1. Naming Skeletal Muscles
Named according to a number of criteria:
Direction of muscle fibers relative to longitudinal axis of the muscle
Rectus: Fibers oriented straight with respect to longitudinal axis
Oblique: Fibers run at an angle to the longitudinal axis
Orbicularis: Fibers run in a circular path
Relative size
Major for bigger and minor for smaller;
Maximus for biggest, intermedius for middle and minimus for smallest
Longus for longest and brevis for shortest.
Location
Pectoralis major is found in the chest region
Rectus femoris is found near the femur
Location of the origin and insertion
Brachioradialis attaches to the humerus (origin) and the radius (insertion)
Number of origins
Biceps means two heads
Triceps means three heads
Shape
Deltoid means triangular in shape.
Trapezius is shaped like a trapezium or kite
Action
Flexor and extensor
Adductor and abductor

2. Skeletal Muscles Of Facial Expression

3. Skeletal Muscles Of Facial Expression
Frontalis: Lies over forehead; wrinkles forehead and raises eyebrows
Orbicularis oculi: Encircle eye; close eyes, squint, blink and wink
Zygomaticus: From cheek to corner of mouth; raises corners of mouth for smiling
Orbicularis oris: Present in lips; closes mouth and protrudes lips
Mentalis: In mental region; wrinkles chin, protrudes lower lip
Buccinator: Thin muscles, attach to orbicularis oris; compress cheek as in whistling and sucking

4. Skeletal Muscles Of Mastication
Masseter: Powerful muscle covering lateral aspect of mandibular ramus; elevates mandible during chewing
Temporalis: Covers parts of temporal, frontal and parietal bones; works with masseter to elevate mandible during chewing
Digastric: Two bellies united by an intermediate tendon, forming V shape under the chin; open mouth and depress mandible

5. Muscles That Act The Head And Neck
Sternocleidomastoid:
Extends from manubrium of sternum and clavicle to mastoid process of temporal; flexes and rotates the head laterally

6. Muscles Of Respiration
External intercostals: Lie between ribs; fibers run downwards and anteriorly; pull ribs towards one another to lift rib cage Internal intercostals: Lie between ribs; fibers run deep and at right angles to external intercostals (i.e. run downward and posteriorly); depress rib cage Diaphragm

7. Muscles Of Respiration
Diaphragm: Broad muscle, pierced by aorta, inferior vena cava and oesophagus; forms floor of thoracic cavity; fibers converge from margins of thoracic cage towards central tendon; prime muscle for inspiration

8. Muscles Of Abdominal Wall
Rectus abdominis: Medial superficial muscle pair extending from pubis to rib cage; segmented by 3 tendinous intersections; used in sit ups and curls
External oblique: Largest and most superficial of 3 lateral muscles; fibers run downward and medially; flex vertebral column and compress abdominal cavity
Internal oblique: Most fibers run upward and medially
Transverse abdominis: Deepest layer, fibers run horizontally; compress abdominal contents
Linea Alba: Tendinous raphe (seam) between right and left rectus abdominus

9. Muscles Of Anterior Thorax
Pectoralis major: Large fan-shaped muscle covering superior part of chest; major muscle for flexion, rotation and adduction of arm
Serratus anterior: Fan-shaped muscle, inferior to pectoral muscles on lateral rib cage; deep to scapula; origins have saw-tooth appearance; rotates scapula to inferior angle laterally and upwards

10. Trapezius Of Posterior Thorax
Kite-shaped flat muscle
Upper fibers run inferiorly to scapula
Middle fibers run horizontally to scapula
Lower fibers run superiorly to scapula
Major muscle for stabilizing, raising, retracting and rotating scapula

11. Muscles Of Posterior Thorax
Trapezius: Most superficial muscle of posterior thorax; stabilizes, raises, retracts and rotates scapula
Levator scapulae: Located at back and side of neck, deep to trapezius; elevates or adducts scapula
Rhomboids: Deep to trapezius, inferior to levator scapulae; the minor muscle is more superficial; stabilize scapula

12. Muscles Of The Arm Pectoralis major: Prime mover of arm flexion
Latissimus dorsi: Prime mover of arm extension
Deltoid: Thick, rounded shoulder mass, common site of intramuscular injection; prime mover of arm abduction
Biceps brachii: Two-headed fusiform muscle; stabilizes shoulder joint; flexes elbow joint and supinates forearm
Brachialis: Strong muscle, immediately deep to biceps brachii on humerus; major forearm flexer
Brachioradialis: Superficial muscle of lateral forearm, extends from distal humerus to distal forearm; forearm flexer
Triceps brachii: Large fleshy muscle of posterior compartment of arm, has 3 heads (long and lateral heads lie superficial to medial head); powerful forearm extensor

13. Latissimus dorsi
Broad, flat triangular muscle of lower back; covered by trapezius superiorly
Powerful mover of arm extension, adducts arm and medially rotates arm at shoulder

14. Rotator Cuff Muscles
Group of 4 muscles and their tendons in the shoulder
Muscles form a cuff around shoulder joint and attach at upper portion of arm
Supraspinatus: Deep to trapezius, superior to scacpular spine; stabilizes shoulder joint, prevents downward dislocation of humerus
Infraspinatus: Partially covered by deltoid and trapezius, inferior to scapular spine; rotates humerus laterally
Teres minor : small elongated muscle, inferior to infraspinatus muscle; rotates humerus laterally
Subscapularis: Forms part of posterior wall of axilla, tendon passes in front of shoulder joint; chief medial rotator of humerus

15. Muscles Of The Thigh, Leg, Foot And Ankle

16. Muscles Of The Thigh, Leg, Foot And Ankle

17. Muscles Of The Thigh, Leg, Foot And Ankle