Bones and Joints of Equine Distal Limb Q's

Question 1

what are the components of the carpus

Answer 1

proximal row: radial carpal bone (RCB), intermediate carpal bone (ICB), ulnar carpal bone (UCB), accessory carpal bone (ACB) distal row: 1st, 2nd, 3rd, 4th carpal bone

Question 2

what are the differences in the equine carpus

Answer 2

3rd CB largest 1st CB absent

Question 3

what are the differences in the canine carpus

Answer 3

radial and intermediate CBs are fused

Question 4

how many centres of ossification does the carpus develop from

Answer 4

one centre

Question 5

which carpal bones develop from more than 1 centre of ossification

Answer 5

accessory carpal bone (2) and the fused radio-intermediate CB in dog and cat (2)

Question 6

what are the intercarpal joint spaces (3)

Answer 6

1. antebrachio-carpal joint 2. middle carpal joint 3. carpo-metacarpal joint

Question 7

what is the antebrachio-carpal joint composed of

Answer 7

antebrachium + proximal row of carpal bones *most movement

Question 8

what is the middle carpal joint composed of

Answer 8

proximal + distal rows of carpal bones

Question 9

what is the carpo-metacarpal joint composed of

Answer 9

distal row + metacarpal bones *least movement

Question 10

what type of joints are intracarpal joints

Answer 10

fibrous joints held tightly

Question 11

how is the carpus joint stabilized (3)

Answer 11

1. collateral ligaments 2. cartilage plate on palmar aspect of joint capsule 3. retinaculum

Question 12

what is the function of the accessory carpal bone

Answer 12

1. lever for distal limb 2. insertion of major carpal flexor muscles

Question 13

what is the function of the palmar ligament

Answer 13

stabilizes ACB flexion

Question 14

how many digits to dogs and cats have

Answer 14

shed 1st digit for speed

Question 15

how many digits do unguligrades have

Answer 15

shed more for speed

Question 16

how many digits do artyrodactyla

Answer 16

ruminants an even number –> 3rd and 4th digits remain

Question 17

which digit remain in perissodactyla

Answer 17

equines have the 3rd digit

Question 18

what are the 3 types of stances

Answer 18

1. plantegrade (rabbits, bears, humans) –> bear weight on digits + metatarsals + tarsal bones 2. digitigrade (dogs, cats) –> bear weight on digits/phalanges protected by foot pads 3. unguligrade (ruminant, horses) –> bear weight on distal phalanx only, protected by hoof

Question 19

how many centres of ossification are in the distal limb bones

Answer 19

2 centres except the distal phalanx has 1

Question 20

what are the metacarpal bones in the horse

Answer 20

3rd metacarpal/metarsal bone = cannon bone 2nd

and 4th MC/MT = splint bones

Question 21

what are the features of the 3rd metacarpal/metatarsal bone

Answer 21

weight bearing distal articular surface –> sagittal ridge

Question 22

what are the features of the 2nd and 4th MC/MT bone

Answer 22

vestigial/non weight bearing button at distal end (palpable)

Question 23

where are the proximal sesamoid bones in the horse

Answer 23

palmaro-distal to every MC3/MT3 paired

Question 24

what is the function of the proximal sesamoid bones

Answer 24

protect the SDFT, DDFT embedded in suspensory ligament

Question 25

where are the dorsal sesamoid bones in the dog

Answer 25

single dorsal aspect of MCP/MTP joint

Question 26

what are the functions of dorsal sesamoid bones in the dog

Answer 26

embedded in and protect extensor tendons

Question 27

where is the proximal phalanx

Answer 27

long pastern bone/P1

Question 28

what are the features of the proximal phalanx

Answer 28

raised V on palmar surface

Question 29

what is the ligament attached to the proximal phalanx

Answer 29

oblique distal sesamoidean ligament

Question 30

how many grooves are on the proximal phalanx

Answer 30

2 sagittal grooves

Question 31

what are the components of the metacarpo-phalangeal (MCP)/metatarsal-phalangeal (MTP) joint

Answer 31

1. 3rd metacarpal/metatarsal bone 2. proximal phalanx 3. proximal sesamoid bones

Question 32

what are the functions of the palmar and dorsal pouch in the MCP/MTP joint

Answer 32

palmar pouch incorporates proximal sesamoids dorsal pouch cushions extensor tendons

Question 33

how is the MCP/MTP joint stabilized

Answer 33

1. collateral ligaments 2. sagittal ride/groove

Question 34

what is the movement of the MCP/MTP

Answer 34

limited to flexion and extension high motion joint \*\*very large articular surface + joint capsule

Question 35

where does the suspensory ligament originate

Answer 35

proximal palmar MC3/MT3

Question 36

where does the suspensory ligament run

Answer 36

fills area between splint bones and divides into two --\> attaches to abaxial aspect of proximal sesamoids passes to dorsal aspect limb

Question 37

what does the suspensory ligament fuse to

Answer 37

fuses with common digital extensor tendon

Question 38

what is the function of the suspensory ligament

Answer 38

acts like a sling returns joint to resting position relies on stability of proximal sesamoids

Question 39

what is the function of the sesamoidean ligaments

Answer 39

stability of proximal sesamoids

Question 40

what are the sesamoidean ligaments (3)

Answer 40

1. inter-sesamoidean ligament 2. collateral sesamoidean ligaments (medial and lateral) 3. distal sesamoidean ligament --\> 1. cruciate 2. short 3. oblique ligament 4. straight ligament

Question 41

where is the inter-sesamoidean ligament

Answer 41

fibrocartilage plate between proximal sesamoid bones

Question 42

what is the function of the inter-sesamoidean ligament

Answer 42

smooth passage of DDFT and SDFT

Question 43

where is the collateral sesamoidean ligaments

Answer 43

proximal sesamoids to MC/MT 3 and PP medial & lateral

Question 44

what are the distal sesamoidean ligaments

Answer 44

1. cruciate - PP 2. short - PP 3. oblique ligament - PP (v-shaped through on PP) 4. straight ligament - MP

Question 45

what is the suspensory apparatus composed of (4)

Answer 45

1. suspensory ligament 2. proximal sesamoids 3. sesamoidean ligaments 4. common digital extensor tendon

Question 46

what is the middle phalanx (MP) bone

Answer 46

short pastern bone/P2

Question 47

where is the sagittal ridge in the middle phalanx

Answer 47

proximal

Question 48

where is the sagittal groove in the middle phalanx

Answer 48

distal

Question 49

what are the components of the proximal interphalangeal joint (PIP)

Answer 49

proximal and middle phalanges

Question 50

what are the features of the PIP joint

Answer 50

typical synovial joint extensive joint capsule

Question 51

what does the PIP form

Answer 51

dorsal bursa to cushion the extensor tendon

Question 52

what stabilizes the PIP joint

Answer 52

collateral ligaments

Question 53

what is another name for the distal phalanx

Answer 53

DP pedal bone/P3

Question 54

what is the function of the extensor process on the distal phalanx

Answer 54

attachment of the common digital extensor tendon (CDE)

Question 55

what is the function of the palmar process

Answer 55

support lateral cartilages

Question 56

what attaches onto the solar surface of the distal phalanx

Answer 56

attachment of deep digital flexor tendon (DDFT)

Question 57

what are the features of the distal phalanx

Answer 57

striations for hoof attachment and vascular channels for blood vessels

Question 58

where is the distal interphalangeal joint (DIP)

Answer 58

coffin joint is buried within the hoof

Question 59

what are the components of the DIP joint

Answer 59

1. middle and distal phalanges 2. distal sesamoid (navicular bone) and distal phalanx 3. distal sesamoid and middle phalanx

Question 60

how is the DIP stabilized

Answer 60

collateral ligaments

Question 61

what movement is in the DIP

Answer 61

flexion and extension some rotation to accommodate uneven ground

Question 62

what is the distal sesamoid

Answer 62

navicular bone

Question 63

how many articular surfaces are on the navicular bone

Answer 63

2 smooth articular surfaces with a cancellous centre with vascular channels

Question 64

what is the function of the navicular/podotrochlear bursa

Answer 64

fluid filled pocket between distal sesamoid and DDFT acts to cushion DDFT

Question 65

how is the navicular bursa separated from the joint space

Answer 65

separated by impar ligament

Question 66

what are the functions of the ungual process, ungual crest, extensor process and palmar process in the distal phalanx of a carnivore

Answer 66

ungual process - supports claw ungual crest - vascular root of claw extensor process - extensor tendons palmar process - flexor tendons

Question 67

identify the structures of the equine distal limb

Answer 67

Question 68

identify the structures of the equine distal limb

Answer 68

Question 69

identify the distal structures of the canine paw

Answer 69

Question 70

identify the distal limb structures

Answer 70

Question 71

identify the sesamoidean ligaments

Answer 71

1. intersesamoidean ligament 2. collateral sesamoidean ligaments 3. distal sesamoidean ligaments --\> 1. cruciate 2. short 3. oblique ligament 4. straight ligament

Question 72

identify the sesamoidean ligaments

Answer 72

A. intersesamoidean ligament B. collateral sesamoidean ligaments (medial and lateral) C. distal sesamoidean ligaments C1. cruciate C2. short C3. oblique ligament C4. straight ligament

Question 73

identify the structures of the dorsopalmar radiographs of hoof and the palmar and dorsal surfaces of the distal phalanx

Answer 73

Question 74

identify the structures of the navicular bone (distal sesamoid)

Answer 74