180 likes | 441 Views
CHAPTER 6. The Muscular System Skeletal Muscles of the Head, Neck, Trunk, Arm and Leg. STUDY GUIDE FOR TEST ON FRIDAY FEB. 10, 2012. Head and Neck Muscles. Facial M uscles Frontalis —raises eyebrows Orbicularis oculi —closes eyes, squints,
E N D
CHAPTER 6 The Muscular System Skeletal Muscles of the Head, Neck, Trunk, Arm and Leg STUDY GUIDE FOR TEST ON FRIDAY FEB. 10, 2012
Head and Neck Muscles Facial Muscles Frontalis—raises eyebrows Orbicularisoculi—closes eyes, squints, Orbicularisoris—closes mouth and protrudes the lips Buccinator—flattens the cheek, chews Zygomaticus—raises corners of the mouth – smile Occipitalis – stabilize the frontalis Chewing Muscles Masseter —closes the jaw and elevates mandible Temporalis —synergist , of the masseter, closes jaw Neck muscles Platysma —pulls the corners of the mouth inferiorly, lower jaw Sternocleidomastoid —flexes the neck, rotates the head, turn ear to chest
Cranial aponeurosis Frontalis Temporalis Orbicularis oculi Occipitalis Zygomaticus Buccinator Masseter Orbicularis oris Sternocleidomastoid Trapezius Platysma Figure 6.16
Muscles of Trunk, Shoulder, Arm Anterior muscles of the chest Pectoralis major—adducts and flexes the humerus Intercostal muscles – Aid in breathing – not shown in picture – muscle in between the ribs Muscles of the abdominal girdle Rectus abdominis—flexes vertebral column External oblique—flex vertebral column; rotate trunk and bend it laterally
Deltoid Pectoralismajor Bicepsbrachii Brachialis Brachio-radialis (a) Figure 6.17a
Pectoralismajor Serratus Anterior Rectusabdominis Linea Alba Externaloblique (b) Figure 6.17b
Muscles of Trunk, Shoulder, Arm Posterior muscles of the back Trapezius—elevates, depresses, adducts, and stabilizes the scapula Latissimusdorsi—extends and adducts the humerus Erector spinae—back extension – not seen in picture Serratus Anterior – rotates scapula
Trapezius Deltoid Triceps brachii Latissimus dorsi (a) Figure 6.18a
Muscles of the Arm Biceps brachii- flexes elbow Brachialis—elbow flexion Brachioradialis—elbow flexion Triceps brachii—elbow extension Deltoid – abducts the arm
Deltoid Pectoralismajor Bicepsbrachii Brachialis Brachio-radialis (a) Figure 6.17a
Muscles of the Posterior Lower Limb Muscles causing movement at the hip joint include: Gluteus maximus—hip extension Gluteus medius—hip abduction, steadies pelvis when walking Muscles causing movement at the knee joint Hamstring group—thigh extension and knee flexion Biceps femoris Semimembranosus Semitendinosus
Gluteus medius Gluteus maximus Iliotibialtract (IT Band) Biceps femoris Hamstring group Semitendinosus Semimembranosus Gastrocnemius (a) Figure 6.20a
Muscles of the Anterior Lower Limb Muscles causing movement at the knee joint Sartorius—flexes the thigh Quadriceps group—extends the knee Rectus femoris VastusLateralis VastusMedialis VastusIntermedius (internal – not seen) Gracilis – adducts the thigh
Sartorius Rectus femoris Gracilis Vastus lateralis Quadriceps Vastus medialis (c) Figure 6.20c
Muscles of the Lower Limb ANTERIOR Tibialis anterior—dorsiflexion Soleus—plantar flexion POSTERIOR Gastrocnemius – plantar flexion
Gastrocnemius Tibialis anterior Soleus Soleus Calcaneal (Achilles)tendon anterior posterior
Facial • Frontalis Facial • Orbicularis oculi • Temporalis • Zygomaticus • Masseter • Orbicularis oris Neck Shoulder • Platysma • Trapezius • Sternocleidomastoid Thorax • Deltoid • Pectoralis major Arm • Serratus anterior • Triceps brachii • Biceps brachii • Intercostals • Brachialis Abdomen • Rectus abdominis Forearm • External oblique • Brachioradialis Pelvis/thigh Thigh • Sartorius Thigh (Quadriceps) • Gracilis • Rectus femoris • Vastus lateralis • Vastus medialis • Gastrocnemius • Tibialis anterior • Soleus Figure 6.22
Neck • Occipitalis • Sternocleidomastoid • Trapezius Shoulder/Back • Deltoid Arm • Triceps brachii • Brachialis • Latissimus dorsi Forearm • Brachioradialis Hip • Gluteus medius • Gluteus maximus lliotibial tract • Hamstrings: Biceps femoris Semitendinosus Semimembranosus Leg • Gastrocnemius • Soleus Calcaneal(Achilles)tendon Figure 6.23