Final answer:
The digestive and excretory systems are responsible for nutrient absorption and waste elimination in the human body. The digestive system breaks down and absorbs nutrients, while the excretory system, including the kidneys, eliminates waste through urine.
Step-by-step explanation:
The human body systems responsible for ensuring nutrients are properly absorbed and waste is eliminated are the digestive system and the excretory system. The digestive system breaks down food, absorbs nutrients through processes such as mechanical digestion and chemical digestion, and ultimately eliminates solid food waste.
Significant organs in this process include the mouth, stomach, and intestines, where enzymes like amylase and pepsin aid digestion. The small intestine, through structures such as villi and microvilli, plays a critical role in the absorption of nutrients into the circulatory system. Meanwhile, the excretory system, with the kidneys as a primary component, filters blood to maintain ion concentrations, and eliminates waste through urine, which is expelled through the urethra.