Appetite is not linked to hunger since appetite is the activity and drive in order to eat whereas hunger is the physical and mental state in which a person needs to eat.
Also appetite is linked to many unhealthy behaviors that can result to other symptoms of eating disorders which causes deletrious effects on one's mental and biological state.
The lens of the eye loses its ELASTICITY with age and cannot change from viewing distant objects and close objects as readily as before.
Answer: the contraction and relaxation of the muscles in the gut and the airways
Explanation: I hope this answers your question