Immunity Flashcards
What are the portals of entry for pathogens?
Cutaneous
Mucosal surfaces
Respiratory tract (cilia)
GI/GU systems
What is innate immunity
Immunity you are born with
First line of defense
What are the characteristics of the innate immune system?
Epithelial barriers
Inflammation
Non-specific
No memory
Rapid defense
What is adaptive immunity
Acquired
What characteristics does adaptive immunity have?
Memory cells
Specific antigen response
Initiated by inflammation response
What structures make up the innate immune system?
Secretory molecules (saliva)
Cilia
Epithelial cells
Cell derived chemicals
Normal flora
Why is the top layer of skin beneficial to the innate immune system?
It sloughs off and Carrie’s bacteria with it
What enzymes make up the innate immune system?
Lysozymes (kill gram +)
Sebaceous glands ( lower pH)
Defensins
Collectins
What are defensins?
Antimicrobial peptides that disrupt the bacterial cell wall-> made by neutrophils
What are collectins?
Active macrophages which increases phagocytosis
What is the second line of defense in the innate immune system?
Inflammatory response
What physically occurs during the inflammation response?
Redness, swelling, heat, pain, functional loss
What happens when the mast cells are triggered?
Histamines are released to increase vascular permeability and vasodilation
Also starts the clotting cascade
What does increase in vascular permeability allow for?
Diapedesis of neutrophils
How does the clotting cascade help in the immune system?
Clots will create a fibrin net to trap bacteria
Where are selectins found and what do they do?
Intravascularly and they attract neutrophils to the area so they can diapedese
Where is the plasma protein made and where is it found?
Plasma protein are made in the liver and circulate the blood inactively until activated by inflammation (histamine release)
What processes make up the plasma protein system of the inflammation process?
Complement system, kinin system, and clotting system
What does the complement system do in innate immunity?
Allows for tagging bacteria and chemically attracting neutrophils- complements antibodies and phagocytosis
What does the clotting system do during innate immunity?
Intrinsically and extrinsically stimulates the clotting cascade
What does the kinin system do for the innate immune system
Triggers the release of bradykinin which stimulates nociceptors
What are the steps in the complement system for innate immunity?
-Increase vasodilation and permeability
-mast cell degranulation
-increase leukocyte chemotaxis
-Opsonization (tag pathogens)
-ultimately forms MAC proteins
What do MAC proteins do?
Put pores I. The bacterial cell wall which causes cellular lysis
What cells make up the innate immune system?
Leukocytes
Macrophages
Dendritic cells
Complement proteins
Mast cells
Inflammation mediators
Neutrophils
Eosinophils/basophils
What do mast cells release?
Histamines
Cytokines
Chemotaxic factors
What is the most important activator of the inflammation response?
Mast cells
What else will histamine do besides permeability and vasodilation?
Constriction of smooth muscles by connecting with H1 or H2 receptors
What makes up leukocytes?
Neutrophils
Eosinophils
Basophils
Monocyte
Lymphocyte
Granulocyte
What is the dendritic cells?
Antigen presenting cell “APC”
What does the dendritic cell do?
Links the innate and adaptive immune systems by activating the T-Lymphocytes on the adaptive immunity
What do neutrophils do?
Predominant at site of pathogen immediately, phagocytize bacteria & dead cells, makes up most purulent discharge
What do eosinophils defend against?
Parasites
What do basophils defend against?
Allergies and asthma
What are monocytes and where are they found
Precursor for a macrophage and it’s found circulating the blood. Once in the tissue -> becomes macrophage
What do monocytes do?
-Respond to chemotactic factor that neutrophils release
-nom nom cellular debris
-promote synthesis of extra cellular matrix
What do NK cells do
Recognize and kill viruses as well as defend against cancer cells
What do lymphatic vessels do?
Drains the interstitial fluid that drains out of the vascular system and empties it into the venous systwm
What part of the lymphatic system empties into the venous system?
Efferent
What does the afferent part of the lymphatic system do?
Brings fluid to the node… it’s 1 way flow
What else is found in the afferent vessels
Lots of macrophages
How much fluid does the lymphatic system drain a day?
Roughly 4 liters
What does the cortex of lymph nodes contains?
Lymphoid tissue which holds B-cells (inactive) and dendritic cells
What are secondary lymph nodes
Nodes that grow after the primary nodes have been stimulated
-> much bigger than lymph nodules
What does the medullary sinus of the lymph nodes do?
Slows down lymph flow, allows lymph to interact with B-cells and then empty into the efferent system
What else besides dendritic cells link innate and adaptive immunity?
Cytokines
How do cytokines link the innate and adaptive immune system?
Signal molecules that bind and alter cellular function… can be both pro inflammatory or reduce inflammation
What do cytokines contain
Interleukins
What are interleukins
Type of cytokine that is released by macrophages and lymphocytes
What do interleukins do?
- Induce proliferation and maturation of leukocytes in bone marrow
-help turn on/off parts of adaptive immunity
What are immunoglobulins?
Antibodies
What do antibodies do?
Fight what’s in front of them at that immediate time
What is MHC
Major Histocompatibility Complex
Where is MHC found?
On a cell surface of all nucleated cells
What does MHC do?
Presents the antigen to the T-cells and identifies self cells to prevent cellular damage
What is HLA
Human Leukocyte Antigen Complex which is coated of chromosome 6
Where is MHC 1 found?
On all cells
What does MHC 1 do?
Identifies cells with intracellular issues (cancer/flu)
Where is MHC 2 found?
On APC
What does MHC 2 do?
Identifies antigens/pathogens on cell wall and tags them for killing
What makes up the third line of adaptive immunity?
T and B cells
Where are T cells made
Thymus
What are the different T cells
T helper
T lymphocytes
Cytotoxic T cells
Suppressor T cells
Memory T cells
Where are B cells made
Bone marrow
What do the B&T cells do as a whole
Bind with macrophages and self induce apoptosis
Where does the third line adaptive immunity originate
Lymphoid stem cells -> stops growing in adolescence
What are the 2 main B-cells
B Helper and plasma cells
What are mature B-cells
Plasma cells
What do the plasma cells do
Make antibodies (better for bacteria) and then secretes them
What do the antibodies do to pathogens
Tag the antigen (destroy extracellular antigen)
Form antibody-antigen complexes
Induce opsonization
What are the classes of immunoglobulins
IgG
IgE
IgA
IgM
Where are IgG antibodies found
Found in secretions and have bacterial or toxin neutralization
What are IgM antibodies
Largest, first secreted in response to antigen, cause agglutination
What are IgG antibodies?
Most numerous, help neutralize toxins, activates complement cascade, long term immunity (thanks mom)
What are IgE antibodies
Allergic response and secreted during parasitic infections
What is the general T-Cell function
Cellular immunity (T-helper is #1 guy)
What do the T regulator cells do
Limit the immune response
What aids with intracellular signaling
CD accessory proteins
What are the two main CD accessory proteins
CD 4 (important in HIV)
CD 8
What are accessory organs for immunity
Tonsils
Spleen
What makes up the tonsils
Adenoids
Palentine tonsils
Lingual tonsils
Why do adenoids get removed
For sleep apnea
Which tonsils usually get inflamed when sick
Palentine
What does the spleen do
Filters antigens
Cleans blood via phagocytosis
Can be stimulated via sympathetic nervous system in times of crisis
