wbc granulocytes Flashcards
What are granulocytes and what are the types of granulocytes?
Granulocytes: A type of white blood cell (WBC) that contains granules in their cytoplasm. They have lobed nuclei made up of several rounded nuclear areas connected by thin strands of nuclear material.
Types of Granulocytes:
Neutrophils: The most abundant type, crucial in fighting bacterial infections.
Eosinophils: Involved in allergic reactions and parasitic infections.
Basophils: Play a role in allergic responses and inflammation.
What are neutrophils and what is their role in immune defense?
Neutrophils: The most numerous type of white blood cell (WBC), characterized by a multilobed nucleus and fine granules that stain pink due to their response to both acidic and basic stains.
Role:
Phagocytosis: Neutrophils are powerful phagocytes, meaning they engulf and digest pathogens, especially bacteria and fungi, at sites of acute infection.
Respiratory burst: During this process, neutrophils release oxidizing substances (like bleach, hydrogen peroxide, and others) to destroy the engulfed invaders.
What are eosinophils and what is their role in immune defense?
Eosinophils: A type of white blood cell with a blue-red nucleus (often resembling earmuffs) and brick-red cytoplasmic granules.
Role:
Parasitic infections: Eosinophils increase in number during infections caused by parasitic worms (e.g., tapeworms), which can be ingested through food (like raw fish) or enter through the skin.
Action: When eosinophils encounter a parasitic worm, they gather around it and release enzymes from their granules, which help digest and destroy the parasite.
: What are basophils and what role do they play in the immune response?
Basophils: The rarest type of white blood cell (WBC) with large histamine-containing granules that stain dark blue to purple.
Role:
Histamine release: Basophils release histamine, a potent inflammatory chemical that:
Makes blood vessels leaky, allowing immune cells and proteins to reach the site of infection or injury.
Attracts other WBCs to the area, enhancing the immune response.
What are agranulocytes and what types of white blood cells belong to this group?
Agranulocytes: A group of white blood cells (WBCs) that lack visible cytoplasmic granules when stained. Their nuclei are generally spherical, oval, or kidney-shaped.
Types of Agranulocytes:
Lymphocytes: Involved in adaptive immunity, including T cells, B cells, and natural killer cells.
Monocytes: The largest type of WBC, which differentiate into macrophages and dendritic cells when they enter tissues and help with phagocytosis.
Memory Tip: “All lymphocytes are leukocytes, but not all leukocytes are lymphocytes.” (Lymphocytes are a subset of WBCs, or leukocytes.)
What are lymphocytes and what is their role in the immune system?
Lymphocytes: A type of white blood cell (WBC) with a large, dark purple nucleus that takes up most of the cell’s volume. They are slightly larger than red blood cells (RBCs).
Role:
Lymphocytes are primarily found in lymphatic tissues (like the tonsils) and are crucial in the immune response.
They play a central role in adaptive immunity, recognizing and responding to specific pathogens.
Prevalence: Lymphocytes are the second most numerous type of leukocytes in the blood.
s. They are a type of white blood cell involved in adaptive immunity, meaning they recognize and remember specific pathogens.
There are two main types of lymphocytes:
B cells: Produce antibodies that target and neutralize harmful invaders.
T cells: Attack infected or abnormal cells and help regulate the immune response.
Since they are mostly found in lymphatic tissues (like the lymph nodes and tonsils), they act as a surveillance system, constantly monitoring for harmful microbes. Their ability to recognize past infections helps the body respond faster and stronger if the same pathogen attacks again
What are monocytes and how do they function in the immune system?
Monocytes: The largest type of white blood cell (WBC). They have a U- or kidney-shaped nucleus and more abundant cytoplasm compared to other WBCs. They resemble large lymphocytes.
Role:
When monocytes migrate into tissues, they transform into macrophages—large cells with a “huge appetite” for engulfing pathogens and debris. The term “macrophage” comes from Greek words meaning “big eater” (macro = large; phage = one that eats).
Macrophages are key in fighting chronic infections (e.g., tuberculosis) and in activating lymphocytes to respond to infection.
Monocytes are a type of white blood cell (WBC) and they’re the biggest of all the WBCs.
What they do: Monocytes move from the bloodstream into different body tissues (like lungs or organs) and change into macrophages. Think of macrophages as “big eaters” because they eat and destroy things like bacteria, viruses, and dead cells in the body.
Why they matter: Macrophages are super important for fighting infections, especially chronic ones (like tuberculosis), where the body has trouble getting rid of the bacteria. They also help other immune cells (like lymphocytes) kick in and do their part in fighting infections.
In short, monocytes are like soldiers that travel to infection sites and then become macrophages, the big eaters that destroy harmful stuff and activate other immune cells to help fight off infections. Does that help clear things up?
Students are often asked to list the WBCs in order of relative abundance in the blood
—from most to least. The following phrase may help you with this task: Never let monkeys eat bananas (neutrophils, lymphocytes, monocytes, eosinophils, basophils).
What are platelets, and how do they function in blood clotting?
Platelets are fragments of multinucleate cells called megakaryocytes. They are anucleate pieces that pinch off from the megakaryocytes, sealing themselves from surrounding fluids. Platelets are irregularly shaped, dark-staining bodies found in blood, with a normal count of about 300,000 per mm³. They are essential for blood clotting, which stops blood loss from broken blood vessels.
