D3.3 - The Lymphatic System and Immunity

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Questions and Answers

What is the primary function of the lymphatic system?

To facilitate blood circulation

To transport oxygen throughout the body

To regulate body temperature

To collect lymph and support immune functions (correct)

Which type of immunity involves the use of antibodies?

Antibody-mediated immunity (correct)

Humoral immunity

Cell-mediated immunity

Innate immunity

Where do B-Lymphocytes mature?

Spleen

Lymph nodes

Bone marrow (correct)

Thymus gland

What role do macrophages play in the lymphatic system?

Trap and destroy bacteria Signup and view all the answers

What are antigens?

Molecules on the surface of cells and pathogens Signup and view all the answers

Which white blood cells are responsible for cell-mediated immunity?

Neutrophils and macrophages Signup and view all the answers

Which component of the immune system signals an attack on foreign invaders?

T-Lymphocytes Signup and view all the answers

What is the first line of defense in the human body?

Skin and mucus membranes Signup and view all the answers

What role do antibodies play in relation to toxins?

They bind to toxins, preventing them from entering cells. Signup and view all the answers

What happens after a macrophage destroys an invader?

The antigen goes to the macrophage surface. Signup and view all the answers

How do helper T-cells function in the immune response?

They release signals that stimulate other immune cells. Signup and view all the answers

What is the role of suppressor T-cells in the immune system?

To signal the immune system to shut down. Signup and view all the answers

What characterizes Type O blood in terms of antigens?

It has no antigens. Signup and view all the answers

What occurs during agglutination?

Red blood cells clump together. Signup and view all the answers

What defines the ABO blood group system?

The presence of both A and B antigens. Signup and view all the answers

Why can HIV hide from the immune system?

It hides inside T-cells. Signup and view all the answers

Study Notes

Lymphatic System and Immunity

The lymphatic system is a network of vessels, glands, and nodes spread throughout the body
It collects fluid (lymph) made of interstitial fluid
Lymph connects to the circulatory system at the subclavian veins
Lymph works with white blood cells to protect the body from infection
Lymphocytes mature in lymph nodes
Lymph nodes contain macrophages, which trap and destroy bacteria

Human Defense System

The first line of defense prevents organisms from entering the body
Skin and mucus lining respiratory passages keep out most microbes
Stomach acids, oils in skin, and enzymes in tears break down bacteria

Non-Specific Defenses

The second line of defense is cell-mediated immunity
This includes neutrophils, monocytes, and macrophages
Phagocytosis, where cells engulf bacteria, is used to kill bacteria
Natural killer cells target cancerous or virus-infected body cells

Specific Defenses (Antibody Mediated Immunity)

The third line of defense is immunity developed by specific defenses using antibodies
Antibodies are proteins that recognize and destroy foreign substances
Lymphocytes (T and B cells) are primarily responsible for the immune response
The body recognizes its own molecules ("self") and protects against foreign invaders

T & B Cells – Lymphocytes

Lymphocytes are divided into B-cells and T-cells based on where they mature
B-cells mature in bone marrow and produce Y-shaped antibodies
T-cells mature in the thymus gland and signal an attack from foreign invaders

Antigens & Antibodies

Antigens are molecules found on cells and pathogens
Antigens identify cells for T and B cells
Antibodies are Y-shaped proteins that attach to specific antigens
Antibody-antigen complexes make invaders visible to macrophages
Antibodies prevent toxins from entering cells

Recognizing Antigens

When an invader is destroyed, its antigen goes to the macrophage surface
The macrophage couples with helper T-cells
Helper T-cells release chemical signals to activate macrophages, B-cells, and T-cells
Activated B-cells divide and produce antibodies

Recognizing Antigens (continued)

Helper T-cells activate killer T-cells that destroy invading cells and body cells infected by viruses by puncturing their membranes
Killer T-cells can be activated indirectly by chemical signals from helper T-cells or directly by invading pathogens
Suppressor T-cells signal the immune system to shut down after the infection is fought off
Phagocytes clean up dead/injured B and T-cells, and memory T-cells remain in the bloodstream for future responses to antigens

Blood Types

Blood transfusion is the transfer of blood from one person to another
Different blood types result from different groups of red blood cell antigens (ABO system)
The ABO system determines blood type based on the presence of Type A and B antigens on red blood cells
Agglutination is the clumping of red blood cells when incompatible blood types are mixed

Blood Groups – How They Work

Blood types have specific antigens and antibodies, for example A blood type has "A" antigen and Anti-B antibodies in plasma
Different blood types can receive blood from certain other types

Rhesus (Rh) Factor

Rh factor is a second antigen found in red blood cells
People can either have Rh+ (with antigens) or Rh- (without antigens) antigen
An Rh- individual may form antibodies against Rh+ blood when exposed via transfusion or pregnancy

Rhesus Factor and Pregnancy

If a Rh- mother carries a Rh+ baby, the mother's immune system can produce antibodies against the baby's blood cells.
In subsequent pregnancies with Rh+ fetuses, this can cause clumping of blood in the fetus's veins
Treatment may include blood transfusion for the child

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Description

Test your knowledge on the lymphatic system and the human immune response. This quiz covers the components of the lymphatic system, non-specific and specific defenses, and how the body protects itself from infections. Perfect for students studying human anatomy and physiology.