Basophils

Basophils are granulocytes, meaning that there are darkly stained granules in the cytoplasmThe gel-like substance within a cell that contains organelles and cytosol..  In basophils, these granules are quite large, appearing like little bubbles in the cytoplasm. Basophils are characterized by a nucleusThe control center of the cell that contains DNA and directs cellular activities. with two lobes and densely packed, darkly stained cytoplasmic granules.

Cytoplasm

Basophils contain darkly staining granules in the cytoplasm.  These granules are larger than those that are seen the in the cytoplasm of neutrophils.  Basophilcells that stain with basic dyes Anterior pituitary that secrete FSH, LH, TSH, and ACTH. granules are usually vesicles of substances such as heparin and histamine.  

Function

Basophils are involved in allergic reactions and hypersensitivity responses.  They can release their granules of histamine and heparin and contribute to inflammation.  Many students are familiar with heparin as a substance that prevents blood clotting in bed-bound patients. Heparin is an anti-coagulant.  Histamine is a substance that causes vasodilationThe widening of blood vessels due to relaxation of smooth muscle, decreasing blood pressure and incr, increasing the diameter of blood vessels and making them more permeable.  Fluids then leak from the blood vessels causing the swelling and redness associated with inflammation.  Combined, these two substances amplify the effects of inflammation, which is a beneficial process occurring after initial injury. 

Seasonal allergies are commonly produced by pollen irritating the nasalTwo small rectangular bones forming the bridge of the nose. mucosaThe innermost lining of the digestive tract that contains mucus-secreting cells for protection and a, resulting in a condition called rhinitis.  Antihistamines are commonly used to mediate seasonal allergies. They quell the effects of histamine released by basophils reacting to allergens. 

Confused With

Eosinophils and basophils have similar nucleiClusters of neurons in the CNS responsible for processing information., but can always be differentiated by the color of the granules in their cytoplasm.  

All Figures: Slide 86X Human blood smear, Giemsa stain, 86X scan from hematopathology normals collection
All by University of Michigan Histology, licensed under CC BY-NC-SA 3.0.