Final answer:
The accessory organ connected to the small intestine by a duct that secretes enzymes is the pancreas, which releases pancreatic juice containing pancreatic amylase for carbohydrate digestion.
Step-by-step explanation:
The accessory organ which is connected to the small intestine by a duct and secretes enzymes into the small intestine is the pancreas. The pancreas secretes pancreatic juice, which contains the enzyme pancreatic amylase. This enzyme is crucial for the completion of the chemical digestion of carbohydrates within the small intestine. In addition to pancreatic amylase, the pancreas also produces other enzymes that are essential for breaking down proteins and fats. This organ is part of a group of accessory digestive organs that also includes the teeth, tongue, salivary glands, gallbladder, and liver, all of which contribute to the breakdown of food into nutrients essential for the body.