Muscles of the Upper Extremity: Intrinsic Muscles of the Hand

Question 1

Abductor Pollicis Brevis Proximal Attachment

Answer 1

Flexor retinaculum and tubercle of the scaphoid and trapezium

Question 2

Abductor Pollicis Brevis Distal Attachment

Answer 2

Base of the proximal phalanx of thumb

Question 3

Abductor Pollicis Brevis Innervation

Answer 3

Median n. [*C8,T1]

Question 4

Abductor Pollicis Brevis Action

Answer 4

Abducts CMC & MCP joints of the thumb
Assists with:
-Thumb opposition

Question 5

Flexor Pollicis Brevis Proximal Attachment

Answer 5

Superficial head: Flexor retinaculum and trapezium bone

Deep head: Trapezoid and capitate bones

Question 6

Flexor Pollicis Brevis Distal Attachment

Answer 6

Base of the proximal phalanx of thumb

Question 7

Flexor Pollicis Brevis Innervation

Answer 7

Median n. (superficial head) [*C8,T1]

Ulnar n. (deep head) [C8,*T1]

Question 8

Flexor Pollicis Brevis Action

Answer 8

Flexes CMC & MCP joints of the thumb
Assists with:
-Thumb opposition

Question 9

Oppenens Pollicis Proximal Attachment

Answer 9

Flexor retinaculum and trapezium bone

Question 10

Opponens Pollicis Distal Attachment

Answer 10

Entire length of metacarpal I

Question 11

Opponens Pollicis Innervation

Answer 11

Median n. [*C8,T1]

Question 12

Opponens Pollicis Action

Answer 12

Opposes CMC joint of the thumb

Question 13

Adductor Pollicis Proximal Attachment

Answer 13

Oblique head: Capitate bone and bases of metacarpals II & III
Transverse hea: Metacarpal III

Question 14

Adductor Pollicis Distal Attachment

Answer 14

Base of the proximal phalanx of thumb

Question 15

Adductor Pollicis Innervation

Answer 15

Ulnar n. [C8,*T1]

Question 16

Adductor Pollicis Action

Answer 16

Adducts CMC & MCP joints of the thumb
Assists with:
-MCP joint flexion

Question 17

Abductor Digiti Minimi Proximal Attachment

Answer 17

Pisiform and the tendon of FCI

Question 18

Abductor Digiti Minimi

Answer 18

Base of the proximal phalanx of the little finger

Question 19

Abductor Digiti Minimi Innervation

Answer 19

Ulnar n. [C8,*T1]

Question 20

Abductor Digiti Minimi Action

Answer 20

Abducts MCP joint of the little finger
Flexes MCP joint of the little finger
Assist with:
-Little finger opposition

Question 21

Flexor Digiti Minimi Proximal Attachment

Answer 21

Hook of the hamate and flexor retinaculum

Question 22

Flexor Digiti Minimi Distal Attachment

Answer 22

Base of the proximal phalanx of the little finger

Question 23

Flexor Digiti Minimi Innervation

Answer 23

Ulnar n. [C8,*T1]

Question 24

Flexor Digiti Minimi Action

Answer 24

Abducts MCP joint of the little finger
Flexes MCP joint of the little finger
Assist with:
-Little finger opposition

Question 25

Opponens Digiti Minimi Proximal Attachment

Answer 25

Hook of the hamate and flexor retinaculum

Question 26

Opponens Digiti Minimi Distal Attachment

Answer 26

Entire length of metacarpal V

Question 27

Opponens Digiti Minimi Innervation

Answer 27

Ulnar n. [C8,*T1]

Question 28

Opponens Digiti Minimi Action

Answer 28

Opposes CMC joint of the little finger

Question 29

Lumbricals Proximal Attachment

Answer 29

I and II: FDP tendons of digits II and III | III and IV: FDP tendons of digits III, IV, and V

Question 30

Lumbricals Distal Attachment

Answer 30

Lateral side of the extensor hood of the respective digit

Question 31

Lumbricals Innervation

Answer 31

I and II: Median n. [C8,*T1] | III and IV: Ulnar n. [C8,*T1]

Question 32

Lumbricals Action

Answer 32

Flex MCP joints of digits 2-5 | Extend PIP & DIP joints of digits 2-5

Question 33

Dorsal Interossei Proximal Attachment

Answer 33

First: Adjacent sides of 1st and 2nd metacarpals Second: Adjacent sides of 2nd & 3rd metacarpals Third: Adjacent sides of 3rd and 4th metacarpals Fourth: Adjacent sides of 4th and 5th metacarpals

Question 34

Dorsal Interossei Distal Attachment

Answer 34

``` Into the extensor hoods of the proximal phalanges of their respective digits as follows: First: Lateral side of digit II SecondL Lateral side of digit III Third: Medial side of digit III Fourth: Medial side of digit IV ```

Question 35

Dorsal Interossei Innervation

Answer 35

Ulnar n. [C8,*T1]

Question 36

Dorsal Interossei Action

Answer 36

Abduct MCP joints of digits 2-4 Assists with: -Flexion of MCP joints of digits 2-4 -Extension of PIP & DIP joints of digits 2-4

Question 37

Palmar Interossei Proximal Attachment

Answer 37

First: Medial side of metacarpal II Second: Lateral side of metacarpal IV Third: Lateral side of metacarpal V

Question 38

Palmar Interossei Distal Attachment

Answer 38

Into the extensor hoods of the proximal phalanges of their respective digits as follows: First: Medial side of digit II Second: Lateral side of digit IV Third: Lateral side of digit V

Question 39

Palmar Interossei Innervation

Answer 39

Ulnar n. [C8,*T1]

Question 40

Palmar Interossei Action

Answer 40

Adduct MCP joints of digits 2, 4, & 5 Assists with: -Flexion of MCP joints of digits 2, 4, & 5 -Extension of PIP & DIP joints of digits 2, 4, & 5