Lymphatic and Immune System: Key Concepts and Clinical Conditions

What are the primary functions of the lymphatic system?

responsible for fluid balance, fat absorption, and immune responses

Lymphatic vessels

larger and have valves

Lymphatic capillaries

small, blind-ended tubes that absorb interstitial fluid

How does lymph move through the lymphatic system?

through vessels by the contraction of surrounding muscles and the presence of valves that prevent backflow

What is lymphedema?

a condition characterized by swelling due to the accumulation of lymph fluid, often caused by blockage of lymphatic vessels

What are the types of immune system cells?

phagocytes (like neutrophils and macrophages), natural killer (NK) cells, B cells, and T cells

What are primary lymphoid organs?

include the thymus and bone marrow, where lymphocytes develop

What are secondary lymphoid organs?

include lymph nodes and the spleen, where immune responses occur

What are the characteristics and functions of lymph nodes?

• filter lymph fluid

• trap pathogens

• house immune cells that respond to infections

What is the function of the spleen?

• filters blood

• removes old red blood cells

• helps mount immune responses

What are the two types of pulp found in the spleen?

white and red

Red pulp

filters blood

White pulp

involved in immune responses

What is the role of the thymus in the immune system?

where T cells mature and differentiate, playing a crucial role in adaptive immunity

What is the significance of MALT?

a component of the immune system found in mucosal tissues, providing localized immune responses

What does MALT stand for?

Mucosa-associated lymphoid tissue

What are the types of tonsils and their function?

• palatine

• pharyngeal

• lingual tonsils

• help trap pathogens entering through the mouth and throat

What are Peyer's patches and their function?

lymphoid tissues in the intestines that monitor intestinal bacteria and prevent the growth of pathogenic bacteria

What triggers inflammation?

tissue injury or infection

What are the benefits of inflammation?

isolates pathogens and initiates healing

What are the three stages of inflammation?

• vascular response

• cellular response

• tissue repair

What causes a fever?

the release of pyrogens during infection

Why is a fever beneficial?

helps enhance immune function and inhibit pathogen growth

Humoral immunity

involves B cells and antibodies

Cellular immunity

involves T cells that directly attack infected cells

What are antigens?

substances that trigger an immune response

Complete antigens?

can provoke a response on their own

Haptens antigens

require a carrier to elicit a response

Primary humoral responses

occurs upon first exposure to an antigen

Secondary humoral response

faster and more robust due to memory cells

What are the classes of antibodies?

• IgG

• IgA

• IgM

• IgE

• IgD

How do antibodies defend the body?

• neutralize pathogens

• opsonize them for phagocytosis

• activate the complement system

What is the role of helper T cells in the immune response?

activate B cells and cytotoxic T cells, coordinating the adaptive immune response.

What are NK cells?

involved in the innate immune response against tumors and virally infected cells

What are regulatory T cells?

help maintain immune tolerance

What are organ transplants?

involve transferring organs from one individual to another

What are the associated risk of rejection in an organ transplant?

occurrs when the recipient's immune system attacks the foreign tissue

SCID

• (Severe Combined Immunodeficiency)

• a genetic disorder affecting immune function

AIDS

• (Acquired Immunodeficiency Syndrome)

• caused by HIV, leading to immune system failure

Hodgkin's disease

a type of lymphoma

What are autoimmune diseases?

occur when the immune system mistakenly attacks the body's own tissues