blood and the immune system Flashcards
What makes up the Innate Immune System?
- 1st line of defense (physical & chemical surface barriers)
- 2nd line of defense (internal cellular & chemical defense)
What does the Humoral Theory state?
- the humors are blood, phlegm, black bile and yellow bile
- an imbalance in these humors causes disease
What did Galen do?
- formalized the relationship between humoral medicine and Greek natural philosophy
- the four humors are made up of qualities (hot, cold, dry, wet
- body humors and physical world elements shared a common qualitative nature
What is the 1st line of defense?
physical & chemical surface barriers
What is microcosm?
little world of human body
What is the 2nd line of defense?
internal cellular & chemical defense
What is macrocosm?
greater world
What was the solution to restore health balance before the 17th century?
- Lifestyle - diet and exercise
- medication - herbs
* opposites cure opposites - cold remedy cures hot illness
* illness was seen as internal disorder of the body, not as the result of a specific agent like bacteria
What makes up the Adaptive Immune System?
- 3rd line of defense: (immune response – if pathogen survives nonspecific, internal defenses)
What is the 3rd line of defense?
immune response (if pathogen survives
nonspecific, internal defenses))
What was aristotelian, qualitative, natural philosophy replaced with after the late 17th century?
mechanical, chemical mathematical vision of the world and body (Galileo, Descartes, Newton, Boyle)
What is Leukopoiesis?
Uncommitted stem cells in bone marrow also give rise to the
progenitor cells for the remaining blood cells & platelets…
-
Platelets: develop to the megakaryocyte stage in the bone
marrow, & are released as platelets in the circulation -
Neutrophils, monocytes, basophils: progenitor cells give rise
to these cells which are found in circulation -
Lymphocytes: derived from their own lineage of lymphocyte
stem cells in the bone marrow, which give rise to
lymphocytes in the circulation
What species was the first recorded blood transfusion between?
dog -> dog
Neutrophils, Eosinophils and Basophils are a type of (1), which are all types of (2).
- Granulocytes
- Leukocytes
Which species was used for the first human blood transfusion
lamb
What years were the first successful human blood transplants?
1800-1900s
What are the three functions of the circulatory system?
- Transportation of substances essential for cellular metabolism (respiratory, nutritive, excretory)
- Regulation (hormonal and temp.)
- Protection (from injury and pathogens)
Lymphocytes, Monocytes, and Macrophages are a type of (1), which are all types of (2).
- Agranulocytes
- Leukocytes
What are the key characteristics of Neutrophils?
i.e. morphology, stain, and function
- Morphology: segmented nucleus with 2-5 lobes
- Stain: cytoplasmic granules stain slightly pink
- Function: immunity (early first responders to infections, and phagocytose ~5-20 bacteria during their short lifespan)
What are the key characteristics of Basophils & Mast Cells?
i.e. morphology, stain, abundance and function
- Morphology: lobed nucleus
- Stain: cytoplasmic granules stain blue in hematoxylin dye
- Abundance: most abundant leukocyte (make up 54-62% of white blood cells)
- Function: inflammatory reactions & allergies (release anticoagulant heparin to slow blood clotting, and histamine to increasing blood flow to tissues)
What are the key characteristics of Eosinophils?
i.e. morphology, stain, abundance and function
- Morphology: bilobed nucleus
- Stain: cytoplasmic granules stain bright red
- Abundance: make up ~1.3% of white blood cells
- Function: defence against parasites (in GI tract, lungs, urinary & genital epithelia – attach to large, antibody-coated parasites & release substances from granules to damage/kill)
What are the key characteristics of Monocytes & Macrophages?
i.e. morphology, abundance and function
- Morphology: 2-3 times larger than RBCs
- Abundance: make up ~3-9% of white blood cells
- Function: phagocytic (primary tissue scavengers that are larger & more effective than neutrophils – ingest 100 bacteria per lifetime and remove debris such as old RBCs & dead neutrophils)
What are the key characteristics of Lymphocytes?
i.e. morphology, abundance and function
- Morphology: only slightly larger than RBCs
-
Abundance: make up ~25-33% of white blood cells (~5% are circulating while the rest are in tissues encountering
pathogens) - Function: Immune response (Natural killer [NK] cells, T lymphocytes [T cells], B lymphocytes [B cells])
What is hematopoiesis?
Formation of blood cells
Where do hematopoietic stem cells originate?
embryo
What is the major hematopoietic organ after birth
bone marrow
Which are the most abundant blood cells?
Red blood cells
What is found after centrifugation of the blood and where are they found in the tube?
- RBCs packed at the bottom
- WBC, platelets in the middle
- Plasma fluid at the very top
What is erythropoiesis?
- when uncommitted stem cells go through a series of stages in the bone marrow
- once the nucleus is expressed, the reticulocyte forms and the cell is released into the circulation where it becomes a mature RBC (erythrocyte)
- one the nucleus is expelled, the reticulocyte moves into circulation and becomes an RBC
Where are basophils found?
in circulation in low numbers (make up <1% of
WBC)
Where are mast cells found?
in tissues
What is the most abundant leukocyte?
neutrophils (make up 54-62% of
white blood cells)
What is the shape of erythrocytes?
- cytoskeleton creates a concave shape
- flexible - swell in hypotonic, shrink in hypertonic
- illnesses can impact RBC shape ie: sickle cell anemia
What are the steps of Neutrophil Extravasation?
- Roll along endothelial wall
- Are tethered, captured, & activated
- Crawl to exit sites (endothelial cell junctions)
- Exit sites open due to signals between leukocytes & endothelial cells
How is most O2 found in the blood?
bound to hemoglobin in RBCs
What gives blood its red colour?
hemoglobin
What is an RBC made up of?
- 4 globin proteins (2 alpha, 2 beta)
- each globin protein has a heme group binding an iron molecule
What is the function of hemoglobin?
- aids in O2 delivery to tissues
- Heme iron combines with O2 in the lungs and releases oxygen into tissue
What is the equation for the arterial O2 carrying capacity in the blood?
O2 bound to Hb + unbound
How many molecules of oxygen can each RBC carry?
over a billion (280 million Hb molecules / RBC x 4 heme groups)
What does oxygen saturation depend on?
location
What percentage of hemoglobin is saturated with oxygen (oxyhemoglobin) in the systemic arteries? Leaving in systemic veins?
97% ; 75% (ie: 22% of oxygen is unloaded to tissues
From a volume perspective, how much O2 does blood entering and leaving tissues contain?
200mL O2/L blood ; 155mL O2/L blood (ie: 45mL O2 unloaded to the tissues)
What physiological factors can change Hb conformation and impact O binding?
- Decrease in pH decreases affinity for O2 - more O2 offloaded into tissues
- Increase in temp. decreases Hb affinity for O2 - more offloaded into tissues - bond between O2 and Hb is weakened
Where are monocytes found?
found in the bloodstream
Where are macrophages found?
in tissues
monocytes are precursors for…
macrophages (monocytes enlarge & differentiate into macrophages during their 8 hour commute from blood to tissue)