Question 1
Where in the small intestines are lymphocytes, plasma cells, and macrophages produced?
◦ Brush border
◦ Microvilli
◦ Lamina propria
◦ Crypts of Lieberkühn
Question 2
The student asks the professor why water and electrolytes are transported in both directions through tight junctions and intercellular spaces rather than across cell membranes. What response by the professor is best?
◦ The intercellular hydrostatic pressure is inadequate to push the water and electrolytes across the cell membranes.
◦ A balance of cations and ions among the electrolytes on each side of the cell membranes cannot be maintained.
◦ The epithelial cell membranes are formed of lipids that are hydrophobic and therefore repel water.
◦ Receptors on those cell membranes are occupied with a diffusion of amino acids and monosaccharides.
Structure of the water molecule
Whale in water
How water moves through a tree
Depleted ground water
Better land and water management and appropriate crop selection can help eliminate hunger
The Distribution of Water on Earth