HEMOSTASIS
Dr MOHAMMED H SAIEMALDAHR
FACULTY of Applied Medical
Sciences
@KAAU
MED TECH DEP
Room # 513 ext. 21060
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HEMOSTASIS
An overview of Haemostatic Mechanism,
Platelet structure and function,
Define the term hemostasis, coagulation,
fibrinolysis, and hemorrhage.
List the major and minor systems involved in
maintaining hemostasis.
Describe the events that take place in primary
hemostasis.
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HEMOSTASIS
List the function of the vascular system.
Describe the major functions of the endothelium.
Name the three structural zones of platelets.
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HEMOSTASIS OBJECTINES
Describe the composition and functions of the
peripheral zone, the sol-gel zone, and the
organelle zone.
Explain the role of platelets in the haemostatic
process.
List steps in platelet plug formation
Name essential elements for the process of
platelet adhesion.
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HEMOSTASIS OBJECTINES
Describe the process of platelet aggregation.
Describe the events take place in secondary
hemostasis.
Name the product responsible for stabilization
of the haemostatic plug.
List characteristics for the contact coagulation
proteins.
List characteristics for the prothrombin
proteins.
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HEMOSTASIS OBJECTINES
Interaction of the Fibrinolytic, Coagulation
Systems and Related Pathology.
Name the component of the coagulation and
fibrinolytic system.
List plasminogen activators and negative
feedback clotting mechanisms.
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HEMOSTASIS OBJECTINES
Describe plasmin’s action in forming the
intermediate degradation product, D dimer.
Name the primary inhibitor of the fibrinolytic
system.
Describe the physiologic interactions of the
proteolytic system.
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HEMOSTASIS OBJECTINES
Acquired coagulation disorders
Objectives
Following this conference, the student will be able to
Explain the classification of acquired disorder of
haemostasis such as:
Hepatic disease, vitamin K deficiency , renal disease,
haeorrhagic disease of the newborn, overdosage with
anticoagulant, massive transfusion syndrome.
Explain the action of oral anticoagulants
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HEMOSTASIS OBJECTINES
Acquired coagulation disorders
Objectives
Name the most common laboratory test used to monitor
oral anticoagulant therapy
List mechanisms and clinical conditions associated with
DIC.
Define the three generalized clinical states of DIC with
regard to the typical
Laboratory abnormalities associated with each state.
Describe the use of laboratory tests to distinguish
primary fibrnolysis from DIC.
Identify therapies for treatment of DIC
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HEMOSTASIS OBJECTINES
Quantitative and Qualitative Vascular and Platelet
Disorders.
Both Congenital and Acquired.
Congenital Disorder of platelet Function
1- Bernard Soulier Syndrome (BSs).
2- Glanzmann’s thrombasthenia
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HEMOSTASIS
Objectives.
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Definition of Hemostasis
Haemostatic components
Concepts of Normal Hemostasis
Role of Coagulation in Hemostasis
Primary and Secondary
Role of Blood Vessels in Hemostasis
Coagulation Proteins
Factor Nomenclature
Coagulation Groups
Phospholipids Contribution to Coagulation.
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Vessel wall, Blood flow & Coagulation Substances
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In Case if there is an Endothelial Injury
(Bleeding must be prevented at site of injury)
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Flow must be Maintained
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HEMOSTASIS
Definition
Hemostasis: drives from the Greek meaning “The
stoppage of blood flow”.
There are three haemostatic components:
1- The extra-vascular (The tissues surrounding blood
vessels) involved in Hemostasis when local vessel is
injured.
It plays a part in Hemostasis by providing back-pressure
on the injured vessel through swelling and trapping of
escaped blood.
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HEMOSTASIS
The three haemostatic components
2- The vascular (The blood vessels through which blood
flow) it depends on the size, amount, of smooth muscle
within their walls and integrity of the endothelial cell
lining.
3- The intra-vascular (The platelets and plasma proteins
that circulate within the blood vessels).
These components are involved in Coagulation (clot or
thrombus formation) or Fibrinolysis (clot or thrombus
dissolution).
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HEMOSTASIS
Concepts of Normal Hemostasis
Under normal conditions, the formation and dissolution
of thrombi is maintained in a delicate balance. (fig ).
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Without this balance, the individual may experience either excessive
bleeding (poor clot formation or excessive Fibrinolysis)
Vaso-occlusion (uncontrolled formation of thrombin in vascular system,
occluding vessels and depriving organs of blood).
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HEMOSTASIS
There are certain conditions associated with excessive
bleeding are referred to as: Hypo-coagulable states.
Such as, Hemophilia or deficiency in one of the plasma
coagulation proteins such as factors VIII.
Acquired conditions such as DIC, Liver and Kidney
diseases.
In addition to Coagulation promotion, vessel injury
initiates Fibrinolysis through endothelial cell release of
tissue Plasminogen activators (tPAS).
This is to ensure that excessive coagulation does not
occur.
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HEMOSTASIS
Role of Coagulation in Hemostasis
Coagulation: Is the process where by on vessel injury,
Plasma protein, Tissue factors and Calcium interact on
the surface of the platelets to form a Fibrin clot.
Platelets provide a surface for the coagulation reaction,
and interact with fibrin to form a stable platelet fibrin
clot.
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HEMOSTASIS
Tissue factors (except Ca and Tissue Thromboplastin)
normally circulate in the plasma as inactive proteins.
On activation some factors form enzymatic proteins
known as Seiren Proteases that activate other specific
factors in the coagulation sequence.
Other conditions are related to uncontrolled thrombosis
are called Hyper-coagulable state. This is related to an
appropriate formation of thrombi in the vascular vessels
that occlude normal blood flow.
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HEMOSTASIS
Hemostasis can be divided into two stages:
Primary and Secondary.
Primary hemostasis includes the platelet and vascular
response to vessel injury.
Secondary hemostasis includes the coagulation factors
response to such injury.
Together, platelets, vessels, and coagulation factors
combine to stop bleeding and allow for vessel repair
through formation of a stable fibrin-platelet plug at the
site of injury.
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HEMOSTASIS
Role of Blood Vessels in Hemostasis
Blood flows through the vascular system to and from all
parts of the body. The vascular system consists of
capillaries, arteries, and veins.
Blood normally carried within vessels whose physical
capabilities include Contraction (narrowing) and
Dilation, which are controlled by the smooth muscle of
the vessel media.
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HEMOSTASIS
Vasoconstriction and Vasodilatation provide the means
for control blood flow rate and blood pressure.
Substances released from the endothelial cells and subendothelial smooth muscles also contribute to normal
blood flow and prevent abnormal formation of clot.
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