MEDS 7/1 - Bones

1. Describe bone function, structure and components in overview. 2. Describe bone classifications with examples and Identify selected individual bones of the human skeleton. 3. Describe and discuss the human skeleton using anatomical terminology. 4. Describe and identify marking and features on bones. 5. Describe the basic vasculature system in relation to bone

What are the major functions of the skeletal system? (5)

1. Movement

2. Storage

3. Stability

4. Protection

5. Blood cell production

What are the two types of cells involved in bone formation?

• Osteoblasts

• Osteoclasts

What are osteoblasts responsible for?

Building bone

What are osteoclasts responsible for?

Breaking down damaged bone.

Why are bones constantly changing?

• Adapting to loading and activity

• Healing

• Responding to changes in muscle

What are the two types of tissue that make up bones?

• Cancellous

• Cortical

Describe Cancellous bone tissue.

• Spongy

• Inside of bone

• Made up of trabeculae

Describe Cortical bone tissue.

• Dense

• Outside of bone

• Made up of osteons

What are trabeculae?

Small beams of bone making up cancellous tissue.

What is the function of trabeculae?

• Structural support

• Distribute force

• Ensure our bones aren’t super heavy

What are osteons?

• Cyclindrical units which form compact bone.

• Include: Osteocytes, lamellae, blood vessels and nerves.

What is the Periosteum?

• Fibrous sheet that covers the bone

• Includes blood vessels and nerves

What does the Periosteum provide to the bone?

• Nourishment (blood vessels)

• Sensation (nerves)

What are the two main components of bones?

• Hydroxyapatite

• Collagen

What is Hydroxyapatite and what is its function in bones?

• Mainly calcium and phosporus

• Provides strength and rigidity

What is collagen and its purpose in bones?

• Made up of protein

• Provides flexibility and elasticity to bone.

What are the four sections of a bone?

• Epiphysis - End of bone

• Epiphiseal Line - growth plate

• Metaphysis - part of shaft next to growth plate

• Diaphysis - shaft

What is the Epiphyseal line (growth plate)?

• Section of cartilage which is gradually replaced by bone until the metaphysis and epiphysis join and growth stops.

What are the two divisions of the skeleton?

• Axial

• Appendicular

What makes up the Axial portion of the skeleton?

• Skull

• Thoracic cage

• Vertebral Column

What makes up the appendicular portion of the skeleton?

All of the bones in our appendages.

What are the 5 shape classifications of bone?

• Long

• Short

• Irregular

• Sesamoid

• Flat

What is the function and an example of a long bone?

• Lever for movement

• Humerus

What are two examples of short bones?

• Carpals

• Tarsals

What is the function and an example of a flat bone?

• Protection of internal organs.

• Frontal bone of the skull

What are two examples of irregular bones?

• Vertebra

• Maxilla

What is unique about sesamoid bones (location)

They are embedded in a tendon.

What is the function and an example of a sesamoid bone?

• Improve mechanical efficiency of tendons

• Patella

What are markings on bones?

The attachment sites of tendons, ligaments and fascia.

What are features of bones?

• Hollows and elevations

• Holes/openings

What is a bone crest (+ example)?

• Ridge of bone

• Iliac crest

What is a bone foramen (+ example)?

• Opening/hole in bone

• Obturator foramen in the hip bone.

What is a bone fossa (+ example)?

• Hollow/depression in bone surface

• Iliac fossa

What is a bone tuberosity (+ example)?

• Roughened area for muscle/ligament attachment.

• Ischial tuberosity - attachment point for hamstrings.