What does it mean when we say that a lever operates at a mechanical disadvantage, and what benefits does such a lever system provide? Which muscles act to propel food down the length of the pharynx to...

What does it mean when we say that a lever operates at a mechanical disadvantage, and what benefits does such a lever system provide?

Which muscles act to propel food down the length of the pharynx to the esophagus?

Name and describe the action of muscles used to shake your head no; to nod yes.