Week 6 - power point

Vocabulary practice flashcards covering the lymphatic system, innate and adaptive immunity, vaccine types, active vs. passive immunity, and herd immunity from BIOS-150 Week 6.

Lymphatic System

A network of organs, tissues, and vessels populated with immune system cells that functions in fluid balance, immunity, and lipid absorption.

Lacteals

Specialized lymphatic vessels in the small intestine that absorb dietary lipids and transport them to the bloodstream.

Lymph

A clear, colorless fluid similar to blood plasma and identical in composition to interstitial fluid that transports white blood cells throughout the body, except in the brain, spinal cord, and bone marrow.

Lymphatic Capillaries

Tiny, thin-walled vessels that collect excess fluid from tissues and merge to form larger lymphatic vessels.

Right Lymphatic Duct

A lymphatic vessel that drains lymph from the right upper arm, head, neck, and upper torso.

Thoracic Duct

The largest lymphatic vessel in the body, responsible for draining the majority of the body's lymph.

Lymph Nodes

Small, bean-shaped structures housing immune cells like lymphocytes and macrophages that filter lymph by identifying, engulfing, and ingesting harmful substances.

Primary Lymphatic Organs

The red bone marrow and thymus, where B-lymphocytes and T-lymphocytes form through hematopoiesis and mature.

Secondary Lymphatic Organs

Organs such as the spleen, tonsils, and lymph nodes where mature lymphocytes encounter and bind to foreign antigens.

Spleen

A secondary lymphatic organ that filters blood and stores red and white blood cells in red and white pulp.

Tonsils

Secondary lymphatic structures that filter germs that are ingested or inhaled.

Innate Immunity

Nonspecific immune defense mechanisms providing a general, immediate response to foreign invaders through physical and chemical barriers.

Acquired Immunity

A highly specialized adaptive defense mechanism acquired when the immune system recognizes foreign antigens on pathogens.

Antigens

Unique molecules found on the surface of pathogens that trigger an adaptive immune response.

B Cells

Lymphocytes that produce antibodies that bind to antigens, neutralizing pathogens or marking them for destruction.

Helper T Cells

Lymphocytes that activate other immune cells, including cytotoxic T cells and B cells.

Cytotoxic T Cells

Lymphocytes that directly destroy virally infected cells or cancer cells as part of cell-mediated immunity.

Memory Cells

Immune cells retained after an infection to remember the pathogen, enabling a faster and stronger response upon re-exposure.

Humoral Immunity

Adaptive immunity mediated by B cells and antibodies that targets pathogens present in body fluids.

Cell-Mediated Immunity

Adaptive immunity involving T cells that attack infected or abnormal cells.

Vaccines

Products containing weakened or inactive parts of pathogens that train the immune system to recognize and fight pathogens without causing disease.

Live-Attenuated Vaccines

Vaccines using a weakened version of the pathogen to induce a strong immune response, such as MMR and chickenpox vaccines.

Inactivated Vaccines

Vaccines containing killed pathogens that trigger a weaker immune response requiring booster shots, such as polio and hepatitis A vaccines.

mRNA Vaccines

Vaccines delivering genetic instructions for cells to produce a harmless viral protein to trigger an immune response, such as Pfizer-BioNTech and Moderna COVID-19 vaccines.

Viral Vector Vaccines

Vaccines utilizing a modified harmless virus to deliver genetic instructions into host cells, such as Johnson & Johnson COVID-19 and Ebola vaccines.

Subunit Vaccines

Vaccines using only specific pieces of a pathogen rather than the whole organism, such as HPV and hepatitis B vaccines.

Active Immunity

Long-lasting or lifelong immunity produced when the body generates its own antibodies in response to an infection or vaccine.

Natural Active Immunity

Active immunity developed after natural exposure to a disease, such as recovering from chickenpox.

Artificial Active Immunity

Active immunity acquired through vaccination using a weakened or inactive pathogen, such as the measles vaccine.

Passive Immunity

Temporary protection lasting weeks or months obtained by receiving pre-formed antibodies from an outside source.

Natural Passive Immunity

Passive immunity transferred naturally from mother to baby via the placenta or breast milk.

Artificial Passive Immunity

Passive immunity acquired by injecting pre-formed antibodies, such as immune globulin for rabies exposure.

Herd Immunity

The protection provided to unvaccinated individuals when a large portion of the population becomes immune, reducing disease spread.

COVID-19 Herd Immunity Threshold

The proportion of immune individuals needed for herd immunity against COVID-19, estimated at $60\% - 70\%$ initially and rising up to $85\%$ for delta and omicron variants.