Lab 4- Immune system Flashcards
The Lymphatic System
-lymph and lymphocytes
-lymphatic vessels
-lymphatic organs
-lymphatic tissue/nodules
lymphatic organs
-thymus gland
-spleen
-lymph nodes
MALT
Mucosa-
Associated
Lymphoid
Tissue
Un-encapsulated
lymphatic ciruclation
-Lymph transportation from the tissues through lymphatic vessels back to the blood circulation
-Vessels from the right arm
empty into the right lymphatic duct which empties into the right subclavian vein
-The rest of the body empties
into the thoracic duct which
empties into the left subclavian
vein
Lymph
is mostly water with
small amount of plasma
proteins in solution
lymphatic capillaries
-Pumped back to heart by
skeletal muscles and
respiration
-Excess fluid in the tissue
spaces (interstices)
becomes lymph
-3 litres/day more fluid filters
out of blood capillaries than
back in
lymph nodes 2 major functions
-cleanse the lymph
-act as a site of T and B cell activation
lymph nodes
-most numerous lymphatic organs
-elongated bean shape with hilum
-enclosed with fibrous capsule with trabeculae that divide interior into compartments
1st line of defence for innate response
physical barriers= prevent access to body (skin, mucus membranes)
2nd line of defence for innate immune response
phagocytes, immunological surveillance, interferon, complement system, inflammatory response, fever
phagocytes
-remove debris and pathogens
-fixed macrophages, neutrophils, free macrophages, eosinophils, monocytes
immunological surveillance
-destroys abnormal cells
-natural killer cells (destroy abnormal cells, react same way, looking for anything bad)
interferon
-increase resistance of cells to viral infection; slow the spread of disease
-interferons released by lymphocytes, macrophages or virus infected cells
complement system
-attacks and breaks down cell walls; attracts phagocytes; stimulates inflmmation
inflammatory response
-blood flow increased
-phagocytes activated
-capillary permeability increased
-clotting reaction walls of region
-regional temp increased
-specific defences activated
fever
-mobilizes defences; accelerates repair; inhibits pathogens
-body temp rises above 37.2 in response to pyrogens
pyrogens
go to hypothlamus and reset body temp
pathogens
-agents capable of producing disease
-viruses, bacteria, fungi
natural killer cells
-a non specific type of lymphocyte that provides immunological surveillance
-present in blood, spleen, lymph nodes and red bone marrow
-attack any body cells that fail to display MHC I
cells in adaptive immunity
B cells (B lymphocytes) humoral immunity, and
T cells (T lymphocytes) cell-mediated immunity
– Recognize antigens, start the specific immune responses
benefits to specific/adaptive immunity
Memory
– remembers previously encountered foreign agents (e.g. chicken pox
virus)
Specificity
– memory is very accurate and specific
Ability to differentiate self from non-self
– to prevent body destroying its own cells
Two types of adaptive immunity
-Cellular (cell-mediated) immunity
-Humoral (antibody-mediated) immunity
Cellular (cell-mediated) immunity
– Lymphocytes directly attack and destroy foreign cells or diseased
host cells
– Rids the body of pathogens that reside inside human cells, where
they are inaccessible to antibodies
– Kills cells that harbor them
-T CELLS
Humoral (antibody-mediated) immunity
– Mediated by antibodies that do not directly destroy a pathogen but
tag it for destruction
– Many antibodies are dissolved in body fluids (“humors”)
– Effective against extracellular viruses, bacteria, yeasts, protozoans,
and molecular (noncellular) disease agents such as toxins,
venoms, and allergens
-B CELLS
