MAP Unit 5: Bones Part 2 - Bone Physiology

What are the six major functions of bones?

Support, protection, movement facilitation, mineral storage, energy storage, and hematopoiesis.

What is the support function of bones?

Bones provide a framework for the body and support soft tissues.

What structures attach to bones?

Ligaments, tendons, fascia, and muscles.

What is the protection function of bones?

Bones protect delicate internal organs from injury.

What does the skull protect?

The brain.

What does the vertebral column protect?

The spinal cord.

What do the ribs protect?

The heart and lungs.

What do the pelvic bones protect?

The internal reproductive organs.

What is the movement facilitation function of bones?

Bones serve as levers that convert muscular contractions into movement.

What minerals do bones store?

Calcium and phosphorus.

Where are calcium and phosphorus stored in bones?

In the bone matrix.

What is the energy storage function of bones?

Yellow bone marrow stores lipids and serves as an energy reservoir.

What is hematopoiesis?

The process of producing blood cells in red bone marrow.

Where does hematopoiesis occur?

In red bone marrow.

What are erythrocytes?

Red blood cells.

What are leukocytes?

White blood cells.

What are thrombocytes?

Platelets.

What are the three major types of bone cells?

Osteoblasts, osteocytes, and osteoclasts.

What are osteoblasts?

Bone-forming cells that secrete an organic matrix and mineral salts.

What is the primary function of osteoblasts?

To build and form new bone tissue.

What are osteocytes?

Mature bone cells and the principal cells of bone tissue.

How are osteocytes formed?

Osteoblasts become surrounded and isolated within the mineralized bone matrix in spaces called lacunae.

Where are osteocytes located?

In lacunae within the bony intercellular matrix.

What is the function of osteocytes?

They maintain the daily cellular activities of bone tissue.

Do osteocytes have mitotic potential?

No. They cannot divide through mitosis.

What are osteoclasts?

Cells that break down and resorb bone tissue.

What are the functions of osteoclasts?

They help with bone development, growth, maintenance, and repair.

How do osteoclasts help regulate blood calcium?

They break down bone tissue, releasing calcium into the bloodstream.

What is bone growth?

The process in which existing connective tissues are replaced by bone tissue.

What are the two types of bone growth?

Intramembranous bone growth and endochondral bone growth.

What is intramembranous bone growth?

Bone formation that occurs directly within membrane-like layers of connective tissue.

Where does intramembranous bone growth occur?

In the skull bones.

How does intramembranous bone growth occur?

Primitive cells in connective tissue membranes develop into osteoblasts, which produce bone matrix and become osteocytes.

What is endochondral bone growth?

Bone formation that occurs by replacing a preexisting hyaline cartilage model with bone.

Where does endochondral bone growth occur?

In most bones of the skeleton.

What type of tissue forms the model during endochondral bone growth?

Hyaline cartilage.

What happens to cartilage cells during endochondral bone growth?

The cartilage cells enlarge and destroy the cartilage matrix.

What happens when osteoblasts form during endochondral bone growth?

They deposit bony matrix, creating bone tissue.

Where else does endochondral bone growth occur in long bones?

At the epiphyseal plate, also called the growth plate.

What is the epiphyseal plate?

The growth plate of a long bone where bone lengthening occurs.

What is ossification?

The process of bone formation by replacing preexisting connective tissue with bone.

When does ossification occur?

During bone growth.

What is the difference between osteoblasts and osteoclasts?

Osteoblasts build bone, while osteoclasts break down bone.

What is the difference between osteoblasts and osteocytes?

Osteoblasts form new bone, while osteocytes are mature bone cells that maintain bone tissue.

What is the difference between red and yellow bone marrow?

Red bone marrow produces blood cells; yellow bone marrow stores lipids for energy.