skeletal system 2

What is the appendicular skeleton?

The bones of the limbs.

What are the 2 parts of the appendicular skeleton?

Pectoral limb (front limb) and pelvic limb (rear limb).

List the bones of the pectoral limb.

Scapula, clavicle, humerus, radius, ulna, carpal bones, metacarpals, phalanges.

How is the pectoral limb attached to the axial skeleton in humans and birds?

By the clavicle, from the shoulder joint to sternum.

How is the pectoral limb attached to the axial skeleton in horses, dogs, and cattle?

By muscles and connective tissue; no bony attachment.

How is the pectoral limb attached to the axial skeleton in cats?

By muscles; cats have small clavicles that do not attach bone to bone.

What is the informal name for the scapula?

Shoulder blade.

Do the scapulas form a joint with the ribs?

No.

Where is the spine of the scapula located?

On the lateral side of the scapula.

What is the shallow cup-shaped depression in the distal end of the scapula?

Glenoid cavity.

What is the technical and informal name of the clavicle in birds?

Furcula (technical), wishbone (informal).

What is the informal name of the clavicle in humans?

Collarbone.

Do dogs, horses, and cattle have clavicles?

No.

Why do we need to know about the clavicle of the cat?

It appears on radiographs, and it is normal.

What bone is located in the upper arm area?

Humerus.

What fits into the glenoid cavity of the scapula?

The head of the humerus.

What is the bony projection beside the head of the humerus?

Greater tubercle.

What are the two knuckle-like projections on the distal end of the humerus?

Condyles (medial and lateral).

Is the humerus the 'funny bone'?

No, the funny bone is the ulna.

What two bones are located in the forearm area?

Radius and ulna.

Which bone connects to the thumb?

Radius.

Which bone is thickest and supports most of the weight?

Radius.

In which species are the radius and ulna separate bones?

Dogs, cats, pigs.

In which species are the radius and ulna fused together at maturity?

Cattle, sheep, horses.

Which bone is longer, the radius or the ulna?

Ulna.

What is the proximal end of the ulna called?

Olecranon.

What is the point of the elbow?

The tip of the olecranon that can be palpated in living animals.

What is the technical name for the wrist joint?

Carpus.

About how many carpal bones are there?

Up to 8.

What is the name of the carpal bone that ‘sticks out’ in the back?

Accessory carpal bone.

Name the bones located in the palm of the human hand.

Metacarpals.

How are metacarpal bones identified?

By number, from 1 medially to 5 laterally.

What species have 5 metacarpals?

Dogs, cats, humans.

What species has 3 metacarpals?

Horses.

What species has 2 main metacarpals?

Cattle.

How many metacarpal bones do horses have?

3.

What is the common name for metacarpal 3?

Cannon bone.

What is the common name for metacarpals 2 and 4?

Splint bones.

How many main metacarpal bones do cattle have?

2.

Which metacarpals do cattle have?

Metacarpals 3 and 4, which are fused together.

What is a digit?

A finger or a toe.

How are digits identified?

Numbered 1-5 from medial to lateral.

How many digits do dogs and cats have on their front paws?

5. On their rear paws, they have 4.

How many digits does a horse have per foot?

1.

How many digits does a cow walk on per foot?

2.

How many total digits do cattle have per foot?

4 (2 walking claws and 2 dewclaws).

What is a phalanx?

A toe or finger bone.

What are phalanges?

The plural form of phalanx.

List the names of the 3 phalanges in most digits.

Proximal phalanx (P1), middle phalanx (P2), distal phalanx (P3).

Which digits on dogs, cats, and people have 2 phalanges instead of 3?

Dogs and cats - dewclaws; humans - thumbs (P1 and P3).

Which digit does the horse have?

Digit 3.

List the 3 names of the phalanges of the equine digit.

P1 – long pastern bone (proximal), P2 – short pastern bone (intermediate), P3 – coffin bone (distal).

What are the 3 sesamoid bones per foot in horses?

2 proximal sesamoids (posterior fetlock joint), 1 distal sesamoid (navicular bone, posterior coffin joint).

Which digits are weight-bearing in cattle?

3 and 4.

True or false: Each cow digit is similar to a horse’s toe regarding the bones.

True.

List the bones of the pelvic limb.

Pelvis, femur, patella, fabellae, tibia, fibula, tarsal bones, metatarsals, phalanges.

What is half of the pelvis called?

Os coxae.

Where are the two halves of the pelvis fused together?

Pelvic symphysis.

Is the pelvic symphysis located at the dorsal or ventral part of the pelvis?

Ventral.

List the 4 bones that make up the pelvis.

Ilium, ischium, pubis, acetabular bone.

Which pelvic bone is the largest and most cranial?

Ilium.

Which pelvic bone is second largest and most caudal?

Ischium.

Which pelvic bone is third largest and ventral?

Pubis (pubic bone).

Which is the smallest pelvic bone and where is it located?

Acetabular bone – in the acetabulum.

What are the 2 main parts of the ilium?

Body and wings.

Which pelvic bones articulate with vertebrae to form a connection to the axial skeleton?

Ilium connects to sacrum at the sacroiliac joint.

What is the point of the hip?

The tuber coxae on the lateral wing of the ilium.

What is the cup-shaped depression in os coxae for the femur called?

Acetabulum.

What is the big hole in os coxae called?

Obturator foramen.

Which foramen is the largest in the body?

Obturator foramen.

Where is the foramen magnum located?

In the occipital bone of the skull.

What is another name for the pelvic canal?

Birth canal.

What is the thigh bone?

Femur.

What is the largest bone in the body?

Femur.

What is the rounded proximal part of the femur called?

Head of the femur.

Where is the greater trochanter located on the femur?

Proximal end, lateral to the head.

What is the depression between the head and greater trochanter?

Trochanteric fossa.

What articulates with the tibia on the distal femur?

Condyles.

What articulates with the patella on the distal femur?

Trochlea.

What is the technical name for the kneecap?

Patella.

Where is the patella located?

At the stifle joint in the rear leg.

What are the fabellae and where are they located?

2 small sesamoid bones at the posterior distal femur.

Which species has fabellae?

Dogs and cats.

Why do we have to know about the fabellae?

They appear on radiographs, indicating they are normal.

List the sesamoid bones discussed in class.

Patella, fabella, proximal sesamoids, navicular bone.

Which is the largest sesamoid bone in the body?

Patella.

What is the technical name for the shinbone?

Tibia.

Where does the patellar ligament attach on the tibia?

Tibial tuberosity – proximal anterior tibia.

What is the name of the smaller bone beside the tibia?

Fibula.

In which species are the tibia and fibula fused at maturity?

Horses and cattle.

What is another name for the tarsus in animals?

Hock.

What is another name for the tarsus in people?

Ankle.

How many bones are in the tarsus?

7.

Which tarsal bone articulates with the tibia?

Talus.

What is the tarsal bone that forms the point of the hock?

Calcaneus.

What is the name of the large tendon that inserts on the calcaneus?

Achilles tendon (calcanean tendon).

What are the bones just distal to the tarsus called?

Metatarsals.

What are the metatarsals similar to?

Metacarpals.

Where are the metatarsals located?

Just distal to the tarsus in the pelvic limb.

What is the visceral skeleton?

Bones that develop in soft tissue.