The Skeletal System

I. Bone StructureChapter 6

Osteology• Osteology is the scientific study of bones. A

subdiscipline of anatomy, anthropology, and archeology, osteology is a detailed study of the structure of bones, skeletal elements, teeth, morphology, function, disease, pathology, the process of ossification (from cartilaginous molds), the resistance and hardness of bones (biophysics)

• often used by scientists with identification of human remains with regard to age, death, sex, growth, and development in a biocultural context.

A. Functions of the skeletal system

• Support• Protection• Leverage- for motion• Mineral Homeostasis• Blood cell production– Hemopoiesis in red bone marrow

• Triglyceride Storage

B. Types of Bones1. Long bones- longer than wide

– e.g. thigh, leg, arm, forearm, fingers & toes

2. Short bones- almost cube shaped– Most wrist & ankle bones

3. Flat bones- thin & extensive surface– e.g. Cranial bones sternum, ribs & scapulae

4. Irregular bones- don’t fit above-e.g. vertebrae and some facial bones

5. Sesamoid bones- small more or less rounded masses embedded in certain tendons and usually related to joint surfaces-e.g. palmar surface of the hand, thumb, middle and ring finger, patella, feet and toes

Sesamoid bone

C. Surface Markings on Bones

1. Foramen (hole)An opening through which blood vessels, nerves, and ligaments pass.

Example: foramen magnum2. Meatus (canal)

A tube-like passageway running within a bone.Example: external auditory meatus

C. Surface Markings on Bones

3. Paranasal sinus (cavity) An air filled cavity within a bone connected to the nasal sinus.

Example: sinus in frontal bone

4 Fossa (basin-like depression) Depression in or on a bone.

Example: olecranon fossa

D. Process that form joints

1. Condyle (knuckle-like process) A large rounded articular process.

Example: medial condyle of femur

2. Head A rounded articular projection supported on a constricted neck.

Example: head of the femur 3. Facet Smooth flat surface

Example: facet of a vertebra

E. Processes to which tendons, ligaments, and other connective tissue attach1. Tuberosity

A large, rounded, usually roughened processExample: deltoid tuberosity of the

humerus 2. Spinuous Process (spine)

A sharp, slender projectionExample: spinuous process of a vertebra

E. Processes to which tendons, ligaments, and other connective tissue attach3. Trochanter

A large, blunt projection found only on the femur

Example: greater trochanter 4. Crest

A prominent border or ridgeExample: iliac crest of hip bone

F. Parts of a long bone:

1. Diaphysis- shaft of the bone 2. Epiphysis- end of the bone- usually larger

than the bone; contains spongy bone with red marrow

3. Metaphysis- region of long bone between the diaphysisi and the epiphysis- contains the epiphysal plate or growth plate

4. Articular cartilage- hyaline cartilage attached to the bone surface around synovial joint- where bones articulate

5. Periosteum- membrane that covers bone- connective tissue, osteoblasts growth, repair, nutrition

6. Medullary cavity- space within diaphysis- contains yellow marrow- is the marrow cavity

7. Endosteum- membrane that lines the marrow cavity- has osteoclasts

Figure 6.1a

Figure 6.1b