CompAnat: Hindlimbs: Part 2

femur

strongest of the long bones

strongest of the long bones

can be found located in the soft tissues of the thigh

Patella/Kneecap

The largest sesamoid bone is the

Quadriceps Muscle

patella or kneecap, which is embedded in the tendon of insertion of the

Gastrocnemius, Popliteal

In carnivores two additional sesamoid bones are embedded in the heads of the

Proximal Extremity bearing head, Shaft of femur, Distal extremity bearing medial and lateral condyle

Femur can be divided into three basic segments:

Patella/Kneecap

large sesamoid bone located in the tendon of insertion of the quadriceps muscle of the thigh.

articular surface

faces caudally towards the femur

free surface

faces cranially (facies cranialis) and is palpable under the skin.

base of the patella

directed proximally and is roughened for muscular attachment; the apex faces distally.

horse and the ox

patella is extended medially by the fibrocartilage of the patella

Zeugopodium

The skeleton of the distal part

Tibia and FIbula

The skeleton of the distal part (zeugopodium) of the free appendage of the hindlimb consists of two bones,

Tibia, Fibula

These bones are very dissimilar in strength, like their analogous elements in the forelimb

Tibia

Stronger medial bone

fibula

runs along the lateral border of the tibia and does not articulate with the femur proximally.

tibia

supports the weight of the animal, which is reflected in an increase in stoutness of this bone

tibia

contributes a major part to the formation of the stifle joint, which is reflected in the expanded proximal extremity of this bone

The tibia can be divided into three segments:

Proximal extremity presenting the articular surface, Tibial Shaft, Distal extremity bearing cochlea

cochlea

the articulation with the talus.

Proximal head, Neck, Shaft, lateral malleolus

The fibula can be divided into a

fibula

undergone remarked reduction during evolution, the degree of which varies among the species

pig and the carnivore

Retained its whole length, but is reduced in strength and function.

Long interosseous space

The fibula is separated from the tibia by a

ruminants

shaft of the fibula is completely reduced.

horse

proximal part of the fibula remains isolated

Basipodium, Metapodium, Acropodium

The skeleton of the pes forms the osseous part of the autopodium and consists from proximal to distal of three segments:

basipodium

Segment of tarsal bones

Metapodium

Segment of metatarsal bones

Acropodium

Segment of Phalanges

Tarsocrucal joint

The proximal row articulates with the tibia

Tarsometatarsal joint

distal row articulates with the metatarsal bones

Talus, Calcaneus

Proximal or crural row (in mediolateral sequence):

Central Tarsal Bone

Middle or intertarsal row:

First, Second, Third Fourt tarsal bones

Distal or metatarsal row (in mediolateral sequence):

7 tarsals

Tarsal count of CARNIVORES and PIGS

5 tarsals

Tarsal count of RUMINANTS

6 Tarsals

Tarsal count of HORSE

Talus

medial bone of the proximal row of the tarsus.

Calcaneus

lies lateral and plantar to the talus and provides the osseous base of the point of the hock

Metatarsals

longer and more slender with a stronger cortex than the corresponding metacarpal bones.

Circular

Cross section of cannon bone (third metatarsal bone) of the equine hindlimb

Oval

Cross section of cannon bone (third metatarsal bone) of the equine forelimb

cattle

additional sesamoid bone can be present just proximal to the third metatarsal bone

narrower

Hoof of the hindfoot is ___________ than that of the front foot, the toe longer and the angle of the hoofwall steeper.