वायुमंडल की आर्द्रता नापने के साधनों को आर्द्रतामापी (हाइग्रोमीटर / Hygrometer) कहते हैं।

Answer: B) Myogenic heart Explanation: Hearts are of several types. In some invertebrates the heart is simulated by the nervous system to do its work. Such hearts are called Neurogenic hearts. The Human heart is myogenic. i.e, it recieves the stimuli for contraction from the muscular node called sinu-auricular node or pace maker.