m6: forearm, wrist, hand Flashcards
● Positions the hand.
● Provides a stable platform from which the hand functions.
● Finely tuned hand positioning.
● Global positioning of the hand.
Wrist
● Predominant part of the body serving many purpose.
● Contains the _ and _.
○ Both sturdy and mobile.
● Complex, multipurpose organ
● As a prehensile organ, it can grasp with forces exceeding _ lb (445 N or 45 kg) or manipulate a delicate thread
● Conform around objects
● Pushing and pulling
Hand
palm and fingers
100 lb
“Pollex”
1st digit or thumb
Often used to point, and pointing is a method of making things clearer and it is the purpose of an index.
2nd digit or Index/Pointing/Forefinger
Longest finger of the hand
3rd digit or Middle Finger
It was believed that this finger contained a “vein of love” that flowed directly to the heart
4th digit or Ring Finger
Smallest finger
5th digit or Pinky/Little finger
●
● Although the primary forearm bone for the elbow joint is the ulna, the primary forearm bone of the _ is the .
● There are two proximal carpal bones ( + _) that interact with the radius to form the wrist joint.
Wrist
wrist; radius
Scaphoid + Lunate
●
● Not in direct contact with the carpal bones.
● _ _ separates the ulna from the carpal bones.
● _ portion of the _ is an important part of the wrist.
● The distal ulna has three parts:
1.
2.
3.
Distal Ulna
Fibrocartilaginous disc
Distal portion of the ulna
- Ulnar styloid process
- Fovea
- Pole
the part of the distal ulna that has bony projection, easily palpated with the forearm pronated, on the ulnar side of the wrist
ulnar styloid process
the part of the distal ulna that has a depression at the base of this styloid process and provides attachment for the fibrocartilaginous disc.
fovea
the part of the distal ulna that’s a concave articular surface allowing ulnar articulation with the fibrocartilaginous disc
pole
●
● The dorsal surface has a palpable tubercle that is known as the
○
○
○
Distal Radius
○ tubercle of the radius
○ Lister’s tubercle
○ dorsal tubercle
●
● Lies about _/- of the wrist’s width from the radial styloid process.
● Has grooves on either side of it that serve as a pulley for the:
○ extensor _ _ tendon on the _ side
○ extensor _ and extensor _ tendons on the _ side.
Lister’s tubercle
1/3
○ extensor pollicis longus tendon on the ulnar side
○ extensor digitorum and extensor indicis tendons on the radial side.
●
● Distal projection on the radial surface of the radius.
● More _ than ulnar styloid process.
● Ulnar and radial styloid processes serve as attachment sites for the _ and _ _ _ ligaments, respectively.
Radial Styloid Process
distal
Ulnar and radial styloid processes serve as attachment sites for the ulnar and radial carpal collateral ligaments, respectively.
●
● Sigmoid notch
● On the _ (lateral) aspect of the distal radius is the articulating surface for the _ _ joint
Ulnar notch
On the ulnar (lateral) aspect of the distal radius is the articulating surface for the distal radioulnar joint
●
● The _ surface of the _ makes up the proximal joint surface of the wrist and articulates with the _ and _ carpal bones.
Distal Radius + Scaphoid + Lunate
● Carpal bones
● PROXIMAL ROW:
1.
2.
3.
4.
● DISTAL ROW:
1.
2.
3.
4.
Proximal:
○ Scaphoid
○ Lunate
○ Triquetrum
○ Pisiform
Distal:
○ Trapezium
○ Trapezoid
○ Capitate
○ Hamate
● Navicular
● Most frequently FRACTURED carpal bone
● Floor of the anatomic snuffbox
Scaphoid
● Most frequently DISLOCATED carpal bone
Lunate
● “Triangular”
Triquetrum
● Pea-shaped
Pisiform
● “Greater multangular”
Trapezium
● “Lesser multangular”
Trapezoid
● Occupying a central position at the wrist (in line with the middle finger)
● Os magnum
● Best approached from the_, where a slight depression indicates its location
● The axis of motion for ulnar and radial deviation goes through this bone in a _ direction
Capitate
dorsum
dorsopalmar direction
● It has a hooked process on its palmar side, called the _ of the hamate
Hamate
hook
●
○ most commonly fractured carpal bone
○ MOI: _ _ _ _ _
○ articular risk of avascular necrosis after fracture | ‘_ _ supply’
Scaphoid Fracture
FOOSH
retrograde blood supply
● A triangular skin depression on the _ side of the wrist that is bounded medially by the tendon of the extensor pollicis longus and laterally by the tendons of the abductor pollicis longus and extensor pollicis brevis
● Its clinical importance lies in the fact that the _ bone is most easily palpated here and that the _ of the radial artery can be felt here
Anatomic Snuffbox
lateral side
scaphoid bone
pulsations of the radial artery
● These bones comprise the hand: _ and _
● The _ make up the digits.
● The metacarpals and digits are identified
numerically, laterally to medially (from the anatomical position), one through five.
Metacarpals and phalanges
phalanges