CBSE Class 12 Physical Education Physiology And Sports Worksheet

 CHAPTER – 8

PHYSIOLOGY AND SPORTS

Q.1 – What do you mean by flexibility?

Ans – Up to some extent, flexibility also determines the speed. In fact, good flexibility allows maximum range of movement without much internal resistance. Flexibility also enables complete utilization of explosive strength.

Q.2 – What is physical fitness?

Ans – Dr. K.L. Anderson has defined physical fitness as “The ability for respiration and circulation to recover from a standard work load.”

Q.3 – What is cardiac output?

Ans – Cardiac output is the amount of blood pumped by the heart in one minute. It is measured in litre/minute. Cardiac output is a product of stroke volume and heart rate. If either heart rate or stroke volume increases or both, the cardiac output increases also.

Q.4 – What do you mean by ageing?

Ans - Ageing is an inevitable and extremely complex, multi-factorial process. It is characterized by the progressive degeneration of organ systems and tissues. It is largely determined by genetics and influenced by a wide range of environmental factors such as diet, exercise, exposure to microorganism, pollutants etc.

Q.5 – Explaint any 3 physiological factors determining strength.

Ans – 1. Size of muscles: The strength of the muscle largely depends upon the size of the muscle. It is a well known fact that bigger and larger muscles can produce more force. The force produced by the same size of muscle in males and females is approximately the same but males are found to be stronger because they have larger muscles and bigger muscles in comparison to females.

2. Body weight:  It is also a well known fact that the individuals who are heavier are stronger than the individuals who are lighter. There is a positive correlation between body weight and strength among international weightlifters. The heavier weightlifters lift the heavier weight. So, body weight also determines the strength of an individual.

3. Intensity of the nerve impulse: A muscle is composed of a number of motor units. The total force of the muscle depends on the number of contracting motor units. Whenever, a stronger nerve impulse from central nervous system excites more number of motor units, the muscles will contract more strongly or it can said that the muscle will produce more force or strength. So, the intensity of the nerve impulse also determines the amount of strength.

Q.6 – Discuss any three immediate effects of exercise on cardiovascular system.

Ans – 1. Increase in heart rate: Generally the resting heart rate of an adult remains at 72 beats per minute. The elite endurance athletes usually have 28 to 40 beats per minute. Even before the beginning of exercise the heart rate increases in anticipation. It is known as anticipatory response. When an individual starts exercise his heart rate increases as per the internsity and duration of the exercise.

2. Increase in stroke volume: Stroke volume is the amount of blood ejected per beat from the left ventricle. It is measured in ml/beat. Stroke volume increases proportionally with exercise intensity. In untrained individuals the stroke volume at rest remains at 50 to 70 ml/beat. It 

increases up to 110 to 130 ml/beat during intense exercise. The stroke volume of experienced athletes at rest remains at 90 to 110 ml/beat. It increases up to 15 to 22 ml/beat during intense exercise.

3. Increase in cardiac output: Cardiac output is the amount of blood pumped by the heart in one minute. It is measured in litre/minute. Cardiac output is a product of stroke volume and heart rate. If either heart rate or stroke volume increases or both, the cardiac output increases also.

Q.7. – Discuss any three effects of exercise on circulatory system.

Ans – 1. Increase in number and efficiency of capillaries: With the regular exercise, the efficiency and number of capillaries are increased. Te unused and new capillaries become efficient and nourish the various cells efficiently.

2. Increase in number of RBC: The number of RBC (Red Blood Cells) increases when exercises are taken on regular basis. These RBC’s are the carriers of nutritients, including hemoglobin and O₂  to the muscles.

3. Delay in fatigue: Regular exercise delays the fatigue in an individual. Fatigue is felt due to the formation of lactic acid and phosphate in the muscles. These waste products are easily and very fastly removed from muscles, if exercises are performed regularly. Even muscles can bear the formation of lactic acid, so it delay the fatigue.

Q.8 – Discuss ay three effects of exercise on respiratory system.

Ans – 1. Increase in residual air volume: Residual air is the amount of air, which is left in the lungs after exhalation. If an individual performs regular exercise, his residual air capacity increases in comparison to an individual who does not perform regular exercise.

2. Increase in size of lungs and chest: When a person performs exercise regularly, he requires more amount of O₂. He inhales more amount of air during exercise. Consequently, his lungs and chest are exercised. After some period, the size of his lungs and chest increases.

3. Increase in vital air capacity: It is the amount of air which an individual can inhale and exhale with maximum effort. Its capacity varies from 3500 cc to 4500 cc in a normal adult. It is the sum of tidal volume, inspiratory reserve volume and expiratory reserve volume due to regular exercise its capacity increases up 5500 cc.

Q.9 – Describe the Physiological factors determining speed as a component of physical fitness.

Ans – 1. Mobility of the nervous system: Our muscles contract and relax at maximum possible speed such as in sprinting events. This rapid contraction and relaxation of muscles is made possible by rapid excitation and inhibition of the concerned motor centres.

2. Muscle composition: The muscles, which have more percentage of fast twitch fibres contract with more speed in comparison to the muscle composition is genetically determined and cannot be changed by training. Different muscles of the body have different percentages of fast twitch fibres. So, different parts of body have different speed performances.

3. Explosive strength: For every quick and explosive movement, explosive strength is indispensable. For example, a quick pouch in boxing cannot be delivered if the boxer lacks explosive strength. Explosive strength further depends on muscles composition, muscle size and muscle coordination. It also depends on metabolic process. Except muscle composition, the remaining factors can be improved through training which ultimately improve the speed up to limited extent.

4. Flexibility: Up to some extent, flexibility also determines the speed. In fact, good flexibility allows maximum range of movement without much internal resistance. Flexibility also enables complete utilization of explosive strength.

5. Bio-chemical reserves and metabolic power: For maximum speed performance the muscles require more amount of energy at a very high rate of consumption. For this purpose the phosphagen adenosine triphosphate (ATP) and creative phosphate (CP) stores in the muscles should be enough. If ATP and CP store is less in contracting muscles, the muscles contractions due to insufficient energy supply becomes slow after a short period.

Q.10 – Elucidate any 5 physiological changes due to ageing process.

Ans – 1. Changes in metabolism and body composition: With advancement of age our body needs less energy and the metabolism slows down. Consequently there is an increase in the accumulation of body, fat and lean body weight (bones, ligaments, tissues, tendons, muscles and water) decreases. The metabolic rate decreases gradually with the increasing age. It also results in more accumulation of body fat.

2. Changes in nervous system: A number of research studies indicate that reaction time and moment time slow down with increasing age. They brain’s weight, the size of this network and its blood flow decrease with the age. However, the brain adopts to these changes growing new patterns of nerve endings. To recall memories becomes slow.

3. Changes in the gastrointestinal system: With increasing age, there is a reduction in the production of hydrochloric acid, digestive enzymes and saliva. These changes may result in delayed emptying of stomach, impaired swallowing. The breakdown and absorption of foods may also be impaired. The liver becomes less efficient in metabolizing drugs and repairing damaged liver cells.

4. Changes in urinary system: As the age, the mass of the kidneys decreases. This leads to reduction in the rate of blood filtration by the kidneys. The capacity of bladder decreases and there is an increase in residual urine. These changes increase the changes of urinary infection.

5. Changes in flexibility: The elasticity of tendons, ligaments and joint capsules is decreased with ageing. The elderly persons lose 8-10 cm of lower back and hip flexibility according to a research study. The range of movement is restricted as the age increases.

Q.11 – Enumerate any five effects of exercise on muscular system.

Ans – When we do regular exercise, some permanent changes take place in our muscular system. These changes occur only when exercises are performed daily. If we perform exercise onece, there will be changes in our muscular system but only for a temporary phase. Following changes in our muscular system can be seen if exercise are done on regular basis.

1.    Change in shape and size of muscle: Trough regular exercise, the shape and size of muscle is changed. In fact, cells of muscles are enlarged which change the shape and size of muscle.

2.   Formation of more capillaries: When exercises are done, the colour of muscles is changed, because a number of new capillaries are formed for a better efficiency of blood circulation.

3.   Muscle Remains in Tone Position: When exercises are done on regular basis then our muscles remain in toned position. Indeed, muscle remains under some degree of contraction. Muscle becomes firm and maintains a slight, steady pull on the attachments.

4.   Controls Extra Fat: Regular exercise controls the extra fat of body. Exercises burn the calories which is taken in the form of fat.

5.   Change in the Connective Tissue: The connective tissue, which connects fibres, becomes powerful. These tissues can bear stress of strenuous activity and can be extended up to some degree.

6.   Efficiency in the Movement of Muscles: The movement of muscles become efficient and smooth. The movements during different activities become attractive.

7.  Delays fatigue: Regular exercise delays fatigue. The fatigue is mainly due to formation of carbon dioxide, lactic acid and acid phosphate. The accumulation of co_2, acid phosphate and lactic acid becomes less in an individual who performs exercise regularly. Hence, fatigue can be delayed if exercises are performed daily.

8.   Increases Food Storage: The food storage capacity is increased when regular exercises are done. This storage of food can be utilized immediately when it is needed.

Exercise Makes the figure Beautiful:If we perform regular exercise, we will be able to make our body beautiful. It can be seen in Miss Universe completion. Beautiful figures are appreciated in such contest. The 36”-24”-36” figure does not come up by chance. It  

9.  Is only possible through regular and various types of exercises. It is actually the muscle, which makes the shape of body.

10.   Non-Functioning Fibres become Active: When we do not do any strenuous worl, all the muscle fibres of our body do nto perform any work. In fat, these fibres do not need to the active. But when we perform exercise regularly, the non-functioning fibres also begin to be active. Consequently, the strength of the body increases, because the total contractile power of the muscle fibres increases.

11.   Body posture remains correct: By doing exercise regularly, the strength of muscles increases, which in turn, keeps the body posture in correct position. The postural deformities do not occur. If there is any physical deformity, it is removed by doing regular exercise.

12.   Improves Reaction Time: Due to regular exercise, the speed of nerve impulses increases which ultimately improves the reaction time. These nerve impulses move very quickly through motor nerves from nervous system to muscles fibre. Owing to this the reaction time improves.

Q.12 – Elaborate the role of regular physical activity in maintaining functional fitness of aged population.

Ans – No one can stop the clock of ageing, but everyman can slow its tick with the help of physical activity. As a matter of fact, physical activity can play a very significant role in maintaining functional fitness in aged population. Physical activity is the most powerful tool in the hands of aged persons that it can improve as well as maintain functional fitness of aged persons very effectively. With the help of physical activity they can perform daily routine work more efficiently. It makes the person move energetic and removes the signs of ageing. It can reverse the common signs of old age such as muscle and bone loss, increased body fat, memory and cognitive decline, decreased metabolism, decreased flexibility and decreased blood flow etc. it is well recognized fact that physical activity keeps the human body livelier, fitter and in better condition for long years. Regular physical acitivity can protect the individual against a number of chronic diseases off old age. Regular physical activity helsp aged people to live healthier and more vigorous lives.

 Regular physical activity can play a very effective role in maintaining functional fitness but it should be implemented in a proper way. First of all, the aged persons should consult to doctor regarding their level of physical fitness and health. The recommended amount of physical activity should be no more than their capacity. They must not feel tired on the following day. The physical activity prescription for aged persons should include aerobic, muscle strengthening and flexibility exercises. The intensity and duration of physical activity should be low in ht beginning. Regular activity can play an effective role in maintaining functional fitness in aged population in the following ways:

1.      Reduces the loss of muscle mass: Muscle mass deceases with advancing age. Ageing has a negative effect on metabolism. Regular physical activity decreases the loss of lean body mass and drop in the metabolic rate. Regular physical activity also reduces the accumulation of fats.

2.      Helps in maintaining bone density: Bone density decreases with age. It usually leads to fracture and osteoporosis. Physical activity helps to maintain bone mass and prevents osteoporosis. Resistance exercise stimulated bone growth. Research studies show that the aged persons can increase their bone density with the help of regular exercise.

3.      Slows down brain ageing: The regular physical activity reduces the risk of mild cognitive impairment. It is a condition characterized by memory and thinking problems. Mild cognitive impairment may lead to dematia later on. Regular physical activity reduces the risk of developing this problem in the first place. Regular physical activity improves memory and cognitive skills. It stimulates the growth of new nerve cells and builds new capillaries to supply the brain with more oxygen.

4.      Reduces the risk of age-related diseases: Regular physical activity reduces the risk of a number of health problems many ageing persons face. Such health problems are type 2 diabetes, obesity, hypertension and heart diseases etc. regular physical activity decreases blood sugar level, decreases LDL (bad cholesterol), increases HDL (good cholesterol), decreases blood pressure and decreases blood vessel stiffness. It can be alluded that physical exercise reduces the risk of diseases related with age.

5.      Improves muscular strength: Ageing process does not hinder the individual’s ability to enhance muscle strength. Regular physical activity increases the strength of muscles. As a matter of fact, physical activities increase the size of muscles which ultimately increases muscular strength.

6.      Enhances the capacity of lungs: Regular physical activity enhances the capacity of lungs. It reduces the loss of elasticity of the lungs and chest wall. It also plays a key role in keeping the lungs strong. Regular physical activity increases oxygen uptake and oxygen exchange .

7.      Improves flexibility: Regular physical activity improves the elasticity of tendons, ligaments and joint capsules. Physical activity decreases the stiffness of joints. In this way, there is improvement in flexibility. Aged persons can perform various functions which require flexibility.

8.      Reduces stress and tension: Regular physical activity has a unique capacity to exhilarate and relax to depression and reduce stress and tension. In fact, regular exercise reduces levels of body’s stress hormones such as adrenaline and cortisol. Regular physical activity also stimulates the production of endorphins, the body’s natural painkillers and mood elevators. Such benefits of physical activity help in maintaining functional fitness of aged persons.

It can be concluded that regular physical activity can play a very effective role in maintaining functional fitness in aged population because it has ample benefits which usually help the aged persons

Q.13 – Elucidate the gender differences in physical and physiological parameters.

Ans – Main deferences in physical and physiological Parameters:

1.     Muscular Strength: Females have less muscular mass as compared to males. Males convert more of their caloric intake into muscles while females tend to convert caloric intake more into fat deposit. Thus men are physically more stronger than females.

2.      Endurance: Males have large lung volume (i.e., more vital capacity), moreover higher oxygen carrying capacity. This causes more endurance in males.

3.      Sensitivity: It is a fact that females are more sensitive to smell as compared to males.

4.      Flexibility and Speed: Females are more flexible as compared to males whereas males have more speed ability.

5.      Skin: Males have hard, more prone to redness and darker skin, whereas skin of females is soft, sensitive and fair.

6.      Age and Gender: Physical fitness is related to age and gender. It depends on gender difference. Male has more strength and endurance as compared to female and females dominate in flexibility and co-ordination dominating physical activities.

7.      Blood components: Females usually have lower Blood Pressure than males. Males have higher concentration of androgens while females have higher level of estrogens. Females have more WBC (White blood cells), Granulocytes and Lymphocytes; thus females have better immune system than males.

8.      Skeleton difference: Female skeleton is generally lighter, smooth and delicate than males, female pelvis is wider. Males have heavier, longer and stronger bones.

9.      Weight: Males are heavier (about 15% more). i.e. males have more weight as compared to females of same height.

10.  Height and Waist: Males are taller than females (about six inches). On average men have large waist whereas women have wider hips as compared to men.