Sphincters
Sphincters
Sphincters (circular muscles)
Circular Muscles are found at the openings of the body
Sphincter muscles. They are smooth muscles found in various parts of the body, such as the digestive system and urinary tract, and control the opening and closing of tubes or openings.
Quadriceps
Involuntary muscles found inside organs are called smooth muscles. These muscles control processes like digestion, blood vessel constriction, and breathing without our conscious effort.
Raid is what I've found.
No, the small openings on a sponge are called ostia. Setae are bristles or hair-like structures found on some invertebrates like worms or arthropods that help with movement or sensory functions.
There are some muscles in the body we cannot control: they are called involuntary muscles and cardiac muscles. Involuntary muscles are found in the digestive tract for example. Cardiac muscles are found in the heart. Neither these two muscle types are controlled. We can control what are called voluntary muscles which are the muscles that were used to move our bones.
They are called the deltoid muscles. See the related link for more information.
Skeletal muscles are found in pairs called flexors and extensors. The flexors bend a joint, and the extensors straighten the joint. Muscles cannot push; they only pull.
There are no muscles that are controlled by force of will. Your brain sends messages to the nerves that control your muscles and that is what moves them.