Bone Histology and Skeletal Structure Review

What is bone?

Bone is living tissue that makes up the body's skeleton. There are three types of bone tissue, including the following:

Compact (dense) bone tissue the harder, outer tissue of bones; made up

of precise arrangements of microscopic cylindrical structures called osteons. The matrix and osteocytes of osteon are laid down in concentric rings around a central (Haversian) canal which contains blood vessels and nerves.

If you look at compact bone tissue with naked eye, it look very dense: you cannot see any cavities in it.

Spongy (cancellous) bone tissue

the sponge-like tissue inside bones. In contrast, made up of irregular latticework of thin blades of bone called trabeculae. The spaces between the trabeculae contain blood vessels and red marrow which produces blood cells.

The spaces between the trabeculae can be seen with naked eye and give spongy bone tissue its "spongy" look.

subchondral tissue

the smooth tissue at the ends of bones, which is covered with another type of tissue called cartilage. Cartilage is the specialized, gristly connective tissue that is present in adults, and the tissue from which most bones develop in children.

What are the different types of bone cells? The different types of bone cells include the following:

osteoblast - found within the bone, its function is to form the tissue and minerals that give bone its strength.

osteoclast - a very large cell formed in bone marrow, its function is to absorb and remove unwanted tissue; remodeling

osteocyte - found within the bone, its function is to help maintain bone as living tissue.

Fat cells and hematopoietic cells are found within the bone marrow.

Hematopoietic cells are those that produce blood cells.

Bone's function? shape, support, and protect body structures; aid

in body movement

serve as a site for development and storage of blood cells disorders and diseases that can affect bone.

serves as a storage site for minerals; provides the medium - marrow - for the development and storage of blood cells.

But How? Support

bones of the leg, pelvic, and vertebral column hold up the bodythe mandible supports the teethprovide support for muscles and other soft organs

Protectionbones enclose and protect the brain, spinal chord, lungs, heart, pelvic viscera, and bone marrow

Movementof course, to walk, reach, touch (limb leverage)lung ventilation depends on by movement of ribs by skeletal muscles

But How? Blood Formation red bone marrow is major producer of blood cells Electrolyte Balance the skeleton is the body’s main mineral reservoir; it

sores calcium and phosphates and releases them according to physiological needs of the body

Acid-base balance bone buffers the blood against excessive pH

changes by absorbing/releasing alkaline mineral salts

Types of Bone Long Bone

Example: Femur Short Bone

Example: Carpal Flat Bone

Example: Pelvic Irregular Bone

Example: facial Sesamoid Bone

Example: Patella

Skeletal Structure Tissue cartilage osseous tissue bone marrow periosteum/endosteum

The Skull

Anterior View of Skull

Right Lateral Aspect of Skull

Posterior View of Skull

Midsagittal View of Skull

Inferior Superficial View of Skull

Superior View of Cranial Cavity

Nasal Cavity

Vertebrae, Ribs, and Sternum

How many bones are there in the vertebral column?

Answer: 26

How regions are there in the vertebral column and what are their names?

Answer: 5 regions: cervical, thoracic, lumbar, sacral,

coccygeal

What are the name of the first two bones of the vertebral column and their functions?

Answer: Atlas and Axis the support and movement

of the skull

What type of vertebrae is this picture?

Answer: Cervical vertebrae

What are these three sections of the cervical vertebrae?

Answer1) Spinous Process

2) Superior Articular Facet

3) Body

What type of vertebrae is this picture?

Answer: Thoracic Vertebrae

What are these three sections of the thoracic vertebrae?

Answer1) Superior Costal Facet

2) Lamina

3) Vertebral Foramen

How many pair’s ribs does the human

body have?

Answer: 12 pairs

What are the names of the types of ribs?

Answer: True and False Ribs

What is the difference between True and

False Ribs?

Answer: True ribs are attached to the sternum.

What bone is this?

Answer Sternum

What are the names of theses sections of the Sternum?

Answer1) Manubrium

2) Body

3)Xiphoid Process

The Pectoral Girdle and Superior Appendages

Pectoral girdles are responsible for attaching the superior appendages (the arms, forearms, wrists, and hands) to the axial skeleton.

On each side of the body the pectoral girdle consists of two bones: the scapula and the clavicle.

Scapula

The scapula is also known as the shoulder blade.

It is connected to the humerus by a ball and socket joint.

It is an irregular bone.

Clavicleis an irregular bone

Humerus The humerus is a long

bone.

It connects to the ulna by the elbow which is a hinge joint.

Ulna and Radius Are both long bones

Hand Most of these bones

are long bones.

Pelvic Girdle and Inferior Appendages

The hip bone is composed of threeelements:

Which also fuse at the acetabulum (the

socket of the hip joint).

Here’s your chance at the extra point!

Comparison of Male and FemalePelvic Structure

Comparison of Male and FemalePelvic StructureFemale pelvis Tilted forward,

adapted for childbearing

True pelvis defines birth canal

Cavity of the true pelvis is broad, shallow, and has greater capacity

Male pelvis Tilted less forward Adapted for support

of heavier male build and stronger muscles

Cavity of true pelvis is narrow and deep

Thigh, Leg and Foot