<p> Observing Capillary Circulation in Goldfish Anatomy and Physiology Purpose: To see how capillaries appear and work in a living organism.</p><p>Materials: cotton petri dish 2 glass slides goldfish eyedropper pipette microscope beaker Procedure: 1. Gather your materials for your station, including your fish in a beaker. </p><p>2. Soak a piece of cotton (enough to wrap around the fish like a blanket) in the water in the beaker with the </p><p> fish. </p><p>3. Flatten out (unwrap) the piece of soaking wet cotton ball and place it in the bottom of a clean petri dish.</p><p>4. Gently remove the goldfish with a clean hand from your beaker, and place it GENTLY onto the wet cotton so</p><p> that the gill and head areas (not mouth!) are covered and the tail fin, the caudel fin, is showing.</p><p>5. Place the petri dish on the stage of the microscope so that the tail fin is visible under the low power</p><p> objective. Examine the goldfish’s tail under low power only. Move the petri dish around until you see blood</p><p> moving in the blood vessels. </p><p>6. While one-partner views the caudel fin under the microscope, the other partner should be monitoring the</p><p> fish’s wellbeing. Using the eyedropper, count, “1, 2, 3, 4, 5…..drip” and place a drop of water on to the</p><p> cotton ball above the fish’s gills. This constant adding should help the fish breathe while out of water.</p><p>7. Locate a blood vessel in which blood cells are passing in a single file. This is a capillary. Note the direction of</p><p> the flow of blood. Follow the capillary in the direction opposite the blood flow to where it joins a slightly</p><p> larger vessel (arteriole). Then follow it in the direction of blood flow until it joins a slighter larger vessel</p><p>(venule). In your lab notebook, draw and label the different types of blood vessels that you see. Use</p><p> arrows to show the direction of the blood flow. </p><p>8. If at any time while viewing the capillaries the blood appears to dramatically slow down, return the fish to </p><p> the beaker of water to avoid trauma. When finished, clean up your station and return the goldfish alive </p><p> and well!</p><p>Questions: Answer the following using complete sentences in your lab notebook.</p><p>1. Describe the blood cells’ shape and color.</p><p>2. What happens at the site of the capillaries? </p><p>3. What is the purpose of blood? How is the heart involved?</p><p>4. Why might an organism’s heart speed up or slow down during daily life?</p><p>5. Do you think the fish’s blood-flow might slow down after being out of water too long? Why or why not?</p>