Lecture 6: Anatomy of Leg and Tarsus

Question 1

What two structures is the leg in between

Answer 1

Stifle and hock

Question 2

How is movement of the leg achieved

Answer 2

Via muscles that move the stifle joint

Question 3

What are the three tiers of hock and tarsus

Answer 3

Proximal, middle, and distal

Question 4

What is in the proximal tier

Answer 4

Talus/astragalus (medial) and calcaneus (lateral)

Question 5

What is in the middle tier

Answer 5

Central tarsal bone

Question 6

What is in the distal tier

Answer 6

Tarsals 1-4 number medial-lateral
4th tarsal intrudes into middle tier

Question 7

What is the equine variation in the distal tier

Answer 7

1+2 tarsals fuse

Question 8

What is the bovine variation in the distal tier

Answer 8

2+3 tarsals fuse and central bone and 4 tarsal fuse

Question 9

Describe the layout of the Carnivora hock and tarsus tiers

Answer 9

Tibia and fibula articulate with talus and calcaneous

Talus articulates with the central bone and calcaneous with the 4th tarsal

None of the tarsals are fused and they articulate with metatarsals

Question 10

Describe the layout of the equine hock and tarsus tiers

Answer 10

Tibia and fibula articulate with talus and calcaneus

Talus articulates with the central bone and the calcaneus articulates with the 4th metatarsal
The 1st and 2nd metatarsal are fused
tarsals fuse with metatarsals (mainly 3)

Question 11

Describe the layout of the bovine hock and tarsus tiers

Answer 11

The tibia and fibula articulate with talus and calcaneus.

The talus and calcaneus articulate with the fused central bone and 4th metatarsal which fuse to the metatarsals

Metatarsals 2 and 3 are fused

Question 12

Trochlea of talus

Answer 12

Proximal surface, articulates with tibia and fibia

Question 13

Head of talus

Answer 13

Distal articulate surface articulates with central tarsal

Question 14

Sustentaculum tali

Answer 14

Supports plantar surface of talus (in between talus and calcaneus), supports tendon of flexor digitorium superficialis

Question 15

Tuber calcanei

Answer 15

Proximal end of calcaneus, attachment for calcaneal tendon. Level for movement at hock

Question 16

Head of calcaneus

Answer 16

Articulates with fourth tarsal

Question 17

Base of metatarsals

Answer 17

Articulates with tarsals

Question 18

Body of metatarsals

Answer 18

Middle of metatarsal

Question 19

Head of metatarsal

Answer 19

Articulates with phalange

Question 20

How is the proximal trochlea surface of talus in the dog shaped

Answer 20

Shaped to fit tibia and fibula

Question 21

How is the head of talus in dog shaped

Answer 21

Articulates with central bone and is rounded to permit mid foot rotation- for grasping things

Question 22

How is the trochlea of talus in the horse shaped

Answer 22

Conforms with cochlea of tibia providing extension and flexion at talo-crural joint

Question 23

Describe the Talar head in the horse

Answer 23

Very small and flattened providing greater stability at talar-central articulation

Question 24

What is the function of the obliquity of joint surfaces at talo-crural joint in horse

Answer 24

Causes distal limb to be carried laterally when flexion occurs at hock

Question 25

In most mammals what does the talar head articulate with

Answer 25

Central bone

Question 26

What happens to talar head in artiodactyl’s

Answer 26

Talar head expands to articulate with central and 4th tarsal

Question 27

What are the 4 levels of articulation at the hock

Answer 27

Tarso-crural joint Proximal intertarsal joint Distal intertarsal joint Tarsometatarsal joint

Question 28

In most species where does almost all movement occur in the hock

Answer 28

Talocrural joint

Question 29

What are the main ligaments of the hock

Answer 29

Medial and lateral collateral ligaments and the long plantar ligaments

Question 30

What are the medial and lateral collateral ligaments

Answer 30

Extend from the tibia and tibia to base of metatarsus. Each have a long superficial part that ends full length of ligament and then a short deeper part that is restricted to proximal level of articulation

Question 31

What is the long plantar ligament

Answer 31

Extends from plantar surface of calcaneus over 4th tarsal bone to metatarsus

Question 32

What is the role of the smaller ligaments in the hock

Answer 32

Hold tarsal bones together and maintain integrity of peas

Question 33

What are the three synovial compartments of the hock

Answer 33

Tarsocrural and proximal intertarsal joints Distal intertarsal joint Tarsometatarsal joints

Question 34

What are the 4 components of the tarsocrural and proximal intertarsal joints

Answer 34

1. Lateraldorsal pouch 2. Mediodorsal pouch 3. Medial plantar pouch 4. Lateral plantar pouch Weaker parts of joint where swelling may occur due to over-distension

Question 35

What muscles make up the caudal compartment of the leg

Answer 35

Gastrocnemius Flexor digitorium superficialis Flexor digitorium profundus (lateralis, medialis, and caudal is) Popliteus

Question 36

What artery supplies the caudal compartment of the leg

Answer 36

Saphenous

Question 37

What nerve innervates the caudal compartment of the leg

Answer 37

Tibial

Question 38

What is the main action of the caudal compartment of the leg

Answer 38

Extension of tarsus and flexion of digits

Question 39

What two muscles make up the common calcaneal tendon

Answer 39

Superficial flexor and gastrocnemius

Question 40

Politeus OINA

Answer 40

O: caudal aspect of the articular surface of the lateral condyles of the femur I: medial border of the tibia and its proximal third N: tibial A: medial rotation of the tibia relative to the femur during flexion or swing phase locomotion

Question 41

What are the muscles in the craniolateral compartment of the leg

Answer 41

Tibialis cranialis Extensor digitorium Longus Peroenus longus Peroneus brevis Peroneus tertius

Question 42

What artery supplies the craniolateral compartment

Answer 42

Cranial tibial artery

Question 43

What nerve innervates the craniolateral compartment

Answer 43

Fibular(peroneal)

Question 44

What is the main function of the craniolateral compartment

Answer 44

Flexion of tarsus, extension of digits

Question 45

Peroneus tertius OINA

Answer 45

O: extensor fossa with extensor digitorium longus I: bifurcates at hock - lateral branch: calcaneus and 4th tarsal - dorsal branch- proximal part of 3rd tarsal and 3rd metatarsal N: fibular nerve A: connects the actions of the stifle and hock so they extend simultaneously

Question 46

What two nerves innervate the leg and tarsus

Answer 46

Tibial and fibular nerves that branched off sciatic

Question 47

Describe the pathway of the tibial nerve

Answer 47

Enters the leg between heads of gastrocnemius then gives off caudal aural branch as well as innervating caudal leg muscles. The nerve enters between the tarsus and common calcaneal tendon and caudal crural muscles then splits into medial and lateral plantar nerves that innervate the pes

Question 48

Describe the pathway of the fibular nerve

Answer 48

Enters the leg lateral to gastrocnemius then gives of lateral sural cutaneous branch as well as innervating the craniolateral muscles. The nerve continues into the dorsum of the pes

Question 49

Describe the blood supply of hindlimb for dog and cat

Answer 49

External iliac gives off femoral artery, the deep femoral artery and saphenous branch off femoral artery The saphenous has a cranial and caudal branch Cranial branch of saphenous gives off dorsal metatarsal artery and the caudal branch gives off medial and lateral plantar and metatarsal arteries Further distally past the femoral artery is the popliteal artery which will give off the popliteal artery and dorsal pedal artery

Question 50

Describe the main arteries of the horse hindlimb

Answer 50

External iliac to the femoral artery which gives off the deep femoral artery and the saphenous The saphenous will for a loop and anastomose with the caudal tibial. The saphenous also gives off the medial and lateral plantar and metatarsal arteries as well as the medial and lateral digital arteries Further distal of femur is the popliteal artery which gives off the caudal tibial artery which anastomose with saphenous. It also gives off the cranial tibial artery.

Question 51

Where does Lateral saphenous vein drain

Answer 51

Popliteal vein

Question 52

Where does medial saphenous vein drain

Answer 52

Femoral vein