What is the term for break down of muscle tissue?

The term for the break down of muscle tissue is "muscle atrophy". Muscle atrophy occurs when there is a decrease in the size and strength of skeletal muscles. It can be caused by a variety of factors, including disuse, aging, malnutrition, and disease. There are two main types of muscle atrophy:

1. Disuse atrophy: This type of atrophy occurs when a muscle is not used for a prolonged period of time. For example, when a person is immobilized due to an injury or illness, their muscles can start to atrophy.

2. Age-related atrophy: This type of atrophy occurs as a result of the natural aging process. As people age, their muscles lose strength and mass.

3. Denervation atrophy: This type of atrophy occurs when a muscle loses its nerve supply. This can happen as a result of a spinal cord injury or a stroke.