Upper Body O, I, A, N Flashcards
1
Q
Trapezius Origin
A
Medial 1/3 of superior nuchal line; external occipital protuberance; nuchal ligament; spinous processes of C7-T12
2
Q
Trapezius Insertion
A
Lateral 1/3 of clavicle; acromion process; spine of scapula
3
Q
Trapezius Action
A
Descending part: elevates shoulder
Ascending part: depresses shoulder
Middle part or all: retracts scapula
Ascending & descending together: rotate glenoid superiorly
4
Q
Trapezius Innervation
A
Spinal accessory nerve (Cranial XI) and C3&C4 spinal nerves
5
Q
Latissimus Dorsi Origin
A
Spinous processes of T7-T12; thoracolumbar fascia; iliac crest; ribs 9-12
6
Q
Latissimus Dorsi Insertion
A
Floor of intertubercular sulcus of humerus
7
Q
Latissimus Dorsi Action
A
Extends, adducts, and medially rotates shoulder joint; raises body during climbing
8
Q
Latissimus Dorsi Innervation
A
Thoracodorsal nerve (C6, C7, C8)
9
Q
Rhomboid Major Origin
A
Spinous processes of T2-T5
10
Q
Rhomboid Major Insertion
A
Medial border of scapula from spine to inferior angle
11
Q
Rhomboid Major Action
A
Retracts scapula; rotates to depress glenoid cavity; holds scapula to body wall
12
Q
Rhomboid Major Innervation
A
Dorsal scapular nerve (C4, C5)
13
Q
Rhomboid Minor Origin
A
Nuchal ligament; spinous processes of C7-T1
14
Q
Rhomboid Minor Insertion
A
Scapula at medial end of scapular spine
15
Q
Rhomboid Minor Action
A
Retracts scapula; rotates to depress glenoid cavity; holds scapula to body wall
16
Q
Rhomboid Minor Innervation
A
Dorsal scapular nerve (C4, C5)
17
Q
Levator Scapulae Origin
A
Posterior tubercles of transverse processes of C1-C4
18
Q
Levator Scapulae Insertion
A
Medial border of scapula from superior angle to spine
19
Q
Levator Scapulae Action
A
Dorsal scapular (C5) and cervical (C3,C4) spinal nerves
20
Q
Levator Scapulae Innervation
A
Elevates scapula; rotates glenoid inferiorly
21
Q
Erector Spinae: Origin
Iliocostalis
Longissimus
Spinalis
A
Broad tendon from posterior iliac crest, posterior sacrum, sacro-iliac ligaments, inferior lumbar and sacral spinous processes, and supraspinous ligament
22
Q
Erector Spinae: Inseriton
Iliocostalis
Longissimus
Spinalis
A
Iliocostalis: run superiorly to angles of ribs and transverse processes of cervical verts
Longissimus: run superiorly to ribs between tubercles and angles; to transverse processes on thoracic and cervical verts; and to mastoid process
Spinalis: run superiorly to spinous processes of upper thoracic and cervical verts
23
Q
Erector Spinae: Action
Iliocostalis
Longissimus
Spinalis
A
Extend head and vertebral column; laterally flex vertebral column
24
Q
Erector Spinae: Innervation
Iliocostalis
Longissimus
Spinalis
A
Dorsal (posterior) rami of spinal nerves
25
Splenius Capitis
Splenius Cervicis
Origin
Nuchal ligament and spinous processes of C7-T6
26
Splenius Capitis
Splenius Cervicis
Insertion
Capitis: superolaterally to mastoid process and lateral 1/3 of nuchal line
Cervicis: tubercles of transverse processes of C1-C4
27
Splenius Capitis
Splenius Cervicis
Action
Flex neck; rotate head; extend head and neck
28
Splenius Capitis
Splenius Cervicis
Innervation
Dorsal (posterior) rami of spinal nerves
29
Semispinalis Capitis Origin
Transverse processes of C7-T6; articular processes of C4-C6
30
Semispinalis Capitis Insertion
Occipital bone
31
Semispinalis Capitis Action
Extends head
32
Semispinalis Capitis Innervation
Dorsal (posterior) rami of spinal nerves
33
Serratus Posterior Superior Origin
Nuchal ligament; spinous processes of C7-T3
34
Serratus Posterior Superior Insertion
Ribs 2-4 on superior borders
35
Serratus Posterior Superior Action
Elevate ribs
36
Serratus Posterior Superior Innervation
2nd-5th intercostal nerves
37
Serratus Posterior Inferior Origin
Spinous processes of T11-L2
38
Serratus Posterior Inferior Insertion
Ribs 8-12 on inferior borders near their angles
39
Serratus Posterior Inferior Action
Depresses ribs
40
Serratus Posterior Inferior Innervation
9th-11th intercostal nerves, subcostal (T12) nerve
41
Semispinalis Origin
Transverse processes of C4-T10
42
Semispinalis Insertion
Occipital bone and spinous processes in upper thoracic and cervical regions 4-6 segments superior
43
Semispinalis Action
Extends head + thoracic and cervical regions of vertebral column; rotates column contralaterally
44
Semispinalis Innervation
Dorsal (posterior) rami of spinal nerves
45
Multifidus Origin
Posterior sacrum; PSIS of ilium; aponeurosis of erector spinae; sacro-iliac ligaments; mammillary processes of lumbar verts., transverse processes of thoracic verts., articular processes of C4-C7
46
Multifidus Insertion
Spinous processes of vertebrae 2-4 segments superior
47
Multifidus Action
Stabilizes vertebrae during movements of vertebral column; rotates column contralaterally
48
Multifidus Innervation
Dorsal (posterior) rami of spinal nerves
49
Rotatores Origin
Transverse processes of vertebrae
50
Rotatores Insertion
Junctions of lamina and either transverse processes or spinous processes 1 (brevis)-2 (longus) segments superior.
51
Rotatores Action
Stabilizes vertebrae during movements of vertebral column; rotates column contralaterally; may be organs of proprioceptions
52
Rotatores Innervation
Dorsal (posterior) rami of spinal nerves
53
Interspinales Origin
Superior surfaces of spinous processes of cervical and thoracic vertebrae
54
Interspinales Insertion
Inferior surfaces of spinous processes of vertebrae superior to vertebra of origin.
55
Interspinales Action
Extension and rotation of vertebral column
56
Interspinales Innervation
Dorsal (posterior) rami of spinal nerves
57
Intertransversarii Origin
Transverse processes of cervical and thoracic verts
58
Intertransversarii Insertion
Transverse processes of adjacent vertebrae
59
Intertransversarii Action
Dorsal (posterior) and ventral (anterior) rami of spinal nerves
60
Intertransversarii Innervation
Lateral flexion of vertebral column; stabilize vertebral column
61
Levatores Costarum Origin
Tips of transverse processes of C7 + T1-T11
62
Levatores Costarum Insertion
Pass inferolaterally and insert on rib between tubercle and angle
63
Levatores Costarum Action
Elevate ribs, assisting in respiration; lateral flexion of vertebral column
64
Levatores Costarum Innervation
Posterior rami of C8-T11 spinal nerves
65
External intercostal Origin
Inferior border of ribs
66
External intercostal Insertion
Superior border of ribs inferiorly
67
External intercostal Action
During forced inspiration – elevate ribs
68
External intercostal Innervation
Intercostal nerve
69
Internal intercostal Origin
Inferior border of ribs
70
Internal intercostal Insertion
Superior border of ribs inferiorly
71
Internal intercostal Action
During forced respiration – interosseus part depresses ribs, interchondral part elevates ribs
72
Internal intercostal Innervation
Intercostal nerve
73
Innermost intercostal Origin
Inferior border of ribs
74
Innermost intercostal Insertion
Superior border of ribs inferiorly
75
Innermost intercostal Action
During forced respiration – interosseus part depresses ribs, interchondral part elevates ribs
76
Innermost intercostal Innervation
Intercostal nerve
77
Transversus thoracis Origin
Posterior surface of inferior sternum
78
Transversus thoracis Insertion
Internal surface of costal cartilages 2-6
79
Transversus thoracis Action
Weakly depresses limbs
80
Transversus thoracis Innervation
Intercostal nerve
81
Subcostal Origin
Internal surface of lower ribs near their angles
82
Subcostal Insertion
Superior borders of 2nd or 3rd ribs below
83
Subcostal Action
Probably during forced respiration – interosseus part depresses ribs, interchondral part elevates ribs
84
Subcostal Innervation
Intercostal nerve
85
Pectoralis Major Origin
Clavicular head: anterior surface of medial half o clavicle
| Sternocostal head: anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle
86
Pectoralis Major Insertion
Lateral lip of intertubercular sulcus of humerus
87
Pectoralis Major Action
Adducts and medially rotates shoulder joint, draws scapula anteriorly and inferiorly
Clavicular head: flexes shoulder joint
Sternocostal head: extends shoulder joint from the flexed position
88
Pectoralis Major Innervation
Lateral and medial pectoral nerves, clavicular head (C5, C6), sternocostal head (C7, C8, T1)
89
Pectoralis Minor Origin
3rd-5th ribs near their costal cartilages
90
Pectoralis Minor Insertion
Medial border and superior surface of coracoid process of scapula
91
Pectoralis Minor Action
Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall; depresses shoulder
92
Pectoralis Minor Innervation
Medial pectoral nerve (C8, T1)
93
Subclavius Origin
Junction of 1st rib and its costal cartilage
94
Subclavius Insertion
Inferior surface of middle third of clavicle
95
Subclavius Action
Anchors and depresses clavicle
96
Subclavius Innervation
Subclavian nerve (C5, C6)
97
Serratus Anterior Origin
External surfaces of lateral parts of 1st-8th ribs
98
Serratus Anterior Insertion
Anterior surface of medial border of scapula
99
Serratus Anterior Action
Protracts scapula and holds against thoracic wall; rotates scapula
100
Serratus Anterior Innervation
Long thoracic nerve (C5, C6, C7)
101
Deltoid Origin
Lateral third of clavicle; acromion; spine of scapula
102
Deltoid Insertion
Deltoid tuberosity of humerus
103
Deltoid Action
Clavicular (anterior): flexes and medially rotates shoulder
Acromial (middle) or all together: abducts shoulder joint after first 15°
Spinal (posterior): extends and laterally rotates shoulder joint
104
Deltoid Innervation
Axillary nerve (C5, C6)
105
Supraspinatus Origin
Supraspinous fossa of scapula
106
Supraspinatus Inseriton
Superior facet of greater tubercle of humerus
107
Supraspinatus Action
Initiates (first 15°) and assists deltoid in abduction of shoulder joint; part of rotator cuff
108
Supraspinatus Innervation
Suprascapular nerve (C4, C5, C6)
109
Infraspinatus Origin
Infraspinous fossa of scapula
110
Infraspinatus Insertion
Middle facet of greater tubercle of humerus
111
Infraspinatus Action
Laterally rotates shoulder joint; part of rotator cuff
112
Infraspinatus Innervation
Suprascapular nerve (C4, C5, C6)
113
Teres Major Origin
Middle part of lateral border of scapula
114
Teres Major Insertion
Inferior facet of greater tubercle of humerus
115
Teres Major Action
Laterally rotates shoulder joint; part of rotator cuff
116
Teres Major Innervation
Axillary nerve (C5, C6)
117
Teres Minor Origin
upper two-thirds of the lateral border of scapula
118
Teres Minor Insertion
Medial lip of intertubercular sulcus of humerus
119
Teres Minor Action
Adducts and medially rotates shoulder joint
120
Teres Minor Innervation
Lower subscapular nerve (C5, C6)
121
Subscapularis Origin
Subscapular fossa
122
Subscapularis Insertion
Lesser tubercle of humerus
123
Subscapularis Action
Medially rotates and adducts shoulder joint; part of rotator cuff
124
Subscapularis Innervation
Upper and lower subscapular nerves (C5, C6, C7)
125
Biceps brachii Origin
Short head: tip of coracoid process of scapula
| Long head: supraglenoid tubercle of scapula
126
Biceps brachii Insertion
Tuberosity of radius and fascia of forearm via bicipital aponeurosis
127
Biceps brachii Action
Supinates forearm and, when it is supinated, flexes elbow joint. Flexes shoulder joint. Short head resists shoulder dislocation.
128
Biceps brachii Innervation
Musculocutaneous nerve (C5, C6)
129
Brachialis Origin
Distal half of anterior surface of humerus
130
Brachialis Insertion
Coronoid process and tuberosity of ulna
131
Brachialis Action
Flexes elbow joint
132
Brachialis Innervation
Musculocutaneous nerve (C5, C6)
133
Coracobrachialis Origin
Tip of coracoid process of scapula
134
Coracobrachialis Insertion
Middle third of medial surface of humerus
135
Coracobrachialis Action
Flexes and adducts shoulder joint; resists shoulder dislocation
136
Coracobrachialis Innervation
Musculocutaneous nerve (C5, C6)
137
Triceps brachii Origin
Long head: infraglenoid tubercle of scapula
Lateral head: posterior surface of humerus superior to radial groove
Medial head: posterior surface of humerus inferior to radial groove
138
Triceps brachii Insertion
Proximal end of olecranon of ulna and fascia of forearm
139
Triceps brachii Action
Chief extensor of elbow joint
| Long head: extends shoulder joint and resists dislocation of humerus (esp during abduction)
140
Triceps brachii Innervation
Radial nerve (C6, C7, C8)
141
Anconeus Origin
Lateral epicondyle of humerus
142
Anconeus Insertion
Lateral surface of olecranon and superior part of posterior surface of ulna
143
Anconeus Action
Assists triceps in extending elbow joint; stabilizes elbow joint; abducts ulna during pronation
144
Anconeus Innervation
Radial nerve (C7, C8, T1)
145
Pronator Teres (PT) Origin
Ulnar head: coronoid process of ulna
| Humeral head: medial epicondyle of humerus
146
Pronator Teres (PT) Insertion
Middle of convexity of lateral surface of radius
147
Pronator Teres (PT) Action
Pronates and flexes forearm
148
Pronator Teres (PT) Innervation
Median nerve (C6, C7)
149
Flexor carpi radialis (FCR) Origin
Medial epicondyle of humerus
150
Flexor carpi radialis (FCR) Insertion
Base of 2nd (3rd) metacarpal
151
Flexor carpi radialis (FCR) Action
Flexes and abducts hand at wrist
152
Flexor carpi radialis (FCR) Innervation
Median nerve (C6, C7)
153
Palmaris longus Origin
Medial epicondyle of humerus
154
Palmaris longus Insertion
Distal half of flexor retinaculum, palmar aponeurosis
155
Palmaris longus Action
Flexes hand at wrist and tenses palmar aponeurosis
156
Palmaris longus Innervation
Median nerve (C7, C8)
157
Flexor carpi ulnaris
Humeral head and ulnar head
Origin
Ulnar head: Olecranon and posterior border of ulna (via aponeurosis)
Humeral head: medial epicondyle of humerus
158
Flexor carpi ulnaris
Humeral head and ulnar head
Insertion
Pisiform, hook of hamate, 5th metacarpal
159
Flexor carpi ulnaris
Humeral head and ulnar head
Action
Flexes and adducts hand at wrist
160
Flexor carpi ulnaris
Humeral head and ulnar head
Innervation
Ulnar nerve (C7, C8)
161
Flexor digitorum superficialis (FDS) Origin
Humero-ulnar head: medial epicondyle of humerus and coronoid process of ulna
Radial head: oblique line of radius
162
Flexor digitorum superficialis (FDS) Insertion
Shafts (bodies) of middle phalanges of medial four digits
163
Flexor digitorum superficialis (FDS) Action
Flexes wrist joint
Flexes proximal interphalangeal joins of middle four digits; also flexes proximal phalanges at metacarpophalangeal joints
164
Flexor digitorum superficialis (FDS) Innervation
Median nerve (C7, C8, T1)
165
Flexor digitorum profundus (FDP) Origin
Proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane
166
Flexor digitorum profundus (FDP) Insertion
Bases of distal phalanges of medial four digits
167
Flexor digitorum profundus (FDP) Action
Flexes wrist joint
| Flexes distal interphalangeal joints of medial four digits; assists with writs flexion
168
Flexor digitorum profundus (FDP) Innervation
```
Lateral part (digits 2-3): Median nerve (C8, T1) (anterior interosseous branch)
Medial part (digits 4-5): Ulnar nerve (C8, T1)
```
169
Flexor pollicis longus (FPL) Origin
Anterior surface of radius and adjacent interosseous membrane
170
Flexor pollicis longus (FPL) Insertion
Base of distal phalanx of thumb
171
Flexor pollicis longus (FPL) Action
Flexes wrist
| Flexes metacarpophalangeal and interphalangeal joints of the thumb
172
Flexor pollicis longus (FPL) Innervation
Anterior interosseous nerve from Median nerve (C8, T1)
173
Pronator Quadratus Origin
Distal quarter of anterior surface of ulna
174
Pronator Quadratus Insertion
Distal quarter of anterior surface of radius
175
Pronator Quadratus Action
Pronates forearm. Deep fibers bind radius and ulna together.
176
Pronator Quadratus Innervation
Anterior interosseous nerve from Median nerve (C8, T1)
177
Brachioradialis Origin
Proximal 2/3 of lateral supraepicondylar ridge of humerus
178
Brachioradialis Insertion
Lateral surface of distal end of radius proximal to styloid process
179
Brachioradialis Action
Relatively weak flexion of elbow joint, maximal when forearm is in midpronated position
180
Brachioradialis Innervation
Radial nerve (C5, C6, C7)
181
Extensor carpi radialis longus Origin
Lateral supra-epicondylar ridge of humerus
182
Extensor carpi radialis longus Insertion
Dorsal aspect of base of 2nd metacarpal
183
Extensor carpi radialis longus Action
Extend and abduct wrist joint
184
Extensor carpi radialis longus Innervation
Radial nerve (C6, C7)
185
Extensor carpi radialis brevis Origin
Lateral epicondyle of humerus
186
Extensor carpi radialis brevis Insertion
Dorsal aspect of base of 3rd metacarpal
187
Extensor carpi radialis brevis Action
Extend and abduct wrist joint; active during fist clenching.
188
Extensor carpi radialis brevis Innervation
Deep branch of radial nerve (C7, C8)
189
Extensor digitorum Origin
Lateral epicondyle of humerus
190
Extensor digitorum Insertion
Extensor expansions of medial four fingers
191
Extensor digitorum Action
Extend wrist joint.
| Extend medial four fingers primarily at metacarpophalangeal joints, secondarily at interphalangeal joints.
192
Extensor digitorum Innervation
Posterior interosseous nerve (C7, C8); continuation of deep branch of radial nerve
193
Extensor digiti minimi Origin
Lateral epicondyle of humerus
194
Extensor digiti minimi Insertion
Extensor expansion of 5th finger
195
Extensor digiti minimi Action
Extends wrist joint.
| Extends 5th finger primarily at metacarpophalangeal joint, secondarily at interphalangeal joint
196
Extensor digiti minimi Innervation
Posterior interosseous nerve (C7, C8); continuation of deep branch of radial nerve
197
Extensor carpi ulnaris Origin
Lateral epicondyle of humerus; posterior border of ulna via a shared aponeurosis
198
Extensor carpi ulnaris Insertion
Dorsal aspect of base of 5th metacarpal
199
Extensor carpi ulnaris Action
Extends and adducts wrist joint; active during fist clenching
200
Extensor carpi ulnaris Innervation
Posterior interosseous nerve (C7, C8); continuation of deep branch of radial nerve
201
Supinator Origin
Lateral epicondyle of humerus; radial collateral and anular ligaments; supinator fossa; crest of ulna
202
Supinator Insertion
Lateral, posterior, and anterior surfaces of proximal third of radius
203
Supinator Action
Supinates forearm; rotates radius to turn palm anteriorly or superiorly (if elbow is flexed)
204
Supinator Innervation
Deep branch of radial nerve (C7, C8)
205
Abductor pollicis longus Origin
Posterior surface of proximal halves of ulna, radius, and interosseous membrane
206
Abductor pollicis longus Insertion
Base of 1st metacarpal
207
Abductor pollicis longus Action
Extends wrist joint
| Abducts thumb and extends it at carpometacarpal joint
208
Abductor pollicis longus Innervation
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
209
Extensor pollicis longus Origin
Posterior surface of middle third of ulna and interosseous membrane
210
Extensor pollicis longus Insertion
Dorsal aspect of base of distal phalanx of thumb
211
Extensor pollicis longus Action
Extends wrist joint
| Extends distal phalanx of thumb at interphalangeal joint, extends metacarpophalangeal and
212
Extensor pollicis longus Innervation
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
213
Extensor pollicis brevis Origin
Posterior surface of distal third of radius and interosseous membrane
214
Extensor pollicis brevis Insertion
Dorsal aspect of base of proximal phalanx of thumb
215
Extensor pollicis brevis Action
Extends wrist joint
| Extends proximal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal joint
216
Extensor pollicis brevis Innervation
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
217
Extensor Indicis Origin
Posterior surface of distal 1/3 of ulna and interosseous membrane
218
Extensor Indicis Insertion
Extensor expansion of 2nd finger
219
Extensor Indicis Action
Extends wrist joint
| Extends 2nd finger (enabling its independent extension); helps extend hand at wrist.
220
Extensor Indicis Innervation
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
221
Opponens pollicis Origin
Flexor retinaculum and tubercles of scaphoid and trapezium
222
Opponens pollicis Insertion
Lateral side of 1st metacarpal
223
Opponens pollicis Action
To oppose thumb, it draws 1st metacarpal medially to center of palm and rotates it medially
224
Opponens pollicis Innervation
Recurrent branch of median nerve (C8, T1)
225
Abductor pollicis brevis Origin
Flexor retinaculum and tubercles of scaphoid and trapezium
226
Abductor pollicis brevis Insertion
Lateral side of base of proximal phalanx of thumb
227
Abductor pollicis brevis Action
Abducts thumb, helps oppose it
228
Abductor pollicis brevis Innervation
Recurrent branch of median nerve (C8, T1)
229
Flexor pollicis brevis:
superficial head, deep head
Origin
Flexor retinaculum and tubercles of scaphoid and trapezium
230
Flexor pollicis brevis:
superficial head, deep head
Insertion
Lateral side of base of proximal phalanx of thumb
231
Flexor pollicis brevis:
superficial head, deep head
Action
Flexes thumb
232
Flexor pollicis brevis:
superficial head, deep head
Innervation
Superficial head: Recurrent branch of median nerve (C8, T1)
| Deep head: Deep branch of ulnar nerve (C8, T1)
233
Adductor pollicis:
oblique head, transverse head
Origin
Bases of 2nd and 3rd metacarpals, capitate, adjacent carpals.
Anterior surface of shaft of 3rd metacarpal.
234
Adductor pollicis:
oblique head, transverse head
Insertion
Medial head side of base of proximal phalanx of thumb
235
Adductor pollicis:
oblique head, transverse head
Action
Adducts thumb toward lateral border of palm
236
Adductor pollicis:
oblique head, transverse head
Innervation
Deep branch of ulnar nerve (C8, T1)
237
Abductor digiti minimi Origin
Pisiform
238
Abductor digiti minimi Inseriton
Medial side of base of proximal phalanx of 5th finger
239
Abductor digiti minimi Action
Abducts 5th finger, assists in flexion of its proximal phalanx
240
Abductor digiti minimi Innervation
Deep branch of ulnar nerve (C8, T1)
241
Flexor digiti minimi Origin
Hook of hamate and flexor retinaculum
242
Flexor digiti minimi Insertion
Medial side of base of proximal phalanx of 5th finger
243
Flexor digiti minimi Action
Flexes proximal phalanx of 5th finger
244
Flexor digiti minimi Innervation
Deep branch of ulnar nerve (C8, T1)
245
Opponens digiti minimi Origin
Hook of hamate and flexor retinaculum
246
Opponens digiti minimi Insertion
Medial border of 5th metacarpal
247
Opponens digiti minimi Action
Draws 5th metacarpal anterior and rotates it, bringing 5th finger into opposition with thumb
248
Opponens digiti minimi Innervation
Deep branch of ulnar nerve (C8, T1)
249
Lumbricals 1-2 Origin
Lateral two tendons of flexor digitorum profundus (as unipennate muscles)
250
Lumbricals 1-2 Insertion
Lateral sides of extensor expansions of 2nd – 5th fingers
251
Lumbricals 1-2 Action
Flex metacarpophalangeal joints, extend interphalangeal joints of 2nd - 5th fingers
252
Lumbricals 1-2 Innervation
Median nerve (C8, T1)
253
Lumbricals 3-4 Origin
Medial three tendons of flexor digitorum profundus (as bipennate muscles)
254
Lumbricals 3-4 Insertion
Lateral sides of extensor expansions of 2nd – 5th fingers
255
Lumbricals 3-4 Action
Flex metacarpophalangeal joints, extend interphalangeal joints of 2nd - 5th fingers
256
Lumbricals 3-4 Innervation
Deep branch of ulnar nerve (C8, T1)
257
Dorsal interossei 1-4 Origin
Adjacent sides of two metacarpals (as bipennate muscles)
258
Dorsal interossei 1-4 Insertion
Bases of proximal phalanges, extensor expansions of 2nd – 4th fingers
259
Dorsal interossei 1-4 Action
Abduct 2nd – 4th fingers from axial line, act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
260
Dorsal interossei 1-4 Innervaition
Deep branch of ulnar nerve (C8, T1)
261
Palmer interossei 1-4 Origin
Palmar surfaces of 2nd, 4th, and 5th metacarpals (as unipennate muscles)
262
Palmer interossei 1-4 Insertion
Bases of proximal phalanges, extensor expansions of 2nd , 4th , 5th fingers
263
Palmer interossei 1-4 Action
Adduct 2nd , 4th , 5th fingers toward axial line, assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
264
Palmer interossei 1-4 Innervation
Deep branch of ulnar nerve (C8, T1)
