Lab 5: Introduction to Skeletal Tissues/The Axial Skeleton

Before coming to lab:

1. Familiarize yourself with the major bones of the axial skeleton.
2. Look over Lab Manual Fig. 9.3 (p. 116) so that you’re comfortable with the structures and vocabulary associated with compact bone histology.

During the lab period (can be completed in any order):

1. For your Histology Notebook:
   • hyaline cartilage – Brief Atlas: Plate 17 (p. 8); Histology Atlas: Fig. 5.3 (p. 45)
     • Recommended # of pages: 1-2
     • Draw at 400x total magnification.
       • A view at 100x may be helpful, too.
     • Label the following: chondrocyte, lacuna, matrix, perichondrium
   • compact bone – Brief Atlas: Plate 20 (p. 9); Histology Atlas: Fig. 6.4 (p. 53)
     • Recommended # of pages: 1-2
     • Draw at 100x total magnification.
     • Label the following: osteon, central (Haversian) canal, lacuna, lamella, canaliculus
       • We also have a model of compact bone. Try to find these structures on the model as well.
2. View additional slides of skeletal tissues: (these do not have to be included in the Histology Notebook, but they may show up on Lab Exam 1)
   • elastic cartilage – note the presence of the darkly-stained elastic fibers in the matrix.
   • fibrocartilage – this tissue is notable for the presence of thick collagen fibers; it appears like a hybrid of hyaline cartilage and dense regular connective tissue.
   • growing long bone – you should be able to see the cartilage at the epiphyseal plate with the naked eye!
3. Sawed bone (stored in a clear, plastic bag)
   • You should be able to see the compact bone surrounding the medullary cavity.
     • The cavity itself is filled with yellow bone marrow.
   • Also, find the periosteum; it’s the flaky membrane surrounding the bone.
4. Acid-soaked bone (stored in a small, ziplock bag)
   • Acid dissolves the inorganic component of bone, leaving only the organic component (mostly collagen).
5. Baked bones
   • Baking bones dehydrates them, essentially drying away the organic component. The inorganic component (i.e., hydroxyapatites) remains.
6. Looking at axial skeleton bones:
   • Note: Much of the rest of this will seem a bit overwhelming, but we’ll cover a great deal of this material in lecture as well.
   • Cranial bones
     • Use the skull provided and the Brief Atlas (Figs. 1-5, pp. 27-31) to identify the following bones and sutures:
       • frontal bone
       • parietal bones
       • temporal bones
       • occipital bone
       • sphenoid bone (Brief Atlas: Fig. 9, p. 36)
       • ethmoid bone (Brief Atlas: Fig. 10, p. 37)
       • coronal suture
       • sagittal suture
       • squamous suture
       • lambdoid suture
   • Facial bones
     • Use the Beauchene skull and Marieb Lab Manual Fig. 10.14 (p. 129) to identify the following facial bones.
       • mandible
       • maxillae
       • palatine bones
       • zygomatic bones
       • lacrimal bones
       • nasal bones
       • vomer
   • Vertebral column
     • Your lab group has been given three vertebrae.
       • There is one cervical, one thoracic and one lumbar vertebra.
       • Use Marieb Lab Manual Fig. 10.14 (p. 125) to determine which is which.
     • Once you’re confident you can tell the difference, there is a pink Tupperware box of vertebrae on the front bench. Try to sort them out.
   • Bony thorax
     • On the skeleton, identify the ribs and the sternum.
       • Note how the ribs attach to the sternum.
       • The clay on the skeletons is meant to represent the costal cartilages.

By the next lab:

1. Come into the lab when you are free.
   • The bones will be available in the back room.
   • If there’s something missing (or something you’d like to see), I’ll be happy to get it out for you.
2. Next week’s lab will be dedicated to the appendicular skeleton.
   • I suggest you practice labeling the attached figure.
   • I will post the answers outside of my office. (Note: This is optional.)
3. Spend time looking over the Lab Exam 1 Review Sheet to see what you’re responsible for regarding the bones.