copyright © 2010 pearson education, inc. muscles of the body part c adapted for h. biology ii...
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Copyright © 2010 Pearson Education, Inc.
Muscles of the Body Part C
• Adapted for H. Biology II 2014-2015
• Muscles of Upper Extremities and Shoulder
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Muscles Crossing the Shoulder Joint
• Nine muscles cross the shoulder joint to insert on and move the humerus
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Muscles Crossing the Shoulder Joint
• Some originate off the scapula; others originate off the axial skeleton
• Three are prime movers of the arm
• Pectoralis major
• Latissimus dorsi
• Deltoid
• Actions include flexion, extension, adduction, abduction, and rotation of humerus
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Muscles Crossing the Shoulder Joint
• Four muscles are rotator cuff muscles
• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis
• Reinforce the capsule of the shoulder
• Act as synergists and fixators
• Two additional muscles are synergists: coracobrachialis and teres major
Copyright © 2010 Pearson Education, Inc. Figure 10.14a
Clavicle
Deltoid
Sternum
Pectoralis major
Lateral headLong headMedial head
CoracobrachialisTriceps brachii:
Biceps brachiiBrachialisBrachioradialis
(a) Anterior view
Copyright © 2010 Pearson Education, Inc. Figure 10.14b
Supraspinatus*Spine of scapula
(b) Posterior view
Deltoid (cut)Greater tubercleof humerusInfraspinatus*
Teres minor*
Teres major
Triceps brachii:
Latissimus dorsi
HumerusOlecranon processof ulna
Lateral head Long head
Anconeus
* Rotator cuff muscles
Copyright © 2010 Pearson Education, Inc. Figure 10.14a
Clavicle
Deltoid
Sternum
Pectoralis major
Lateral headLong headMedial head
CoracobrachialisTriceps brachii:
Biceps brachiiBrachialisBrachioradialis
(a) Anterior view
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Muscles Crossing the Elbow Joint
• Posterior extensor muscles
• Triceps brachii—prime mover of forearm extension
• Anconeus—weak synergist
Copyright © 2010 Pearson Education, Inc. Figure 10.14b
Supraspinatus*Spine of scapula
(b) Posterior view
Deltoid (cut)Greater tubercleof humerusInfraspinatus*
Teres minor*
Teres major
Triceps brachii:
Latissimus dorsi
HumerusOlecranon processof ulna
Lateral head Long head
Anconeus
* Rotator cuff muscles
Copyright © 2010 Pearson Education, Inc. Figure 10.17a
Tricepsbrachii
Lateralhead
Humerus
LongheadMedialhead
(a)
Brachialis
Short headLong head
(a) Muscles of the arm
Extensors
Flexors
Others
Posteriorcompartment
of arm (extendselbow); innervation:
radial nerve
Biceps brachii
Anterior compartment of arm (flexes elbow); innervation:musculocutaneous nerve
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Muscles of the Forearm
• Actions: movements of the wrist, hand, and fingers
• Most anterior muscles are flexors and insert via the flexor retinaculum
• Most posterior muscles are extensors and insert via the extensor retinaculum
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Muscles of the Forearm
• Some forearm muscles act to produce pronation and supination of the forearm
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Muscles of the Forearm
• Pronators: pronator teres and pronator quadratus
• Supinator: a synergist with the biceps brachii
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Muscles of the Forearm: Anterior Compartment
• Flexors
• Flexor carpi radialis
• Palmaris longus
• Flexor carpi ulnaris
• Flexor digitorum muscles (superficialis and profundus)
• Flexor pollicis longus
Copyright © 2010 Pearson Education, Inc. Figure 10.15a
Biceps brachii
Tendon of biceps brachii
Pronator teres
Brachioradialis
Extensor carpi radialis longus
Flexor pollicis longus
Pronator quadratus
Flexor retinaculum
Medial head oftriceps brachii
Medial epicondyleof humerus
Flexor carpi radialis
Palmar aponeurosis
Superficial transverseligament of palm
Palmaris longus
Flexor carpi ulnaris
Flexor digitorumsuperficialis
(a)
Copyright © 2010 Pearson Education, Inc. Figure 10.15c
Supinator
Tendon of flexorcarpi ulnaris (cut)
Tendon of flexordigitorum profundus
Flexor pollicis longus
Thenar muscles of thumb
Tendon of flexorpollicis longus
Lumbricals
Tendon of flexor digitorumsuperficialis (cut)
Pronator quadratus
Flexor digitorumprofundus
(c)
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Muscles of the Forearm: Posterior Compartment
• Extensors
• Extensor carpi radialis longus and brevis
• Extensor digitorum
• Extensor carpi ulnaris
• Extensor pollicis brevis and longus
• Extensor indicis
• Abductor pollicis longus
Copyright © 2010 Pearson Education, Inc. Figure 10.16a
Insertion oftriceps brachii
Anconeus
Flexor carpiulnaris
Extensor carpiulnaris
Extensor digitiminimi
Extensor indicis
Tendons of extensor carpiradialis brevis and longus
Extensorexpansion
(a)
Extensor pollicislongusExtensor pollicisbrevisAbductorpollicis longusExtensor digitorum
Extensor carpiradialis brevis
Extensor carpiradialis longus
Brachioradialis
Tendons ofextensordigitorum
Copyright © 2010 Pearson Education, Inc. Figure 10.16b
Olecranon process of ulna
Interossei
Anconeus
Supinator
Abductor pollicis longus
Extensor pollicis longus
Extensor pollicis brevis
Extensor indicis
(b)
Copyright © 2010 Pearson Education, Inc. Figure 10.17b
Extensors
Flexors
Others
(b)
Flexors
Extensors
Ulna
Posterior compartment of forearm(extends wrist and fingers);innervation: radial nerve
Others
Radius
Pronatorteres Brachioradialis(elbow flexor)
Abductorpollicis longus
(b) Muscles of the forearm
Anterior compartment of forearm (flexes wrist and fingers); innervation: median or ulnar nerve
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Intrinsic Muscles of the Hand
• Small weak muscles
• Lie entirely within the palm of the hand
• Control precise movements of metacarpals and fingers (e.g., threading a needle)
• Abductors and adductors of the fingers
• Produce opposition—move the thumb toward the little finger
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Finger and Thumb Movements
• Flexion
• Thumb—bends medially along the palm
• Fingers—bend anteriorly
• Extension
• Thumb—points laterally
• Fingers—move posteriorly
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Intrinsic Muscles of the Hand
• Three groups
• Thenar eminence (ball of the thumb)
• Hypothenar eminence (ball of the little finger)
• Each of the above groups has a flexor, an abductor, and an opponens muscle
• Midpalmar muscles: lumbricals and palmar and dorsal interossei extend the fingers
• Interossei muscles also abduct and adduct the fingers
Copyright © 2010 Pearson Education, Inc. Figure 10.18a
Flexor digitorumprofundus
Tendons of:
Flexor digitorumsuperficialis
Thirdlumbrical
Fourthlumbrical
Opponensdigiti minimi
Flexor digitiminimi brevis
Abductordigiti minimi
Pisiform bone
Flexor carpiulnaris tendon
Flexor digitorumsuperficialistendons Flexor pollicis longus
Flexor carpi radialisPalmaris longus
Flexor retinaculum
Abductor pollicislongus
Opponens pollicis
Abductor pollicisbrevis
Flexor pollicisbrevis
Adductor pollicis
Dorsal interossei
First lumbrical
Second lumbrical
Fibrous sheath
(a) First superficial layer
Tendons of:
Copyright © 2010 Pearson Education, Inc. Figure 10.18b
Flexor digitorumprofundus tendon
Flexor digitorumsuperficialis tendon
Palmar interossei
Opponens digitiminimi
Flexor digiti minimibrevis (cut)
Abductor digiti minimi(cut)
Flexor pollicis longustendon
Opponens pollicis
Abductor pollicisbrevis
Flexor pollicisbrevis
Adductor pollicis
Dorsal interossei
(b) Second layer
Copyright © 2010 Pearson Education, Inc. Figure 10.18c
Palmar interossei
(c) Palmar interossei (isolated)