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GROSS ANATOMY OF THE MUSCULAR SYSTEM
Figure 6.21
Figure 6.22
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Naming Skeletal Muscles (I)
3. By direction of muscle fibers
Ex: Rectus (straight)
4. By relative size of muscle
Ex: Maximus (largest)
1. By location of muscle
Ex: Temporalis (temporal bone),
Oris (mouth)
2. By number of origins
Ex: Triceps (three heads)
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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)
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I. Head & Neck Muscles
Figure 6.15
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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
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B. Chewing Muscles
Masseter—closes jaw & elevates mandible
Temporalis—closes jaw
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C. Neck Muscles
Platysma—pulls corners of mouth inferiorly
Sternocleidomastoid—flexes neck, rotates head
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Table 6.3 (1 of 3)
Knowthese!
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II. Muscles of Trunk, Shoulder, Arm
Figure 6.16a
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A. Chest Muscles
Pectoralis major—adducts & flexes humerus
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B. Abdominal Muscles
Rectus abdominis—flexes vertebral column
External & internal obliques—flex vertebral column;rotate trunk and bend it laterally
Transversus abdominis—compresses abdomen
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Table 6.3 (2 of 3)
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C. Shoulder & Back Muscles
Trapezius—elevates, depresses, & adducts scapula
Latissimus dorsi—extends & adducts humerus
Deltoid—arm abduction
Figure 6.17a
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Table 6.4 (1 of 3)
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D. Arm Muscles
Biceps brachii—supinates forearm, flexes elbow
Brachialis—elbow flexion
Triceps brachii—elbow extension
Figure 6.17a
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Table 6.4 (2 of 3)
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III. Muscles of Lower Limb
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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
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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
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Table 6.3 (3 of 3)
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C. Muscles of the Thigh (Posterior)
Hamstring group—thigh extension & knee flexion
Biceps femoris
Semimembranosus
Semitendinosus
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D. Muscles of the Lower Leg
Tibialis anterior—dorsiflexion of foot
Gastrocnemius & Soleus—plantar flexion
Figure 6.20a
Figure 6.20b
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Table 6.4 (3 of 3)
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Intramuscular Injection Sites
Figure 6.18, 6.19b, d
