Classes of Bones (Long Bones) - A&P

What are the 4 classes of bones

Long, short, flat, wide

Long Bones

Longer v.s wide and has two regions

Short Bones

All roughly cubed shaped

Sesamoid Bone

Specially type of short bone that forms in a tendon

Flat Bones

Thin, flattened, and usually a bit curved

Irregular Bones

Have complex shapes that don’t fit into other 3 categories

Long bones 2 regions

Epiphysis and Diaphysis

Epiphysis

Located at the ends of long bone

Diaphysis

In between epiphysis of long bone

what is the epiphysis made of

Spongy bone tissue covered by thin layer of compact bone tissue

What are the ends of long bones covered with

Articulate cartilage that protects the ends of bone

Lacunae

Filled with red bone marrow which is the primary site of hematoplesis

What is the diaphysis made of

Compact bone tissue

Medullary cavity

Hollowed out center of diaphysis that contains yellow bone marrow (typically inactive in adults, mostly fat, and only active in blood emergencies)

What are the two membranes found in the diaphysis

Periosteum and Endosteum

Periosteum

Found around outer diaphysis, protects and helps guide remodeling/repair of bone

Endosteum

Lines medullary cavity

Example of long bones

Humerus, tibia, femur

Examples of short bones

Carpals, tarsals

Examples of flat bones

Scapula, ribs, sternum

Examples of irregular bones

Vertebrae, ischium, pubis