Immune system

Page 1: Introduction

• Overview of the immune system and its disorders in the context of human health and disease processes.

Page 2: Objectives

• Identify structures of the immune system.

• Explain functions of the immune system.

• Identify different types of immunity.

• Differentiate between active and passive immunity.

• Discuss lifestyle effects on the immune system.

• Identify common disorders related to the immune system.

• Discuss purpose of immunization.

• Differentiate between antigens and antibodies.

• Discuss common medications used with the immune system.

Page 3: Introduction to the Immune System

• The immune system protects the human body from diseases caused by microorganisms through a complex network known as the host defense system.

Page 4: Structures of the Immune System

• Components include:

  • White Blood Cells (WBCs)

  • Bone Marrow

  • Thymus

  • Lymph Nodes

  • Spleen

  • Lymphatic Vessels

  • Tonsils and Adenoids

Page 5: White Blood Cells (WBCs)

• Also known as leukocytes, crucial for protection against infections.

• Types include lymphocytes (B cells and T cells):

  • B cells produce antibodies.

  • T cells attack infected cells and coordinate the immune response.

  • Essential for active immunity.

Page 6: Types of Leukocytes

• Two main groups:

  • Granulocytes: Neutrophils, eosinophils, basophils.

  • Agranulocytes: Lymphocytes and monocytes.

Page 7: Function of White Blood Cells

• WBCs act as generals, locating infection sites and recruiting more WBCs to fight off unknown organisms, producing antibodies to destroy invaders.

Page 8: Location of WBCs

• Found in the bloodstream and able to navigate through blood vessel walls to tissues for infection site localization.

Page 9: Formation of WBCs

• Formed in bone marrow from stem cells.

• T cells migrate to the thymus; B cells mature in bone marrow and travel to the spleen and lymph nodes.

Page 10: Bone Marrow

• Function: Produces all blood cells, including WBCs.

• Contains hematopoietic stem cells necessary for immune cell development.

• Rapidly increases immune cell production during infections.

Page 11: Thymus

• Located in the upper chest, behind the sternum.

• Essential for adaptive immune response; T cells mature here.

• Different T cell types shape and control immune response.

Page 12: Spleen

• Location: Upper left abdomen, behind the stomach and below diaphragm.

• Functions as a blood filter, recognizing pathogens and releasing lymphocytes to combat them.

Page 13: Other Immune Structures

• Includes:

  • Lymph Nodes, Tonsils and Adenoids, Peyer’s Patches, Appendix

• Key checkpoints that identify, filter, and respond to pathogens.

Page 14: Immunity Overview

• Body's ability to protect against infections and diseases.

• All immune parts cooperate to identify and eliminate harmful microorganisms.

Page 15: Mechanism of Immunity

• Recognizes own body cells and beneficial microorganisms.

• Identifies threats and mounts an immune response involving various cells and proteins.

Page 16: Types of Immune Responses

• Innate Immunity: Rapid, non-specific response to a wide range of microbes.

• Acquired Immunity: Slower, specific responses tailored to particular pathogens.

Page 17: Innate Immunity Characteristics

• Body's first defense line, responding quickly within hours, non-specific, and does not remember past infections.

• Components: Skin, mucous membranes, white blood cells, chemical defenses.

Page 18: Acquired Immunity Characteristics

• Specialized immune response developing over time, specific to toxins, delayed response, and memory formation from past exposures or vaccinations.

Page 19: Comparison of Innate and Acquired Immunity

• Innate Immunity:

  • Immediate response, non-specific, no memory.

• Acquired Immunity:

  • Delayed response, specific, has memory.

Page 20: Innate Immunity - External Defenses

• Designed to prevent infections by reinforcing physical barriers like skin, mucus, and cilia, and activating internal defenses.

Page 21: Role of Skin

• Acts as a physical barrier, produces chemicals to kill pathogens, and hosts a microbiome that prevents harmful bacteria from thriving.

Page 22: Role of Mucus and Cilia

• Mucus contains lysozymes to destroy bacteria; cilia in the respiratory tract help clear mucus and pathogens.

Page 23: Mucous Membranes

• Include saliva, stomach mucosa, tears, and hair in the nose that trap pathogens and contain enzymes to aid in neutralizing bacteria.

Page 24: Innate Immunity - Internal Defenses

• Activated when physical barriers are breached; phagocytes and natural killer cells recognize and attack invaders.

Page 25: Role of Phagocytes

• Types of white blood cells (macrophages, neutrophils) that hunt and destroy pathogens, activated by inflammation signals.

Page 26: Role of Inflammation

• Inflammation is signaled by mast cells releasing histamine, enhancing blood flow and recruiting immune cells to sites of infection.

Page 27: Effects of Inflammation

• Involves vasodilation, increased blood flow, warmth, redness, and swelling to support healing.

Page 28: Role of Fever

• Fever functions as a defense mechanism to inhibit microbial activity and boost immune cell functionality.

Page 29: Acquired Immunity - Natural Exposure

• Exposure through infection leads to antibody production and memory cell formation for future protection.

Page 30: Types of Acquired Immunity

• Active Acquired Immunity: Body creates antibodies through infection or vaccination.

• Passive Acquired Immunity: Antibodies transferred from another source; temporary and does not involve memory cell creation.

Page 31: Mechanism of Natural Exposure

• 1. Pathogen entry leads to antigen recognition by the immune system.

• 2. Antigen presentation activates T and B cells to fight the invader, supported by memory formation for future recognition.

Page 32: Detailed Immune Response

• Sequence follows pathogen entry, recognition, cell activation, pathogenesis killing, and memory formation.

Page 33: White Blood Cell Types - T Cells

• They travel the body to find and destroy pathogens, displaying antigens for further immune action.

Page 34: Role of Antigens

• Antigens are unique surface proteins on pathogens, crucial for immune recognition and response.

Page 35: Role of B Cells

• B cells produce antibodies in response to recognized antigens, either from memory or new production.

Page 36: Antibodies Overview

• Antibodies attach to antigens, blocking pathogen entry or marking them for destruction by immune cells.

Page 37: Immune System Dynamics

• Antigens trigger immune responses; B lymphocytes produce antibodies, while T cells destroy infected cells.

Page 38: Understanding Immunity

• Immunity reflects the body's capability to recognize and produce antibodies against specific diseases via exposure and recovery.

Page 39: Types of Immunity Explained

• Active Immunity: Developed through infection or vaccination; Passive Immunity: Short-term immunity from another source with no memory formation.

Page 40: Summary of Acquired Immunity

• Acquired throughout life via exposure or vaccination; can be natural or artificial with distinct pathways of immunity.

Page 41: Vaccines Overview

• Lead to artificially acquired immunity through injections of vaccines or immunoglobulins.

Page 42: Importance of Vaccinations

• Routine vaccinations protect against diseases in children, vital for public health and prevention of infections.

Page 43: Lifestyle Factors Affecting Immunity

• Poor lifestyle choices hinder WBC function and immune response; stress, sleep deprivation, and lack of exercise impact overall immune health.

Page 44: Healthy Eating and Immunity

• Nutrient-rich diets support immune function; specific vitamins contribute to the production of immune cells and the prevention of inflammation.

Page 45: Consequences of Sleep Deprivation

• Higher infection risk and hormonal imbalances weaken immune responses; adequate sleep is essential for immunity.

Page 46: Effects of Lack of Exercise

• Poor circulation and weakened immune response; regular exercise is crucial for maintaining effective immune cell activity.

Page 47: Stress Impacts on Immunity

• Chronic stress elevates cortisol, suppressing immune function and leading to decreased immune cell activity.

Page 48: Autoimmune Disorders

• Conditions where the immune system attacks the body's own cells, disrupting normal organ function and causing potential abnormalities.

Page 49: Examples of Autoimmune Diseases

• Include: Multiple sclerosis, Hashimoto's thyroiditis, asthma, systemic lupus erythematosus, celiac disease, rheumatoid arthritis, eczema, and psoriasis.

Page 50: Overview of Lupus Erythematosus

• Chronic inflammatory autoimmune disorder affecting connective tissues with possible organ damage.

Page 51: Forms of Lupus Erythematosus

• Two forms include Discoid Lupus Erythematosus (DLE) and Systemic Lupus Erythematosus (SLE).

Page 52: Symptoms of Lupus Erythematosus

• Symptoms include fever, weight loss, fatigue, abdominal pain, and distinctive butterfly rash.

Page 53: Consequences of Systemic Lupus Erythematosus

• Leads to potential dysfunction and damage across multiple organs including brain, heart, and kidneys.

Page 55: Graves’ Disease

• Autoimmune disorder causing hyperthyroidism due to immune attack on the thyroid gland.

Page 57: Hashimoto’s Disease

• Autoimmune disorder that leads to gradual thyroid gland damage and hypothyroidism symptoms.

Page 58: Understanding Allergies

• Allergies occur when the immune system misidentifies harmless substances as threats leading to inflammatory responses and possible anaphylactic reactions.

Page 59: Medications Related to the Immune System

• Types include antihistamines, corticosteroids, immunosuppressants, monoclonal antibodies, vaccines, antiviral medications, antibiotics, immune modulators, and probiotics.

Page 60: Antihistamines

• Block histamine receptors to alleviate allergy symptoms.

• Examples: Diphenhydramine, Cetirizine.

Page 61: Corticosteroids

• Anti-inflammatory drugs that suppress immune responses.

• Examples: Prednisone, Methylprednisolone.

Page 62: Immunosuppressants

• Used to prevent organ rejection and treat autoimmune disorders by inhibiting immune responses.

• Examples: Azathioprine, Cyclosporine.

Page 63: Monoclonal Antibodies

• Lab-made antibodies targeting specific immune components, used in various treatments.

• Examples: Rituximab, Adalimumab.

Page 64: Vaccines Overview

• Stimulate acquired immunity and are crucial for disease prevention.

• Examples: Influenza vaccine, COVID-19 vaccines.

Page 65: Antiviral Medications

• Inhibit viral development to aid immune responses against infections.

• Examples: Oseltamivir, Acyclovir.

Page 66: Antibiotics

• Treat bacterial infections, supporting the immune system against illness.

• Examples: Amoxicillin, Ciprofloxacin.

Page 67: Immune Modulators

• Adjust immune response levels and can be used to reduce inflammation.

• Examples: Interferons for multiple sclerosis.

Page 68: Probiotics

• Live microorganisms that enhance health and support immune response, particularly for gut health.

• Examples: Lactobacillus, Bifidobacterium.