third class lever {Ans: REF ex: The effort of a biceps curl is applied to the forearm between the elbow joint (fulcrum) and the weight in the hand (resistance)}What are mature bone cells called {Ans: osteocytes}Molecule that blocks myosin and actin {Ans: Tropomyosin}What happens for an action potential {Ans: Action potentials are electrical signals produced by the coordinated opening and closing of voltage-gated ion channels in flow of sodium ions outflow of potassium}what is the external surface of the long bone known as {Ans: periosteum}Layers of the skin in order {Ans: epidermis, dermis, hypodermis (subcutaneous)}