1. GROSS ANATOMY OF THE MUSCULAR SYSTEM
Figure 6.21
Figure 6.22

2. Naming Skeletal Muscles (I)
1. By location of muscle
Ex: Temporalis (temporal bone),
Oris (mouth)
2. By number of origins
Ex: Triceps (three heads)
3. By direction of muscle fibers
Ex: Rectus (straight)
4. By relative size of muscle
Ex: Maximus (largest)

3. Naming Skeletal Muscles (II)
5. By location of muscle’s origin & insertion
Ex: Sterno (on sternum),
Cleido (clavicle)
6. By shape of muscle
Ex: Deltoid (triangular),
Trapezius (diamond)
7. By action of muscle
Ex: Flexor & extensor (flexes or extends bone)

4. I. Head & Neck Muscles
Figure 6.15

5. A. Facial Muscles Frontalis—raises eyebrows
Orbicularis oculi—closes eyes, squints, blinks, winks
Orbicularis oris—closes mouth & protrudes lips
Buccinator—flattens cheek, chews
Zygomaticus—raises corners of the mouth

6. B. Chewing Muscles Masseter—closes jaw & elevates mandible
Temporalis—closes jaw

7. C. Neck Muscles Platysma—pulls corners of mouth inferiorly
Sternocleidomastoid—flexes neck, rotates head

8. Know these!
Table 6.3 (1 of 3)

9. II. Muscles of Trunk, Shoulder, Arm
Figure 6.16a

10. A. Chest Muscles
Pectoralis major—adducts & flexes humerus

11. B. Abdominal Muscles Rectus abdominis—flexes vertebral column
External & internal obliques—flex vertebral column; rotate trunk and bend it laterally
Transversus abdominis—compresses abdomen

12. Table 6.3 (2 of 3)

13. C. Shoulder & Back Muscles
Trapezius—elevates, depresses, & adducts scapula
Latissimus dorsi—extends & adducts humerus
Deltoid—arm abduction
Figure 6.17a

14. Table 6.4 (1 of 3)

15. D. Arm Muscles Biceps brachii—supinates forearm, flexes elbow
Brachialis—elbow flexion
Triceps brachii—elbow extension
Figure 6.17a

16. Table 6.4 (2 of 3)

18. III. Muscles of Lower Limb

19. A. Muscles of the Pelvis (Hips)
Gluteus maximus—hip extension
Gluteus medius—hip abduction, steadies pelvis in walking
Iliopsoas—hip flexion, keeps the upper body from falling backward when standing erect

20. B. Muscles of the Thigh (Anterior)
Sartorius—flexes the thigh; “Tailor’s Muscle”
Quadriceps group—extends the knee
Rectus femoris
Vastus muscles – medialis, intermedius, lateralis

21. Table 6.3 (3 of 3)

22. C. Muscles of the Thigh (Posterior)
Hamstring group—thigh extension & knee flexion
Biceps femoris
Semimembranosus
Semitendinosus

23. D. Muscles of the Lower Leg
Tibialis anterior—dorsiflexion of foot
Gastrocnemius & Soleus—plantar flexion
Figure 6.20a
Figure 6.20b

24. Table 6.4 (3 of 3)

25. Intramuscular Injection Sites
Figure 6.18, 6.19b, d