Kines100: Exercise Nutrition and Health Last Lecture Outline Lecture 7 1. Comparing systems 2. Physiology of Aerobic Fitness• Systems- respiratory, cardiovascular, muscular • Diffusion • Ventilation 3. Respiratory fitness adaptationCurrent Lecture 1. Finish up of the heart2. Blood Vessels3. Blood4. Muscle SystemFinish up of the heart• Contractility of the heart◦ heart beats stronger as we exercise harder ◦ trying to get as much blood in and out of the heart as possible• Fitness adaptation◦ Improve Cardiac efficiency◦ short term: decrease resting and exercise heart rate▪ Parasympathetic Nervous System and blood volume increases▪ get increased stroke volume ◦ Long term: get morphological changes ▪ left ventricle size increases (ejects blood to the rest of the body)▪ Increase diameter of coronary arteries Blood Vessels • Transport blood throughout the system• Types: ◦ Arteries- “Away from,” moves blood away from the heart◦ Arterioles- small arteries, have ability to dilate and constrict (has chemoreceptors to tell when to open and close and determines where the blood goes)◦ Capillaries: at the end of arterioles, location of diffusion◦ Venules: small vessels formed by capillaries, connect to larger vessels called veins◦ Veins: Toward heart, sometimes called the 2nd pump, one way valves,▪ Light headed after stopping a workout is caused by the muscle stopping its contraction which was helping the blood get back to the heart.• Arteriole response to exercise: redistribution of blood flow to working tissue◦ Rest: 5L of blood per minute◦ Exercise: 25 L of blood per minute • Fitness adaptation to Blood Vessels ◦ Increased number of blood vessels (especially capillaries, get increased capillary density in muscle)◦ Increased size of blood vessels (arteries can increase in size as well as other vessels)Blood • Carry oxygen and carbon dioxide • Components: plasma and red blood cells (hemoglobin)• Fitness adaptation to blood◦ increase in volume ▪ Primarily increase in plasma▪ Red blood cell and hemoglobin volume also increase▪ Hematocrit: red blood cell concentration decreases◦ Blood is thinner Muscle System• Burn up oxygen• Components involved in aerobic metabolism◦ myoglobin ◦ mitochondria◦ aerobic enzymes • Myoglobin: muscle hemoglobin, oxygen holding tank in muscle • Mitochondria: aerobic enzymes • Response to exercise◦ Increased oxygen consumption◦ Increased ATP synthesis◦ Increased caloric expenditure• Need 1 L of oxygen to burn 5 calories • Fitness adaptation ◦ myoglobin increases dramatically◦ mitochondria size and number increase ◦ aerobic enzyme increases◦ muscle capillary density
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