Studied by 0 people
Looks like no one added any tags here yet for you.
What type, surface, and organs are involved in the defense mechanism of the skin barrier?
Type: Physical
Surface: Epithelial
Organs: Skin
What type, surface, and organs are involved in the defense mechanism of sebum production?
Type: Chemical
Surface: Epithelial
Organs: Skin
What type, surface, and organs are involved in the defense mechanism of desquamation?
Type: Mechanical
Surface: Epithelial
Organs: Skin
What type, surface, and organs are involved in the defense mechanism of respiratory mucociliary flow?
Type: Physical
Surface: Epithelial
Organs: Respiratory tract
What type, surface, and organs are involved in the defense mechanism of stomach acid?
Type: Chemical
Surface: Epithelial
Organs: Stomach
What type, surface, and organs are involved in the defense mechanism of coughing and sneezing?
Type: Mechanical
Surface: Mucosal
Organs: Respiratory Tract
What type, surface, and organs are involved in the defense mechanism of peristalsis?
Type: Mechanical
Surface: Smooth muscle cells, enteric neurons, interstitial cells
Organs: GI tract
What type, surface, and organs are involved in the defense mechanism of mucus production?
Type: Mechanical
Surface: Mucosal
Organs: Respiratory and GI tract
What does SALT stand for?
Skin-associated lymphoid tissues
What type of defense mechanism are skin-associated lymphoid tissues?
Not a direct physical/chemical/mechanical defense mechanism
What types of cells do SALTs consist of?
Consist of cells of the innate and adaptive immune system
What do SALTs serve as sites for?
Immune cell activation and proliferation in response to antigens encountered in the skin
Cells of the innate immune system
Keratinocytes and Langerhans cells (LCs)
Keratinocytes
-specialized epithelial cell
-can act as antigen-presenting cells (APCs) and secrete cytokines that induce local inflammatory reactions
Langerhans cells (type of dendritic cell)
can phagocytose, migrate from the epidermis to regional lymph nodes, where they differentiate and function as potent activators of skintrophic naive T cells of the adaptive immune system
Phagocytosis
the internalization of particulate matter by cells by a process of engulfment, in which the cell membrane surrounds the material, eventually forming an intracellular vesicle (phagosome) containing the ingested material
3 types of phagocytic cells
Macrophages
Neutrophils
Dendritic cells
What do phagocytic cells do?
Trap and kill pathogens
Trap and degrade cellular debris
Phases of phagocytosis
Chemotaxis
Adherence
Ingestion
Destruction
PRR’s
Pattern recognition receptors
PAMPs
Pathogen-associated molecular patterns
How do phagocytic cells recognize microbes?
By expressing PRRs that recognize PAMPs on the microbes
Expressing receptors for opsonins that are bound to the microbe
Opsonins
Molecules that facilitate phagocytosis by phagocytic cells
A particular complement protein
Certain kinds of antibodies
There are ____ kinds of PRRs
several
_____ and ____ can express the same PRRs and multiple PRRs at the same time
Macrophages and neutrophils
PRRs allow phagocytes to…..
recognize groups of pathogens like gram positive and gram negative bacteria
What happens when a PRR on a phagocytic cell interact with a PAMP on a microbe?
Signals are generated to the phagocyte to become activated and get ready to ingest and kill the microbe
What does TLR stand for?
Toll-like receptors
TLRs
Most important group among the PRRs on phagocytic cells
-more than 10 different TLRs identified
-being investigated to modulate inflammation
The interaction between the TLR and the PAMP allows for…..
-microbial recognition (attachment) followed by phagocytosis
-signals that activate genes in the phagocytic cell that result in the production of cytokines
Cytokines
Help to activate inflammation and aspects of the adaptive immune system
Main phagocytic cells
Macrophages and Neutrophils
Main function of dendritic cells
Antigen presenting cells
What family tree do neutrophils and macrophages stem from?
Myeloid cell family tree
What common progenitor do the neutrophils and macrophages come from?
-Common myeloid progenitor cells
-Granulocyte/macrophage progenitor
Macrophages main function is what?
Phagocytosis
Shared functions of macrophages and dendritic cells
Sentinel cells and antigen-presenting cells
Sentinel cells
Identifying and capturing microbes in tissues
Antigen-presenting cells (ACPs)
cells that trigger immune response through the presentation and process of foreign material
Other functions of macrophages besides phagocytosis
Secretory cells and wound healing
How do neutrophils respond to infection?
Called in by cytokines from sentinel cells
What is the first phagocyte to respond to infection?
Neutrophils
What do neutrophils specifically respond to?
Bacterial infections
Where do neutrophils reside?
Bone marrow and blood
Parts of the bone marrow where neutrophils reside
proliferation pool, maturation pool, storage pool
Where are neutrophils found in the blood?
Mature neutrophils are found in the blood initially
Circulating pool in blood (CP)
What we count in a CBC
Neutrophilia
Above normal concentration of neutrophils in the circulating pool
Marginating pool in blood
Neutrophils that adhere to endothelium
