Lymphatic system Flashcards
(28 cards)
What is the primary function of the lymphatic system?
Returns fluids to circulation and protects against pathogens
The lymphatic system plays a crucial role in maintaining fluid balance and immune responses.
Define pathogen.
Any disease-causing agent: bacteria, viruses, fungi, toxins, etc.
Pathogens can affect various systems in the body and lead to diseases.
What is lymph?
The fluid that moves through the lymphatic system
Lymph is derived from interstitial fluid and helps protect against pathogens.
What types of cells are abundant in lymphatic tissue?
White blood cells, especially lymphocytes and macrophages
These cells are crucial for responding to infections and tissue damage.
Name the organized structures of lymphatic tissue.
Lymphatic organs and nodules
Lymphatic organs include lymph nodes, thymus, and spleen; nodules include tonsils and MALT.
What are lacteals?
Specialized capillaries that absorb fats from food in the intestine
Lacteals play a key role in the digestion and absorption of dietary fats.
How many types of tonsils are there?
Five total: pharyngeal, palatine, and lingual
Tonsils help filter inhaled and ingested pathogens.
What is the role of the thymus gland?
Produces thymosin; site of T lymphocyte development
The thymus is crucial for the maturation of T cells, which are vital for immune responses.
What is the largest lymphatic organ?
Spleen
The spleen filters pathogens, stores blood, and removes damaged red blood cells.
What is the function of lymph nodes?
Filter lymph and remove pathogens, debris, and abnormal cells
Lymph nodes contain lymphocytes and macrophages that play a key role in immune defense.
What are the major clusters of lymph nodes?
- Cervical
- Axillary
- Inguinal
- Pelvic
- Lumbar
These clusters are strategically located to filter lymph from different body regions.
What are the two types of immune defenses?
- Non-specific (innate)
- Specific (adaptive)
Non-specific defenses are immediate and general, while specific defenses are tailored to particular pathogens.
What are mechanical barriers in the immune system?
- Skin
- Mucous membranes
- Cilia
These physical barriers help prevent pathogen entry into the body.
What is the role of fever in the immune response?
Inhibits reproduction of pathogens and activates phagocytes
Fever is a systemic response that helps the body fight infections.
What is phagocytosis?
Process by which cells like neutrophils and macrophages engulf pathogens
Phagocytosis is a key mechanism of the immune system to eliminate infections.
What is immunological surveillance?
Natural killer (NK) cells destroy abnormal cells like cancer cells
NK cells are part of the innate immune response and play a critical role in tumor surveillance.
What triggers the complement system?
Cell rupture, phagocyte attraction, inflammation
The complement system enhances the ability of antibodies and phagocytic cells to clear pathogens.
What is the inflammatory response?
Local tissue reaction to injury with redness, heat, swelling, pain
This response helps to isolate and eliminate pathogens and begin the healing process.
What is immunity?
The ability to fight specific pathogens
Immunity can be innate (present at birth) or acquired (develops after exposure).
Differentiate between active and passive acquired immunity.
- Active: Own body produces antibodies
- Passive: Antibodies from another source
Active immunity can be natural (exposure to pathogens) or artificial (vaccination), while passive immunity can be natural (breastfeeding) or artificial (injections).
What cells are primarily involved in the immune response?
Lymphocytes
Lymphocytes include T cells, B cells, and NK cells, each with specific roles in immunity.
What is cell-mediated immunity?
Involves cytotoxic T cells that destroy infected cells
This type of immunity is crucial for fighting intracellular pathogens like viruses.
What is antibody-mediated immunity?
Involves B cells, Helper T cells, and plasma cells
This immunity focuses on the production of antibodies to neutralize extracellular pathogens.
List the actions of antibodies.
- Neutralization
- Opsonization
- Activation of complement
- Agglutination and precipitation
- Enhance NK cell activity
- Prevent adhesion of pathogens
Antibodies help mark pathogens for destruction and prevent their spread.
