BIOL 319- Osteology- The Axial Skeleton

How many bones are there in the adult skeleton?

206

How many bones are there in the axial skeleton?

80

How many bones are there in the appendicular skeleton?

126

Characteristics of Compact Bone?

Smooth and Homogeneous

Characteristics of Spongy Bone?

Small trabeculae of bone and lots of open space

What are 4 types of bone?

Long, Short, Flat, Irregular

What are the characteristics of long bone?

Longer than wide

Shaft with heads at each end

Composed of compact bone

What are the characteristics of short bone?

Cube-shaped

More spongy than compact bone

What are the characteristics of flat bones?

Flat wafer like

3 layers, 2 compact on the outside and 1 spongy on the middle

What are the characteristics of Irregular bones?

Do not fit to any category

What are the two divisions of the skeletal system?

Axial Skeleton (80)

Appendicular Skeleton (126)

What are the major bones of the cranium?

Frontal

Parietal

Temporal

Occipital

Sphenoid

Ethmoid

Maxilla

Mandible

Why must the fetal cranium remain flexible?

-Easily move through the birth canal

-Allow for brain growth and expansion

What are the 12 cranial nerves?

I. Olfactory

II. Optic

III. Oculomotor

IV. Trochlear

V. Trigeminal

VI. Abducens

VII. Facial

VIII. Vestibulocochlear

IX. Glossopharyngeal

X. Vagus

XI. Accessory (Spinal)

XII. Hypoglossal

What is periosteum?

-Fibrous membrane, covers compact bone

-2 layers:

Outer Fibrous Layer- tendons and ligaments attach

Inner Cellular Layer- Produces osteoblast (growth)

What is the diaphysis?

central shaft of long bone

What is Epiphysis?

They are located at each end of the bone

Proximal and Distal in relation to the trunk

What is the articular cartilage?

Hyaline cartilage that covers epiphysis when articulating with another bone

Where is the marrow cavity?

In the hollow center of the diaphysis

What is contained within the marrow cavity of long bones?

Yellow marrow- high concentration of lipids

What membrane lines the marrow cavity?

Endosteum

What is in between the epiphysis and diaphysis?

Metaphysis

What is the metaphysis called in young people?

Epiphyseal Cartilage

What is the purpose of Epiphyseal cartilage?

Hyaline Cartilage that allows for bone growth

What does the Epiphyseal cartilage turn to?

Epiphyseal line

What are the compact layers of the flat bone collectively called? Individually?

-Cortex of the bone

- External and Internal Tables

What is the spongy bone in the flat bones called?

Diploe, Filled with Red Marrow

What are Bone markings?

Where bone form joints

Muscles, Tendons, Ligaments are attached

Blood vessels and nerves pass

What are the two categories of bone markings?

Projections- grow out of the bone

Depressions- Indentation or openings in the bone

Tuberosity

Large Rounded Projection

Crest

Narrow ridge of a bone

Trochanter

Very large, blunt, Irregular shaped process

Line

Narrow ridge of bone, less predominant than crest

Tubercle

Small Rounded projection

Enrique

Central part in melissa's heart

Epicondyle

Raised area above condyle

Spine

Sharp slender, pointed projection

Head

Body expansion carried by neck

Facet

Smooth flat articular surface

Condyle

Rounded articular projection

Articulates with fossa

Ramus

Armlike bar

Foramen

Round opening though a bone

Groove

Furrow

Fissure

Narrow slit opening

Notch

Indentation at edge of structure

Fossa

Shallow basin like depression

Meatus

Canal like passageway

Sinus

Cavity filled with air, lined with mucous membrane