Blood Physiology Flashcards
4 general functions of blood:
- Vehicle of transport
- Regulation of pH and ion composition of interstitial fluids
- Defense against toxins and pathogens
- Stabilization of body temperature
Fluid medium of the blood/non-cellular part of the blood
Plasma
Plasma minus clotting proteins; closer to water in composition
Serum
Whole blood is __% plasma and __% formed elements
55% plasma, 45% formed elements
Major component of plasma:
Water (90%) (plasma protein: 8%, inorganic salts 1%, lipids 0.5%, sugar 0.1%)
Plasma protein which is an essentail component of the clotting system
Blood coagulation proteins
Plasma protein which is the major contributor to osmotic pressure of plasma
Albumin
Plasma globulin: proteases, antiproteases, transport proteins
Alpha globulin
Plasma globulin: transferrin and other transport proteins
Beta globulin
Plasma globulin: immunoglobulin
Gamma globulin
Process of forming blood cells in the bone marrow
Hematopoiesis
Site of blood cell formation beginning from 3rd week AOG
Yolk sac/aortic gonad mesonephros (AGM) region
Site of blood cell formation from 3rd month AOG to birth
Liver (with minor contributions from spleen)
Only source of blood cells postnatally; begins at 4th month AOG
Bone marrow
Life period where all bone marrow are active
Birth to puberty
Life period where only bone marrow of vertebra, ribs, sternum, skull, pelvis, proximal epiphyseal region of humerus active
Age 20 (remaining bone marrow: fatty, yellow, inactive)
Post embryonic extramedullary hematopoiesis in full term infant
Always abnormal
Functions of the red blood cells
Transports hemoglobin from lungs to tissues
Transports CO2 (bicarbonate ion) from tissue to lungs
Acts as an acid-base buffer (contains carbonic anhydrase)
Normal biconcave disc shape of the RBC is due to:
Spectrin
Deformability of the RBC that allows it to travel through narrow capillaries is a characteristic called:
Bag pliability (Normal RBC size: 6-8 micrometers)
Protein inside the RBC that binds with oxygen
Hemoglobin
Males: 14 - 18 g/dL
Females: 12 - 18 g/dL
Percent of cells in whole blood
Hematocrit
Males: 46 (40 - 54)
Females: 42 (37 - 47)
Hemoglobin vs Myoglobin:
Transport protein for O2
Hemoglobin
Hemoglobin vs Myoglobin:
Storage protein for O2
Myoglobin
Hemoglobin vs Myoglobin:
Binds with 4 O2
Hemoglobin
Hemoglobin vs Myoglobin:
Binds with 1 O2
Myoglobin
Hemoglobin vs Myoglobin:
Exhibits sigmoidal curve, positive cooperativity
Hemoglobin
Hemoglobin vs Myoglobin:
Exhibits hyperbolic curve
Myoglobin
Most common form of hemoglobin in adult human
Hemoglobin A (2 alpha and 2 beta)
Hemoglobin form with higher affinity for oxygen
Hemoglobin F (2 alpha and 2 gamma)
Hemoglobin form with higher affinity for 2,3 BPG
Hemoglobin A
Total iron in the body:
4-5 g (65% hemoglobin, 4% myoglobin)
Primary storage protein found in the liver
Ferritin
Transport protein of iron:
Transferrin
Secondary storage protein found outside the liver such as macrophages
Hemosiderin
Last RBC stage that has a nucleus
Orthochromatic erythroblast
Form of RBC released into the blood; no nucleus; needs 2 days to mature into mature RBCs
Reticulocyte
Hormone stimulating RBC production
Erythropoietin
Main stimulus for EPO production
Hypoxia
Effect of EPO will manifest after this many days
5 days
Time to convert reticulocytes to mature RBCs
1 - 2 days
Characteristics of mature RBCs
No nucleus, no mitochondria, no ER
Lifespan of adult RBCs
120 days
Lifespan of fetal RBCs
90 days
Intravascular destruction of old or damaged RBCs occurs here
Spleen
Extravascular destruction of RBCs is due to
Macrophages
Fate of Heme in destroyed RBC
Bilirubin
Nutrient essential for DNA synthesis
Vitamin B12, Folic acid
Megaloblastic anemia + neural deficits
Vitmain B12 deficiency
Megaloblastic anemia + neural tube disorders
Folic acid deficiency
Needed to absorb Vitamin B12
Intrinsic factor
Needed to absorb Iron in the duodenum
Vitamin C
Sources of vitamin B12
Meats
Sources of folic acid
Leafy vegetables: cauliflower, brocolli
Capability of the body to resist almost all types of organisms and toxins that tend to damage tissues and organs
Immunity
Innate or Acquired:
Pre-existing (skin, mucous membranes, phagocytic cells, inflammatory mediators, complement system)
Innate
Innate or Acquired:
Antibody mediated/lymphoid cells
Acquired
Innate or Acquired:
Not acquired through contact with a non-self
Innate
Innate or Acquired:
Occurs after exposure to an antigen
Acquired
Innate or Acquired:
Non-specific
Innate
Innate or Acquired:
Specific
Acquired
Innate or Acquired:
Quick response
Innate
Innate or Acquired:
Delayed response
Acquired
Innate or Acquired:
1st line of defense
Innate
Innate or Acquired:
2nd line of defense
Acquired
WBC: Basophils, eosinophils, neutrophils
Granulocytes/PML/Myeloid cells
WBC: monocytes, lymphocytes
Agranulocytes
WBC: site of production of granulocytes, monocytes
Bone marrow
WBC: site of production of lymphocytes, plasma cells
LN, spleen, thymus, tonsils, Peyer’s patches
WBC: lifespan of granulocytes
4-8 hours in the blood, 4-5 days in tissues (shortened during infection)
WBC: lifespan of monocytes
10-20 hours in the blood, several months in the tissues
WBC: lifespan of lymphocytes
weeks to months
Lifespan of platelets
7-10 days
Most common type of WBC
Neutrophils (62%)
Lymphocytes: 30%, Monocytes 5.3%, Eosinophils 2.3%, Basophils 0.4%
Responsible for acute inflammatory response to tissue injury (degrade tissue components, destroy damaged tissue and kills bacteria)
Neutrophils
Prominent feature: highly lobulated nucleus
Neutrophils
Considered as weak phagocytes; for parasitic and allergic reactions; bilobed nucleus, stain bright red with eosin dye
Eosinophils
Released by mast cells and basophils which causes eosinophils to migrate to inflamed allergic tissue
Eosinophilic chemotactic factor
Least common type of WBC; produces histamine, heparin, bradykinin, serotonin; share functional similarities with mast cells; bilobed/trilobed nucleus
Basophils
Largest type of WBC; prominent feature: eccentrically placed nucleus
Monocytes (In tissue: macrophages)
Platelets are small, non-nucleated cells derived from:
Megakaryocytes
2nd most common type of WBC, smallest, involved in adaptive immunity
Lymphocytes
Round, densely stained nucleus with a pale basophilic, non-granular cytoplasm
Lymphocytes
Neutrophils are released as mature cells and can phagocytize ___ bacteria before dying
3 - 20 bacteria
Macrophages are release as immature cells and can phagocytize up to ___ bacteria, and can extrude these particles and survive after for months
up to 100 bacteria
Movement of neutrophils and macrophages towards a chemical signal
Chemotaxis
Movement out of the circulatory system and into the site of injury
Diapedesis
What is the requirement to say that diapedesis has occurred?
Invasion of the basement membrane
When tissue injury occurs, the first to react are the:
Mast cells - will release histamine causing vasodilation and increased vascular permeability
When tissue injury occurs, the 1st line of defense that present within minutes to identify and phagocytize the pathogen is:
Tissue macrophages
When tissue injury occurs, the 2nd line of defense which start migrating in response to inflammatory cytokines and cause phagocytosis is:
Neutrophils
When tissue injury occurs, the 3rd line of defense, which takes at least 8 hours for response to occur is:
Monocytes (blood monocytes (inactive) are converted to tissue macrophages (active))
When tissue injury occurs, the 4th line of defense, which takes 3-4 days is:
Increased monocytes and granulocytes production by bone marrow
Increase in monocyte and granulocyte production in response to tissue injury is mediated by:
TNF, IL-1, GM-CSF, M-CSF
Battlefiled of dead cells and pathogens
Pus
Caused by a special immune system that forms antibodies and/or activated lymphocytes that attack and destory the specific invading organism or toxin
Adaptive immunity
Gamma globulins called immunoglobulins which constitute 20% of plasma proteins, formed by plasma cells
Antibodies
The portion of the antibody which determines specificity to antigen
Variable portion
The portion of the antibody which determines other properties of antibodies
Constant portion
Divalent antibody, 75% of antibodies (most abundant); predominant antibody in secondary responses; smallest and the only one that can cross the placenta
IgG
Main immunoglobulin concerned with primary immune response; present on all uncommitted B cells; largest
IgM
Main immunoglobulin in secretions
secretory IgA
Antibody mediated allergies and hypersensitivity
IgE
Acts as an antigen receptor when present on the surface of certain B lymphocytes
IgD
Steps in the direct attack of antibody to the antigen
Agglutination (clumping)
Precipitation (insoluble antigen-antibody complex)
Neutralization (AB covers the toxic sites of the antigenic agent)
Lysis (rupture of the agent)
Indirect attack of antibodies is via the activation of:
Complement system
The complement system is responsible of 3 things:
Opsonization
Membrane attack complex
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 attack complex?
C5b - C9
T-helper cells is also known as:
CD4 cells (bind to MHC2)
Cytotoxic T cells is also known as:
CD8 cells (bind to MHC1)
Most numerous of T cells, responsible for activation of the macrophage system
T-helper cells
Responsible for the direct attack, capable of killing microorganisms, create holes (perforins)
Cytotoxic T cell
Three types of cells that CD8 T cells target:
Virally infected cells
Cancer cells
Transplanted cells
Has a regulatory function by suppressing action of helper T cells and cytotoxic T cells, limiting the ability of the immune system to attack a person’s own body tissue
Suppressor T cells
Type of immunity induced after contact with foreign antigen which confers long term protection, but with slow onset of action
Active immunity
Type of immunity by administration of antibody in a vaccine, that allows prompt availability of large amount of antibodies, however may present with hypersensitivity reactions
Passive immunity
Antigen present in Type A blood
N-Acetyl-Galactosamine
Antigen present in Type B blood
Galactose
Antigen present in Type AB blood
N-acetyl galactosamine, galactose
Antigen present in Type O blood
None
Antigen present in Rh+ blood
D antigen
Determined by genotype from mother and father
Agglutinogens
Spontaneously acquired from food, bacteria, etc; produced at 2-8 months, maximum titer at 8-10 years
Agglutinins
Blood type O has ____ agglutinogen and ____ agglutinins
No agglutinogen, Anti A and Anti B agglutinin
Blood type A has ____ agglutinogen and ____ agglutinins
A agglutinogen, Anti B agglutinin
Blood type B has ____ agglutinogen and ____ agglutinins
B agglutinogen, Anti A agglutinin
Blood type AB has ____ agglutinogen and ____ agglutinins
A and B agglutinogen, no agglutinin
Blood type with clotting in an anti-A serum
Blood type A
Blood type with clotting in an anti-B serum
Blood type B
Blood type with clotting in both anti-A and anti-B serum
Blood type AB
Blood type with no clotting in both anti-A and anti-B serum
Blood type O
4 types of organ transplantation:
autograft
isograft/syngeneic graft (identical twin)
allograft (same species; most common)
xenograft (other species)
Mechanism to prevent blood loss whenever a vessel is severed or ruptured
Hemostasis
Sequence of events in hemostasis
Vascular constriction (endothelin-1)
Platelet plug formation
Blood coagulatoin
Resolution: formation of fibrous tissue, or dissolution of clot
2 mediators of platelet adhesion:
vWF, glycoprotein Ib
2 mediators of platelet aggregation:
Fibrinogen, glycoprotein IIb-IIIa
Cascade of chemical reaction in response to vessel damage/trauma to blood results in formation of:
Prothrombin activator
What is the action of prothrombin activator?
Converts prothrombin (Factor II) to thrombin
What is the action of thrombin?
Converts fibronogen (Factor I) to fibrin
What is the action of fibrin?
Acts as a net/meshwork: trap platelets, blood cells and plasma; adhere to damaged endothelium
Pathway activated due to trauma to vascular walls; faster
Extrinsic pathway
Pathway activated due to trauma to blood cells or exposure of blood to collagen; slower
Intrinsic pathway
Extrinsic pathway is initiated by:
Tissue factor (Factor III/Tissue thromboplastin) Thrombin cause positive feedback via activation of Factor V
Intrinsic pathway is initiated by:
Factor XII and Platelets
Which clotting factors are common to both the extrinsic and intrinsic pathway?
Factors X, V
What factor is also called the Stuart factor?
Factor X
What factor is also called the Hageman factor?
Factor XII
What factor is also called the Christmas factor?
Factor IX
What substance converts plasminogen to plasmin?
Tissue plasminogen activator
The most crucial even in wound healing
Hemostasis
