Where does most nutrient absorption actually happen in the digestive system?
AMouth
BStomach
CSmall intestine
DLarge intestine
The small intestine is where the vast majority of nutrient absorption takes place. Its inner walls are covered with tiny finger-like projections called villi that create an enormous surface area for absorbing nutrients into the bloodstream. The stomach mainly breaks food down mechanically and chemically, but it absorbs very little into the blood.
Question 2 True / False
The small intestine is called 'small' because it is shorter than the large intestine.
TTrue
FFalse
Answer: False
The small intestine is actually much longer than the large intestine -- about 20 feet compared to about 5 feet. It's called 'small' because of its narrower diameter (about 1 inch wide vs. the large intestine's 3 inches). The naming refers to width, not length, which is one of the most common points of confusion about digestive anatomy.
Question 3 Short Answer
Trace the path food takes from the moment you eat a bite of apple to the point where nutrients enter your bloodstream. Name the major organs in order.
Think about your answer, then reveal below.
Model answer: Mouth (chewing and saliva begin breaking food down) → esophagus (muscular tube pushes food to stomach) → stomach (acid and churning break food into a paste) → small intestine (nutrients are absorbed into the bloodstream through the intestinal walls). The large intestine then absorbs remaining water before waste is eliminated.
Digestion is a sequential process where each organ has a specific role. The mouth starts mechanical and chemical breakdown. The esophagus is just a transport tube. The stomach does heavy chemical breakdown with acid. The small intestine is the absorption workhorse. Understanding this sequence shows that digestion is a multi-step process, not something that happens all at once in the stomach.