Lecture 10 - Wrist & Hand

Question 1

What are carpals?

Answer 1

• they are wrist bones
• they are distal (further away) from the radius
• there are 8 carpal bones; arranged in 2 rows, 4 in each
• made up of small bones of various shapes

Question 2

What are 4 carpal bones in the proximal row?

Answer 2

• scaphoid
• lunate
• Triquetrum
• pisiform

Question 3

What is the scaphoid ?

Answer 3

• articulates with the radius (located on the thumb side)
• important for motion & stability; common to fracture
• boat shaped

Question 4

What is the lunate?

Answer 4

• articulates with the radius (medial to the scaphoid)
• helps shape the wrist & maintain flexibility
• most likely to dislocate

Question 5

What is the triquetrum?

Answer 5

• lateral to the lunate
• pyramid shaped
• participates in the motion of the mid carpal & radiocarpal joints of the wrist

Question 6

What is the pisiform?

Answer 6

• sits on the palmer/anterior side of the triquetrum
• pea shaped
• serves as an attachment point for tendons & ligaments

Question 7

What are the 4 carpal bones in the distal row?

Answer 7

• Trapezium
• trapezoid
• capitate
• hamate

Question 8

What is the trapezium?

Answer 8

• superior (above) to the scaphoid & right below the thumb
• 4 sided bone
• plays a role in stability & movement of the thumb

Question 9

What is the trapezoid ?

Answer 9

• medial (beside the trapezium)
• wedge shaped but similar to the trapezium
• gives the bony structure to the wrist & hand

Question 10

What is the capitate?

Answer 10

• found in the Center of hand, distal end of the radius & ulna; next to trapezoid
• round shape
• forms the third carpometacarpal bone

Question 11

What is the hamate?

Answer 11

• beside the capitate, above the triquetrum & pisiform
• wedge shaped, connects the distal row of carpal bones with the 4th & 5th metacarpal bones

Question 12

How to remember the proximal row from lateral to medial?

Answer 12

• She Likes To Play:

S - Scaphoid
L - Lunate
T - Triquetrum
P - Pisiform

Question 13

How to remember the distal row from lateral to medial?

Answer 13

• Try To Catch Her

T - Trapezium
T - Trapezoid
C - Capitate
H - Hamate

Question 14

What is the classification of the wrist joint?

Answer 14

• the wrist joint is a synovial joint
• there are 2 types of synovial joint:
• the radiocarpal joint (condyloid, forward/backward, side to side movement)
• the mid-carpal joints are gliding

Question 15

What is Ulnar collateral ligament of the wrist?

Answer 15

• prevents hyper abduction
• located on the ulnar styloid process to triquetrum and pisiform

Question 16

What is the radial collateral ligament of the wrist ?

Answer 16

• prevents the wrist from bending too far to the side opposing the thumb
• located on the radial styloid process to scaphoid and trapezium

Question 17

Importance of joints in the wrist?

Answer 17

• Joints are also reinforced with ligaments anteriorly and posteriorly
• This ensures the carpals move together during pronation & supination

Question 18

Metacarpals of the hand

Answer 18

• meta = after; the row after the carpals
• head = knuckles
• 5 metacarpals make up the palm of the hand; thumb (metacarpal 1), index finger (metacarpal 2), middle finger (metacarpal 3), ring finger (metacarpal 4), pinky (metacarpal 5)

Question 19

What are the metacarpal joints?

Answer 19

• carpometacarpal joint (CMC joint)
• metacarpophalangeal joint (MCP joint)

Question 20

What is the carpometacarpal joint (CMC joint)?

Answer 20

• The base of the thumb where it meets the hand
• lets the thumb move freely in many directions; also provides strength so the hand can grasp and grip
• 1st CMC is a synovial saddle joint, 2nd-5th CMC are synovial condyloid joints

Question 21

What is the metacarpophalangeal joint (MCP joint)?

Answer 21

• All are synovial condyloid joints
• joint between head of metacarpal and proximal phalange (cracking your knuckles happens here)
• allows flexion and extension as well as abduction and adduction motions

Question 22

What are palmer/volar plates?

Answer 22

• found in the CMC & MCP joints & reinforce the joint capsules enhance joint stability
• A thick ligament on the underside of the middle finger joint
• enhance joint stability & keeps the finger from hyperextending back

Question 23

What is the deep transverse ligament of the palm?

Answer 23

• a narrow fibrous band, which runs across the volar surfaces of the heads of the second, third, fourth and fifth metacarpal bones, connecting them together

Question 24

What are phalanges?

Answer 24

• the bones that make up the fingers
• the thumb only has 2 (proximal & distal)

The other 4 fingers have 3 (proximal, middle, & distal)

Question 25

What is the proximal interphalangeal joint (PIP joint)?

Answer 25

• articulates between the proximal and middle phalanx in the hand
• present in all digits except the thumb
• it is a synovial hinge joint which permits flexion and extension in center of the fingers

Question 26

What is the distal interphalangeal joint (DIP joint)?

Answer 26

• the first knuckle from the top of the finger
• It connects the distal phalanx and middle phalanx, which are the two bones at the tip of the finger
• it is also a synovial hinge joint which permits flexion and extension in center of the fingers

Question 27

How many bones are in the hand?

Answer 27

• 27 total bones
• 8 carpal bones, 5 metacarpals, 2 thumb phalanges (proximal & distal)
• Fingers 2-5 have 3 phalanges each (proximal, intermediate, distal)