Question

Elucidate three physiological changes those occur due to ageing.

Hint:

Regular weight-bearing exercise can significantly slow down the rate of bone mineral loss and muscle atrophy as we age.

Answer 1

Step 1: Understanding the Concept: 
Ageing is a biological process that leads to a gradual decline in the functional capacity of various body systems. 

Step 2: Detailed Explanation:  
 

1. Changes in Muscular System: There is a decrease in muscle mass (sarcopenia) and strength. Muscle fibers decrease in number and size, and connective tissue increases, leading to stiffness.
2. Changes in Cardiovascular System: The heart wall thickens, and the heart's ability to pump blood efficiently (Cardiac Output) decreases. Arteries become stiffer (arteriosclerosis), leading to increased blood pressure.
3. Changes in Bone Density: There is a gradual loss of minerals (calcium) from the bones, making them brittle and porous, which increases the risk of Osteoporosis.

Step 3: Final Answer: 
Ageing causes decreased muscle mass, reduced cardiac output, and lower bone mineral density.

Answer 2

Many of the visible effects of ageing on the body trace back to underlying hormonal and cellular shifts rather than being isolated, unrelated changes. Looking at three key systems through this lens explains why they decline together.

1. Declining muscle mass, sarcopenia: Falling levels of growth hormone and testosterone with age reduce the body's ability to repair and build muscle protein, so muscle fibres shrink and are gradually replaced by connective tissue and fat, leading to reduced strength and increased stiffness.
2. Reduced cardiac efficiency: The heart muscle itself is affected by the same reduced capacity for tissue repair, causing the ventricular walls to thicken slightly while becoming less elastic. Combined with stiffer, less elastic arteries, arteriosclerosis, this raises resting blood pressure and lowers the heart's pumping efficiency, known as cardiac output.
3. Declining bone density, osteopenia and osteoporosis risk: Reduced levels of oestrogen and other bone-maintaining hormones slow the rate at which bone-forming cells replace lost bone tissue, so mineral density, mainly calcium, is lost faster than it is replenished, leaving bones more porous and prone to fracture.

Since all three changes stem from the same underlying decline in hormonal support for tissue repair and maintenance, muscular, cardiovascular and skeletal ageing tend to progress together rather than in isolation.