Answer to Question 1
The sarcoplasm in muscle is comparable to the cytoplasm in other cells. This semifluid substance in muscle contains primarily myosin and actin myofibrils but also large amounts of glycosomes (organelles that store glycogen and enzymes) and myoglobin (the oxygen binding protein in muscle).
Answer to Question 2
Sarcopenia is defined as an age-related loss of muscle mass, strength, and function. How much loss of muscle mass is related to the aging process itself or to actual physical inactivity and faulty nutrition is unknown. Sarcopenia leads to mobility disability and loss of independence. Muscle mass loss is also related to a lower metabolic rate, high prevalence of obesity, insulin resistance, type 2 diabetes, abnormal blood lipids, and high blood pressure. Estimates indicate that half of all adults aged 65 and older in the United States currently suffer from age-related muscle loss. Early muscle loss doesn't appear to bother them or hold them back. They think they are fine until they lose functional independence; at that point they realize the serious mistake made and subsequent loss of quality of life.
CARDIAC MUSCLE TISSUE
How to approximate the area of a function using midpoints
How to find the domain when sine and cosine are in the same function
Testing the strength of the trapezius muscle against resistance
Dog Muscle Anatomy
Structure of a skeletal muscle.