Exam 2 Flashcards
What is Apoptosis and in what ways is it activated?
Programmed Cell Death
Extrinsic Activation - death receptor mediated
Intrinsic Activation - mitochondrial activation
What is the purpose of Apoptosis?
Eliminate cells that are worn out, are produced in excess, have developed improperly, or have genetic damage
What is Necrosis?
Cell death in an organ or tissues that is still part of a living person
What are the 3 different types of Necrosis?
Liquifactive - cellular or bacterial enzymes degrade cell contents (absesses)
Coagulation - proteins are denatured; typical of infraction (e.g. heart attack)
Caseous - dead cells persist and form a “cheese-like debris” (common in granulomas)
What form of Necrosis is Wet Gangrene and what is it?
Liquefactive
Edema as venous return from the tissue is affected; this area is cold and no pulse can be found
Skin is moist, dark in color, and often has blisters
Contains no line of demarcation
Spread of tissue damage is rapid
What form of Necrosis is Dry Gangrene and what is it?
Coagulative
Tissue dies from arterial ischemia with no impairment of venous return from the tissue
Affected tissue becomes dry and shrinks, changing color to dark brown or black
There is a line of demarcation that separates healthy tissue from the necrotic tissue
Slow spread
What is Gas Gangrene?
Caused by bacterial infection
Typically occurs in dirty wounds where the toxins dissolve the cell membranes, causing edema and RBC lysis
Hydrogen sulfide gas forms in the muscles
Which of the following can result in membrane damage?
(A) Inactivation of Na+/K+ ATPase
(B) Oxidation of phospholipid
(C) Ischemic activation of protease
(D) All of the above
(E) None of the above
(D) All of the above
Does Wet Gangrene have a line of demarcation?
No
What is Hutchinson-Gifford Progeria?
Premature aging
Lack of Lamin A gene which is important for DNA replication
Cell Nucleus is unstable and causes only normal growth to occur until 18-24 months of age
1 in 20 million - below average height and weight, prominent eyes, hair loss, large head, high-pitched voice
What are causes of Inflammation?
Immune response to infectious microorganisms
Trauma
Surgery
Caustic chemicals
Extremes of heat and cold
Ischemic damage to body tissues
What are cardinal signs of Inflammation?
Redness
Swelling
Heat
Pain
Loss of Function
What is the difference between Acute and Chronic Inflammation?
Acute: short duration (mins - days), emigration of leukocytes (neutrophils) into the tissue
Chronic: long duration (days - years)
What is the structure of an antibody?
Heavy chain, light chain, variable region, antigen binding site
Which antibody type is LEAST prevalent?
IgE
Which antibody type is released in the breast milk?
IgA
Which antibody type can cross the placenta?
IgG
What two types of leukocytes participate in the acute inflammatory response?
Granulocytes (neutrophils, eosinophils)
Monocytes (largest of WBCs)
What is the role on selectins in the migration of WBCs into the tissue?
They are an adhesion molecule that allows for “rolling” to occur within the WBC as it moves through a capillary
What is the role of integrins in WBC migration into the tissue?
Adhesion molecule that allows for firm adhesion to occur within the capillary wall, allowing for movement into the underlying tissue to occur
What is the role of Histamine?
Dilation of blood vessels
Contraction of airways (narrowing)
Preformed in cells and tissues and released in response to stimuli, trauma, or allergy
What is the role of Serotonin?
Important in healing burn injuries
Increases cell viability
Induces pro-inflammatory cytokine production
Proliferation
Migration of fibroblasts and keratinocytes to close wound
What is the role of TNF and IL1B?
Act together towards endothelial cells, neutrophils, and the acute-phase response
Cause selectins and integrins to be unregulated
Aggregation and priming (ready for battle) in neutrophils
Fever, anorexia, hypotension, increased HR, corticosteroid and ACTH release
What is the function of Platelet-activating Factor?
Allow for platelet aggregation
Attracts PMNs and EOS to tissue
What is Granulomatous Inflammation?
Associated with foreign bodies (splinters, sutures, asbestos)
Associated with microorganisms that cause syphilis, deep fungal infections, or brucellosis
Describe Acute Inflammation
Relatively short duration
Nonspecific early response to injury
Aimed primarily at removing the injurious agent and limiting tissue damage
Infiltration of neutrophils
Exudate
Describe Chronic Inflammation
Longer duration
Recurrent or progressive acute inflammatory process or a low-grade smoldering response that fails to evoke an acute response
Infiltration by mononuclear cells (macrophages) and lymphocytes
Proliferation of fibroblasts
What are the 5 types of Exudates?
Serous
Hemorrhagic
Membranous
Purulent
Fibrinous
Which protein on the surface of endothelial cells causes WBC rolling?
Selectins
What is Serous Exudate and where is it?
watery fluids that are low in protein content
Result from plasma entering the inflammatory site
What is Hemorrhagic Exudate and where is it?
Occurs when there is severe tissue injury that causes damage to blood vessels
When there is significant leakage of red cells from the capillaries
What is Membranous Exudate and where is it?
Develop on mucous membrane surfaces
Composed of necrotic cells enmeshed in a fibro purulent exudate (pus, thick)
What is Purulent Exudate and where is it?
An Abscess
Contains pus, composed of degraded white blood cells, proteins, and tissue debris (needs to be opened to drain it)
What is Fibrinous Exudate and where is it?
Contain large amount of fibrinogen and form a thick and sticky mesh work
What are some of the physical barriers of the Innate Immune System?
Skin
Mucus
What are some of the physiological barriers of our Innate Immune System?
Coughing
Vomiting
Diarrhea
What are some of the chemical barriers of our Innate Immune System?
pH (skin is 3-5; stomach is 2)
Tears (lysozymes)
What is Complement?
Helps antibodies and phagocytic cells to clear pathogens from an organism
Flushing ECF into the cell to cause bacteria to explode
What are the characteristics of adaptive immunity?
Specificity of recognition of antigen
Wide diversity of antigens can be specifically recognized
Memory, whereby immune system responds more quickly than the first time
Ability to distinguish self-antigens from non-self
What are the 2 cells of adaptive immunity and what do they do?
T cells: helper type uses chemical signals to call on the B cells and other T cells while killer type identify infected host cells and employs chemical signals to cause then to die and be eliminated from the body
B cells: create antibodies that identify foreign invaders that need to be killed (flagged)
What are MHC Class I?
Antigens from INSIDE the cell
All cells are this class
CD8 T cells activate “killer T cells”
Kill or release antiviral cytokines
Cell mediated immunity
What are MHC Class II?
Antigens from OUTSIDE the cell
Antigen presenting cells
Activate CD4 T cells to help activate B cells for antibody production
What regions of the body are important for adaptive immunity?
Bone marrow
Thymus
Spleen
Lymph nodes
What do swollen lymph nodes tell us?
Give an idea of where the infection is
First “gateway”
Why is vaccination important?
Helps to produce a ‘em memory of the vaccine antigen so if the pathogen enters the body in the future, the response will be stronger and faster than if it did not first encounter
What is R0?
The number of people that can be affected by someone without immunity of a pathogen
What is Herd Immunity?
Number of people in a population who have seen an antigen
If most of the population gets immunized, the spread of contagious disease is contained
What is the Threshold for R0 when it comes to Herd Immunity?
The percent of the population that needs immunity to contain the spread and allow for herd immunity
What is Primary Immune Response?
The first encounter with a foreign antigen
What occurs in the Primary Immune Response?
Only few B and T cells can recognize the antigen and mount a response
Clónale expansion occurs where hundreds and hundreds of copies are made for memory cells
What is the Secondary Immune Response?
The second encounter with a foreign antigen
What occurs in the Secondary Immune Response?
Large clone of memory cells that can recognize the antigen
Immune response is faster and more effective
What type of antigen is in the primary immune response? Secondary?
IgM
IgG
What is Type I Hypersensitivity?
“Allergy”
IgE mediated
Against environmental antigens (allergens)
Release of histamine
What are some of the responses to Allergies?
Sneezing
Itchy eyes
Runny nose
What is Type II Hypersensitivity?
Antibody mediated
IgG and IgM antibodies
These bind to cell surface receptors or connective tissue
What are the five mechanisms of Type II Hypersensitivity?
Cell is destroyed by antibodies and complement
Cell destruction through phagocytosis
Soluble antigen may enter the circulation and deposit on tissues
Antibody-dependent cell mediated cytotoxicity
Causes target cell malfunction
What is Type III Hypersensitivity?
Immune complex mediated
IgG and IgM
Antigen-antibody complexes are formed in the circulation and are later deposited in vessel walls or extra vascular tissues
NOT organ specific
What is the difference between Type II and Type III hypersensitivities?
Type II antibody binds to antigen on the cell surface
Type III antibody binds to soluble antigen that was released into the blood or other body fluids, and the complex is then deposited in the tissues (also not organ specific)
What is Type IV Hypersensitivity?
Does NOT involve antibody
Cell-mediated immunity
CD8 T cells kill the antigen-bearing target cells as well as delayed-type hypersensitivity reactions in which presensitized CD4 cells release cell-damaging cytokines
What is the definition of Autoimmunity?
Breakdown of tolerance - body recognizes self-antigens as foreign (not normally seen by immune system)
This leads to infectious disease
What is Myasthinia Gravis?
Decreased neuromuscular function as AcH is blocked of action in the neuromuscular junction
Leads to blurred vision, impaired speech, weakness of arms hands fingers and legs, difficulty swallowing and chewing
Type II Hypersensitivity
What is Graves Disease?
Overproduction of Thyroid hormone
Anxiety, irritability
Fine tremor of hands or fingers
Heat sensitivity
Weight loss
Enlargement of thyroid gland
Type II Hypersensitivity
Why have we as humans developed an aversion to fecal material and vomit?
We associate these things with unpleasant experiences (being sick, having food poisoning…)
What is the purpose of pain?
To alert the body away from a danger to prevent further damage (e.g. hand on hot stove)
