LYMPHATIC & IMMUNE SYSTEM (disorders of the Immune system. (Type 1…
LYMPHATIC & IMMUNE SYSTEM
The lymphatic system plays an integral role in the immune functions of the body. It is the first line of defense against disease.
network of vessels and nodes transports and filters lymph fluid containing antibodies and lymphocytes (good) and bacteria (bad)
Anatomy of the immune system
Immune cells develope:
In primary organs (bone marrow, and thymus)
Glandular organ near the heart-where t-cells learn their job
Immune responses occur:
In the secondary organs-adenoids, tonsils, lymph nodes and vessels, spleen
Blood-producing tissue located inside certain bones
Serves as a filter for the blood
-removes old and damaged rbc
-removes infectious agents and uses them to activate cells called lymphocytes
Small organ that filter out dead cells, antigens, and other "stuff" to present to lymphocytes
Collect fluid (lymph) that has leaked out from the blood into tissues and returns it to circulation
When immune system is developing, its protected my immune defenses called antibodies
-traveled across the placenta from the maternal blood to fetal blood (only lasting several weeks)
-antibodies are also found in breast milk
Consists of barriers, cellular response, soluble factors-proteins
Physical: skin, hair, mucous, ear wax
Chemical: sweat, tears, saliva, stomach acid, urine
Types of cells involved: granulocytes (basophils, neutrophils, eosinophils) and monocytes (macrophages)
Found in tissues like skin near blood vessels. Activated after antigen binds to a specific type of antibody, IgE, that is attached nto receptors on mast cell
Activated mast cells:
release substances that contribute to inflammation, such as histamine
Mast cells are important:
In allergic responses, but also part of the innate immune response, helping to protect from infection
Release toxic chemicals that destroy everything in the area, including itself
Nuetophils, tissue cells, and dead pathogens
WBCs responsible for medicating allergic responses like hayfever and asthma.
Actives T-cells and elevates during parasitic infections
WBCs that injest bacteria, viruses, dead cells, dust
-most circulate in the blood, lymph, and extra cellular fluid
-attracted by infection by chemicals given off by dying cells
-after ingesting a foreign invader they "wear" pieces of it, antigens, on their cell membrane receptors-this tells other type of immune system cells what to look for
Chemical and cell response to injury or localized infection
-eliminates the source of infection
-promote wound healing
Inflammatory response-step 1
Circulation to the site increases-tissue warm, red, swollen
Inflammatory response-step 2
WBCs leak into tissues-phagocytes engulf and destroy bacteria
Positive effects on fevers:
Indicate a reaction to infection. Stimulate phagocytosis. Slow bacterial growth-(increases body temp. beyond tolerance of some bacteria, decreases blood iron levels
Negative effects on fevers:
Extreme heat, enzyme denaturation and interruption of normal biochemical reactions (103f is dangerous, 105f can be fatal)
Activated quickly, first line of defense during an infection
Have antigens on their surfaces
-types-prions, specific type of foreign protein that causes disease in the brains of its host
antigens: Proteins that can cause an immune response
ANATOMY of the Lymphatic System
Small masses lymphoid tissue in the upper portion of the throat
Protein made by body to destroy antigen
Substance in body stimulates production of antibodies
fluid in lymphatic system that contains lymphocytes
produce lymphocytes and filter out harmful bacteria
Leukocytes that protect body from infection
General protection by immune system
Body recognizes and responds to a specific pathogen
Organ near the stomach that produces, stores, and eliminates blood cells
makes and matures T-lymphocytes
Protects body from pathogens that enter through mouth; act as a filter
born with, inherited and permanent
Immunity that is present only after exposure to a pathogen and is highly specific.
passive acquired immunity
a form of immunity where the fetus receives antibodies made by the mother through breast milk and placenta; last 3-5 weeks
active acquired immunity
develops following direct exposure to the pathogenic agent; natural by exposure; artificial by vaccine
pertaining to one's immune system attacking its own tissues or cells
Killer T cells
attack and destroy infected body cells, cancerous cells; responsible for transplant rejection
injection of an antigen to form qntibodies
B and T cells that remain in the body after an immune response. Their presence enables a much faster and greater second immune response.
humoral vs. cellular response;
Humoral immunity is also called antibody-mediated immunity. Antibodies produced by the B cells will bind to antigens, neutralizing them, or causing lysis (dissolution or destruction of cells by a lysin) or phagocytosis.
Cellular immunity occurs inside infected cells and is mediated by T lymphocytes.
Adaptive/acquired immune defenses
The defenses and mechanisms of adaptive immunity include (1) cell-mediated immunity, mediated by T lymphocytes against intracellular pathogens, and (2) humoral immunity, mediated by B lymphocytes against extracellular pathogens and toxins
Innate/natural immune defenses
Physical Barriers. such as skin, the gastrointestinal tract, the respiratory tract, the nasopharynx, cilia, eyelashes and other body hair
Defense Mechanisms. such as secretions, mucous, bile, gastric acid, saliva, tears, and sweat
antigens and antibodies
Antigens are molecules capable of stimulating an immune response. Each antigen has distinct surface features, or epitopes, resulting in specific responses. Antibodies (immunoglobins) are Y-shaped proteins produced by B cells of the immune system in response to exposure to antigens.
disorders of the Immune system.
Type 1 diabetes. The immune system attacks the cells in the pancreas that make insulin
Severe combined immunodeficiency (SCID). This is an example of an immune deficiency that is present at birth. Children are in constant danger of infections from bacteria, viruses, and fungi. This disorder is sometimes called “bubble boy disease.”
AIDS. HIV, which causes AIDS, is an acquired viral infection that destroys important white blood cells and weakens the immune system. People with HIV/AIDS become seriously ill with infections that most people can fight off. These infections are called “opportunistic infections” because they take advantage of weak immune systems.
Asthma. The response in your lungs can cause coughing, wheezing, and trouble breathing. Asthma can be triggered by common allergens like dust or pollen or by an irritant like tobacco smoke.
Eczema. An allergen causes an itchy rash known as atopic dermatitis.