Lec 6 Flashcards
What are the three subsets of the immune system?
- Innate Immunity
- Disposal System
- Adaptive Immunity
What are the two subsets of leukocytes?
Granular and Agranular leukocytes
What is leukocytosis?
It is the presence of more than 11,000 leukocytes/ul of blood in response to an immune or inflammatory event
What is the difference between the two types of leukocytes?
Granular leukocytes have granules visible when stained, and agranular ones don’t
What are the three types of granulocytes?
- Neutrophils
- Eosinophils
- Basophils
What type of leukocyte takes up the largest part of the white blood cells?
Neutrophils
What are phagocytes and what is their function? What type of leukocyte are they?
Phagocytes are cells that ingest and destroy bacteria. They are neutrophils.
What type of leukocyte deals with parasitic worms, allergies, and asthma? What is the function?
Eosinophils surround unwanted bodies and release digestive enzymes.
What leukocyte is the rarest and releases histamines to attract other WBCs?
Basophils
What are the two types of agranulocytes?
Lymphocytes and Monocytes
What is the second most common type of leukocytes, and what are the two types of it?
Lymphocytes are divided into T cells and B cells
Where are lymphocytes found?
In lymphoid tissue (lymph nodes, spleen)
What is the largest leukocyte?
A monocyte.
What is the difference between a T lymphocyte and a B lymphocyte?
T cells act directly against virus infected cells and tumor cells, where B cells give rise to plasma cells that produce antibodies
What do monocytes differentiate into?
Macrophages
What is the role of monocytes?
They are phagocytic to chronic infections, viruses, and some bacteria
What is the formation of WBC process called?
leukopoiesis
What are the hormones that effect the production of leukocytes?
Interleukins and colony-stimulating factors
What are the two types of leukocyte stem cells? What types of leukocytes do they differentiate into?
Myeloid stem cells differentiate into granulocytes and lymphoid stem cells differentiate into agranulocytes.
What is the most undifferentiated form of stem cell in the leukopoiesis pathway?
Hemocytoblasts
What is the lymphoid stem cell pathway?
Lymphoid stem cells turn into committed lymphoblasts, and eventually will give a product of lymphocytes.
What are the two committed cell types that are derived from a myeloid stem cell?
A monoblast and a myeloblast.
What cells turn into monocytes?
monoblasts
What are the final products of myeloblasts?
eosinophils, neutrophils, and basophils
What does bone marrow STORE?
Mature granulocytes (neutrophils, basophils, eosinophils) (roughly 10x what is found in blood)
What is the lifespan of a granulocyte?
0.25-9 days
What does a monocyte become in the body?
A macrophage in tissues
What is likely to happen to T cells and B cells?
T cells will likely become Effector T cells, and B cells will become Plasma cells to grow antibodies
What is leukemia? What is the usual form it takes?
It is cancer of the WBCs where descendants of a cell remain unspecialized and mitotic
What differentiates acute and chronic leukemia?
Acute leukemia is where the cancer happen in a blast phase, and chronic leukemia happens later in the leukopoiesis pathway
Where else can leukemia affect the body other than the leukocyte process?
In the bone marrow
What is the treatment for lukemia?
Irradiation, anti-leukemic drugs, bone marrow transplant
What are the three types of leukocyte disorders?
Leukemia, Infectious mononucleosis, and leukopenia
What is infectious mononucleosis?
Mono, caused by the Epstein-Barr virus, and causes excessive lymphocytes
What is an abnormally low WBC count called?
Leukopenia
What are the two subdivisions of the immune system?
The innate defenses and the adaptive defenses
What mechanism drives the adaptive immune system?
Lymphocyte cell subpopulations carry out a targeted immune response
What are the two types of adaptive defense responses? What cell types do they use?
Humoral Immunity uses B cells and Cellular immunity uses T cells
What are the two types of innate defenses?
Surface barriers and Internal Defenses
What does PAMP stand for?
Pathogen associated molecular patterns
What does DAMP stand for?
Damage associated molecular patterns
What molecular pattern deals with molecules that are not normally present in the body? Specifically what type of receptors are used where?
PAMPs use toll-like receptors on phagocytic cells
What is the end result of the PAMP pattern?
Phagocytosis as well as inflammatory response and notification of the adaptive immune system
What does the DAMP system recognize?
It recognizes molecules that are in the wrong place in our bodies
What are the surface barrier innate defenses?
Skin and mucous membranes
What are skin and mucous membranes protective characteristics and uses? (5)
1, Acidic deters bacterial growth
2. Contains Enzymes like lysozymes in saliva, as well as protein digesting enzymes in the stomach
3. Mucin are sticky traps in the respiratory and digestive pathways
4. Defensins, are anti-microbial peptides secreted
5. Other chemicals like lipids in sebum are toxic to bacteria
What are 4 key signs of inflammation?
Redness, heat, swelling, pain
What are the 4 functions of inflammation?
- Prevents the spread of microorganisms
- Disposes of cell debris and pathogens
- It sets the stage for the repair process
- It alerts the adaptive immune system
How does inflammation relate to the types of bodily defenses?
Inflammation is an innate defense that can be amplified by an adaptive immune response
What cells attract immune cells to a site of inflammation, as well as promote arteriole dilation and capillary leakiness? Give some examples
Inflammatory chemicals such as histamines or kinins
What are the 4 steps of inflammation dealing with neutrophils?
- Leukocytosis
- Margination
- Diapedesis
- Chemotaxis
WHAT CAUSES PAIN DURING INFLAMMATION
WHY IS INFLAMMATION A HELPFUL RESPONSE TO TISSUE INJURY
What is leukocytosis in inflammation?
It is the entry of neutrophils into the bloodstream from the bone marrow
What is margination?
It is neutrophils clinging to capillary walls
What is diapedesis?
It is when neutrophils flatten and squeeze out of capillaries.
What is chemotaxis?
It is when the neutrophils follow a chemical trail.
SLIDE 14
What is interferon?
It is a substance that cells release when infected with a virus
What does interferon do?
It activates antiviral proteins in healthy cells, which blocks viral protein synthesis and degrades the viral RNA
It also can activate macrophages and mobilize natural killer cells, which may play a role in anti-cancer
INTERFERON DIAGRAMS
What is a complement?
It is a group of at least 20 plasma proteins circulating in an inactive state
What is an opsonin?
It is a substance that binds to foreign microorganisms making it more susceptible to phagocytosis
SLIDE 18
What substances cause fever?
Pyrogens
What temperature is the human body at normally?
37.4 degrees C
WHY IS HIGH FEVER DANGEROUS
Why is a moderate fever helpful?
It speed up the metabolic rate, it also causes the liver and spleen to sequester iron and zinc
What are natural killer cells? What defense system they a part of?
They are lymphocytes and are part of the innate immune system.
What cells in the body expresses major histocompatibility complex 1?
all nucleated cells
What do natural killer cells target?
Virus cells or cancer cells
What two criteria need to be met for a natural killer cell to attack?
There has to be a stress marker and no MHC1
What do the toll-like receptors on natural killer cells indicate?
They are activatable by PAMPs and DAMPs.
What are the three leukocyte types involved in the adaptive immune system?
B lymphocytes, T lymphocytes, and macrophages
SLIDE 22
What is an antigen?
Something capable of mobilizing adaptive defenses
What is an antigenic determinant?
It is the part of the antigen that is recognized by the immune system
What is the purpose of the MHC?
It is a group of glycoproteins where self-antigens or foreign antigens can be inserted
SLIDE 23
What two things do T cells need to acquire when they mature? What percentage of T cell lymphocytes mature properly?
They need to acquire immunocompetence and self tolerance, which only happen 2 percent of the time.
What happens if the T cell doesn’t recognize self-MHC? (immunocompetence) CHECK SLIDE 24!
Apoptosis
What is the self-tolerance lymphocyte maturation step? Why is it important?
It means T cells must not recognize self antigens, if they do they will undergo apoptosis to avoid self-reactive T cells which cause autoimmune.
Where do T cell lymphocyte precursors migrate?
The thymus
Where to B cells mature?
The bone marrow
What happens once B cells are immunocompetent?
They display a unique receptor which makes them able to react to one foreign antigen
What immune response are B cells responsible for?
The humoral immune response
Where do antigens usually challenge?
Lymph nodes or the spleen
What do B cells turn into (effector B cells)?
Plasma Cells
How long do plasma cells last?
4-5 days
What do plasma cells release?
Antibodies
How long do antibodies last in the body and what is their purpose?
Antibodies last 4-5 days and bind to antigens to mark them for destruction
What are B cells called when they don’t turn into effector B cells?
memory cells
