The bone and cartillage

Classification

Short bones

Irregular

Long bones

Flat bones

Limb bones

Appendages, forelimb hind limb

Two extremities, proximal and distal, these extremities have different structures for articulation

Tarsus and carpus

The bones are also short, but have a lot of processes coming off

Vertebrae

Flat in nature

Scapula and skull

Pneumatic bones

Visceral/ Splanchnic bones

Bones filled with air, connected to appendages

In birds, for light weight

Bones present within the viscera/ organs

Os cordis/ Os penis

Long bone

Parts

Epiphysis

Metaphysis

Shaft

Spongey bone/ cancellous

Middle part of bone

Cortical bone

Dense outer surface of bone

Inside of bone

Extremities on both sides, articular cartilage

Below epiphysis. conical part of bone

Epiphyseal plate

Between epiphysis and metaphysis

Important in growth of young animals

Covered by hyaline cartilage

Little knobby parts

Triangle part

Internal view

Formed by cancellous bone, cortical bone not found everywhere or else it is too heavy

In radiographs, the growth plate is shown dark because it is hyaline cartilage

aka compact bone

Replaces medullary cavity at extremities

Periosteum

Endosteum

Outer layer made of CT

Inner layer made of CT

Thicker

Thinner

Contains trabeculae and spaces containing bone marrow and BV

Medullary Cavity

Contains bone marrow

Red in young animal, older animals it is yellow

Forms RBC

Internal arrangement of bone

Osteon in center, several osteons come together, the osteocyte surrounds the osteon in a circular fashion.

Inside the Osteon is the haversian canal which has BV and nerves, the volkmann canal connects the two osteons

Bone Marrow

In medllary cavity and interstial spaces of spongey bone

Red= young, yellow= adult

Blood and Nerve Supply

Nutrient artery is main artery

5-10% of cardiac output

Largest source of blood, middle diaphysis

Runs through nutrient foramen

Important for quick regeneration

BV are interconnected aka collateral circulation. As BV are connect, one can break and the rest of the BV can help continue circulation

Epiphyseal artery

Enters at extremities, does not enter through articular surface

Metaphyseal artery

Enters through metaphysis

Arteries and Veins

Arteries

Veins

Anastomoses

Between nutrient and metaphyseal arteries

Good collateral circulation

Thin walled and accompany arteries

Cortical capillaries drain into venules within periosteum

NO LYMPHATIC VESSELS

NERVES ACCOMPANY LARGER VESSELS

Two hollow structures connect with each other

Flat, Short, and Irregular bones

Cartilage

made of cells called chondrocytes

Slow healing due to no blood supply

Nutrients and O2 are supplied through diffusion