1. Digestion is important because your body needs nutrients from food and drink to work properly and stay HEALTHY. Proteins, fats, carbohydrates, vitamins link, minerals link, and water are nutrients.2. Helps in breakdown of fats:The saliva has certain enzymes that can help break down the food. For instance, lingual lipase is one of the enzymes produced by the salivary glands under the tongue, which helps break down fats. Longer exposure to saliva while chewing food means longer exposure to this enzyme.3. Functionally, the small intestine is chiefly involved in the digestion and absorption of nutrients. It receives pancreatic secretions and bile through the hepatopancreatic duct which aid with its functions.4. By the time food reaches the large intestine, the work of absorbing nutrients is nearly finished. The large intestine's main job is to remove water from the undigested matter and form solid waste (POOP) to be excreted.5. Functions of brain- The brain controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body. The central nervous system (CNS) is composed of the brain and spinal cord.Functions of lungs- Your lungs are part of the respiratory system, a group of organs and tissues that work TOGETHER to help you breathe. The respiratory system's main job is to move fresh air into your body while removing waste gases.Functions of heart- Blood carries oxygen and other important nutrients that all body organs need to stay healthy and to work properly. Your heart is a MUSCLE, and its job is to pump blood throughout your circulatory systemFunctions of kidney- Their main job is to cleanse the blood of toxins and transform the waste into urine. Each kidney weighs about 160 grams and gets rid of between one and one-and-a-half litres of urine per day. The two kidneys together filter 200 litres of fluid every 24 hours.No, all the body PARTS have their different functionsExplanation:May my answer helps you ☺️