Each Problem is worth the indicated amount (25 points total). Answers should be short, but complete. Usually several sentences are required to answer each question thoroughly. When using diagrams, be sure to draw clearly and label completely. Answers maybe typed or neatly hand written (legible please!!) A problem answer key will be handed out prior to the exam and the problem set will be returned to you with your exam.

1. As you know the adaptive immune system has "memory" which assists in combating repeated exposures to disease causing agents such as viruses. In the space below briefly describe how immunological memory is generated by B cells. In addition explain how the immune response differs between the first exposure to a virus and a later encounter with that same virus. (6 points)

2. In the space below list the types of cells which make up the mature vertebrate (human) immune system. For each cell type provide a short description of its function in the immune response.

(7 points)

3. Using a graph explain how the conditions in an active tissue such as skeletal muscle, alter the oxygen binding properties of hemoglobin such that additional oxygen is released. In addition to your graph list the changes that are found in tissues with increased metabolism and how these factors alter the properties of hemoglobin. (6 points)

4. As you know breathing is an active process, requiring energy. You also now know that some aspects of the ventilation cycle are passive. Answer the following questions I) Which parts of the normal respiratory cycle are active and which parts are passive? II) What are the changes that occur during exercise? III) What are the main muscles of respiration and how do they participate in the process? IV) What is responsible for the passive part of the process? (include the properties of the thoracic compartment and of the lung itself)

(6 points)