Q1 Which of the following would be considered a transport epithelium? A) the porocytes of a sponge that line the incurrent pores B) the longitudinal muscles of the digestive tract. C) the proximal tubule of the kidney D) the myenteric plexus of the digestive tract Q2 What differentiates a closed circulatory system from an open circulatory system? A) whether a heart is present or not B) whether or not there is a circulatory fluid C) the presence or absence of blood vessels D) direct contact of circulatory fluids with target tissues.