Sample Chapter 10 from the Textbook (35559.0K) - McGraw-Hill

344 PART 2 Support and Movement
Table 10.17 Muscles of the Forearm Acting on the Wrist, Hand, and Fingers (see figures 10.25 and 10.26)
Muscle Origin Insertion Nerve Action
Anterior Forearm
Flexor carpi radialis
(kar′pī rā-dē-ā′lis)
Flexor carpi ulnaris
(kar′pī ŭl-nā′ris)
Flexor digitorum profundus
(dij′i-tōr′ŭm prō-fŭn′dŭs)
Flexor digitorum superficialis
(dij′i-tōr′ŭm soo′per-fish-ē-ā′lis)
Flexor pollicis longus
(pol′i-sis lon′gŭs)
Palmaris longus
(pawl-mār′is lon′gŭs)
Posterior Forearm
Abductor pollicis longus
(pol′i-sis lon′gŭs)
Extensor carpi radialis brevis
(kar′pī rā-dē-ā′lis brev′is)
Extensor carpi radialis longus
(kar′pī rā-dē-ā′lis lon′gus)
Extensor carpi ulnaris
(kar′pī ŭl-nā′ris)
Extensor digiti minimi
(dij′i-tī min′i-mī )
Extensor digitorum
(dij′i-tōr′ŭm)
Medial epicondyle of
humerus
Medial epicondyle of
humerus and ulna
Second and third metacarpal
bones
Pisiform, hamate, and fifth
metacarpal bones
Median
Ulnar
Ulna Distal phalanges of digits 2–5 Ulnar and
median
Medial epicondyle of
humerus, coronoid
process, and radius
Flexes and abducts wrist
Flexes and adducts wrist
Flexes fingers at metacarpophalangeal
joints and interphalangeal joints
and wrist
Middle phalanges of digits 2–5 Median Flexes fingers at interphalangeal joints
and wrist
Radius Distal phalanx of thumb Median Flexes thumb
Medial epicondyle
of humerus
Posterior ulna and
radius and interosseous
membrane
Lateral epicondyle
of humerus
Lateral supracondylar
ridge of humerus
Lateral epicondyle
of humerus and ulna
Lateral epicondyle
of humerus
Lateral epicondyle
of humerus
Palmar fascia Median Tenses palmar fascia; flexes wrist
Base of first metacarpal bone Radial Abducts and extends thumb;
abducts wrist
Base of third metacarpal bone Radial Extends and abducts wrist
Base of second metacarpal bone Radial Extends and abducts wrist
Base of fifth metacarpal bone Radial Extends and adducts wrist
Phalanges of digit 5 Radial Extends little finger and wrist
Extensor tendon expansion
over phalanges of digits 2–5
Extensor indicis (in′di-sis) Ulna Extensor tendon expansion
over digit 2
Extensor pollicis brevis
(pol′i-sis brev′is)
Extensor pollicis longus
(pol′i-sis lon′gŭs)
Radial
Radial
Extends fingers and wrist
Extends forefinger and wrist
Radius Proximal phalanx of thumb Radial Extends and abducts thumb;
abducts wrist
Ulna Distal phalanx of thumb Radial Extends thumb
Intrinsic Hand Muscles
The intrinsic hand muscles are entirely within the hand
(table 10.18; figure 10.27). Abduction of the fingers is accomplished
by the dorsal interossei (in′ter-os′e-ī) and the abductor digiti
minimi, whereas adduction is a function of the palmar interossei.
The flexor pollicis brevis, the abductor pollicis brevis, and
the opponens pollicis form a fleshy prominence at the base of the
thumb called the thenar (thē′nar) eminence (figure 10.27a). The
abductor digiti minimi, flexor digiti minimi brevis, and opponens
digiti minimi constitute the hypothenar eminence on the ulnar
side of the hand (figure 10.27c). The thenar and hypothenar muscles
are involved in controlling the thumb and little finger.
ASSESS YOUR PROGRESS
22. Name the seven muscles that attach the scapula to the thorax.
What muscles attach the arm to the thorax?
23. List the muscles forming the rotator cuff, and describe their function.
24. What muscles cause flexion and extension of the shoulder?
Adduction and abduction of the arm? What muscle abducts
the arm to 90 degrees? Above 90 degrees?
25. What muscles cause rotation of the arm?
26. List the muscles that cause flexion and extension of the elbow.
Where are these muscles located?
27. What muscles produce supination and pronation of the
forearm? Where are these muscles located?
28. Describe the muscle groups that cause flexion and extension
of the wrist.