Which of the following is NOT one of the fluid measurements under the apothecary system?

After a muscle has been isometrically contracted for a length of time it will be inhibited from contracting for a period of time known as the ________________ state

a. perfunctory b. refractory c. reciprocal d. objective

A circular lead lined device that slides onto the tube head is a(n):

aperture diaphragm wedge filter collimator extension cone