The inner lining of the human small intestine has numerous finger-like projections called:

The inner lining of the human small intestine is characterized by millions of microscopic, finger-like projections known as villi [2]. These structures are essential for the digestive process as they significantly increase the total surface area of the intestinal mucosa, thereby enhancing the efficiency of nutrient absorption into the bloodstream. Each villus contains a network of capillaries and a specialized lymphatic vessel called a lacteal to transport absorbed nutrients [2]. While the small intestine also features larger circular folds (plicae circulares) and smaller microscopic processes on individual cells called microvilli, the term 'finger-like projections' specifically refers to villi. Other options like sphincters are muscular valves, enzymes are chemical catalysts, and plaques (such as Peyer's patches) are lymphoid aggregates rather than structural projections for absorption [2].

Sources

1. [2] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/small-intestine-mucosa
2. [1] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/upper-digestive-tract