Movement and Function of White Blood Cells

Questions and Answers

What is the primary role of the WBCs in relation to chemotaxis?

To increase inflammation levels in tissues

To directly destroy cancerous cells

To transport oxygen to cells in need

To move toward areas of infection or inflammation (correct)

Which of the following statements about phagocytosis is accurate?

Phagocytosis only occurs in living tissues

Rough surfaces increase the likelihood of phagocytosis (correct)

Antibodies do not influence phagocytosis

Phagocytosis is primarily ineffective against rough surfaces

Which condition makes bacteria susceptible to phagocytosis?

Rapid movement away from phagocytes

Presence of smooth protein coats

Lack of protective protein coats (correct)

High levels of bacterial replication

What characteristic of granulocytes and monocytes enhances their function in immune response?

Their special ability to locate and eliminate foreign invaders Signup and view all the answers

Which factor does not affect chemotaxis?

Smoothness of natural tissue surfaces Signup and view all the answers

Which immune action primarily involves neutrophils and macrophages?

Phagocytosis Signup and view all the answers

What is a key element that assists phagocytes in targeting bacteria?

Antibodies binding to bacterial membranes Signup and view all the answers

In what context do WBCs demonstrate chemotaxis?

Towards areas with higher concentrations of chemotactic substances Signup and view all the answers

What role do smooth surfaces in tissues play in relation to phagocytosis?

They resist phagocytosis by minimizing immune cell adherence. Signup and view all the answers

What characteristic do most dead tissues and foreign particles share?

They lack protective protein coats. Signup and view all the answers

What initiates the inflammatory response in the body?

The invasion of pathogens leading to tissue injury. Signup and view all the answers

How do some bacteria evade phagocytosis?

By secreting substances resistant to lysosomal digestion. Signup and view all the answers

What is the primary effect of inflammation on surrounding tissues?

It causes significant changes in both injured and uninjured tissues. Signup and view all the answers

Which type of enzymes are primarily involved in the digestion of foreign particles by macrophages?

Proteolytic enzymes. Signup and view all the answers

What effect do antibodies have on bacteria in relation to phagocytosis?

They bind to bacteria, making them more susceptible to phagocytosis. Signup and view all the answers

What is a characteristic of neutrophils compared to macrophages related to lysosomal enzymes?

Neutrophils do not have lipase enzymes. Signup and view all the answers

What is the primary function of neutrophils during the inflammatory response?

They directly phagocytize pathogens. Signup and view all the answers

Which of the following adhesion molecules is NOT mentioned as being present on endothelial cells?

L-selectin Signup and view all the answers

What role does local blood clotting play in the inflammatory response?

It creates a physical barrier to prevent infection spread. Signup and view all the answers

Which cell type begins to invade the inflamed area within the first hour after inflammation onset?

Neutrophils Signup and view all the answers

Which of the following correctly describes the function of the macrophages in the inflammatory response?

They phagocytize pathogens. Signup and view all the answers

What distinguishes basophils from mast cells in terms of location?

Basophils circulate in the blood whereas mast cells are located in tissues. Signup and view all the answers

Which substances are released by both mast cells and basophils?

Heparin, histamine, and bradykinin Signup and view all the answers

What role do IgE antibodies play in the function of mast cells and basophils?

IgE binds to mast cells and basophils, triggering their rupture. Signup and view all the answers

Which of the following is NOT a substance released by mast cells and basophils during an allergic reaction?

Prostaglandin Signup and view all the answers

What is the primary function of heparin released by mast cells and basophils?

To prevent coagulation Signup and view all the answers

In the context of allergic reactions, what is the significance of the rupture of mast cells and basophils?

It leads to the release of various inflammatory mediators. Signup and view all the answers

Which of the following best describes the role of bradykinin in allergic reactions?

It contributes to inflammation and pain during allergic responses. Signup and view all the answers

Which statement about mast cells and basophils is false?

Mast cells are located in the blood stream. Signup and view all the answers

What is the time frame for newly formed granulocytes and monocytes to leave the bone marrow after stimulation?

3 to 4 days Signup and view all the answers

What can happen if the stimulus from inflamed tissue continues over time?

Bone marrow can produce these cells at greatly increased rates Signup and view all the answers

What effect do granulocytes and monocytes have on adhesive molecules in the capillaries?

They cause increased expression of adhesive molecules Signup and view all the answers

How do neutrophils move from the blood into tissue spaces?

By diapedesis Signup and view all the answers

What increases on the surface of endothelial cells as a result of granulocyte and monocyte stimulation?

Selectins and ICAM-1 Signup and view all the answers

What is a potential long-term outcome of chronic inflammation related to granulocyte and monocyte production?

Significant increase in granulocyte and monocyte production Signup and view all the answers

What physiological change occurs between endothelial cells as granulocytes and monocytes are stimulated?

Loosening of intercellular attachments Signup and view all the answers

How much can the bone marrow increase granulocyte and monocyte production during chronic inflammation?

20 to 50 times normal Signup and view all the answers

Study Notes

Movement of White Blood Cells (WBCs)

WBCs utilize chemotaxis, a process that guides them to sites of infection and inflammation.
Concentration gradient of chemotactic substances influences WBC movement, with movement directed towards higher concentrations.
Both Granulocytes and Monocytes are capable of seeking and destroying foreign invaders.

Phagocytosis

Neutrophils and macrophages play crucial roles in phagocytosis, defined as the ingestion of harmful agents.
Natural structures with smooth surfaces naturally resist phagocytosis; rough surfaces enhance this process.
Most natural substances possess protective protein coats that repel phagocytes; however, dead tissues and foreign particles lack such coats, making them more susceptible.

Immune Responses

The immune system produces antibodies against pathogens, aiding in targeting and enhancing phagocytosis of bacteria by binding to their membranes.

Inflammation

Inflammatory response is triggered by tissue injury from various causes (bacteria, trauma, chemicals).
Injury releases multiple substances causing drastic changes in surrounding, uninjured areas.
Inflammation serves as a natural defense mechanism, responding to threats that disrupt bodily homeostasis.

Phagocytosis Phase Dynamics

Neutrophils and macrophages deploy lysosomal enzymes (proteolytic enzymes, lipase) to digest harmful agents.
Bacterial resistance to lysosomal digestion can dampen neutrophil and macrophage effectiveness.

Neutrophil Invasion

Following inflammation, neutrophils rapidly invade the affected area from the bloodstream within the first hour.
Endothelial cells lining blood vessels express various adhesion molecules (P-selectin, E-selectin, ICAM) that facilitate neutrophil migration.

Increased Production of Cells

Stimulation from inflamed tissue prompts increased production of granulocytes and monocytes in bone marrow.
It may take 3 to 4 days for newly formed cells to reach circulation, with the body sometimes producing up to 20-50 times the normal amount during chronic conditions.

Interaction between Mast Cells and Basophils

Mast cells (located in tissues) and basophils (in circulating blood) release heparin and histamine, contributing to inflammatory and allergic responses.
IgE antibodies attach to these cells, causing them to release various substances that mediate allergic reactions and inflammation, including histamine and lysosomal enzymes.

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Description

This quiz explores the movement, functions, and roles of white blood cells (WBCs) in the immune response. It covers topics such as chemotaxis, phagocytosis, and the process of inflammation. Test your understanding of how WBCs target and destroy pathogens effectively.