Anatomy and Physiology Chapter 6 Flashcards

Functions of Bone

• Supports and protects soft tissues in the body.
• Provides attachment sites for muscles, facilitating movement.
• Serves as a storage site for minerals, particularly calcium.
• Engages in blood cell production within red bone marrow.
• Acts as an energy reserve in yellow bone marrow.

Bone Structure

• Diaphysis: The long shaft of a bone.
• Epiphysis: The end part of a long bone.
• Metaphyses: Growth areas between the epiphysis and diaphysis, including the epiphyseal plate.

Parts of a Long Bone

• Endosteum: The lining of the marrow cavity.
• Periosteum: A tough membrane that covers bone, excluding cartilage.

Bone Matrix Composition

• Contains inorganic salts (calcium phosphate and calcium carbonate) and collagen fibers.

Bone Cells

• Osteogenic Cells: Stem cells that develop into osteoblasts.
• Osteoblasts: Responsible for forming bone matrix (builders).
• Osteocytes: Mature bone cells that maintain bone tissue.
• Osteoclasts: Cells that resorb (break down) bone matrix (chewers).

Bone Types

• Spongy Bone: Characterized by many spaces that house red bone marrow.
• Compact Bone: Dense structure with very few spaces, found in the shafts of long bones.

Osteons (Haversian Systems)

• Composed of blood vessels, lymphatic vessels, nerves, and osteocytes, all embedded in a calcified matrix, oriented along lines of stress.

Bone Arrangement

• Compact Bone: Arranged in concentric rings; osteocytes are located in lacunae, connected via canaliculi.
• Spongy Bone: Organized into trabeculae that align along stress lines, filled with red bone marrow.

Growth and Development

• Intramembranous Ossification: Direct formation of bone from mesenchyme, primarily resulting in flat bone.
• Endochondral Ossification: Bone formation occurs from hyaline cartilage, mainly forming long bones.
• Lengthening occurs at the epiphyseal plate via cartilage cell division and transformation into bone.
• Width Growth: Involves periosteal cells differentiating into osteoblasts, forming new bone layers.

Factors Influencing Bone Growth

• Nutrition and hormonal levels significantly affect bone development.
• Insulin-like Growth Factor (IGF): Stimulates cellular division and growth influenced by growth hormone and thyroid hormone.

Bone Remodeling

• Continuous process of resorbing old bone and replacing it with new tissue, regulated by osteoclasts and osteoblasts.

Fracture Healing Process

• Hematoma Formation: Clot occurs due to damaged blood vessels, initiating inflammation and capillary growth.
• Fibrocartilage Callus Formation: Fibroblasts and chondroblasts work together to lay down collagen and bridge broken bone ends.
• Bony Callus Formation and Remodeling: Essential for proper healing after fracture.

Calcium Homeostasis

• Critical for maintaining correct levels of calcium and phosphate; small fluctuations can lead to severe physiological issues.

Hormonal Regulation

• Parathyroid Hormone (PTH): Secreted to increase calcium levels, promoting osteoblast activity and renal production of calcitriol.
• Calcitriol: Secreted when calcium levels are high, enhancing osteoclast activity and thus promoting osteoblast function.

Bone and Exercise

• Exercise stimulates bone strength by releasing lactate, enhancing the bone's response to mechanical stress.

Aging Effects on Bones

• Decreased calcium and mineral content in bone matrix.
• Reduced protein synthesis in the skeletal system leads to structural weakness.

Test your knowledge with these flashcards covering essential concepts from Chapter 6 of Anatomy and Physiology. Learn about the functions of bones, as well as important terminology like diaphysis, epiphysis, and metaphyses. Perfect for students looking to reinforce their understanding of skeletal anatomy.