Effectors is the term used for glands or muscles that result in a coordinated response. Receptors are what receive stimuli from the outside environment.
muscles contract and relax by bring about movements.
Abdominal muscles, among others.
Muscles contain certain proteins called contractile proteins which enable it to contract and relax to bring about movements.
bring it on
Hormones such as oxytocin help to prepare the breast for feeding. Once the breast is stimulated by suckling small muscles around the glands contract to help expel the milk. Mechanical suction and manipulation by the tongue also help to bring the milk out.
Sounds like blocked anal glands. Bring him to a vet to have the glands expressed.
No, skeletal muscles do, because smooth muscles deal with your internal organs.
Red Blood cells bring oxygen and nutrients to the cells of the muscles.
The agonists are the muscles that help you to do this exercise. The antagonists are the muscles that bring you back to a regular position instead of being stuck.
Adductors
Adductors
Yes, during puberty your muscles will (in general) get bigger and develop.