The Immune and Lymphoid Systems

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Questions and Answers

What is one of the primary functions of the immune system?

Preventing and limited infection (correct)

Healing only external injuries

Storing nutrients for future use

Producing energy for bodily functions

How does the immune system distinguish between its own cells and foreign invaders?

It relies on the size of the cells to determine their origin

It utilizes memory cells to recall past infections

It activates and mobilizes specific responses against recognized threats (correct)

It sends chemical signals to neighboring cells only

Which of the following is NOT an autoimmune disease?

Diabetes type 1

Rheumatoid arthritis

HIV/AIDS (correct)

Multiple sclerosis

Which of the following is a component of the lymphatic system?

Lymph nodes Signup and view all the answers

What role do antibodies play in the immune system?

They prepare the body to fight against future infections Signup and view all the answers

What describes the lymphatic system?

It is a network of vessels that transports lymph throughout the body. Signup and view all the answers

What happens after the immune system has successfully eliminated a threat?

It learns to recognize and remember the threat Signup and view all the answers

Which of the following describes a function that is NOT performed by the immune system?

Producing hormones for metabolism Signup and view all the answers

Which type of marrow becomes more dominant with age?

Red marrow Signup and view all the answers

What is a primary function of yellow marrow?

Storage of adipose cells Signup and view all the answers

Which organ acts as the first line of defense against harmful pathogens?

Tonsils Signup and view all the answers

Which lymphoid organ is responsible for trapping germs that enter through the nose and mouth?

Tonsils Signup and view all the answers

How many lymph nodes are approximately found in the human body?

About 600 Signup and view all the answers

What is a key function of lymph nodes in the immune system?

Monitor and cleanse lymph Signup and view all the answers

Which of the following organs is NOT classified as a peripheral lymphoid organ?

Liver Signup and view all the answers

What occurs to red marrow under conditions like severe anemia?

It reverts to yellow marrow Signup and view all the answers

What distinguishes specific defense from non-specific defense?

Specific defense involves cell-mediated and humorally mediated antibodies. Signup and view all the answers

In maintaining homeostasis, what is the role of lymphocytes?

They help in achieving a balanced immune response. Signup and view all the answers

What is the purpose of surveillance in the immune response?

To use memory and recognition to enhance immune reactions. Signup and view all the answers

Which factor contributes to the development of acquired immunity?

Artificial antigens from vaccines or disease processes. Signup and view all the answers

How can the level of acquired immunity be monitored?

By measuring titer serum levels. Signup and view all the answers

What is a key characteristic of non-specific defense mechanisms?

They include anatomic and chemical barriers. Signup and view all the answers

What occurs in the body when an antigen is present?

The body initiates its immune response. Signup and view all the answers

Why is repeated administration of vaccinations important?

To boost and maintain immunity levels. Signup and view all the answers

What is the primary function of IgA?

Protecting body surfaces Signup and view all the answers

Which immunoglobulin is associated with allergic reactions?

IgE Signup and view all the answers

Which immunoglobulin is primarily involved in the secondary immune response?

IgG Signup and view all the answers

What type of immune cell does not require prior sensitization?

Natural Killer Cell Signup and view all the answers

Which of the following correctly describes cytokines?

Soluble protein mediators of the immune response Signup and view all the answers

What is the role of tumor necrosis factor (TNF) in the immune system?

Acts as a chemical messenger in the immune response Signup and view all the answers

Which immunoglobulin is present on lymphocytes?

IgD Signup and view all the answers

What characterizes IgM in the immune response?

Involved in primary immune response Signup and view all the answers

What is the main role of plasma cells in humoral immunity?

To secrete immunoglobulins Signup and view all the answers

Which of the following immunoglobulins is primarily involved in allergic reactions?

IgE Signup and view all the answers

How do memory B cells contribute to immune response?

By remembering previous antigens for faster response Signup and view all the answers

In cell-mediated immunity, which cells are primarily activated in response to antigens?

T lymphocytes Signup and view all the answers

What role do CD antigens play in the immune system?

They define T cell specificity and function Signup and view all the answers

What type of immunity is primarily responsible for the destruction of intracellular pathogens?

Cell-mediated immunity Signup and view all the answers

Which statement accurately describes immunoglobulins?

They are glycoproteins that recognize and bind to antigens Signup and view all the answers

What characteristic differentiates IgA from other immunoglobulins?

It is mainly found in mucosal areas and secretions Signup and view all the answers

Study Notes

The Immune System

The immune system is the body's defense mechanism against pathogens.
It has different layers of organs responsible for preventing and fighting infection.
It functions by:
- Keeping invaders out.
- Destroying invaders.
- Limiting harm caused by invaders.
- Healing damage.
- Adapting to new threats.
It works by:
- Distinguishing "self" from "non-self" cells.
- Mobilizing to kill harmful germs.
- Ending attacks after threats are gone.
- Developing antibodies against germs after exposure.
- Sending antibodies to destroy future invaders.

The Lymphoid System

It's a network of vessels, nodes, and ducts that circulate lymph throughout the body.
It's part of the immune system and is essential for immune function.
It includes central and peripheral lymphoid organs.

Central Lymphoid Organs

These include the bone marrow and thymus.
The bone marrow functions as the primary site for hematopoiesis in infants and children.
It produces red blood cells, white blood cells, and platelets.
The thymus is important for T-cell maturation and development.
It becomes more dominant with age and is gradually replaced by yellow marrow.

Peripheral Lymphoid Organs

These are also known as secondary lymphoid organs.
They include:
- Tonsils: first line of defense against bacteria and viruses, located in the back of the throat.
- Adenoids: Located behind the nasal cavity, active during childhood.
- Lymph nodes: Bean-shaped glands that filter lymph, clear out damaged cells and cancer cells, and store lymphocytes.
- Mucosa-associated Lymphoid Tissue (MALT): Found in the lining of the digestive, respiratory, and urinary systems.
- Spleen: Filters blood and stores lymphocytes, removes old red blood cells.

Normal Immune Response

It maintains an immune balance, removing damaged cells and preventing infection.
It's a balanced response of circulating and resident lymphocytes.
It involves surveillance, which enables the body to recognize and remember pathogens.

Types of Immunity

Acquired Immunity: Long-term response with antibody development.
- Humoral Immunity: Antibody-mediated, involves recognition of antigens by B lymphocytes.
  - B lymphocytes differentiate into plasma cells and memory cells.
  - Plasma cells secrete immunoglobulins, which target specific antigens.
- Cell-Mediated Immunity: Involves activation of phagocytes and cytotoxic T-lymphocytes.
  - T lymphocytes recognize specific major histocompatibility complexes (MHC) and elicit an immune response.
  - CD markers are protein markers on T-cells that help identify their function.

Immunoglobulins (Ig)

Also known as antibodies, are glycoproteins produced by plasma cells.
They recognize and bind to specific antigens, aiding their destruction.
There are five classes of immunoglobulins:
- IgA: Found in body secretions, protects body surfaces.
- IgD: Present on lymphocytes.
- IgE: Involved in allergic reactions, binds to mast cells.
- IgG: Most abundant immunoglobulin, crosses placenta, involved in secondary immune responses.
- IgM: First immunoglobulin produced during infection, larger than other classes.

Other Immune System Participants

Natural Killer Cells (NK Cells): Present at birth, do not require prior sensitization, and are not T- or B-lymphocytes.
Cytokines: Soluble protein mediators of the immune response.
- Include interleukins, tumor necrosis factor (TNF), and interferon.
- They are secreted by white blood cells and other cells and play a role in immune regulation.

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Description

Test your knowledge about the immune and lymphoid systems, their functions, and key organs. Understand how the body defends itself against pathogens and the role of lymph in immune response. This quiz covers important concepts of immunology and lymphatics.