HEMA Flashcards by Mariel Christha

FROM AN ANCIENT GRREK WORD THAT MEANS HEME (BLOOD) AND STASIS (HALTING/ STOPPING)

Hemostasis

How well did you know this?

Not at all

Perfectly

It involves the interaction of vasoconstriction, platelets, and coagulation system.

Hemostasis

How well did you know this?

Not at all

Perfectly

refers to the role of blood vessels (vasoconstriction) and platelets (formation of platelet plug) response to a vascular injury

Primary hemostasis

How well did you know this?

Not at all

Perfectly

blood vessels contract to seal the wound or reduce the blood flow, thus reducing the extent of blood loss

Vasoconstriction

How well did you know this?

Not at all

Perfectly

platelets become activated, adhere to the site of injury, secrete the contents of their granules, and aggregate with other platelets to form a platelet plug. The primary platelet plug that is formed is reversible.

Platelet plug formation

How well did you know this?

Not at all

Perfectly

describes the activation of a series of coagulation proteins in the plasma to form a fibrin clot
-with the help of fibrin, an irreversible platelet plug is formed

Secondary hemostasis

How well did you know this?

Not at all

Perfectly

coagulation proteins circulate as inactive zymogens (proenzymes) that become activated during the process of coagulation, and form complexes that activate other zymogens to generate thrombin, an enzyme that converts fibrinogen to a localized fibrin clot
The primary platelet plug must be reinforced by fibrin to control major bleeding in the long term

Coagulation cascade

How well did you know this?

Not at all

Perfectly

final event of hemostasis

- is the gradual digestion and removal of the fibrin clot as healing occurs

Fibrinolysis

How well did you know this?

Not at all

Perfectly

Activated by desquamation and small injuries to blood vessels

Primary Hemostasis

How well did you know this?

Not at all

Perfectly

Involves platelets and coagulation system

Secondary Hemostasis

How well did you know this?

Not at all

Perfectly

Involves the vascular intima and platelets

Primary Hemostasis

How well did you know this?

Not at all

Perfectly

Activated by large injuries to blood vessels and surrounding tissues

Secondary Hemostasis

How well did you know this?

Not at all

Perfectly

Delayed, long-term response

Secondary Hemostasis

How well did you know this?

Not at all

Perfectly

The activator, tissue factor is exposed on cell membranes

Secondary Hemostasis

How well did you know this?

Not at all

Perfectly

Procoagulant substances exposed or released by damaged or activated endothelial cells

Primary Hemostasis

How well did you know this?

Not at all

Perfectly

Involves the vascular intima and platelets

Primary Hemostasis

How well did you know this?

Not at all

Perfectly

Rapid, short-lived response

Primary Hemostasis

How well did you know this?

Not at all

Perfectly

soft tissue hemorrhage – a generalized bleeding that is seen in acquired or congenital defects in secondary hemostasis

Anatomic hemorrhage

How well did you know this?

Not at all

Perfectly

Pattern of inheritance in which the transmission of a dominant allele on an autosome causes a trait to be expressed in heterozygotes

Autosomal dominant

How well did you know this?

Not at all

Perfectly

Pattern of inheritance resulting from the transmission of a recessive allele that is not expressed in heterozygotes

Autosomal recessive

How well did you know this?

Not at all

Perfectly

Hemorrhagic spot, 1 cm or larger in diameter, typically forming an irregular blue or purplish patch. Also known as bruise

Ecchymoses

How well did you know this?

Not at all

Perfectly

Nosebleed that requires intervention

Epistaxis

How well did you know this?

Not at all

Perfectly

Bleeding from multiple sites, spontaneous and recurring bleeds, or hemorrhage that requires physical intervention of transfusion.

Generalized hemorrhage

How well did you know this?

Not at all

Perfectly

Chronic joint bleeds that cause inflammation and immobilization

Hemarthroses

How well did you know this?

Not at all

Perfectly

Vomiting of bright red blood

Hematemesis

Localized collection of extravasated blood, usually clotted, in an organ space or tissue

Hematoma

Intact RBCs in the urine

Hematuria

Free hemoglobin in the urine

Hemoglobinuria

Expectoration of blood secondary to hemorrhage in the larynx, trachea, bronchi and lungs

Hemoptysis

Acute severe blood loss requiring intervention and transfusions

Hemorrhage

Passage of fresh, red blood in your stool

Hematochezia

Bleeding from a single location

Localized hemorrhage

Stool containing dark red or black blood

Melena

Abnormally heavy or prolonged menstrual periods

Menorrhagia

Or systemic bleeding – a generalized bleeding that may indicate a disorder of primary hemostasis

Mucocutaneous hemorrhage

Pinpoint purple or red spots on the skin or mucous membranes, approximately 1mm in diameter

Petechiae

Purple skin discoloration, typically rounded with a diameter of greater than 3mm

Purpura

Purple skin discoloration, typically rounded with a diameter of greater than 3mm

Purpura

Formation, development, or presence of a clot in a blood vessel

Thrombosis

A blood clot that forms in a vessel and remains there

Thrombus

Plural of thrombus; could block the flow of blood

Thrombi

A blood clot that travels in circulation; a piece of blood clot that breaks off (thromboembolus)

Embolus

Plural of embolus

Emboli

There are 3 types of blood vessels

Arteries Veins Capillaries

are large thick-walled blood vessels that propel oxygen-rich blood away from the heart to the capillaries

arteries

are the smallest blood vessels.

Capillaries

have thinner walls than arteries and carry oxygen-poor blood, carbon dioxide, and other waste products back to back to the heart

Veins

The three layers of the blood vessels

Tunica externa Tunica media Tunica intima

- composed of connective tissue

Tunica externa

composed of a lining of epithelial cells

Tunica intima

composed of smooth muscle and elastic tissue

Tunica media

three key elements

intravascular component the vascular intima extravascular tissue factor

Provides the interface between circulating blood and the body tissues.

VASCULAR INTIMA

platelet inhibitor and a vasodilator

Prostacyclin

induces smooth muscle relaxation and subsequent vasodilation

Nitric oxide

controls the activation of the tissue factor pathway

Tissue Factor Pathway Inhibitor

- inhibitor of thrombin formation

Thrombomodulin

enhances activity of antithrombin- a serine protease inhibitor

Heparan sulfate

activates plasminogen into plasmin; degrades fibrin clot

Tissue plasminogen activator

regulates formation of plasmin | TAFI (Thrombin-activatable fibrinolysis inhibitor) -

Plasminogen activator inhibitor-1

Megakaryocyte progenitors | (arise from the common myeloid progenitor

Burst-forming unit (BFU-Meg) Colony-forming unit (CFU-Meg) Light-density CFU (LD-CFU-Meg)

``` CYTOPLASMIC GRANULES * Absent CYTOPLASMIC TAGS *Present NUCLEAR FEATURES *Single nucleus; fine chromatin structure, nucleoli THROMBOCYTES VISIBLE? *No Accdg to Rodaks -*Least differentiated - has plasma membrane blebs that resemble platelets ```

Megakaryoblast (MK-I)

``` CYTOPLASMIC GRANULES Few CYTOPLASMIC TAGS Present NUCLEAR FEATURES Double nucleus THROMBOCYTES VISIBLE? No Accdg to Rodaks Formation of DMS ```

Promegakaryocyte (MK-II)

``` CYTOPLASMIC GRANULES Numerous CYTOPLASMIC TAGS Usually absent NUCLEAR FEATURES Two or more nuclei THROMBOCYTES VISIBLE? No Accdg to Rodaks - Nucleus is intensely indented or lobulated ```

Megakaryocyte (MK-III)

``` CYTOPLASMIC GRANULES Aggregated CYTOPLASMIC TAGS Absent NUCLEAR FEATURES Four or more nuclei THROMBOCYTES VISIBLE? Yes ```

Metamegakaryocyte

Emphasis should be placed on the cytoplasmic appearance rather than the number of nuclei or the chromatin structure.

Problems in identification of Maturation Stage

normally develop close to the venous sinusoids so that platelet shedding is facilitated.

Megakaryocytes

It has been estimated that each megakaryocyte can shed ________________ platelets.

1000-4000

function as the mitotic spindle; Well-organized displacement.

Microtubules (Within megakaryocyte and megakaryoblast

Dispersed throughout the cell that passes through the platelet fields and cytoplasm in a random pattern; Random displacement

Microtubules (metamegakaryocyte)

Abundant but disorganized

Microfilaments (Immature megakaryocytes

Organized forming a pattern of microfilaments similar to that seen in platelet.

Microfilaments (Mature megakaryocytes)

consists of the platelets outer membrane and related structure

Peripheral zone

links the membrane and the inner cell body

Submembrane

– constitutes the matrix or muscle and skeletal portion of the platelet

Sol- gel zone

consists of granules, dense bodies, lysosomes, and mitochondria

Organelle zone

Consists of the surface coat or glycocalyx, plasma membrane, and submembrane area. Under homeostatic conditions, platelets circulate in the blood as discoid-shaped cells.

Peripheral zone

Underlies the submembrane filaments Randomly arranged microfilaments which contributes support to the plt discoid shape. Serves as a stable gel component to regulate the arrangement of the onternal organelles, and microtubular system within the resting plt body. Treatment of cooling or biochemical agents such as Prostaglandin (PG) I2 restores discoid shape (reappearance of microtubules).

Sol-Gel Zone

Constitutes the major portion of the platelet cytoplasm. These structures include electron-dense granules, a-granules, peroxisomes, lysosomes, and mitochondria.

Organelle zone

Contains adenosine, guanosine, diphosphates and triphosphates calcium, magnesium, and serotonin, ADP.

Dense granules

most important component; rapidly degraded to adenosine which inhibits platelet function by enhancing cAMP levels.

ADP

activation of membrane phospholipases which are Ca++ dependent and subsequent liberation of Arachidonic acid – the precursor of a number of metabolites re for plt function

Ca++

Larger than dense granules; releases coagulation factors, a permeability factor, and cationic proteins such as the PDGF. PF4 and B-thromboglobulin are also released, both of which bind heparin.

Alpha granules

Plt vesicles that contain a number of acid hydrolases

Lysosomes

Opens to the plt external environment

Canalicular system

Surface-connecting canalicular system (indented pores on the platelet surface) – serve as delivery routes for substances ingested by the platelet; as well as route of exit of substances released from the stimulated platelet.

Canalicular system

Channels are randomly dispersed and appear to be close to the circumferential band of microtubules.

Dense tubular system

DTS has an impt role in supporting the discoid platelet shape.

Dense tubular system

Lifespan of platelets is approximately

5 to 10 days.

At least 30% of total circulating platelet is normally sequestered in

spleen.

are hemostatically more effective.

Young platelets

Plasma transports at least 16 procoagulants

coagulation factors

Nearly all are glycoproteins synthesized in

liver

Eight are enzymes that circulate in an inactive form

zymogens

The plasma procoagulants may be

serine proteases or cofact ors

The plasma procoagulants may be serine proteases or cofact ors, except for factor XIII, which is a

transglutaminase .

thrombin (factor Ila); factors VIia, IXa, Xa, Xia, and Xlla; and pre-K.

• Serine proteases.

tissue factor, located on membranes of fibroblasts and smooth muscle cells, and soluble plasma factors V, VIII, and HMWK

Cofactors

: fibrinogen, factor XIII, phospholipids, calcium, and VWF.

Remaining components

is the ultimate substrate of the coagulation pathway

• Fibrinogen

Preferred name Prothrombin Synonym Prethrombin

Ill

Preferred Name Tissue Factor Synonyms Tissue thromboplastin

Preferred Name | Calcium

Preferred Name Proaccelerin Synonyms Labile factor, Accelerator globulin

VII

Preferred Name Proconvertin Synonyms Stable factor, Serum prothrombin conversion accelerator (SPCA), Autoprothrombin I

VIII : C

``` Preferred Name Antihemophilic factor (AHF) ``` Synonyms Antihemophilic globulin (AHG), Anti hemophilic factor A, Platelet cofactor 1.

Preferred name Plasma thromboplastin component (PTC) Synonym Christmas factor, Antihemophilic factor B, Platelet cofactor 2

Preferred name Stuart Prower factor Synonym Stuart factor, Prower factor, Autoprothrombin Ill

Preferred name Plasma thromboplastin antecedent Synonym Anti hemophilic factor C

XII

Preferred name Hageman factor Synonym Glass factor, Contact factor

XIII

Preferred name Fibrin stabilizing factor ``` Synonym Laki-Lorand factor , Fibrinase, Plasma transglutamimase, Fibrinoligase ```

Synonym of Prekallikrein

Fletcher factor

synonym of High molecular weight kininogen (HMWK)

Fitzgerald factor, Contact activation cofactor, Williams factor, Flaujeac factor

CONTACT GROUP

XII, XI, PK, HMWK

Prothrombin (Vitamin K- Dependent) Group

II, VII, IX, X

FIBRINOGEN GROUP

I, V, VIII, XIII

Synthesized by the liver in the presence of Vitamin K, which acts as a cofactor

II, VII, IX, X

Activated by contact with a negatively charged surface such as collagen or the subendothelium in vivo.

XII, XI, PK, HMWK

Highest molecular weights of all fact ors, most labile, and are consumed in coagulation

I, V, VIII, XIII

a large multimeric molecule that has two principal part s: the coagulant

Factor VIII (Vlll/vWF)

a co factor in Intrinsic pathway

coagulant portion (Vlll :C)

found in Pit alpha granules.

vWF portion (Vlll :vWF),

Morawitz's proposed thromboplastic factor is known

tissue factor or tissue thromboplastin.

It acts to control and balance the hemostatic mechanism by providing feedback mechanisms to achieve control of the coagulation process.

Thrombin

- principal regulator of the tissue factor pathway • Protein C Regulatory System - revises thrombin's function from a procoagulant enzyme to an anticoagulant

• Tissue Factor Pathway Inhibitor

first to be identified; inhibits Factor Ila, IXa, Xa, Xia, Xlla, PK, Plasmin

• Antithrombin

inactivates thrombin

• Heparin cofactor II

potent inhibitor of Factor Xa; also inhibits Factor Xia

• Protein Z-dependent protease inhibitor

inhibits APC, Ila, Xa, Xia, urokinase

• Protein C inhibitor