Musculoskeletal System: The effects of exercise on muscle and bone Flashcards
(16 cards)
Where is smooth muscle found and is it voluntary or involuntary?
In the walls of hollow organs, blood vessels, and glands; involuntary.
What are the characteristics of cardiac muscle?
Striated and involuntary; found only in the heart.
What are the general benefits of regular exercise?
Improved health, strength, flexibility, posture, cardiovascular function, appetite, relaxation, social life, and reduced disease risk.
What are two main muscular benefits of exercise?
Increased endurance and increased strength.
What cellular changes occur with increased endurance?
More and larger mitochondria, more capillaries, more myoglobin.
What changes occur with strength training?
Increased muscle fiber size, more myofibrils, and enhanced motor unit recruitment.
Does exercise increase the number of muscle fibers?
No, it increases the size and number of myofibrils, but not the number of fibers.
How does exercise affect bone mineral density (BMD) in adulthood?
Improves BMD; athletes and lifelong exercisers have significantly higher BMD.
Why is early-life exercise important for bones?
It helps achieve peak BMD by around age 20, reducing fracture risk later in life.
What principle explains how bone adapts to stress?
Wolff’s Law – bone remodels in response to stress.
What is sarcopenia?
Age-related loss of muscle mass and function.
What is osteosarcopenia?
Combined loss of bone and muscle due to aging.
How do osteocytes respond to mechanical loading?
They act as mechanosensors, triggering bone formation under intermittent compression.
What role does fluid shear-stress play in bone formation?
Compression moves fluid in canaliculi, creating shear stress that stimulates osteocytes to release signaling molecules like nitric oxide.
What does nitric oxide do in bone remodeling?
Stimulates osteoblasts to form collagen and deposit bone minerals.
What type of compression is most effective for stimulating bone formation?
Intermittent compression; static or high-frequency compression is ineffective.
