'); spawn.document.close(); // Increment variables for the next question questionIndex++; preventer++; } function gradeTest() { // Increment the variables for the last time questionIndex++; preventer++; // Compare student answers with correct answers for (var i = 0; i < killers.length; i++) { if (keeper[i] == answers[i]) { correctAnswers++; } } // Print the test results printResults(); } // Print the questions, answer options, and other info function printResults() { spawn.document.clear(); spawn.document.open(); spawn.document.writeln(''); spawn.document.writeln('Quiz Results'); spawn.document.writeln(''); spawn.document.writeln(''); spawn.document.writeln('

You scored ' + correctAnswers + '/' + killers.length + ' correctly.

'); spawn.document.writeln('Here are your results:

'); for (var i = 0; i < killers.length; i++) { spawn.document.writeln('\n\nQuestion ' + (i + 1) + '
'); spawn.document.writeln(killers[i].substring(0, killers[i].indexOf('$$'))); spawn.document.writeln('

\na. ' + killers[i].substring((killers[i].indexOf('$$') + 2), killers[i].indexOf('%%')) + '
'); spawn.document.writeln('b. ' + killers[i].substring(killers[i].indexOf('%%') + 2, killers[i].indexOf('^^')) + '
'); spawn.document.writeln('c. ' + killers[i].substring(killers[i].indexOf('^^') + 2, killers[i].indexOf('&&')) + '
'); spawn.document.writeln('d. ' + killers[i].substring(killers[i].indexOf('&&') + 2, killers[i].length) + '
'); // Determine if the student answered each question appropriately, and display accordingly if (keeper[i] == answers[i]) { spawn.document.writeln('You answered this correctly.\n


'); } else { spawn.document.writeln('The correct answer is: ' + answers[i] + '\n


'); } } // Add extra info about the questions, etc. spawn.document.writeln('\n\n If you missed some questions you might want to go back and review this module.'); spawn.document.writeln('You can always retake the quiz. '); spawn.document.close(); } function busted() { alert('Sorry, you only get one shot at each question.'); spawn.history.forward(); spawn.focus(); }
Human Structure Virtual Histology
    Blood Cells and Hematopoiesis
     
    		 

    Granulocytes

    Granulocytes, as their name implies, contain distinctive cytoplasmic granules that are easily visualized in peripheral blood smears stained with Wright’s stain. There are three types of granulocytes: neutrophils, eosinophils, and basophils. These cells are approximately 12-15 microns in diameter, and their nuclei are either segmented or bilobed. In the case of eosinophils and basophils, their nuclei may be obscured by their abundant, intensely stained specific granules.

    Neutrophils are the most abundant granulocyte, representing 50-70% of the WBC population, and are therefore the most readily identifiable leukocyte in a peripheral blood smear. They contain many lysosomes or azurophilic granules and pale staining specific granules, making it easy to visualize their segmented nuclei. Neutrophils are among the first cells to arrive at the site of injury or infection, exiting the vasculature by the process of diapedesis. They enter into the connective tissue where they function as phagocytes, engulfing and killing bacteria and releasing cytokines that modulate inflammation.

    Eosinophils represent about 1-4% of white blood cells in a peripheral smear and are more difficult to locate. They possess distinctive, intensely stained pink granules that may obscure their bilobed nucleus. Eosinophils are involved in immune responses to helminthic infections and allergic reactions.

    Basophils are the least abundant granulocyte, representing 0.5-1% of the WBC count. They possess abundant, basophilic specific granules and a bilobed or sometimes S shaped nucleus. They possess cell surface receptors for IgE, and binding to IgE triggers secretion of the contents in their specific granules. Basophils modulate immune responses and are involved in allergic and hypersensitivity reactions.

    • Use the images below to help you identify the granulocytes in these slides of peripheral blood smears (sample 1 and sample 2). Note their size compared to red blood cells, nuclear morphology, and the appearance of their granules.
    • To review the ultrastructural features of granulocytes in TEM images, please see Figures 12-8 through 12-10 in Junqueira’s Histology 14e.

    Clinical note: A large accumulation of neutrophils, especially dead and dying neutrophils that have engulfed many bacteria, constitutes “pus.” Pus formation is a normal part of an infection that occurs within tissues.  

    Want to try for a lymphocyte?