S: (n) carotid body (a chemoreceptor located near the bifurcations of the carotid arteries; monitors oxygen content of the blood and helps control respiration)
S: (n) nose, olfactory organ (the organ of smell and entrance to the respiratory tract; the prominent part of the face of man or other mammals) "he has a cold in the nose"
S: (n) snout, neb (a long projecting or anterior elongation of an animal's head; especially the nose)
S: (n) naked eye (the eye unaided by any optical instrument that alters the power of vision or alters the apparent size or distance of objects) "it is not safe to look directly at the sun with the naked eye"
S: (n) peeper (an informal term referring to the eye)
S: (n) semicircular canal (one of three tube loops filled with fluid and in planes nearly at right angles with one another; concerned with equilibrium)
S: (n) stretch receptor (a receptor in a muscle that responds to stretching of the muscle tissue)