Answer:
Reproductive System
All the body systems have one role or the other to play in digestion and absorption. Even the excretory system removes waste and toxins from the body, leaving the useful materials.
However, the reproductive system is not actively involved in digestion.
I believe the thyroid controls most, if not all of those things. (Again, I'm not entirely sure.)
Answer:
Sarcomere
Explanation:
The muscle fiber / myofibrils consist of 2 types of filaments - actin and myosin. The myosin filaments are thick filament whereas the actin filaments are the thin filament.
In addition to this, the muscles have A-band and I-bands. These bands give the muscles alternate light and dark colour band structure. In the A-band, myosin filaments are present, whereas in the I - band the actin filaments are found.
In I-band 2 Z-lines are located. The area between the Z-lines is called sarcomere. In this sarcomere region both actin and myosin filaments present.
When muscles get contracted the length of the sarcomere shorten. The actin and myosin filaments overlap in this area. A cross-bridge form between them, with the help of filamentous protein titin.
Human evolution known to be a process in which species adapt to certain
conditions of life, and in the battle of life and death, they are forced
to become stronger in order to survive in this world. Diseases have
always been present during the evolution, acting themselves as a natural
selectors - the weaker organisms get sick and die. Not just humans, but
all species have to establish a great protecting mechanism in order to
survive. That is how our bodies are built, to be able to withstand and
survive in the conditions we live in, and that is why our immune system
has to be taken care of.