Chapter 1-7: Introduction, Puny Bone Disease, Old Bone Tissue, Healthy Bone Tissue, Build That Bone, Low Low Bone Mineral Density, Conclusion

Flashcards covering key vocabulary, definitions, and concepts related to COPD, Osteoporosis, bone biology, and bone remodeling based on the lecture notes.

Cardiorespiratory overshoot

A phenomenon where, during exercise, heart rate and blood pressure initially rise beyond what is needed, then normalize as activity continues.

COPD and Inactivity

Inactivity in patients with severe COPD is often a symptom of the disease, rather than a primary risk factor for its development.

Normal Healthy Bone Matrix

Appears as a dense honeycomb structure when viewed microscopically.

Osteoporosis

A disease characterized by the progressive loss of bone density, making bones porous and weak, resembling a beehive structure.

Osteopenia

A pre-disease state of osteoporosis, also known as 'puny bone disease,' where bone density is lower than normal but not yet at a clinically defined osteoporosis level.

Diagnosing Osteopenia

Identified by a bone density scan (DEXA) on areas like the head of the femur, showing a score between -1 and -2.5 standard deviations from normal for age and sex.

Diagnosing Osteoporosis

Confirmed by a bone density scan (DEXA) showing a score lower than -2.5 standard deviations from normal for age and sex.

Impact of Osteoporosis

Significantly increases the risk of mortality and disproportionately affects women, particularly those who are postmenopausal.

Postmenopausal Status

The phase in a woman's life when menstruation stops, with about half of women reaching this status between ages 45 and 49.

Common Osteoporosis-Related Fractures

Predominantly vertebral (spinal) fractures, with wrist and hip fractures also being common.

Osteoporosis and Hospital Admissions

Accounts for more hospital days in women than other major diseases like breast cancer, heart attacks, or diabetes.

Outcomes of Osteoporosis-Related Fractures

Within one year, 1 in 4 patients die, 1/3 are confined to nursing homes, and 80% require assistance with at least one activity of daily living.

Bone Remodeling

The continuous process by which bones maintain their health, involving the dissolution of old bone tissue and the formation of new bone tissue.

Osteoclasts

Specialized bone cells responsible for dissolving and removing old or damaged bone tissue; often referred to as 'cutters'.

Osteoblasts

Bone cells primarily responsible for building new bone tissue; often referred to as 'builders'.

Osteocytes

Mature bone cells that originate from osteoblasts that have become trapped within the bone matrix they secrete; they play a role in bone maintenance and communication.

Mechanism of Osteoporosis/Osteopenia

Involves overactive osteoclasts (dissolving too much bone) and 'lazy' osteoblasts (not building enough new bone tissue).

Healing Time in Osteoporotic Bones

Bones affected by osteoporosis take significantly longer to heal due to the reduced activity of osteoblasts.

Fragility of Osteoporotic Bones

Due to their porous and weak nature, osteoporotic bones can break easily from minimal force, such as a simple rotation of an arm.

Major Symptom of Osteoporosis

A bone fracture occurring from an injury or event that would not typically cause a fracture in healthy bone (e.g., a fall).

Tertiary Prevention for Osteoporosis

Strategies implemented after a fracture has occurred, focusing on rehabilitation, fall-proofing, and minimizing further injury.

Pharmaceuticals for Osteoporosis

Drugs designed to either slow down the activity of osteoclasts or stimulate the production and activity of osteoblasts to improve bone density.

Calcium Supplements and Osteoporosis

Despite common belief, calcium supplements show little benefit in treating existing osteoporosis because the issue often lies with 'lazy' osteoblasts and their inability to incorporate calcium, not a lack of calcium itself.

Fall-Proofing Approaches

Training programs, similar to those for stunt performers, designed to teach individuals how to fall in a way that minimizes the risk of fractures.

Secondary Prevention for Osteoporosis

Involves early detection and diagnosis through regular bone density scans (DEXA scans) to identify osteopenia or osteoporosis before a fracture occurs.

DEXA Scan (Dual X-ray Absorption Machine)

A medical imaging technique that uses low-dose X-rays to measure bone mineral density; typically takes about 20 minutes and is recommended for screening all individuals over 40.

Comorbid Conditions with Osteoporosis

Conditions such as arthritis and chronic low back pain are frequently seen alongside osteoporosis, with the latter sometimes being a symptom of undiagnosed vertebral fractures.

Osteoporosis Risk Factors

Include being female, having a small body frame, a family history of osteoporosis, low early-life calcium intake, tobacco use, and a history of disordered eating.

Low Baseline Bone Mineral Density (BMD)

A significant risk factor for osteoporosis, as individuals who start with lower BMD have less 'reserve' before reaching clinically diagnostic levels of bone loss.

Primary Prevention for Osteoporosis

Focuses on preventing the disease entirely by promoting processes that strengthen bones from an early age, such as mechanical loading through physical activity.

Mechanical Loading

The application of physical forces to bones (e.g., standing, running), which stimulates bone growth and remodeling, with one side of the bone being compressed and the other tensioned.

Trajectory Architecture

A biomechanical modeling concept suggesting that bone optimally places material only along paths where forces are applied, allowing bone to be strong yet lightweight and flexible.

Dynamic Trajectory Architecture

Modern models of trajectory architecture that acknowledge bone remodeling is a dynamic process, reshaping bone continuously based on the varied forces applied to it over time.

Bone Modeling Process

The mechanism by which existing bone is reshaped and adapted in response to the mechanical forces and stresses applied to it.