Human Nutrition and Digestive System Functions

Study Notes

Humans need different nutrients from a balanced diet for survival, including carbohydrates, fats, proteins, vitamins, mineral ions, fiber, and water.
Carbohydrates provide energy for cell respiration, fats are for long-term energy storage and insulation, proteins are essential for growth and tissue repair.
Vitamin C is crucial for healthy skin and gums, while vitamin D aids in calcium absorption for strong bones; mineral ions like calcium and iron are also necessary for nutrition.
Fiber helps with digestion and is found in vegetables, fruits, and whole grains, while water is essential for cellular reactions and can be obtained from both drinks and food.
The digestive system breaks down food into smaller molecules for nutrient absorption, involving organs like the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.
Associated organs of the digestive system include the salivary glands, pancreas, liver, and gall bladder, with functions like ingestion, digestion, absorption, assimilation, and ejection of nutrients.
Physical digestion involves breaking down food without chemical change by the teeth, stomach walls squeezing food to liquefy it, and bile aiding in emulsification of fats to increase surface area for chemical digestion.