निम्नलिखित में से कौन सा मानव शरीर में एक प्रमुख अंतःकोशिकी इलेक्ट्रोलाइट (intracellular electrolyte) नहीं है?

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 ________.