BSC2085L 6 +7

Bone Structure and Tissue Types

• Spongy Bone vs. Compact Bone

  • Spongy bone includes structures like trabeculae, which are less organized and resemble an ant cave.

  • Trabeculae contain lacunae and osteocytes, but lack stability compared to compact bone structures.

• Canaliculi

  • Small channels connecting lacunae, allowing communication between osteocytes and facilitating nutrient exchange.

• Osteocytes and Osteoclasts

  • Osteocytes: Mature bone cells residing in lacunae.

  • Osteoclasts: Bone-resorbing cells, showing the dynamic nature of bone tissue structure.

Skeletal Anatomy

• Anatomical Position

  • Fundamental starting point for defining bone structures.

  • The skeleton is divided into two types:

    • Axial Skeleton: Central part, includes the skull and vertebral column.

    • Appendicular Skeleton: Contains the limb bones, including clavicles and scapulas.

• Clavicles and Scapulas

  • Clavicles connected to the rib cage, but not part of the axial skeleton, they are appendicular.

Skull Structure

• Cranial Features

  • The skull includes four significant sutures:

    • Coronal Suture: Separates anterior from posterior.

    • Sagittal Suture: Divides left from right.

    • Lamboid Suture: Connects occipital to parietal bones.

    • Squamous Suture: Connects the temporal bone to the parietals.

• Important Skull Bones

  • Frontal, Parietal, Temporal, Occipital.

  • Each bone has distinct features, such as the orbital and occipital regions.

Cranial Cavity Details

• Foremen Magnum

  • Large opening in the occipital bone allowing spinal cord passage.

  • Surrounded by Occipital Condyles, smooth protrusions that facilitate neck movement.

• Temporal Bone Structures

  • Contains significant features:

    • Zygomatic Process: Connects to the zygomatic bone.

    • Styloid Process: Pointed protrusion for muscle attachment.

    • Mastoid Process: Lateral and posterior projection for muscle attachment.

• Acoustic Features

  • External and internal acoustic meatuses assist in hearing processes.

Key Features of the Orbit

• Supraorbital Foramen

  • Located in the frontal bone, important for ocular structures.

• Infraorbital Foramen

  • Located in the maxilla, crucial for facial nerves and blood vessels.

• Cribriform Plate

  • Part of the ethmoid bone, facilitates the passage of the olfactory nerve, essential for smell.

Mandible and Other Facial Bones

• Mandible Features

  • Contains structures such as the coronoid process and connects to the skull via the temporomandibular joint.

• Importance of Notation

  • Specificity in anatomical terminology, such as distinguishing left from right bones, is vital for accuracy in medical contexts.