RBCs, WBCs and Immunity Flashcards
♣ Vehicle of transport for gases, nutrients, Hormones and metabolic wastes
♣ Regulation of pH and ion composition of interstitial fluids
♣ Defense against toxins and pathogens
♣ Stabilization of body temperature
General Functions of Blood
♣ Fluid medium of the blood/non cellular part of the blood
♣ It is where the cells are suspended
Plasma
♣ Plasma minus clotting proteins
Serum
♣ Collectively, plasma proteins exert a colloidal osmotic pressure (oncotic pressure) within the circulatory system
♣ are nearly derived from the liver (primary source of plasma proteins) with the exception of immunoglobulins (which are derived from plasma cells)
Plasma Proteins
Formed Elements are made in the Bone Marrow via the process called
Haemopoiesis
♣ 1st site of blood cell production during 3rd week of fetal embryologic development
Yolk Sac / Aorta Gonad Mesonephros (AGM) Region
♣ Chief site of blood cell formation until shortly after birth
♣ begins during the 3rd month of embryogenesis
♣ with minor contribution from spleen and lymph nodes
Liver
♣ only source of hematopoiesis postnatally
♣ begins during the 4th month of development
Bone Marrow
♣ marrow throughout the skeleton remains red and hematopoietically active
Birth to Puberty
♣ only vertebrae, ribs, sternum, skull, pelvis & proximal epiphyseal regions of the humerus retain red marrow remaining marrow becomes yellow, fatty & inactive
Age 20 and Above
Chief Site of Blood Formation PRE-NATALLY
Liver
Chief Site of Blood Formation POST-NATALL
Bone Marrow
♣ most abundant of blood cells
♣ it gives the whole blood its characteristic
♣ functions
1. it transports hemoglobin (carries oxygen) from lungs to tissues for use
2. it transports CO2 (in the form of bicarbonate ion or HCO3-) from tissues to lungs for expulsion
Red Blood Cells (Erythrocyte)
an enzyme that catalyzes the reaction between co2 and h20 to form carbonic acid or h2co
Carbonic Anhydrase
Protein responsible for giving RBC its biconcave shape
Spectrin
is the protein inside the RBC that binds with oxygen
Hemoglobin
is the % of whole blood occupied by cellular elements
Hematocrit
is composed of a 4 polypeptide subunits (2 alpha units and 2 beta units)
Adult Hemoglobin (HbA)
(2 Alpha & 2 Gamma chains) ist most common form of hemoglobin during fetal life
Fetal Hemoglobin (HbF)
an enzyme that causes Shift to the Right of the O2-HgB dissociation curve or increased unloading of O2 compared to HbA
2,3 BPG
♣ iron is an essential metallic component of heme
♣ total iron in the body is 4-5 g
65% hemoglobin (majority)
4% myoglobin
1% in various heme compounds that promote intracellular oxidation
Iron Metabolism
Hormone responsible for RBC production and maturation
EPO (Erythropoietin)
Stimulus for EPO production
Hypoxia
Transport of Iron in the blood
Transferrin
1 storage protein in excess iron in liver
Ferritin
Secondary/supplementary storage for iron
Hemosiderin
one that gives urine its yellow color
Urobilin
one that gives stool its yellow color
Stercobilin
Role of Vitamin B12 and Folic Acid in RBC Formation
♣ Both are essential for the synthesis of DNA
- formation of thymidine triphosphate, building block of DNA
♣ Vitamin B12 or Folic Acid deficiency causes:
- Abnormal or diminished DNA
- Failure of nuclear maturation and cell division in a developing RBC
macrocytes with flimsy membranes that are oval in shape and irregular
Megaloblastic Macrocytic Anemia
Vitamin B12 Deficiency will also cause
Neural Deficits
Folic Acid Deficiency will also cause
Neural Tube Disorder
is the capability of the body to resist almost all types of organisms or toxins that tend to damage tissues and organs
Immunity
Types of Immunity
- Innate Immunity
2. Acquired Immunity
natural immunity; not specific; unlearned; first line
Innate Immunity
second line; specific; learned
Acquired Immunity
♣ Most common type
♣ Acute inflammatory response to tissue injury (degrade tissue components, destroy damaged tissue and kills bacteria)
♣ Prominent feature: Highly lobulated nucleus
Neutrophils
♣ Weak phagocytes
♣ Parasitic infections
♣ Allergic reactions - Eosinophilic chemotactic factor: released by mast cells and basophils causes eosinophils to migrate to inflammed allergic tissue
♣ Prominent feature: bilobed nucleus, stain bright red with eosin dye
Eosinophils
♣ Least common type
♣ Share functional similarities with Mast Cells
♣ Produces histamine, heparin, bradykinin, serotonin
♣ Allergic reactions: IgE
♣ Prominent feature: bilobed/trilobed nucleus, largely densely basophilic (blue) granules
Basophils
♣ Largest of WBC
♣ Tissue: macrophages
♣ Resident phagocytes
♣ Prominent feature: eccentrically placed nucleus
Monocytes
♣ Small, non-nucleated cells from megakaryocytes
♣ Not part of WBC, not involved in immunity
♣ Involved in Hemostasis
♣ Life span: 7-10 days
Platelets
♣ 2nd most common type
♣ Cells of adaptive immunity
♣ T cell (thymus) or B cell (bone marrow)
♣ Smallest of WBC
♣ Prominent feature: round, densely stained nucleus with a pale basophilic, non-granular cytoplasm
Lymphocytes
What is the largest WBC?
Monocyte
What is the most numerous, least numerous WBC?
♣ Most numerous: Neutrophils
♣ Least numerous: Basophils
What are the cells involved in adaptive immunity and parasitic infections?
♣ Adaptive Immunity: Lymphocytes
♣ Parasitic Infections: Eosinophils
Can phagocytize up to 100 bacteria; can engulf larger particles (e.g. RBCs, Plasmodium); can extrude these particles and survive after for months
Macrophages
Can phagocytize 3-20 bacteria before dying
Neutrophils
Movement of neutrophils and macrophages towards a CHEMICAL SIGNAL (bacterial toxins, products of inflammation, complement cascade, products from clotting)
Chemotaxis
Movement out of the circulatory system and into the site of injury
Diapedesis
Mechanisms of INNATE IMMUNITY
Mast Cells: will release histamine causing vasodilation and increased vascular permeability
Tissue Macrophages
- 1st line of defense
Neutrophils
- 2nd line of defense
- Will start migrating in response to inflammatory cytokines
- Cause Phagocytosis
Monocytes
3rd line of defense
- This response takes time (at least 8 hours)
Inc Monocytes & Granulocyte production by BM
- 4th line of defense
- Takes 3-4 days
- Mediated by TNF, IL-1, GM-CSF,M-CSF
♣ is caused by a special immune system that forms Antibodies and/or activated lymphocytes that attack and destroy the specific invading organism or toxin
Adaptive Immunity
♣ Are gamma globulins called immunoglobulins
♣ Constitute 20% of plasma proteins
♣ Formed by Plasma Cells (activated B-Cells)♣ Variable Portion: determines specificity to antigen
♣ Constant Protion: determines other properties of antibodies
Antibodies
Divalent antibody,75% of antibodies (most abundant); predominant antibody in secondary responses; smallest (only one able to cross the placenta)
IgG
Main immunoglobulin concerned with primary immune response; present on all uncommitted B cells; largest
IgM
Main immunoglobulin in secretions (milk, saliva, tears, respiratory, intestinal and genital tract)
IgA
Antibody mediated allergies and hypersensitivity
IgE
Acts as an antigen receptor when present on the surface of certain B lymphocytes
IgD
Mechanisms of Action of Antibodies DIRECTLY
Agglutination: clumping
Precipitation: insoluble antigen-antibody complex
Neutralization: AB covers the toxic sites of the antigenic agent
Lysis: rupture of the agent
Mechanisms of Action of Antibodies INDIRECTLY
Via complement system
♣ Part of your innate and adaptive immunity
♣ Complement proteins are soluble proteins in the blood stream
Complement System
Complement System responsible for 3 things
- Opsonization: serve as marker that makes it easier to phagocytize foreign bodies
- Membrane Attack Complex: perforate foreign organisms
- Stimulate Inflammation
Which complement is responsible for opsonization?
c3b
Which complement is an anaphylatoxin (induces inflammation)?
c3a, c4a, c5a
Which complement is chemotactic to WBCs?
c5a
Which complement is part of the Membrane Attach Complex (MAC)?
c5b to c9b
Types of T cells
♣ T- Helper Cells (CD4, MHC II)
♣ Cytotoxic T Cells (CD8, MHC I)
♣ Suppressor T Cells
♣ Most numerous of T cells
♣ Various “helper” functions
Ð Regulatory function of lymphokines (IL-2, IL-3, IL-4, IL-5, IL-6, G-CSF, Interferon gamma)
Ð Stimulation of growth and proliferation of Cytotoxic T cells & Suppressor T – cells
Ð Stimulation of growth and differentiation of B-cell & antibody formation (IL-4,IL-5&IL-6)
Ð Activation of macrophage system
Helper T cell
♣ Direct attack cell capable of killing microorganisms
♣ Create “holes” (perforins)
♣ Targets virally infected cells, cancer cells, transplanted cells
Cytotoxic T cell
♣ Regulatory function by suppressing action of Helper T cells and Cytotoxic T cells
♣ Plays an important role in limiting the ability of the immune system to attack a person’s own body tissue
Suppressor T cells
- Induced after contact with foreign antigen (usually killed or live attenuated infectious agents)
- Advantage: long term protection
- Disadvantage: slow onset of action
Active immunity
- Administration of antibody (in antisera) in a vaccine
- Advantage: prompt availability of large amount of antibodies
- Disadvantage: short life span of antibodies, hypersenstivity reaction
Passive immunity
