Elucidate physiological changes due to Ageing?

The physiological changes, which take place mentioned below.

1. Change in Nervous System:- During ageing, reaction time and movement time slows done with an increase in age. The brain waits, the size of its network and its blood flow decreases with age.
2. Change in Gastro-Intestinal System: With the increase in age, there is a reduction in the production of Hydrochloric Acid, Digestive Enzymes and Saliva. These changes may result In delayed emptying the stomach, impaired swallowing. The breakdown and absorption of food may also be impaired. The liver becomes less efficient in metabolizing drugs and repairing damaged liver cells.
3. Change in Urinal System: As we age, the mass of the kidney decreases, which leads to a reduction in blood filtration by the kidneys. The capacity of the bladders decreases and there is an increase in residual urine. This increases the chance of urinal infections.
4. The change in senses: With the advance in age, the senses such as vision, hearing, taste, smell and touch may become less active. Vision and hearing are the most affected by ageing. The taste buds are reduced with age so they lose interest in food.
5. Change in Respiratory System: With the age, pulmonary function is impaired with advancing age. The airways and lung tissues become less elastic and less efficient. There is decreased oxygen uptake and oxygen exchange.
6. Change in fitness: The elasticity of tendons, ligaments and joint capsules decrease with Ageing. The range of the movement is restricted and muscle mass decreased as the age increases. This leads to decrease Flexibility, Endurance, Strength, the speed with shortness of Breath, Blood flow, Enzymes etc.