Appendicular Skeleton

What bones make up the thoracic limb?

Scapula, humerus, radius, ulna, carpals, metacarpals, and bones of the digits.

What forms the shoulder joint in the thoracic limb?

The articulation between the glenoid cavity of the scapula and the head of the humerus.

What joints are included in the thoracic limb?

Shoulder joint, elbow joint, carpal joint, fetlock joint, pastern joint, and coffin joint.

What distinguishes the scapula of dogs?

The scapular spine divides the lateral surface into two equal fossae and has a distinct acromion.

How does the horse's scapula differ from that of the dog?

The scapular spine divides the lateral surface into two unequal fossae and lacks an acromion.

Describe the clavicle in most domestic animals.

It is absent or rudimentary since most domestic animals are quadrupeds.

Which animal has a complete set of pectoral girdle including the clavicle?

Birds.

What feature is unique to the humerus of dogs?

It has a supratrochlear foramen.

What characterizes the forearm bones in dogs and cats?

The ulna is not fused with the radius and has a distinct interosseous space.

Which animals have fused radius and ulna?

Ruminants and Horse

How many carpal bones do pigs have?

All eight carpal bones are present.

What is the number of metacarpal bones in dogs?

Five metacarpal bones.

Which is the only fully developed metacarpal bone in horses?

The third metacarpal bone, also called the cannon bone.

What distinguishes the pelvic limb from the thoracic limb?

The pelvic limb includes the hip bone (os coxae), femur, tibia, fibula, tarsals, metatarsals, and digital bones.

What joint connects the pelvic limb to the trunk?

The sacroiliac joint.

Which bones compose the hip bone (os coxae)?

Ilium, ischium, and pubis.

In what position does the gluteal surface face in cattle and horses?

Dorsally.

What feature is found in pigs and dogs regarding the gluteal surface?

The gluteal surface faces laterally.

What is the difference in femoral structure between dogs and cows?

In dogs and cats, the femur is cylindrical; in cattle and horses, the greater trochanter is higher than the head of the femur.

Describe the tibia and fibula in dogs and cats.

The fibula is not fused and is as long as the tibia.

What is unique about the fibula in ruminants?

The fibula is vestigial with no interosseous space.

What arrangement do tarsal bones follow in pigs and dogs?

Proximal, distal, and center rows.

How many terms are fused in the tarsal bone structure of horses?

First and second tarsal bones are fused.

What is the metatarsal structure in birds?

The tarsometatarsus articulates with the phalanges.

What bones develop in the splanchnic skeleton?

Os penis, os clitoridis, os cordis.

In birds, how do digits differentiate in terms of phalanges?

Digit 1 has 2 phalanges, Digit 2 has 3, Digit 3 has 4, Digit 4 has 5 phalanges.

What adaptations do ruminants exhibit in their metatarsals?

The fifth metatarsal bone is absent, and a metatarsal sesamoid bone is present.

What distinguishes the carpus in carnivores?

The radial and intermediate carpal bones are fused, resulting in seven carpal bones.

In birds, which tarsal bones fuse to form the tarsometatarsal bone?

The central and distal tarsal bones fuse with metatarsals 2, 3, and 4.

What feature is found at the distal end of the femur in birds?

It has a patella.

How do ruminants' metacarpal bones differ from other species?

The third and fourth metacarpal bones are united on the proximal and middle parts.

What is the function of the sacroiliac joint?

Connects the pelvic limb to the trunk.

How does the carpometacarpal bone form in birds?

The distal row of carpal bones fuse with the metacarpal bone.

What is unique about the greater tubercle of the humerus in pigs?

It almost converts the bicipital groove into a foramen.

How do birds' scapulas differ from mammals?

They are elongated and blade-like, and firmly held to the ribs.

What identification criteria are used for the hip bone?

Size, shape, orientation of the gluteal surface, and number of gluteal lines.

What modification occurs in the tarsal structure of larger animals?

First and second tarsal bones may be fused.

How does the ulna in horses compare to the radius?

The ulna is shorter than the radius and fused with the proximal two-thirds of it.

What is the function of the obturator foramen in birds?

Transmits the sciatic nerve.

What is found at the proximal end of the tibia regarding the tarsals in birds?

The tibia is fused with the proximal row of tarsal bones, forming the tibiotarsus.