Cells of the Immune System: Neutrophils

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Questions and Answers

Where do neutrophils circulate?

In the tissues

In the heart

In the blood (correct)

In the lungs

What triggers neutrophils to leave the blood vessels?

The presence of nutrients

The presence of macrophages

The presence of oxygen

The presence of bacteria (correct)

What is the main function of macrophages?

To activate T-cells

To produce cytokines

To phagocytose foreign particles (correct)

To produce antibodies

Why do neutrophils need to leave the blood vessels?

To get to the site of infection Signup and view all the answers

What do macrophages notice that triggers their response?

The presence of bacteria Signup and view all the answers

How do neutrophils get to the site of infection?

By squeezing out of the blood vessels Signup and view all the answers

What is the purpose of neutrophils?

To fight infections Signup and view all the answers

Where do macrophages typically reside?

In the tissues Signup and view all the answers

Where does antigen presentation occur?

In the macrophage Signup and view all the answers

What is the direction of lymphatic flow?

One directional Signup and view all the answers

Where do all lymphatic vessels eventually drain into?

The blood Signup and view all the answers

What is the main role of B cells in the immune response?

To release antibodies that can fight bacterial invaders Signup and view all the answers

How do T cells get back into the blood?

Via the lymphatic vessels Signup and view all the answers

What do neutrophils release after they do their job?

Pus Signup and view all the answers

What do antibodies produced by B cells do?

Float around the body and fight bacterial invaders Signup and view all the answers

What type of cells are endothelial cells?

Lining cells Signup and view all the answers

Why do neutrophils need to squeeze between endothelial cells?

To get to the bacteria in the tissue Signup and view all the answers

What is the final destination of the lymph fluid before entering the blood?

The thoracic duct Signup and view all the answers

What is the function of macrophages in this process?

To eat up bacteria Signup and view all the answers

Where do T cells go after getting back into the blood?

The tissues Signup and view all the answers

Why do macrophages need to use a different mode of transport?

Because they can't cross from tissue to blood Signup and view all the answers

What type of vessel do macrophages use to travel to the lymph node?

Lymphatic vessel Signup and view all the answers

What is the purpose of neutrophils in the immune response?

To eat up bacteria Signup and view all the answers

What happens to neutrophils after they eat up bacteria?

They die and become pus Signup and view all the answers

What is the usual lifespan of neutrophils?

5 days Signup and view all the answers

Why can't immune cells cross from tissue to blood?

Because it's an active process Signup and view all the answers

Study Notes

Neutrophils and Blood Circulation

Neutrophils circulate in the blood, which circulates in a closed loop.
Neutrophils are the most common immune cell.

Neutrophil Action in Infection

Neutrophils do their work when there is an infection in the tissues.
To get to the infected tissue, neutrophils squeeze out through the cells of the blood vessels.
Macrophages in the infected tissue release chemical signals that alert endothelial cells lining the blood vessels of the infection.
Endothelial cells then express proteins that attract neutrophils, which stick to these proteins and squeeze through between the endothelial cells.
Neutrophils then gobble up bacteria, chew them up, digest them, and eventually die, becoming pus.

Immune Cell Movement

Immune cells only move from the blood into the tissue, not from the tissue back into the blood.
Macrophages need to use a different mode of transport to get to B and T cells, which involves entering lymphatic vessels.

Lymphatic System

Lymphatic vessels have little holes that allow cells, proteins, and other things to get in.
Macrophages enter lymphatic vessels, which allow them to travel to the nearest lymph node.
In the lymph node, macrophages present antigens to T cells, which leads to the activation of T cells that can fight the infection.

Antigen Presentation and Immune Response

Antigen presentation occurs in the lymph node, where macrophages present antigens to T cells.
Activated T cells then travel through the lymphatic system, eventually entering the blood through the thoracic duct.
In the blood, T cells follow chemical signals to the infected tissue, where they squeeze through between endothelial cells to fight the infection.
B cells remain in the lymph node, producing antibodies that can travel to the infected tissue to fight the infection.

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Description

This quiz covers the functions and movement of neutrophils in the immune system, specifically their circulation in the blood. Learn about their role in immune response and how they navigate the body.