Immune System Aubrey Menchaca P : 5
Major functions of the lymphatic & immune system
Location of lymphatic organs and their functions
Purpose and examples of First, Second, and Third line of defense
Innate ( natural ) immune defense and Adaptive ( acquired ) immune defenses
Humoral response and cellular response
Antigens and antibodies
Artificial vs. Naturally acquired immunity
Passive vs. Active immunity
Cells involved in the Immune system and their functions
Disorders associated with the Immune system
First line
Second line
Third line
Innate defense system
Adaptive immune system
First line - external body membranes
Second line - antimicrobial proteins, phagocytes, and other cells
Constitutes first and second lines of defense
Functional system rather than organ system
T and B cells
Third line of defense attacks particular foreign substances
Both
defenses are interwined
release and recognize many of the same defensive molecules
Innate response release proteins that alert cells of adaptive system to foreign molecules
Physical barrier to most microorganisms
Purpose is to produce productive chemicals that inhibit or destroy microorganisms
Surface barriers are skin and mucous membranes, along with secretions
Respiratory system also has modifications to stop pathogens
Includes - phagocytes, Natural killer cells, Inflammatory response, fever, Antimicrobial proteins
Many have pattern recognition receptors that recognize and bind tightly to structures on microbes, disarming them before they harm
Innate system necessary if microorganisms invade deeper tissues
Immune cells target specific antigens
Defenses are known as B cells and T cells also known as white blood cells
B cells produce antibodies while T cells help identify pathogenic cells and destroy the specific cells
Active
Passive
Humoral
Cellular
When B cell encounters target antigen, it provokes a response
Specific antibodies are produced for particular antigen
Antibodies, produced by lymphocytes, circulate freely in body fluids
Ex : cells infected with viruses or bacteria, cancerous or abnormal cells, foreign transplanted cells
Some T cells directly kill cells ; others release chemicals that regulate immune response
T cells provide defense against intracellular antigens
primary and secondary responses
Primary - responds to antigen A occurs after a delay
Secondary - responds to antigen A is faster and larger ; primary is similar to A
Two types of active humoral immunity
B cells encounter antigens and produce specific antibodies against them
Naturally acquired - formed response for bacterial or viral infection
Artificially acquired - formed response to vaccine of dead pathogens
Ready-made antibodies are introduced into the body
B cells are not challenged by antigens ; immunological memory wont occur
Two types of passive humoral immunity
Protections ends leading to antibodies degrading
Naturally acquired - delivered to fetus through placenta or through milk
Artificially acquired - serum such as gamma globulin
Through humoral immunity and is categorized from active and passive
Active
Passive
Naturally acquired - Antibodies passed from mother to fetus via placenta ; or to infant in milk
Artificially acquired - injection of exogenous antibodies ( gamma globulin )
Artificially acquired - Vaccine ; dead or attenuated pathogens
Naturally acquired - infection ; contact with pathogen
Two populations of T cells
CD4 cells - become helper T cells which activate B cells
CD8 cells - become cytotoxic cells that are capable of destroying cells harboring foreign antigens
Maintains fluids and balance
absorb dietary fats from gastrointestinal tract
Provides resistance to disease
Natural killer cells -Nonphagocytic, large granular lymphocytes that police blood and lymph
Can kill cancer and virus infected cells before adaptive immune system is activated
Kill by inducing apoptosis in cancer or virus cells
Phagocytes - White blood cells that ingest and digest
Neutrophils - most abundant phagocytes but die fighting
Macrophages - develop from monocytes and are chief phagocytes
Lymphocytes
T cells - cellular immunity
B cells - humoral immunity
Dendritic cells - Act as mobile sentinels of boundary tissues found in epidermis and connective tissues
Hepatitis B - Disease that is caused by virus that attacks liver
Small pox - Serious infection caused by variola virus
Cholera - An acute diarrhea illness caused by infection of the intestine
Meningitis - infection / inflammation of fluid and membranes surrounding brain and spinal cord
Rubella - Viral infection caused by RVV
Malaria - Disease caused by bites of infected mosquitos
Chicken pox - Highly contagious disease caused by varicella
Tetanus - serious viral infection
Antigens
Antibodies
Substances that can mobilize adaptive defenses and provoke an immune response
Targets of all adaptive immune response
Most are large, complex molecules not normally found in body
Proteins secreted by plasma cells
Capable of binding specifically with antigen detected by B cells
Grouped into one of five Ig classes
Thymus - produces immune cells and in between lungs
Peyer's patch - located in small intestine and protects digestive system
Spleen - fights against infecting blood cells and located under stomach
Red bone Marrow - In flat bone where it contains the T and B cells
Tonsils - Protect germs from entering body and fight against infection. located in the back of mouth
Fights against pathogens