Topic 3 effects of physical activity and exercise on the human body Flashcards
What are some facts?
What does Physical exercises modify in our organisms
Energetic, Biochemical and physiological modifications and balance
What are smooth muscles?
spindle shaped, non striated, uninucleate fibers, involuntary, found in inner organs
What are cardiac muscles?
involuntary, occurs in striated branch of uninucleate, occurs in walls of the heart
what are skeletal muscles?
striated tubular, multinucleate fibers, attached to skeletal, voluntary
what is muscular hypertrophy?
increase or enlargement of muscle fiber or cross sectional area after post training. positive relationship with muscular strength.
what does mechanical loading regulate?
gene expression
what is a result of actin and myosin in muscle hypertrophy?
Increase synthesis in actin and myosin
what is required for increase in myofibrils within muscle fiber?
long period of training <16 workouts
Which type of muscle fibers experience greater size increases, and what does this imply for hypertrophy potential
Type II muscle fibers experience greater increases in size compared to Type I fibers. This implies that athletes with a higher proportion of Type II fibers have greater potential for hypertrophy
What is the significance of fiber type transitions in the muscular system?
Fiber type transitions occur with training, allowing muscle fibers to adapt and shift between different types, which influences muscle performance and growth potential
How does the pennation angle affect muscle function, and how is it influenced by resistance training?
The pennation angle affects both the force production capabilities and the range of motion of a muscle. Resistance training increases the pennation angle in pennate muscles, enhancing force generation
What structural change has been observed in strength-trained athletes regarding fascicle length?
Strength-trained athletes tend to have longer fascicles, which is a structural adaptation that contributes to improved muscle performance and strength?
What cellular and structural adaptations occur in response to resistance training?
Resistance training leads to increases in myofibrillar volume, cytoplasmic density, sarcoplasmic reticulum and T-tubule density, sodium-potassium ATPase activity, ATP concentration, and glycogen content. These changes support muscle strength and performance.
What are some reductions in muscle characteristics due to resistance training?
Resistance training reduces mitochondrial density, muscle and blood pH, and capillary density, reflecting shifts in muscle metabolism towards anaerobic energy systems.
What are the two types of bone tissue, and how do they differ?
The two types of bone tissue are trabecular bone (spongy) and cortical bone (compact). Trabecular bone has a porous, spongy structure, while cortical bone is denser and forms the outer layer of bones, providing strength and protection.
What is minimal essential strain (MES), and why is it important for bone health?
Minimal essential strain (MES) is the threshold stimulus that initiates new bone formation, typically about 1/10 of the force required to fracture bone. It is important for maintaining and strengthening bone tissue in response to mechanical loading.
How does an increase in muscle strength or mass affect bone mineral density (BMD)
An increase in muscle strength or mass results in a corresponding increase in bone mineral density (BMD), promoting stronger and denser bones.
What is the principle of specificity of training in relation to bone growth?
The specificity of training refers to using exercises that directly load a particular region of the skeleton. This targeted loading stimulates bone growth in the areas receiving strain.
What types of exercises are effective in reducing the risk of osteoporosis?
High-impact cyclical loading exercises for the lower body, following the principle of progressive overload, are effective in reducing the risk of osteoporosis by providing osteogenic stimuli to the bones.
What factors influence bone loading during exercise?
Factors influencing bone loading during exercise include load intensity, speed (rate) of loading, direction of loading, and volume (repetitions) of the exercises performed. These factors collectively contribute to the effectiveness of the training stimulus on bone health.
How can bone mass be metaphorically compared to a bank savings account?
Bone mass can be viewed as a bank savings account, where bone growth during adolescence and young adulthood adds to the account (positive bone mineral reserves). However, by midlife, withdrawals from these “savings” often exceed deposits
What happens to bone mass in midlife, and why is it significant?
In midlife, withdrawals from bone mass (bone loss) typically exceed deposits (bone growth), which is significant because it increases the risk of fractures as the bone becomes weaker.
What is the critical threshold in bone mass, and what does it indicate?
The critical threshold in bone mass refers to the point at which withdrawals exceed deposits. Once this threshold is crossed, the risk of bone fractures significantly increases.
What stages of life contribute positively to bone mass accumulation?
Adolescence and young adulthood are the key stages that contribute positively to bone mass accumulation, as this is when significant bone growth occurs.
What effect does heavy resistance training have on connective tissue, specifically tendons?
Heavy resistance training leads to growth in connective tissue, particularly tendons, enhancing their strength and resilience.
How does muscle hypertrophy influence fibroblast activity in connective tissues?
Muscle hypertrophy increases both the number and size of fibroblasts, resulting in a greater supply of total collagen within the connective tissues, which contributes to their strength.
What is the impact of high-loading versus low-loading on tendon stiffness?
High-loading leads to increased tendon stiffness, enhancing their ability to withstand greater forces, while low-loads do not significantly affect tendon stiffness
What role do collagen fibers play in the adaptations of tendons, ligaments, and fascia?
Collagen fibers provide structural integrity and strength to tendons, ligaments, and fascia, and an increase in collagen due to resistance training contributes to the overall resilience and functional capacity of these connective tissues.
What is the primary function of cartilage in the muscular system?
Cartilage is dense connective tissue that acts as a shock absorber, capable of withstanding considerable force without damage to its structure, particularly at joints.
What is hyaline cartilage, and where is it typically found?
Hyaline cartilage, also known as articular cartilage, is located on the articulating surfaces of bones, providing a smooth, lubricated surface for joint movement.
What is fibrous cartilage, and where can it be found in the body?
Fibrous cartilage is a tough form of cartilage found in structures such as the intervertebral disks, providing support and cushioning between vertebrae.
How does cartilage receive its nutrient supply, and why is joint mobility important for cartilage health?
Cartilage receives its nutrients via diffusion from synovial fluid. Joint mobility is important for cartilage health because it facilitates this nutrient supply, helping maintain the cartilage’s integrity and function.
What are the primary functions of blood in the cardiovascular system?
The primary functions of blood include the transport of nutrients, oxygen, and hormones to cells throughout the body, as well as the removal of metabolic wastes such as carbon dioxide and nitrogenous wastes.
What role do blood vessels play in the cardiovascular system?
Blood vessels are responsible for carrying blood throughout the body, facilitating the delivery of essential substances to tissues and the removal of waste products.
What are the main components of the cardiovascular system?
The main components of the cardiovascular system are blood, blood vessels, and the heart, all working together to ensure proper circulation and overall bodily function.
How does the cardiovascular system contribute to homeostasis?
The cardiovascular system contributes to homeostasis by regulating blood flow to tissues, ensuring adequate delivery of oxygen and nutrients, and facilitating the removal of metabolic wastes, thus maintaining internal balance and health
What is cardiac output, and how is it calculated?
Cardiac output is the amount of blood pumped by the heart per minute (L/min) and is calculated using the formula: Cardiac Output (Q) = Stroke Volume x Heart Rate.
How does cardiac output change during maximal exercise?
During maximal exercise, cardiac output can increase significantly, reaching up to four times the resting level of about 5 L/min, resulting in a maximum cardiac output of approximately 20 to 22 L/min
How does heart rate respond to increasing intensity during aerobic exercise?
Heart rate increases linearly with increases in exercise intensity during aerobic exercise, reflecting the body’s increased demand for oxygen and nutrients
What factors influence cardiac output during exercise?
Cardiac output during exercise is influenced by two primary factors: stroke volume (the amount of blood ejected with each heartbeat) and heart rate (the number of beats per minute), both of which increase with exercise intensity
What is stroke volume, and how is it defined in the context of the cardiovascular system?
Stroke volume is the volume of blood pumped by the left ventricle of the heart with each contraction. It is a key component of cardiac output and is influenced by various physiological factors.
What role does end-diastolic volume play in regulating stroke volume?
End-diastolic volume is the volume of blood in the ventricles at the end of filling (diastole) and directly affects stroke volume. A greater end-diastolic volume leads to a more forceful contraction, increasing the amount of blood ejected with each heartbeat
How do catecholamines and the sympathetic nervous system influence stroke volume during exercise?
Catecholamines from the sympathetic nervous system increase myocardial contractility, resulting in more forceful contractions and higher stroke volume during exercise.
What is the Frank-Starling mechanism, and how does it affect stroke volume?
The Frank-Starling mechanism states that greater myocardial fiber stretch (from increased blood volume) leads to stronger contractions and higher stroke volume
What is oxygen uptake, and how is it defined?
Oxygen uptake is the amount of oxygen consumed by the body’s tissues during physical activity.
What does the Fick Equation represent in relation to oxygen uptake?
The Fick Equation expresses oxygen uptake (VO2) as the product of cardiac output (Q) and the arteriovenous oxygen difference (a-vO2): VO2 = Q x a-vO2 difference.
What is VO2max, and what does it indicate?
VO2max is the maximum amount of oxygen that can be utilized at the cellular level by the body. Healthy individuals typically range from 25 to 80 ml·kg−1·min−1.
What components contribute to oxygen uptake during exercise?
Oxygen uptake is influenced by cardiac output (Q) and the arteriovenous oxygen difference (a-vO2), reflecting the efficiency of oxygen delivery and utilization by tissues
What is systolic blood pressure, and when does it occur?
Systolic blood pressure is the pressure against arterial walls during ventricular contraction when blood is forcefully ejected
What is the Double Product (Rate Pressure Product), and how is it calculated?
The Double Product is calculated as heart rate (HR) multiplied by systolic blood pressure (Syst BP), indicating the myocardial oxygen demand during exercise
What is diastolic blood pressure, and what does it represent?
Diastolic blood pressure is the pressure against arterial walls when the heart is at rest and no blood is being forcefully ejected
How is mean arterial pressure (MAP) calculated, and what does it represent?
MAP is the average blood pressure throughout the cardiac cycle, calculated as MAP = [(Syst BP − Diast BP) ÷ 3] + Diast BP. It reflects overall blood flow to organs.
How is oxygen transported in the blood?
Oxygen is transported in the blood either dissolved in plasma or combined with hemoglobin
What is the oxygen-carrying capacity of 100 ml of blood?
The oxygen-carrying capacity of 100 ml of blood is about 20 ml of O2.
How is carbon dioxide primarily removed from the body?
About 70% of carbon dioxide is removed from the body by combining with water and being transported to the lungs in the form of bicarbonate (HCO3−).
What role does hemoglobin play in oxygen transport?
Hemoglobin binds to oxygen in the lungs, allowing for efficient transport of oxygen from the lungs to tissues throughout the body.
How much can cardiac output increase during maximal exercise?
Cardiac output can increase up to four times the resting level of about 5 L/min to a maximum of 20 to 22 L/min during maximal exercise
How does heart rate respond to increasing intensity during aerobic exercise?
Heart rate increases linearly with increases in intensity during aerobic exercise
What is stroke volume and how is it regulated?
Stroke volume is the amount of blood pumped by the left ventricle during each heartbeat. It is regulated by the end-diastolic volume and the action of catecholamines, which increase the force of contraction.
What role does the Frank-Starling mechanism play in stroke volume?
The Frank-Starling mechanism states that the force of contraction increases as the myocardial fibers lengthen, which helps increase stroke volume
How does the sympathetic nervous system affect stroke volume during exercise?
At the onset of exercise, sympathetic stimulation increases myocardial contractility, leading to a more forceful ventricular contraction and an increase in stroke volume.
What is oxygen uptake, and how is it calculated?
Oxygen uptake is the amount of oxygen consumed by the body’s tissues. It is calculated using the formula:
VO2 = Q x a-vO2 difference,
where Q is cardiac output, and a-vO2 difference is the arteriovenous oxygen difference.
What is maximal oxygen uptake (VO2max)?
Maximal oxygen uptake (VO2max) is the greatest amount of oxygen that can be used at the cellular level for the entire body. In healthy individuals, it generally ranges from 25 to 80 ml·kg⁻¹·min⁻¹
What does the Fick Equation describe in terms of oxygen uptake?
The Fick Equation describes the relationship between oxygen uptake (VO2), cardiac output (Q), and the arteriovenous oxygen difference (a-vO2 difference).
VO2 = Q x a-vO2 difference.
What is systolic blood pressure?
The pressure exerted against the arterial walls during ventricular contraction.
What is diastolic blood pressure?
The pressure exerted against the arterial walls when no blood is being ejected
How is the mean arterial pressure (MAP) calculated?
MAP = [(Syst BP − Diast BP) ÷ 3] + Diast BP.
What happens to systolic and diastolic pressure during maximal aerobic exercise
Systolic pressure can rise to 220–260 mmHg, while diastolic remains stable or decreases slightly.
How is oxygen carried in the blood?
Oxygen is carried either dissolved in plasma or combined with hemoglobin
What is the oxygen-carrying capacity of 100 ml of blood?
About 20 ml of O2