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.

    1. 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.

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