2nd & 3rd metacarpals 2. Palmaris Longus A: Flexion of the wrist and hand I: Palmar aponerosis & flexor retinaculum

4. Extensor Carpi Radialis Longus 3. Flexor Carpi Ulnaris A: Flexion & adduction of wrist & hand O: Medial epicondlye of humerus, medial surface of olecranon, anteromedial part of ulna I: Pisiform & hamate bones & 5th metacarpal 4. Extensor Carpi Radialis Longus A: Extension & abduction of wrist & hand O: Lateral supracondylar ridge of humerus I: 2nd metacarpal

6. Extensor Carpi Ulnaris 5. Extensor Digitorum A: Extension of the fingers & hand O: Lateral epicondyle of humerus I: Posterior surfaces of phalanges 2-5 6. Extensor Carpi Ulnaris A: Extension & adduction of wrist & hand O: Lateral epicondyle of humerus, dorsal surface of ulna I: Base of 5th metacarpal

Flexors

Extensors

Shoulder, Arm, Forearm, Wrist & Hand Muscles Quiz Tomorrow Shoulder, Arm, Forearm, Wrist & Hand Muscles