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