Ex8: Bone Classification, Structure & Relationships: An Overview

This lab is designed to provide students with an overview of bones through a variety of investigative activities. https://sites.google.com/site/physiolablist/
The Objectives for this lab are:

1. To list at least three functions of the skeletal system.
2. To identify the four main kinds of bones.
3. To identify surface bone markings and their function.
4. To identify the major anatomical areas on a longitudinally cut long bone (or diagram of one).
5. To identify the major regions and structures of an osteon in a histological specimen of compact bone (or diagram or model of one).
6. To explain the role of the inorganic slats and organic matrix in providing flexibility and hardness to bone.

Hypotheses & Procedures
Part 1: Bone Markings & Classification.
     If students examine a variety of disarticulated bones then they will be able to classify them into one of the four anatomical groups: long, short, flat, or irregular and point out examples of bone markings.

Part 2: Gross Anatomy of the Typical Long Bone.
      If students examine a fresh cut bone as well as a cleaned dry bone that has been cut along its longitudinal axis, then they will be able to identify the major anatomical structures of a bone as an organ.

Part 3 Microscopic Structure of Compact Bone.
     If students observe a prepared slide of ground bone as well as a model of microscopic compact bone, then they will be able to identify the major regions and structures of an osteon.

Part 4: Chemical Composition of Bone:
     If students observe a sample of bone that has been baked then they will be able to identify the role of the organic compounds in bone because baking removes the collagen fibers of the matrix.
     If students observe a sample of bone that has been soaked in acid then they will be able to identify the role of the inorganic compounds in bone because acids dissolve the calcium salts.

Materials (on lab sheet)

Experiment/Data and lab questions

Part 1: Bone Markings & Classification.  

     Insert a picture of each type of bone, with a caption identifying its shape as long, short, flat, or irregular.  Within your caption, also identify any bone markings that show up in your picture.

irregular- vertebrea

long bone- femur

short bone- patella

flat bone- sternum

Part 2: Gross Anatomy of the Typical Long Bone. 

      Insert at least one picture your partner pointing out a specific feature of long bone. Provide a caption to identify the specific feature.

this is compact bone

Bone marrow would be in the cavity down the middle of the bone

Part 3 Microscopic Structure of Compact Bone. 

     Copy/paste this image into a draw program (like MS Paint).  Label the parts of the osteon that you can identify.  Save the image and use it to replace the unlabeled one into your blog, .

Part 4: Chemical Composition of Bone: 

Do treated bones retain the structure of untreated specimens?

     No, treated bones do not retain the same structure as untreated specimens because the treated bone does not contain collagen fibers and calcium.

Describe what happened to the matrix when the bone was baked.  How does this bone feel?

When the bone was baked it became hard. This is because the collogen proteins left the matrix. 
Describe what happened to the matrix when the bone was soaked in acid.  How does this bone feel?
The bone that was soaked in acid is soft because it has had the calcium removed from the matrix, resulting in a weaker bone.
Optional: Include a video of your lab team demonstrating the effects of baking and acid on the matrix of bone.

The bone soaked in acid has a permeable matrix, while the bone that was baked is hard.

Conclusion:

1.  List at least three functions of the skeletal system.                                                                 -The bone provides structure, supports muscles to move, and stores nutrients.
2. Identify the four main kinds of bones.                                                                                    -The four main types of bone are short, long, flat, and irregular.  Examples of a short bone are carpals and the patella.  The femur and tibia are examples of long bone. The sternum is a flat bone and the vertebrae are irregular bones.  
3. Which surface bone markings and their function can you identify and describe?              -A tuberosity is a large rounded projection, a crest is a narrow ridge of bone, a trochanter is a very large and irregularly shaped process on the femur, a tubercle is a small rounded projection, and a epicondyle is a raised area on or above the condyle all of which are the site of muscle attachment. A bone head, facet, condyle, and ramus are all projections that help form joints.  The bone meatus, sinus, fossa, groove, fissure, and foramen are all depressions or openings in the bone that allow blood vessels and nerves to pass through.  
4. Which major anatomical areas on a longitudinally cut long bone (or diagram of one) can you identify?                                                                                                                     -I can identify the medullary cavity that houses the yellow bone marrow, the epiphyseal line that acts as the growth plate, and the epiphysis and diaphysis, which are the ends and middle part of the bone respectively.  
5. Which major regions and structures of an osteon in a histological specimen of compact bone (or diagram or model of one) can you identify?                                                        -I can identify the lacuna(cavity that holds the osteocyte), the canaliculi(tiny canals), the haversian canal(central canal), and the lamella(concentrict circles around cell).
6. Explain the role of the inorganic salts and organic matrix in providing flexibility and hardness to bone.                                                                                                         -The inorganic salts, such as calcium, provide bone density and create a strong and hard bone, as seen in the acid experiment above.  The organic matrix, collagen proteins, provide the bone with flexibility, which is why the bone that was baked and had the fibers removed was very stiff and inflexible.