Lecture 10: Bone Tissue, Growth and Remodeling

What is the primary function of bone tissue?

To support and protect organs, facilitate movement, and store minerals.

What are the two types of bone tissue?

Compact bone and spongy bone.

What is the role of osteoblasts?

To form new bone and secrete the bone matrix.

What is hemopoiesis?

The process of blood cell production occurring in red bone marrow.

Where is yellow bone marrow primarily found?

In the medullary cavity of long bones.

What is the function of osteoclasts?

To resorb bone by breaking down the bone matrix.

What is the diaphysis of a long bone?

The shaft or main portion of the bone.

What is the epiphysis?

The ends of a long bone, including distal and proximal extremities.

What is the periosteum?

A connective tissue membrane covering the bone, serving as an attachment point for ligaments and tendons.

What is the function of red bone marrow?

To produce mature blood cells, including white blood cells.

What is the process of ossification?

The formation of bone from preexisting connective tissue.

What is the role of the endosteum?

To line the medullary cavity and contain osteogenic cells.

What happens to red bone marrow as a person ages?

It decreases and is replaced by yellow bone marrow.

What is the primary mineral found in bone matrix?

Hydroxyapatite.

What is the difference between intramembranous and endochondral ossification?

Intramembranous ossification occurs directly from mesenchymal tissue, while endochondral ossification involves a cartilage model.

What is the function of collagen fibers in bone?

To provide tensile strength and support the bone structure.

What are trabeculae?

Thin plates of bone that make up spongy bone.

What is the significance of the metaphysis in immature bones?

It contains the epiphyseal plate, which is important for bone growth.

What is the primary role of mineral homeostasis in bones?

To store and release minerals like calcium and phosphate as needed.

What type of cells are osteogenic cells?

Undifferentiated cells that can become osteoblasts.

What is the role of osteocytes?

To maintain bone tissue.

What is the composition of the bone matrix?

It consists of mineral salts and collagen fibers.

What is the role of ligaments?

To connect bone to bone.

What is the role of tendons?

To connect bone to muscle.

How does the body utilize yellow bone marrow?

As an energy source stored in adipocytes.

What is the primary function of compact bone?

To provide strength and support to the skeleton.

What is the significance of the articular cartilage?

It covers the epiphysis and facilitates smooth joint movement.

What is intramembranous ossification?

The process of bone formation within fibrous connective tissue membranes.

What is endochondral ossification?

The formation of bone within a hyaline cartilage model.

What is the primary ossification center?

The area in the diaphysis where bone formation begins during endochondral ossification.

What are osteoblasts?

Bone builder, cells that lay down the osteoid matrix and eventually become osteocytes.

What is the role of osteoclasts?

Cells that absorb old bone tissue during bone remodeling.

What is the metaphysis?

The region of the long bone where the epiphyseal plate is located, consisting of transitional zones.

What are the five zones of the metaphysis?

1) Zone of reserve cartilage, 2) Zone of proliferating cartilage, 3) Zone of hypertrophic cartilage, 4) Zone of calcified cartilage, 5) Zone of bone deposition.

What is Wolff's Law?

The principle that bone restructures in response to stress and strain.

How does exercise affect bone growth?

Weight-bearing exercises promote bone mineral accumulation and help build or maintain bone mass.

What is myositis ossificans?

A condition where bone forms within skeletal muscles due to heterotopic bone formation.

What hormones regulate bone growth prior to puberty?

Human Growth Hormone (hGH), Insulin-Growth Factor (IGF), thyroid hormones, parathyroid hormone, and insulin.

What is the role of vitamin D in bone health?

Vitamin D is essential for calcium and phosphate absorption and utilization from the digestive tract.

What happens to bone growth after the epiphyseal line is formed?

Bone growth stops once the epiphyseal line forms, marking the closure of the epiphyseal plate.

What is the significance of the secondary ossification centers?

They develop in the epiphyses where bone replaces cartilage, except for the epiphyseal plate.

What is the difference between interstitial and appositional growth?

Interstitial growth increases bone length, while appositional growth increases bone thickness.

What is heterotopic bone formation?

The formation of bone in locations where it should not normally occur.

What is the effect of mechanical stress on bone?

Mechanical stress increases deposition of mineral salts and production of collagen fibers in bone.

What can cause vitamin D deficiency?

Lack of sunlight exposure, not drinking fortified milk, or keeping skin covered outdoors.

What is the role of calcitriol?

Calcitriol promotes calcium absorption in the digestive tract and reabsorption in the kidneys.

What is the consequence of removing mechanical stress from bones?

It leads to demineralization and weakening of bones.

What is the clinical application of heterotopic bone formation?

It can lead to complications when bone forms in inappropriate locations, such as muscles.

What is the role of estrogen and testosterone at puberty?

They stimulate rapid growth and skeletal modifications for biological males and females.

What is the significance of the zones of the epiphyseal plate?

They are crucial for the growth in length of long bones during development.

How does bone remodeling occur?

Old bone is destroyed by osteoclasts and new bone is constructed by osteoblasts.

What is the role of chondroblasts in endochondral ossification?

Chondroblasts produce hyaline cartilage that is later replaced by bone.

What happens during the zone of calcified cartilage?

Mineral deposition occurs, leading to the calcification of cartilage.