The Skeletal System
I. Bone Structure
Chapter 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
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Support
Protection
Leverage- for motion
Mineral Homeostasis
Blood cell production
– Hemopoiesis in red bone marrow
• Triglyceride Storage
B. Types of Bones
1. 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 magnum
2. 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
attach
1. Tuberosity
A large, rounded, usually roughened process
Example: deltoid tuberosity of the humerus
2. Spinuous Process (spine)
A sharp, slender projection
Example: spinuous process of a vertebra
E. Processes to which tendons,
ligaments, and other connective tissue
attach
3. Trochanter
A large, blunt projection found only on the
femur
Example: greater trochanter
4. Crest
A prominent border or ridge
Example: 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 jointwhere bones articulate
5. Periosteum- membrane that covers boneconnective tissue, osteoblasts growth, repair,
nutrition
6. Medullary cavity- space within diaphysiscontains yellow marrow- is the marrow cavity
7. Endosteum- membrane that lines the
marrow cavity- has osteoclasts
Figure 6.1a
Figure 6.1b