Final answer:
The gallbladder is the organ that stores and secretes bile salts, aiding in the breakdown of fat in the digestive process, particularly in the duodenum after a meal.
Step-by-step explanation:
The organ that stores and secretes bile salts, which help break down fat, is the gallbladder. The liver produces bile, which contains bile acids needed to emulsify lipids during the digestive process. It is the gallbladder's role to store this bile and concentrate the bile salts. When there is food in the duodenum that contains fat, such as the chyme following a meal, the bile is secreted from the gallbladder into the duodenum where it breaks down the large globules of lipids into smaller ones. These smaller globules are more accessible to digestive enzymes, making it easier for the body to absorb the fats.