Figure shows the human digestive system.
Add each label to the appropriateness of the diagram. Some labels should be written in two places.
Labels to add
- Physical digestion, increases the surface area of food (two places)
- The gall bladder
- Amylase is secreted (two places)
- Amylase acts on starch (two places)
- Lipase breaks down fats
- Absorption happens
- Secretes a liquid with a low pH, which kills bacteria
- Protease is secreted (two places)
Important Questions on Human Nutrition
In an investigation into the absorption of vitamin D from the alimentary canal, a volunteer ate a measured quantity of vitamin D on a piece of roast. Blood samples were then taken from him at intervals over a period of 72 hours, and the concentration of vitamin D in each blood sample was measured.
The results are shown in the graph in figure 7.2.
Describe the changes in the concentration of vitamin D in the blood over the 72-hour period.
Vitamin D is soluble in fat, but insoluble in water. It is present in the fat component of foods that eat.
Use this information to suggest how bile helps to absorb vitamin D from food.
Vitamin D is soluble in fat, but insoluble in water. It is present in the fat component of foods that eat.
Suggest into which part of the villi is absorbed. Explain your suggestion.
