Bones

1.1.3 - State the four types of bone.

1.1.4 - Draw and annotate the structure of a long bone. 

1.1.5 - Apply anatomical terminology to the location of bones. 

Types of Bones

Long bones are longer than they are wide. ie. femur, humerus

Short bones are as wide as they are long. ie. carpals, tarsals

Flat bones have a broad, flat shape. ie. cranium, scapula

Irregular bones do not have any of the other regular bone shapes. ie. vertebrae, sacrum

Long Bone Structure

Diaphysis - Shaft/midsection of the bone consisting of mostly compact/hard bone. Compact bone is relatively solid and dense. Has few spaces and is also found in the outer layer of most other types of bones.

Epiphysis (Proximal & Distal) - Made up of cancellous or spongy bone. Cancellous/Spongy bone has an irregular latticework structure (like honeycomb) where there are many spaces. It is also found in short, flat, and irregular bones. Red marrow is stored there, blood cell production occurs here.

Articular Cartilage - Thin layer covers the ends of the bone where they articulate with other bones to form joints. The main functions are to reduce friction between the bones and absorb shock. 

Periosteum - This forms the outer lining of the bone and is important for bone growth, repair, nutrition, and attachment of ligaments and tendons.

Medullary (Marrow) Cavity - Space within the diaphysis where yellow bone marrow is stored. There is a small opening in the diaphysis called the nutrient foramen. Blood vessels pass through here, enter the medullary cavity and provide the marrow and compact bone with blood and nutrients.


Anatomical Terminology used to Identify Locations of Bones

Superior - towards the head (above)

Inferior - away from the head (below)

Proximal - near to center of the body

Distal - away from center of the body

Medial - midline of the body

Lateral - side of the body

Anterior - front of the body

Posterior - back of the body