HEMATOLOGY 2 - PAGE 1 TO 25 (IN HOUSE REVIEW)

Hemostasis

This is the term for the maintenance of blood flow within the vascular system.

1 to 5 minutes

Pressure Bandage

For blood collection for hemostasis testing if the patient has many bruises or mentions a tendency to bleed the phlebotomist should extend the time for observing the venipuncture site from ____ to _____ minutes and should apply a __________ before dismissing the patient.

Factors V and VIII

These factors are labile and they degrade rapidly at room temperature must be tested promptly or stored properly.

1. Precipitation: Factors VII, IX, X, XI (Vitamin K-dependent), and Fibrinogen

2. Activation: Factor VII

3. Destruction: Factors V and VIII (Labile factors)

Cold temperature (1 to 6°C) storage causes these reactions to what factors:

1. Precipitation:

2. Activation:

3. Destruction:

0.105 to 0.109 M (3.2%) buffered Sodium Citrate

Preferred % anticoagulant for coagulation testing. This bind to calcium to prevent clotting.

CTAD:

1. Citrate

2. Theophylline

3. Adenosine

4. Dipyridamole

These 4 anticoagulants is used to prevent platelet activation. PF4 and beta-TG (beta-thromboglobulin) assays.

Hemolysis

Excessive Agitation

Prolonged Tourniquet Application

Excessive needle manipulation

Platelet contamination

5 factors that may shorten coagulation test results (PT and APTT)

9:1 ratio

Blood to anticoagulant ratio for Sodium Citrate.

Underfilled/short-draw specimen
High hematocrit (>55%)

2 factors that may prolonged coagulation test results (PT and APTT)

C = (1.85 X 10^-3) (100-H) V

Patients whose hematocrit is high the anticoagulant must be adjusted by what formula:

C is the volume of sodium citrate in milliliters

V is volume of whole blood-sodium citrate solution in milliliters

H is the hematocrit in percent

Petechiae

Related term for Hemostasis that is described as a small pinpoint hemorrhages into the skin

Purpura

Related term for Hemostasis that is described as a larger hemorrhagic lesions than petechiae.

Ecchymosis (Bruise)

Related term for Hemostasis that is described as a larger area of blood extravasation into the skin/subcutaneous tissue.

Epitaxis

Fancy word for nosebleeding.

Hemarthrosis

Term for a hemorrhage into a joint.

Hemoptysis

Term for expectoration of blood from some part of the respiratory tract.

Hematemesis

Term for vomiting of blood.

Menorrhagia

Term for unusually heavy or prolonged menstrual periods.

Hematochezia

Term for passage of fresh blood per anus, usually in or with stools.

Melena

Term for passage of black, tarry stools.

Thrombosis

This is the term for pathological formation of blood clots in veins/arteries that obstruct blood flow.

Hypofibrinogenemia

Term for reduced levels of fibrinogen in the blood

Dysfibrinogenemia

Term for fibrinogen that does not function normally or optimally.

Platelet Adhesion and Platelet aggregation

(Remember: Vessel - Platelet Adhesion - Activation - Aggregation - Primary platelet plug.)

Primary Hemostasis includes these two mechanism.

Coagulation and Fibrin formation

(Remember: Coagulation factors - Thrombin - Fibrin - Stable clot)

Secondary Hemostasis includes these two mechanism.

Tunica intima

One of the coats composing the tissue in a blood vessel wall. This is also known as tunica interna. Forms the smooth glistening surface of endothelium that lines the inner tubular cavity.

Tunica media

One of the coats composing the tissue in a blood vessel wall. This is the thickest coat. It is composed of smooth muscle and elastic fibers.

Tunica adventitia

One of the coats composing the tissue in a blood vessel wall. This is also known as tunic externa. It is composed of fibrous connective tissue that contain autonomic nerve endings and the vasa vasorum.

Arteries (Size: 4mm)

Type of blood vessels that leaves the heart. These have the thickest walls of the vascular system

Arterioles (30 micrometer)

This is the microscopic continuation of arteries that give off branches called meta______, which in turn join the capillaries.

Veins (Size: 5mm)

Type of blood vessels that returns to the heart, This is larger than its counterpart and have a more irregular lumen than its counterpart.

Venules (Size:20 micrometer)

Microscopically sized veins, connect the capillaries to the veins.

Capillaries (8 micrometer)

Type of blood vessel where the blood passes from the arterial to the venous system. The thinnest walled and most numerous among the blood vessels. Composed of one cell alter of simple squamous epithelium.

Sinusoid

Specialized type of capillaries found in the locations such as the bone marrow, spleen, and liver.

Prostacyclin or Prostaglandin

This substance is a potent vasodilator and inhibitor of platelet aggregation. Penetrates the platelet and bind its IP receptor.

Eicosanoid pathway of endothelial cells.

Prostaglandin is produced by this pathway of endothelial cells,

Adenosine

This substance is a metabolic product of ATP and ADP. it also inhibits platelet aggregation.

Thrombomodulin (TM)

A substance that is a thrombin cofactor. This binds thrombin and reduces its ability to participate in the clotting process.

Protein C and TAFI (Thrombin activatable fibrinolysis inhibitor)

Thrombomodulin + thrombin activate these 2 substances.

Heparan Sulfate

This substance weakly enhances Antithrombin (previously called Antithrombin III)

Tissue plasminogen activator

This substance is a major plasminogen activator. This turn plasminogen into plasmin.

Plasmin

An activated plasminogen that is a serine protease that degrades fibrin clots called fibrinolysis

Von Willebrand Factor

This substance aids in platelet adhesion. Specifically it mediates platelet attachment to exposed subendothelial collagen. It also acts as a carrier/stabilizing protein for Factor VIII.

Endothelial cells (Specifically Weibel-Palade Bodies)

Megakaryocytes (Specifically alpha-granules)

These two cell is the site of synthesis for VWF.

Endothelial cells (Weibel-Palade bodies)

Platelets (Alpha-granules)

These two are the site of storage for VWF.

ADAMTS13

A Von Willebrand factor-cleaving protease. This regulates the size of circulating VWF by cleaving ultra long VWF multimers into shorter segments.

Liver (Hepatic stellate cells)

The ADAMTS13 is a plasma enzyme secreted by these specific organ and cells.

Thrombotic Thrombocytopenic Purpura

This condition is usually associated with severe ADAMTS13 deficiency, resulting in accumulation of ultra large VWF multimers and platelet-rich microthrombi.

Platelets or Thrombocytes

Arise from a bone marrow cell called megakaryocytes. Important in both primary and secondary hemostasis. Described as cells with granular cytoplasm but no nuclear material.

Two days

Platelets is believed to enter the spleen initially where they remain for ____ days.

2/3

Approximately ___/___ of the total number of platelets are in the systemic circulation.

1/3

Approximately ___/___ of the total number of platelets are in the spleen.

9.0 days ± 1 day

Life span of platelets is approximately?

1. To form an aggregate plug of platelets to stop/slow blood loss

2. To participate in plasma coagulation

3. To preserve the endothelial lining of the blood cells.

3 major functions of thrombocyte.

Reticulated platelets or Immature platelets

This precursor appear in compensation for thrombocytopenia. It is a newly released for megakaryocytes and still contain RNA. Markedly larger than the usual platelets.

Reticulated platelets

This precursor can help differentiate bone marrow failure from peripheral destruction in thrombocytopenia and an early predictor of bone marrow recovery after chemotherapy and transplantation.

2.5 micrometer (Average)

This is the normal size of platelets.

Mean Platelet Volume

The average volume individual platelets in a specimen.

7.5 to 11.5 fL or 7 to 12 fL

Reference range of mean platelet volume (MPV)

EDTA

This anticoagulant causes swelling of platelets by 20% increase in MPB during the first hour.

Wiskot-Aldrich Syndrome

TORCH infections:

1. Toxoplasma

2. Other agents

3. Rubella

4. Cytomegalovirus

5. Herpesvirus

These 2 disorders is characterized by SMALL PLATELETS

1. Bernard-Soulier Syndrome

2. Gray Platelet Syndrome

3. MYH9 gene mutations

   1. Fechtner

   2. Sebastian

   3. Epstein

These 3 disorders is characterized by LARGE/GIANT platelets.

WAS: X-linked recessive

BSS: Autosomal recessive

GPS: Autosomal recessive

MYH9 Disorders: Autosomal dominant

Conditions on their type of inheritance:
WAS:

BSS:

GPS:

MYH9 Disorders:

Discoid with a smooth surface

Shape of the platelets when resting and circulating.

Irregular spiculated with pseudopods

Shape of the platelets when it is activated.

Lavender and granular

On a wright-stained PBS, platelets appear in this color and texture.

Chromomere

General part of the platelet where there is a central, darker, granular portion of the platelet containing alpha-granules, dense granules, cell organelles, and glycogen

Hyalomere

General part of the platelet where there is a the peripheral, lighter, non granular portion of the platelet containing microtubules and filaments. The open canalicular system is also there.

Megakaryocytopoiesis or Thrombopoiesis

A process in the bone marrow by which megakaryocytes develop from hematopoietic stem cell.

Thrombopoietin (TPO) or C-mpl Ligand

This substance stimulates megakaryocytopoiesis. This induces both the proliferation, maturation of megakaryocytes, and thrombocytopoiesis.

Liver

TPO is primarily produced by this specific organ.

MPL

TPO receptor site that is present at all maturation stages from BFU-Mega to Platelets)

Megakaryocyte

This is the largest cells in the bone marrow (50 to 100 micrometer)

Burst-forming unit (BFU-Meg)

Megakaryocyte progenitor that is the least mature. This participate in normal mitosis.

Colony forming unit (CFU-Meg)

Megakaryocyte progenitor that participate in normal mitosis. Middle stage of its life.

Light-density CFU (LD-CFU-Meg)

Megakaryocyte progenitor that is the most mature. Loses its capacity to divide and performs endomitosis.

Lymphocyte

The three megakaryocyte progenitor all look like this type of WBC

Endomitosis

A process of chromosome replication (DNA synthesis) without cytokinesis, resulting in polyploid cells.

MK-I stage (megakaryoblast)

Megakaryocyte precursor that is least differentiated. This cannot be reliably distinguished from myeloblasts or pronormoblasts (Light microscopy). This is where it begins to develop most of its cytoplasmic ultrastructure (includes alpha-granules, dense grnaules, and the DMS)

MK-II stage (promegakaryocyte)

Megakaryocyte precursor that is identified by the appearance of nuclear lobularity.

MK-III stage (Megakaryocyte)

This is the most abundant megakaryocyte precursor. Easily recognized 10x magnification.

Platelet Shedding

At full maturation of MK-III stage this process starts to proceed to release platelet.

1,000 to 5,000 platelets

One megakaryocyte may shed _____ to ______ platelets.

Thrombopoiesis

Platelet shedding is also known this term of platelet synthesis.

Demarcation System

This is an extensive network of interconnected internal membranes in mature megakaryocyte that acts as a membrane reservoir to form platelets.

Platelet Plasma Membrane

This membrane is selectively permeable. It provides s phospholipids that support platelet activation internally and plasma coagulation externally.

Phosphatidylcholine and Sphingomyelin

The platelet plasma membrane provides these 2 type of neutral phospholipids that is found in the outer, plasma layer.

Phosphatidylinositol

Phosphatidylethanolamine and Phosphatidylserine

The platelet plasma membrane provides these 3 type of anionic or polar phospholipids that is found in inner cytoplasmic layer.

Phosphatidylinositol

This anionic or polar phospholipids support platelet activation by supplying arachidonic acid.

Phosphatidylethanolamine and Phosphatidylserine

These 2 anionic or polar phospholipids flips to the outer surface upon activation and is the charged phospholipid surface on which 2 coagulation pathway complexes assemble.

Tenase complex

Prothrombinase complex

This is the 2 complexes that assemble in the charge phospholipid surface by the Phosphatidylethanolamine and Phosphatidylserine.

Glycocalyx

The outermost layer of the platelet membrane, composed of glycoproteins, glycolipids, and proteoglycans. Contains receptors for platelet adhesion and activation. Absorbs albumin, fibrinogen, and other plasma proteins through endocytosis

Collagen

Glycoprotein Platelet membrane:

Electrophoresis Nomenclature = GPIa/IIa
Current Nomenclature = Integrin α2β1

What is this membrane receptor’s ligand?

Vitronectin

Glycoprotein Platelet membrane:

Electrophoresis Nomenclature = GPIa/IIa
Current Nomenclature = Integrin : αvβ1

What is this membrane receptor’s ligand?

Laminin

Glycoprotein Platelet membrane:

Electrophoresis Nomenclature = GPIa/IIa
Current Nomenclature = Integrin : α5β1

What is this membrane receptor’s ligand?

Fibronectin

Glycoprotein Platelet membrane:

Electrophoresis Nomenclature = GPIa/IIa
Current Nomenclature = Integrin : α6β1

What is this membrane receptor’s ligand?

GP VI

Glycoprotein Platelet membrane that is also known as the cell adhesion molecule of the immunoglobulin gene family.

GP Ib / IX / V

Glycoprotein Platelet membrane that is also known as the cell adhesion molecule of the leucine-rich repeat family.

GP VI

This Glycoprotein platelet membrane is a key collagen receptor. It triggers platelet activation and the release of TXA and ADP that increase the avidity of integrins α2β1 (GP Ia/IIa) and αIIbβ3(GPIIb/IIIa).

Von Willebrand Factor and Thrombin

2 ligand of GP Ib / IX / V.