Bone (Esteology)

What is a Bone?

A DYNAMIC tissue that is strong, lightweight, and responsive to movement/strain

2 Main Components 

Collagen & Hydroxyapatite

Functions of the Bone 

Support and Protection, Movement, Hematopoiesis, Storage of minerals and fat 

2 Types of TISSUE 

Spongy & Cortical

Spongy

Porous, lightweight, Internal bone in areas around joints

Cortical

Solid, dense and smooth
External bone surface

Hematopoiesis

Bone marrow in cow bone 

2 types of bone marrow

RED bone marrow and YELLOW bone marrow 

RED bone marrow (hematopoietic)

Found in areas of spongy bone

YELLOW bone marrow 

Mainly fat reserve found in the medullary cavity

Wolff’s Law

Bone forms in areas of stress and resorbs in areas of non-stress aka REMODELLING 

Example of Wolff’s Law

f a person lost their teeth before death, it reconstruct the positions of the bones, becomes thinner because there are no stresses being placed on the bone.

Types of Bones 

Long Bones, Short Bones (Sesamoid), Flat Bones, Irregular Bones 

Parts of a Long Bone

Epiphysis, Diaphysis, and Metaphysis 

Epiphysis

the rounded end or tip of a long bone

Diaphysis

the main or central tubular shaft of a long bone

Metaphysis

the wide, flared neck portion of a long bone located between the central shaft (diaphysis) and the end section (epiphysis)

The Human Skeleton

Typically composed of 206 elements, Most elements are presented bilaterally, and Some element (phalanges and vertebrae), are present in multiples

The body can be divided into 2 MAJOR SEGMENTS 

Axial & Appendicular

Axial (Blue) - MIDLINE 

• Cranium

• Mandible

• Hyoid

• Sternum

• Ribs

• Vertebral column

Appendicular (Red) - Appendages and Associated Structures 

Upper Limb and Shoulder Girdle 
Lower Limb and Pelvic Girdle

Upper Limb and Shoulder Girdle 

• Clavicle

• Scapula

• Humerus

• Radius

• Ulna

• Hand bones

Lower Limb and Pelvic Girdle

• Os coxa

• Femur

• patella

• tibia

• fibula

• Foot bones

The SKULL

Key to aging, sexing, and understanding the evolutionary history

What is the skull composed of?

Cranium and mandible (Consist of 28 bones)
Splanchonocranium (Face) 
Neurocranium (braincase) 

Functions of the Skull

• Forms the foundation for the senses of sight, smell, taste, and hearing

• Houses and protects the brain

• Chewing

Unpaired Bones

Frontal

Occipital

Sphenoid

Vomer

Ethmoid

Mandible

Paired Bones 

Perietals

Temporals

Zygomatics

Maxillae

Nasals

Palatines

Inferior nasal conchae

Lacrimals Ear ossicles (x3)

Hyoid

NOT a skull bone !

Inferior to the mandible

Anchors the muscles invoked in speech

Does not articulate with any other bones

Cranial Sutures 

Coronal Suture, Sagittal Suture, Squamous Suture, Lambdoidal Suture 

Pterion 

Bony landmark where frontal, parietal temporal, and sphenoid bones articulate