lymphatic system
41 flashcards
- Intracellular fluid (ICF)
- Fluid inside the cell
- Extracellular fluid (ECF)
- Fluid outside the cell = intravascular fluid + interstitial fluid
- Intravascular fluid
- Blood (fluid within the blood vessels); IV fluids such as dextrose go here
- Interstitial fluid
- Fluid in the spaces between cells
- Lymph
- Fluid inside the lymphatic vessels; its cells are lymphocytes
- Functions of lymphatic system
- fluid balance, fat absorption, defense
- Fluid balance
- Drains excess fluid from the tissues
- Fat absorption
- Carries fats and fat-soluble vitamins absorbed in the digestive tract
- Defense
- Carries immune responses
- Components
- Lymph, Lymphatic vessels, Structures and organs that contain lymphatic tissue: lymph nodes, tonsils, spleen, thymus gland
- Palatine
- each side of the oral cavity
- Pharyngeal
- near the internal opening of the nasal cavity
- Lingual
- posterior surface of the tongue
- Lymph nodes
- Round structures that vary in size; located near lymphatic vessels
- Superficial nodes: neck
- armpit (axilla), groin
- Innate immunity
- Present at birth; defends against any pathogen (non-specific)
- Adaptive immunity
- Acquired after birth; specific to each antigen
- Innate Immunity
- (1) physical barriers, (2) chemical mediators, (3) cells, (4) inflammatory response.
- Physical barriers (1st line of defense)
- Skin and mucous membranes act as barriers to pathogens and toxins. Tears, saliva and urine wash away pathogens.
- Chemical mediators
- lysozyme, histamine, interferons
- Lysozyme
- Found in tears and saliva; kills bacteria
- Histamine
- Causes vasodilation and increased capillary permeability
- Interferons
- Proteins that protect against viruses; stimulate surrounding cells to produce antiviral proteins
- 1. Neutrophils
- First responders to infection; die quickly; phagocytic
- 2. Eosinophils
- Release chemicals to reduce inflammation
- 3. Basophils
- Leave the blood and enter infected tissues; release histamine
- 4. Macrophages
- Initially monocytes; ingest more than neutrophils; phagocytic
- Kupffer cells (liver)
- protect the blood; other macrophages protect the lymph, lymph nodes and spleen
- 5. Mast cells
- Found in skin, lungs, GI tract and urogenital tract; release leukotrienes and histamine
- 6. NK (natural killer) cells
- A type of lymphocyte; recognize specific classes of cells (tumor cells, virus-infected cells) and release chemicals that lyse (destroy) them
- IgG
- 80-85% Can cross the placenta and protect the fetus, Increases phagocytosis, Responsible for Rh reactions (Rh antibodies)
- IgA (airway)
- 15%, Secreted into saliva, tears and onto mucous membranes, Protects body surfaces, Found in colostrum (first breast milk)
- IgM(first)
- 5-10%, Found in the blood and lymph, Responsible for ABO reactions, Often the first immunoglobulin produced in response to an antigen
- IgE(allergies)
- 0.002%, Binds to mast cells and basophils, which release histamine, Stimulates the inflammatory response
- IgD
- 0.2%, Least understood, Function: antibody found on the surface of B cells
- Active Immunity
- Immunity provided by the body's own immune system
- natural active
- Exposed to an antigen; the body makes antibodies (e.g., having chickenpox)
- artificial active
- Antigens are deliberately introduced in a vaccine; body produces antibodies
- Passive Immunity
- Transferred from another person or animal
- natural passive
- Antibodies from the mother pass through the placenta or in milk
- artificial passive
- Antibodies produced by another person or animal are injected (e.g., IVIG)