मानव शरीर में वृक्क (किडनी) किस प्रणाली का एक मुख्य हिस्सा हैं?

Which digestive hormone inhibits both gastric secretion and motility, stimulates insulin release, and is secreted mainly when fat is present in the duodenum?

The repeated sequence of gradual onset of apnoea followed by gradual restoration of respiration is called ________.