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Anatomy Test 3 > The hand and wrist > Flashcards

Flashcards in The hand and wrist Deck (58)
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1

Number of carpal (wrist) bones

8

2

Number of metacarpal (hand) bones

5

3

Number of Phalanges

14 bones
5 digits

4

Joints of Wrist and Hand

Carpometacarpal Joints
Metacarpophalangeal Joints
Interphalangeal Joints
Radiocarpal Joint
Midcarpal Joint

5

Where does Flexion of the wrist occur?

40% at radiocarpal joint
60% at midcarpal joint

6

Where does Extension of the wrist occur?

33% at midcarpal joint
67% at radiocarpal joint

7

Where does Adduction/Abduction of the wrist occur?

Mostly occurs at midcarpal joint

8

Extensor Expansion

Moveable hood over the MP and IP joints of the fingers formed by the extensor tendons

9

Extensor Hood Mechanism

Enables the long extensor tendons to strongly extend the MP joint and allows extension of IP joints when MP joints are flexed by lumbricals, which also attach the the "hood" part of the extensor expansion

10

Muscle responsible for strong flexion of MP and IP joints ("Power Grip")

Flexor digitorum profundus

11

Dupuytren's Contracture

Progressive shortening and thickening of the palmar fascia that pulls the 4th and 5th digits into partial flexion.
Tends to be hereditary

12

Tensosynovitis

Infections in the digital synovial sheaths can cause inflammation of the tendon and synovial sheath. For the 5th digit, such an infection can spread into the carpal tunnel and into the forearm because the digital synovial sheath is continuous with the ulnar bursa.

13

Review long flexor tendons & synovial sheaths

Slide 23

14

Intrinsic Thenar Muscles (Thumb)

Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
Adductor pollicis (not part of eminence)

15

Thenar eminence muscles

Abductor pollicis brevis
Flexor pollicis brevis (superficial head and deep head)
Opponens pollicis

16

Heads of the Adductor pollicis

Oblique head and Transverse head

17

Proximal attachment of Opponens pollicis

Flexor retinaculum and tubercles of scaphoid and trapezium

18

Distal attachment of Opponens pollicis

Lateral side of 1st metacarpal

19

Actions of Opponens pollicis

Oppose thumb and medially rotate 1st metacarpal

20

Innervation of Opponens pollicis

Recurrent branch of median nerve

21

Proximal attachment of Abductor pollicis brevis

Flexor retinaculum and tubercles of scaphoid and trapezium

22

Distal attachment of Abductor pollicis brevis

Later side of base of proximal phalanx of thumb

23

Actions of Abductor pollicis brevis

Abduct thumb, aid in opposition

24

Innervation of Abductor pollicis brevis

Recurrent branch of median nerve

25

Proximal attachment of Flexor pollicis brevis

Flexor retinaculum and tubercles of scaphoid and trapezium

26

Distal attachment of Flexor pollicis brevis

Lateral side of base of proximal phalanx of thumb

27

Actions of Flexor pollicis brevis

Flexes thumb

28

Innervation of Flexor pollicis brevis

Recurrent branch of median nerve (superficial head) and deep branch of ulnar nerve (deep head)

29

Proximal attachment of Adductor pollicis

Bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals

30

Distal attachment of Adductor pollicis

Medial side of base of proximal phalanx of thumb