मानव शरीर विज्ञान के प्रमुख तंत्रों में से, रक्त किस अंग तंत्र से संबंधित 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 ________.