Allergy Tests. Guide. Allergy testing involves having a skin or blood test to find out what substance, or allergen, may trigger an allergic response in a person.Skin tests are usually done because they are rapid, reliable, and generally less expensive than blood tests, but either type of test may be used.llergy blood tests look for substances in the blood called antibodies. Blood tests are not as sensitive as skin tests but are often used for people who are not able to have skin tests. The most common type of blood test used is the enzyme-linked immunosorbent assay (ELISA, EIA).
Sensory Structures of a Flatworm. Flatworms live in many environments. Jupiterimages/Photos.com/Getty Images. Flatworms, also called planarians, belong to the phylum Platyhelminthes. Characterized by flat bodies, they have no circulatory or respiratory organs and a very simple digestive tract.This body plan limits them to very small, flat shapes to allow them to absorb oxygen and moisture.owever, a flatwormâs body contains the beginnings of more complex structures found in other animals. For example, eye spots resemble the ancestral forms found in more complex animals. Understanding flatworm sensory structures can help you understand the origins of these organs.
There is a second special characteristic of the sense of smell. For all the other senses (seeing, hearing, tasting, touching), the information from the sensory organs (the eyes, the ears, the skin, the tongue) travels through a brains structure called the thalamus (from Greek: room). The thalamus is something like a gate to our consciousness.