Overview of Bone Tissue and the Human Skeleton

Bone Tissue

Bone Tissue Histology

Bone tissue is a specialized connective tissue that forms the rigid part of the bones in the skeleton. Its histology reveals several key structures:

• Central Canal: The central canal (Haversian canal) is found in the center of osteons and contains blood vessels and nerves.

• Lacunae: Small spaces within the bone matrix that house osteocytes.

• Osteocytes: Mature bone cells responsible for maintaining bone tissue.

• Bone Tissue Models: Includes parts of a long bone such as the epiphysis (ends), diaphysis (shaft), and medullary cavity (central cavity containing marrow).

• Cavity: Refers to spaces within bones, such as the medullary cavity.

Bone Shapes

Bones are classified by their shapes, which relate to their functions:

• Long Bones: e.g., femur, humerus

• Short Bones: e.g., carpals, tarsals

• Flat Bones: e.g., skull, ribs

• Irregular Bones: e.g., vertebrae

Types of Bone Tissue

There are two main types of bone tissue:

• Compact Bone: Dense and forms the outer layer of bones.

• Spongy Bone: Porous and found at the ends of long bones and inside flat bones.

Additional info: Bone tissue is highly vascularized and constantly remodeled throughout life.

Skeleton

Axial Skeleton

The axial skeleton forms the central axis of the body and includes the following bones:

• Skull

  • Parietal

  • Temporal

  • Sphenoid (articulated/disarticulated)

  • Ethmoid (articulated/disarticulated)

  • Occipital

  • Frontal

  • Nasal

  • Zygomatic

  • Inferior nasal concha

  • Maxilla

  • Mandible

  • Vomer

  • Hyoid

• Cervical Vertebrae

  • C1 (Atlas)

  • C2 (Axis)

  • Vertebrae from each region

• Thoracic Cage

  • Ribs

    • True ribs

    • False ribs

    • Floating ribs

  • Sternum

    • Body

    • Manubrium

    • Xiphoid process

Parts of Vertebrae

• Body

• Lamina

• Pedicle

• Spinous process

• Transverse process

Exhaustive List of Testable Skull Features

The skull contains numerous features that are important for identification and function:

• Alveolar process

• Coronal suture

• Coronal sinus

• External acoustic meatus

• External occipital protuberance

• Foramen magnum

• Foramen rotundum

• Glabella

• Internal acoustic meatus

• Jugular foramen

• Lambdoid suture

• Mandibular condyle

• Mastoid process

• Mental foramen

• Occipital condyle

• Optic canal

• Posterior cranial fossa

• Sagittal suture

• Squamous suture

• Superior orbital fissure

Additional info: These features are used to identify bones and their articulations, as well as to understand the passage of nerves and blood vessels.

Ribs

• Types: True, False, Floating

• Features: Head, neck, tubercle, shaft, costal groove

• Number: 12 pairs in humans

Appendicular Skeleton

The appendicular skeleton includes the bones of the limbs and girdles that attach them to the axial skeleton.

• Pectoral Girdle

  • Clavicle

  • Scapula

• Upper Limb

  • Humerus

  • Radius

  • Ulna

  • Metacarpals

  • Phalanges

  • Carpal bones:

    • Scaphoid

    • Lunate

    • Triquetrum

    • Pisiform

    • Hamate

    • Capitate

    • Trapezoid

    • Trapezium

• Pelvic Girdle

  • Pelvis

    • Ilium

    • Pubis

    • Ischium

• Lower Limb

  • Femur

  • Patella

  • Tibia

  • Fibula

  • Tarsal bones:

    • Talus

    • Calcaneus

    • Navicular

    • Cuboid

    • Cuneiform bones (medial, intermediate, lateral)

  • Metatarsals

  • Phalanges

Additional info: The appendicular skeleton is essential for movement and manipulation of the environment.

Summary Table: Major Bone Groups and Examples

Bone Group	Examples	Main Function
Axial Skeleton	Skull, Vertebrae, Ribs, Sternum	Protection of vital organs, support
Appendicular Skeleton	Clavicle, Scapula, Humerus, Femur, Pelvis	Movement, manipulation
Long Bones	Femur, Humerus	Support, movement
Short Bones	Carpals, Tarsals	Stability, support
Flat Bones	Skull, Ribs	Protection, muscle attachment
Irregular Bones	Vertebrae	Protection, support