Lymphatic System Flashcards
Lymphatic vessels
Capillaries that begin peripherally and collect in venous system.
Pathogen
Virus, bacteria, fungus, parasite
* Responsible for disease in the human body
Immunity
The body’s ability to resist disease and infection through activation of specific defenses for these pathogens
White blood cells
- Lymphocytes
- Basophils
- Eosinophils
- Monocytes
Antigen
Pathogen , part of pathogen
Foreign compound
Antibodies
Soluble proteins
Aka - immunoglobulins
Antibodies bond to antigens
Functions of the lymphatic system
1) Production, maintenance, and distribution of lymphocytes
2) Return of fluid and solutes from peripheral tissues
3) Distribution of hormones, water, and nutrients from peripheral tissues to the blood.
Lymph
Fluid following through lymphatic vessels
Natural killer cells
5-10% of lymphocytes
Non specific defense
-Immunological surveillance - attack foreign cells, cells infected, with virus, cancer cells, etc
B cells
(Bone marrow derived) 10-15% of lymphocytes -Differentiate into plasma cells -Plasma cells secrete AB -Antibody mediated immunity -Cell mediated immunity -Specific defense
T cell
Thymus dependent cells 80% of lymphocytes 4 Types of lymphocytes 1)Cytotoxic T cells 2)Helper T cells 3)Suppressor T cell 4) Memory T cells
Cytotoxic T cells
(Killer T cells)
-Attack foreign cells and body cells infected with virus
Helper T cells
(Help in HIV)
-Stimulate T and B cells
Suppressor T cells
-Inhibit T and B cells
Memory T cells
-Remain in reserve for future contact with pathogen.
Lymphoid Tissues
Lymphoid nodules
- Mass of lymphoid tissue not surrounded by a fibrous capsule
- Increase and decrease in size based on number of lymphocytes present
- Beneath epithelial - respiratory, digestive, and renal
Lymphoid organs
- Surrounded by fibrous capsule
- Lymph nodes
- Thymus - in mediastinum posterior to sternum
- Tcell production and maturation
- Spleen - responsible for filtering the blood.
- Removes abnormal cells and components
- Stores iron from recycled RBCs
Non specific defenses
Deny entry or limit the spread of pathogens (does not care which pathogen you are)
1) Physical Barriers
- Skin - anchored by desmonsomes, hair prevents bugs from contacting the surface, secretions of sweat and oil, wash away pathogens
- Insides - mucous/cilia of respiratory tract, digestion of pathogens in stomach, flush pathogens with urine.
2) Immunological Surveillance
Monitor for presence of antigens on cell membranes
*Perforins - makes holes in cell membrane of pathogen for water to come in, pathogen ruptures
3) Interferons
Small protein released by activated lymphocytes , macrophages, and tissue cells infected with viruses.
- Will prevent virus replications and rate of spread in body tissues.
- Works by 2nd messenger
4) Inflammation
Localized tissue response to injury causing local heat, redness, swelling pain
*Caused by stimulus that damages loose connective or kills cells
Goals of inflammation
1) To perform temporary repair at injury site
2) Slow spread of pathogens from injury site
3) Mobilize resources for permanent repair (regeneration)
5) Compliment system
11 compliment protein
- Cascade like clotting cascade
- Membrane attack (MAC) created in membrane > pores in bacterial (pathogen) membrane > cell lysis
- Activation = begins with compliment system attaching to antibody = attraction of phagocytes, phagocytosis, perfection of cell membranes
