linguistic:paraphrasing
Studies of digestion

At the Institute of Experimental Medicine, Pavlov carried out his classical experiments on the digestive glands, which would eventually grant him the aforementioned Nobel prize. Pavlov investigated the gastric function of dogs, and later, homeless children, by externalizing a salivary gland so he could collect, measure, and analyze the saliva and what response it had to food under different conditions. He noticed that the dogs tended to salivate before food was actually delivered to their mouths, and set out to investigate this "psychic secretion", as he called it. Experiments on orphaned children, involving drilling a hole in their cheeks and applying electric shocks, were continued by his assistant Nikolay Krasnogorsky.

Pavlov's laboratory housed a full-scale kennel for the experimental canines. Pavlov was interested in observing their long-term physiological processes. This required keeping them alive and healthy to conduct chronic experiments, as he called them. These were experiments over time, designed to understand the normal functions of dogs. This was a new kind of study, because previously experiments had been "acute", meaning that the dog underwent vivisection which ultimately killed it.