Week 6 - Innate immunity Flashcards
myeloid tissue (fetus and adult) location
Adult- will be found in bone marrow tissue or tissues
Fetus - liver and spleen
reticular connective tissue location
around the kidney, liver, the spleen, and lymph nodes, Peyer’ patches as well as in bone marrow
lymphoid tissue location
The bone marrow and thymus are primary lymphoid tissues and the sites of lymphocyte development. The lymph nodes, spleen, tonsils and Peyer’s patches are examples of secondary lymphoid tissue.
hematopoiesis (hemopoiesis)
Blood formation, continuous process by which the cellular constituents of blood are replenished as needed
b) hemocytoblast (pluripotent stem cell)
Stem cell for blood elements
myeloid stem cell
derived from hematopoietic stem cells. They undergo differentiation to produce precursors of erythrocytes, platelets, dendritic cells, mast cells, monocytes, and granulocytes.
lympoid stem cell
What do lymphoid stem cells produce?
Hematopoiesis and lymphopoiesis
pluorpoent stem cell
a) location in the system
Throughout tissues, in umbilical cord
b) significance in white blood cell formation
The self-renewal is the capacity of the stem cells to divide indefinitely
c) role in production of granular white blood cells and monocytes
Myeloid stem cells are created by pluripotent stem cells
d) role in production of agranular white blood cells
Lymphoid stem cell are created by pluripotent stem cells
neaurophil
S: multilobed nucleus, with 3 to 5 lobes joined by tiny strands of genetic material.
L: go to sites of pathogens and injury to fight off pathogens
F: engulf and destroy bacteria and pathogen
basophil
S: cell with a two nucleus lobe
L: body tissue, blood?
F:chemical (heistiamen) which helps inflammatory response (increase blood flow)
esophil
S: two lobed nucleus
L: go to places that interact with the outside world (lungs, GI tract)
F: contain molecules that kill cells immune system has marked, help clear infections and mediate inflammation
monocyte
Structure: becomes a macrophage when it leaves blood
final destination: body tissue
Function: will disgust debris and display on surface
lymph pathway movement
xthe lymph capillaries, through lymph vessels and lymph nodes and ending in blood plasma of the veins (back in the circulatory system)
4 lympahtic tissues
lymph nodes
Lymph nodes are located in many parts of the body, including the neck, armpit, chest, abdomen (belly), and groin. They contain immune cells that can help fight infection by attacking and destroying germs that are carried in through the lymph fluid.
lymph nodules
The lymph nodules are dense masses of lymphocytes and macrophages and are separated by spaces called lymph sinuses.
Thymus
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders.
Spleen
it fights invading germs in the blood (the spleen contains infection-fighting white blood cells) it controls the level of blood cells (white blood cells, red blood cells and platelets) it filters the blood and removes any old or damaged red blood cells.
lymph nodes function and location
Lymph nodes functions:Lymph nodes filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that hel p the body fight infection and disease.
a)submental (sides of chin)
b)submandibular (under jaw)
c)cervical group along the sternocleidomastoid muscle in the neck
d) supratrochlear (above the bend in the elbow)
e) axillary group (within the underarm and upper chest)
f) inguinal group (in the groin)
wbc and phagoctic cells found in lymph node
c) the types of white blood cells found within the node
Cell of medulla: b cells, plasma cells
Inner cortex: t cells (dendritic cells also found here)
Around germinal center/outer cortex: b cells
germinal center/outer cortex: b cells (follicular dendritic cells found here aswell)
d) the type of phagocytic cells found within the node
Cell of medulla : macrophages
germinal center/outer cortex: macrophages
lymph node hemotpaeotic and immunty function
e) its hematopoietic functions
lymph nodes may be a site of extramedullary hematopoiesis (EMH). EMH in lymph nodes typically occurs as a physiologic response to a dramatic loss or increased need for additional blood cells.
f) its role in specific immune response
Protects body against foreign invaders: produces and releases lymphocytes and other immune cells that monitor and then destroy the foreign invaders such as bacteria, viruses, parasites and fungi
lymph node vs nodule
The nodule differs from a lymph node in that it is much smaller and does not have a well-defined connective-tissue capsule as a boundary. It also does not function as a filter. Lymph nodules frequently contain germinal centers—sites for localized production of lymphocytes. In the small intestine : Peyer’s patches. The tonsils : local regions where the nodules have merged together.
thymus
a) location, in relation to the trachea and sternum
Deep to sternum, inferior to trachea
b) period in life cycle when it is most functional
Fetal development
c) role in specific immunity
The thymus is an organ that is critically important to the immune system which serves as the body’s defense mechanism providing surveillance and protection against diverse pathogens, tumors, antigens and mediators of tissue damage
lymphocutes
a) B lymphocyte
S:
M: Pluripotent stem cell - Lymphoid stem cell - B lymphoblast - B lymphocyte (B cell)
F:effectors of humoral immunity, providing defense against pathogens through different functions including antibody production
b) T helper lymphocyte (via the blood AND the thymus)
S:
M: Pluripotent stem cell - Lymphoid stem cell - T lymphoblast - T lymphocyte (T cell)
F:a key mediator of immune function.
c) T killer lymphocyte (via the blood AND the thymus)
S:
M: Pluripotent stem cell - Lymphoid stem cell - NK lymphoblast - NK cell
F:kill certain cells, including foreign cells, cancer cells, and cells infected with a virus.
spleen
a) location, in relation to diaphragm and stomach
Lateral to stomach, superior to diaphragm
b) constituents of the stroma, white pulp and red pulp
Stroma - organize tissue into red pulp, white pulp and marginal zone,.
White pulp- dispose of antigens, dead cells, and debris by engulfing and digesting them.
Red pulp - filter the blood of antigens, microorganisms, and defective or worn-out red blood cells.
c) two protective functions with regard to:
i) hemopoiesis
Fliter blood
ii) phagocytosis
White pulp engulfs dead cells, antigens etc.
mast cells
a) leukocyte from which it is derived
Myeloid stem cell
b) location in the system
Bloodstream of tissue
c) specific protective function
Release specific chemicals (histamine) that cause inflammation (increased bloodflow)
marcophages
a) leukocyte from which it is derived
Monocyte
b) location in the system
Body tissue
c) specific protective function
Ingest pathogens, cancer cells and other harmful bacteria, which is destroyed, degraded and recycled
innate vs adpative immunity
a) immunity
the body’s ability to prevent the invasion of pathogens.
b) innate immunity (non-specific immunity)
Innate, or nonspecific, immunity is the defense system with which you were born.
c) adaptive immunity (specific immunity)
an immunity that occurs after exposure to an antigen either from a pathogen or a vaccination, specific
virus
A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves. Often, they kill the host cell in the process, and cause damage to the host organism
bacteria
Bacteria are small single-celled organisms. Bacteria are found almost everywhere on Earth and are vital to the planet’s ecosystems. Some species can live under extreme conditions of temperature and pressure. The human body is full of bacteria, and in fact is estimated to contain more bacterial cells than human cells.
fungus
The main types of ‘cells’ produced by human pathogenic fungi are hyphae, yeast cells, and spores. Can cause fungal infections
infection
the invasion of an organism’s body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce.
pathogen
A pathogen is an organism that causes disease.
pathogenicty
the property of causing disease
virulence/ virulenc efactors
the severity or harmfulness of a disease or poison.
the molecules that assist the bacterium colonize the host at the cellular level
nonpathogenic
not capable of causing disease nonpathogenic bacterial strains
normal body flora
microorganisms that live on another living organism (human or animal) or inanimate object without causing disease.
contaimination
the action or state of making or being made impure by polluting or poisoning
optiumal bacteria growth
Bacteria can live in hotter and colder temperatures than humans, but they do best in a warm, moist, protein-rich environment that is pH neutral or slightly acidic
number of mircobes
Microbes cause infectious diseases such as flu and measles. So if there is more of them, there will be a more likely change of disease
exotoxin
Exotoxins are polypeptide proteins excreted by few species of bacteria
endotoxin
Endotoxins are the lipopolysaccharide-protein complexes, produced at the time of cell death
virulence factor enzymes
Enzymes include hyaluronidase, which breaks down the connective tissue component hyaluronic acid; a range of proteases and lipases; DNases, which break down DNA, and hemolysins which break down a variety of host cells, including red blood cells
sebum
Oily substance on skin that helps kill bacteria/virus
infernon
By inducing the expression of hundreds of IFN-stimulated genes, several of which have antiviral functions, IFNs block virus replication at many levels
complement
Proteins of the complement system react with each other to bind pathogens and trigger an inflammatory cascade response to fight infection
fever
A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes
acycloivor/ anti hiv agents
Aciclovir, also known as acyclovir, is an antiviral medication. It is primarily used for the treatment of herpes simplex virus infections, chickenpox, and shingles It works by stopping the spread of the herpes virus in the body. Acyclovir does not cure cold sores or genital herpes, does not prevent outbreaks of these conditions, and does not stop the spread of these conditions to other people.
antiviral. antifungal drugs
a) antiviral
how to stop the virus without damaging the inner workings of healthy cells too.
b) antifungal
Antifungal drugs are relatively difficult to develop compared to antibacterial drugs owing to the eukaryotic nature of the cells
local vs systemic infection
An infection that is in the bloodstream is called a systemic infection. An infection that affects only one body part or organ is called a localized infection
primary vs secondary infection
a primary infection can practically be viewed as the root cause of an individual’s current health problem, a secondary infection is a sequela or complication of that root cause
bacteremia and septicemia
Bacteremia is the simple presence of bacteria in the blood while Septicemia is the presence and multiplication of bacteria in the blood
exogenous and endogenous
exogenous infection, no microbial carriage precedes colonization and infection. In endogenous infection, infection is preceded by oropharyngeal or GI carriage.
communicable and non-communicable
Communicable diseases comprise infectious diseases such as tuberculosis and measles, while non-communicable diseases (NCDs) are mostly chronic diseases such as cardiovascular diseases, cancers, and diabetes
endemic and epidemic
an epidemic as an unexpected increase in the number of disease cases in a specific geographical area, A epidemic is a disease outbreak is endemic when it is consistently present but limited to a particular region.
anti infective theopy
Anti-infectives are used to destroy or suppress the growth of infectious organism. The desire is to use an agent which will inhibit/kill the invading organism without hurting host tissue. The use of the antiinfective drugs will thus assist the normal host defense mechanisms to prevent growth of and eliminate the infectious agent from the system.
antibiotic
is a type of antimicrobial substance active against bacteria
antibacterial agent
are a group of materials that fight against pathogenic bacteria.
antiviral agent
treatment or control of viral infections.
antifungal agent
treat and prevent mycosis
antiprotozoan agent
any agent that kills or inhibits the growth of organisms known as protozoans
anthelmintic agent
a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host
antiparasitic agents
Antiparasitic agents are drugs used to treat parasitic diseases
amebicide
An amebicide is an agent used to treat patients with amebiasis. Amoebiasis is an infection that is caused by the amoeba, or unicellular organisms, of the Entamoeba genus
anti-microbial agents
a natural or synthetic substance that kills or inhibits the growth of microorganisms such as bacteria, fungi and algae.
bacterial restisance
a) definition of the term
Bacterial resistance is the capacity of bacteria to withstand the effects of antibiotics or biocides that are intended to kill or control them
b) two signs indicating its development
Taking urine and blood samples and shwoing the bacteria not dying
c) physiological basis for its development in the bacterial strain
Antibiotic resistance is accelerated when the presence of antibiotics pressure bacteria and fungi to adapt
hypersensitiviely I
a) definition of the term
Type I hypersensitivity is also known as an immediate reaction and involves immunoglobulin E (IgE) mediated release of antibodies against the soluble antigen. This results in mast cell degranulation and release of histamine and other inflammatory mediators.
b) how it develops
Type I hypersensitivity (or immediate hypersensitivity) is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen.
c) list symptoms which indicate an allergic reaction
Trouble breathing, hives, dwelling of eyes and throat, shortness of breath, tightness of breath, wheezing
d) list the symptoms of anaphylaxis.
Skin reactions (hikes, intchings, weak/rapid pulse, low blood pressure, nasua, vomiting diarhaa, dizzinesss/fainting
e) state the standard aids for treating anaphylaxis.
Give epi pen if there, call 911, lay person flat, can give second spi pen shot after 5 minutes
anti infectives
i) specific action of the anti-infective drug
-all of these terms will refer to any drug, synthetic or natural, which has the ability to kill (bactericidal) or suppress the growth of (bacteriostatic) microorganisms without killing or suppressing host tissue. Host tissue has been invaded by parasitic organisms which are damaging that tissue. A drug is needed which will kill or suppress the microorganism but have no effect on the host cells.
ii) explain the bacteriostatic or bacteriocidal effect
the definitions of “bacteriostatic” and “bactericidal” appear to be straightforward: “bacteriostatic” means that the agent prevents the growth of bacteria (i.e., it keeps them in the stationary phase of growth), and “bactericidal” means that it kills bacteria.
iii) possible side effects of the drug
a) penicillins (e.g. amoxicillin)
Principal adverse effect is allergic reaction. May cause diarrhea due to disruption of normal intestinal flora.
b) tetracyclines (e.g. doxycycline)
Gastric irritation. Discoloration of permanent teeth. Suppresses growth of long bones in fetuses and infants.
replication of viral genome
Viral DNA replication takes place in two distinct compartments (genome-length progeny DNA is synthesized in the nucleus, followed by the synthesis of concatemeric DNA in the cytoplasm), whereas virion assembly is confined to cytoplasmic viral ‘assembly sites’.
entrance of the viral particle into the host cell
Virus entry into animal cells is initiated by attachment to receptors and is followed by important conformational changes of viral proteins, penetration through (non-enveloped viruses) or fusion with (enveloped viruses) cellular membranes. The process ends with transfer of viral genomes inside host cells.
production of viral spike and capsid proteins
Viral spike is what is sticking out of the cell membrane of a virus, capsid proteins A capsid is the protein shell of a virus, enclosing its genetic material.
viral particles
Once viral proteins and genomes have been produced, new virions are assembled and released into the environment. Virus assembly is driven, at least in part, by the inherent properties of the viral proteins; in some cases, viral capsid proteins will assemble spontaneously to form capsid-like structures in a test tube
how viruses produce specific tissue damage
Direct cell damage and death from viral infection may result from (1) diversion of the cell’s energy, (2) shutoff of cell macromolecular synthesis, (3) competition of viral mRNA for cellular ribosomes, (4) competition of viral promoters and transcriptional enhancers for cellular transcriptional factors such as RNA
two effects of viral invasion on host cells
Virus-host cell interactions may produce either 1) cytocidal (cytolytic) infections, in which production of new infectious virus kills the cell; 2) persistent infections, in which the virus or its genome resides in some or all of the cells without killing most of them
effectiveness of antimicrobial drugs on viral diseases
Antibiotics DO NOT work on viruses, such as those that cause colds, flu, or COVID-19. Antibiotics also are not needed for many sinus infections and some ear infections.
first line of defense
Skin and mucous membranes produce protective chemicals that inhibit or destroy microorganisms •
Acid: acidity of skin and some mucous secretions inhibits growth; called acid mantle•
Enzymes: lysozyme of saliva, respiratory mucus, and lacrimal fluid kills many microorganisms; enzymes in stomach kill many microorganisms •
Mucin: sticky mucus that lines digestive and respiratory tract traps microorganisms•
Defensins: antimicrobial peptides that inhibit microbial growth•
Other chemicals: lipids in sebum and dermicidinin sweat are toxic to some bacteria
second line of defense
nnate system necessary if microorganisms invade deeper tissues; includes:
- Phagocytes
- Natural killer (NK) cells
- Inflammatory response (macrophages, mast cells, WBCs, and inflammatory chemicals)
- Antimicrobial proteins (interferons and complement proteins)
- Many second-line cells have pattern recognition receptors that recognize and bind tightly to structures on microbes, disarming them before they do harm
phagcytosis
- Process starts when phagocyte recognizes and adheres to pathogen’s carbohydrate “signature”• Some microorganisms have external capsules that hide their surface carbohydrates, helping them evade phagocytosis • Opsonization: immune system uses antibodies or complement proteins as opsoninsthat coat pathogens • Act as “handles” for phagocytes to grab on to, enhancing phagocytosis
- Cytoplasmic extensions (pseudopods) bind to and engulf particle in vesicle called phagosome
- Phagosome fuses with lysosome, forming phagolysosome
- Phagolysosome is acidified, and lysosomal enzymes digest particles
- Indigestible and residual waste is exocytosed from phagocyte
inflammation
Inflammation is triggered whenever body tissues are injured• Injuries can be due to trauma, heat, irritating chemicals, or infections by microorganisms• Benefits of inflammation: • Prevents spread of damaging agents • Disposes of cell debris and pathogens • Alerts adaptive immune system• Sets the stage for repair
acute imflammoraion
develops quickly, solely beneficial, and eliminates cause
chronic inflammation
: long-lasting, damages tissues (even to point of death), causes disease
stage of inflammation
- Inflammatory chemical release
- Vasodilation and increased vascular permeability
- Phagocyte mobilization
stages of r phagocyte mobilization
- Leukocytosis: release of neutrophils from bone marrow in response to leukocytosisinducing factors from injured cells
- Margination: endothelial cells of capillaries in inflamed area project cell adhesion molecules (CAMs) into vessel lumen that grab onto passing neutrophils, causing them to slow and roll along, clinging to vessel wall
- Diapedesis: neutrophils flatten and squeeze between endothelial cells, moving into interstitial spaces
- Chemotaxis: inflammatory chemicals act as chemotactic agentsthat promote positive chemotaxis of neutrophils toward injured area
3 ways to prevent hemoragee
- Vascular Spasm2. Platelet Plug Formation 3. Blood Clotting/Coagulation
Vascular Spasm
The arteries or arterioles, when damaged, reflexively contract immediately in response to the wound
. This limits the blood loss but is only a temporary solution – it could last a couple of minutes up to an hour or so. Doesn’t stop bleeding but reduces it
platelete plug formation
- First, platelets contact and stick to damaged parts of blood vessels, such as collagen (which will now be exposed, they were on the opposite side of the endothelium
- This is called platelet adhesion
- Adhesion activates the platelets, and they change appearance and activity dramatically.
- They start forming projections that allow them to attach to each other, and they also begin to release their vesicles.
- This is called the Platelet release reaction.
- Molecules released, ADP, thromboxane A2 will activate nearby platelets. Serotonin and thromboxane A2 will also maintain the contraction of the blood vessel caused by vascular spasm.
- So all of the platelets in the area are activated thanks to the signals being released. And they all stick together and aggregate, forming a plug.
- The plug of course, limits blood loss
blood clot formation
- The platelet plug will eventually start producing fibrin threads
- The platelet plug will eventually start producing fibrin threads
- The threads will become such a dense network that RBCs will not be able to pass.
- Here you can see the RBC trapped in a network of fibrin threads.
- This process is mediated by 12 clotting factors from various regions of your body, but I will not cover these in this course, just too much detail.
Atrophy
- Decrease in the size of cells
- Results in reduced tissue mass
hypertrphy
- Increase in cell size
- Results in enlarged tissue mass
hyperplasia
Increased number of cells • Results in enlarged tissue mass
metaphlasia
Mature cell type is replaced by a different mature cell type.
dysplasia
Cells vary in size and shape within a tissue
anaplasia
Undifferentiated cells, with variable nuclear and cell structures
neoplasima
New growth”―commonly called tumor
differation
The process where a cell changes from one cell type to another • Zygote to multicellular organism
Necrosis: un-programmed cell death (dangerous)
Passive form of cell death induced by accidental damage of tissue and does not involve activation of any specific cellular program
Apoptosis: one of the main forms of programmed cell death
Not as dangerous to organism as necrosis • Active form of cell death enabling individual cells to commit suicide
passive artifulal immunity
Injection of antibodies • Short-term protection
passive natural immunity
• IgG transferred from mother to fetus: • Across placenta • Through breast milk • Protection of infant for the first few months of life or until weaned
active articfal immunity
Antigen purposefully introduced to body • Stimulation of antibody production • Immunization • Booster immunization
active natural immunity
• Natural exposure to antigen • Development of antibodies
nitric oxide
Potent vasodilator • Produced from the action of nitric oxide synthetase from arginine
sertition
• Serotonin is widely and primarily thought as being a neurotransmitter, but its role in acute inflammation is just as powerful. • Mast cells (also basophils and platelets)
histanime
• Release by nonimmune mechanisms such as cold, trauma, or other chemical mediators • Release by other mediators • Dilates arterioles and increases permeability of venules (wheal and flare reaction)
bradykinyn
• Small peptide released from plasma precursors • Increases vascular permeability • Dilates blood vessels • Causes pain
