Exercise Physiology Quiz

Chapter 3: MSK & CardioPulm

• This chapter covers the musculoskeletal and cardiopulmonary systems, focusing on their functions and relationship to physical activity, exercise, sport, and athletic performance.

Muscular System

• Works to create movement in the human body
• Skeletal Muscle:
  • Voluntary
  • Attached to bone via tendons
  • Creates friction and heat, maintaining body temperature
• Smooth Muscle:
  • Involuntary
  • Found in blood vessels, digestive tract, respiratory airways, urinary tract, uterus
• Cardiac Muscle:
  • Involuntary
  • Found in the heart, generates force to contract the heart and move blood throughout the body

Muscle Fibers

• Function: Contraction
• Different types of muscle have different properties for force and speed of contraction (skeletal, smooth, cardiac).

Cardiac vs Skeletal vs Smooth Muscle

• Cardiac Muscle: Delivers nutrients and oxygen to working tissues, removes waste products, and is responsible for the majority of daily energy expenditure.
• Skeletal Muscle: Generates movement, increasing energy expenditure and heat production. Allows for body movement.
• Smooth Muscle: Regulates the diameter of passageways (cardiovascular and respiratory), allowing for coordinated flow of blood to working tissues and air to the lungs for gas exchange.

Definitions

• Aerobic: Uses oxygen (e.g., longer duration cardio exercise)
• Anaerobic: Does not require oxygen (e.g., sprinting)
• Oxidative: Lots of oxygen required.
• Nonoxidative: No oxygen required.
• Glycolysis: Breaking down glucose for energy.
• Oxidative vs. Anaerobic Glycolysis: Different pathways for glucose breakdown.
• Myosin ATPase: Enzyme providing energy for muscle contraction.
• Muscle Fiber Hypertrophy: Increase in muscle fiber cross-sectional size.
• Muscle Fiber Hyperplasia: Increase in the number of muscle fibers in a muscle.
• Concentric Contraction: Muscle shortens.
• Eccentric Contraction: Muscle lengthens (more responsible for muscle soreness).

Skeletal Muscle Fiber Types

• Type I (Slow Oxidative):
  • Slow speed of contraction
  • High resistance to fatigue
  • Low Myosin ATPase activity
  • High oxidative energy capacity
  • Low nonoxidative energy capacity
• Type IIA (Fast Oxidative Glycolytic):
  • Fast speed of contraction
  • Intermediate resistance to fatigue
  • High Myosin ATPase activity
  • High oxidative energy capacity
  • Intermediate nonoxidative energy capacity
• Type IIX (Fast Glycolytic):
  • Fastest speed of contraction
  • Low resistance to fatigue
  • Highest Myosin ATPase activity
  • Low oxidative energy capacity
  • High nonoxidative energy capacity

How do Skeletal Muscles Contract?

• Sliding filament theory: Actin (thin filaments) and Myosin (thick filaments) slide past each other, resulting in muscle contraction.
• Myosin stays in middle, actin is pulled together. M-line is center of sarcomere, Z-line is boundary of sarcomere

How to Build Muscle

• Muscle Fiber Hypertrophy: Increase in muscle fiber cross-sectional size (resistance exercise).
• Muscle Fiber Hyperplasia: Increase in the number of muscle fibers (can occur to a degree).
• Artificial Muscle Growth: Growth hormone, Myostatin, Anabolic steroids.
• Delayed Onset Muscle Soreness (DOMS): Muscle soreness, often after eccentric muscle contractions.

Skeletal System

• Framework for the body; lever system for movement
• Attachment site for ligaments & tendons
• Protects vital organs
• Stores minerals (calcium & phosphorus)
• Blood cell production (red bone marrow)
• Skeletal system works closely with muscular & neurological systems (MSK, NMasks)

Skeletal System & Exercise

• Combo of physical activity, exercise, nutrition, and aging impacts skeletal health.
• Resistance training builds stronger bones.
• Nutrient deficiencies weaken bones (Calcium, magnesium, Vitamin D).
• Osteopenia = bone mineral density loss.
• Osteoporosis = bone disorder, leading to brittle bones.
• Spongy (cancellous) bone; cortical (compact) bone.

Skeletal System & Exercise (cont.)

• Red bone marrow produces red blood cells (more blood cells = better athletic performance).
• Erythropoietin (EPO) controls red blood cell production.
• Blood doping is the illegal increase in red blood cells.

Cardiovascular System

• Transports blood containing oxygen, nutrients, and other substances throughout the body, removing waste products.
• Assists in body temperature regulation.
• Cardio-respiratory and cardiopulmonary systems often work together.

Cardiovascular System Components

• Heart (cardiac muscle and nerve)
• Arteries (arterioles)
• Veins (venules)
• Capillaries (thin, single cell-thick, transferring gases, nutrients, and waste)
• Blood (RBCs, WBCs, platelets, plasma)

Cardiovascular Disease

• Cardiovascular disease is a major cause of death in the U.S.
• Coronary artery disease (atherosclerosis): Cholesterol and blood lipids build up in arteries.
• Exercise reduces morbidity and mortality for heart-related risks.
• Cardiac rehab is a PT treatment area.

Path of Blood

• Detailed pathway through the heart, showing components and flow directions.

Pressure Gradient in Heart

• Cardiac cycle: Diastole (relaxation) and Systole (contraction), affecting valve position and pressure.

VO2 Max & Athletic Performance

• Measures the maximum amount of oxygen tissues can use during peak athletic performance.
• Strong predictor of athletic performance and overall health and longevity.

Pulmonary System

• Brings air into lungs, facilitate oxygen uptake and carbon dioxide removal.
• Helps maintain acid-base balance (regulating CO2 in blood).
• The lungs create a large surface area for rapid gas exchange (O2 and CO2).

Pulmonary System Components

• Respiratory muscles (internal/external intercostals, diaphragm, ab muscles).
• Respiratory airways (mouth/nose, trachea, bronchi, bronchioles).
• Respiratory units (alveoli, pulmonary capillaries).

How We Breathe

• Pressure gradient (volume and pressure changes).
• Gas laws.

Pulmonary System & Exercise Science

• COPD (Chronic Obstructive Pulmonary Disease) causes difficulty breathing out (chronic bronchitis, emphysema).
• Asthma: Airways constrict (exercise-induced asthma may be triggered by exercise).
• Pneumothorax (collapsed lung).

Pulmonary System & Athletic Performance

• During high-intensity workouts, skeletal muscles increase lactic acid production, which lowers pH (more acidic).
• High acidity can cause cessation/ dropout in athletes.

Questions

• Musculoskeletal (MSK)
• Cardiopulmonary
• Anything else
• Further assignments details: Motivational Interviewing, Professionalism, Quiz 1 (Feb 1st), Exam 1 (Feb 8th).

Test your knowledge on key concepts in exercise physiology, including muscle function, growth, and the role of different systems in the body. This quiz covers topics such as the sliding filament theory, muscle hypertrophy, and the cardiovascular system. Challenge yourself and see how well you understand the interactions between exercise and body systems.