a series of complex enzymatic reactions designed to activate specific coagulation proteins; most are plasma proteins
Activated in a stepwise/cascading fashion
-similar to knocking over dominos
The coagulation proteins are enumerated with Roman numerals (I, II, IV, IX, VIII, etc.)
clotting /coagulation factors
The dominos in in the coagulation game
once one is activated, the new active form stimulates the next factor, which activates the next and so on.
Most of these factors are synthesized in the Liver.
There are two separate pathways to activate ____________, and they merge to form a common _________.
coagulation, pathway
What are the two pathways to activate coagulation?
Extrinsic pathway
Intrinsic
They merge at the common pathway
Extrinsic pathway
activated by damage outside of the vessel, specifically tissue
Tissue factor (TF) or tissue thromboplastin is a tissue protein that is released from the damaged tissue into the blood.
This pathway has fewer steps and occurs rapidly
stages of coagulation
Merge at the common pathway
-Formation of prothrombinase
Formation of thrombin from prothrombin (factor II)
Formation of fibrin from fibrinogen (factor I)
Fibrin forms the clot and strengthens the platelet plug
Ca++ plays a role throughout almost every step of the clotting process.
Fibrin proteins are the threads that form the _____ and strengthen the _______ ____.
clot, platelet plug
What are some examples of cofactors that must be present for clotting factor synthesis and for coagulation to occur?
Vitamin K: helps in the synthesis of clotting factors II, VII, IX, and X.
Calcium: required as a cofactor for almost every step of the coagulation process.
Plasma vs. Serum
They are almost the same liquid: side by side they look the same
Serum: The liquid portion of clotted blood
-if the sample has clotted, the clotting factors have been utilized
Plasma: The liquid portion of unclotted blood
-if a sample of blood hasn't been aloud to clot, it still has available clotting factors.
What are the three kinds of clots?
Thrombus: stationary blood clot
Embolus: a circulating particle, often a clot that may obstruct a blood vessel
-can be fat, air, cholesterol plaque, blood clump or platelets, etc.
Thromboembolus: A stationary clot (Thrombus) That dislodged from its primary site and traveled to another location.
Fibrinolytic System
The "un-clotting" system
As coagulation occurs, tissue and activated clotting factors, result in the conversion of plasminogen to plasmin.
Plasmin: a very potent proteolytic enzyme
-it dissolves the clot by digesting fibrin
-interferes with new clot formation by inactivating fibronogen, prothrombin, and other clotting factors.
Anticoagulants
Given to people who are prone to forming clots
commonly referred to as Blood-thinners
But they do not change the viscosity of the blood, and they don't decrease a persons hematocrit, (do not thin the blood)
they inhibit coagulation
What are some examples of anticoagulants and their uses?
Heprin: Administered intravenously to a stroke or heart attack victim
Coumadin (warfarin): oral medication used to inhibit clotting in high-risk patients
EDTA: Present in blood-draw tubes used for blood counts.
Sodium Citrate: Present in blood collection bags for blood donation.
Aspirin: Inhibits platelet aggregation
True or false
Warfarin is not just used in people. It is used as a pesticide, specifically a rodenticide to control mouse and rat populations.
True.
-D-Con is a common example
-it is not a mouse poison, it is a mouse anticoagulant. The mouse consumes enough over time until they have a lethal dose. Without the ability to clot they, will simply bleed to death.
Thrombolytics
chemicals used in medicine that breakdown clots that have already formed.
-Stroke, myocardial infraction, emboli, and thrombi
Tissue-plasminogen activator (TPA)
Antigens
Specific cell markers that indicates the blood type.
See objective 17 p. 721
True or False
A person is born with either A or B antibodies
false.
-A person isn't born with A and B antibodies but they are formed shortly after birth (within 6 months)
-research doesn't know what causes this, but the current theory is that the immune system reacts to something in the environment that appears, like an A and/or B antigen.
A gene/A blood type
A antigens
B antibodies
B gene/ B blood type
B antigens
A antibodies
A and B genes/ A and B blood type
A and B antigens
no A or B antibodies
Neither A or B gene/ O Blood type
Neither A or B antigens
Neither A or B antibodies
Rh Factor
The Rh blood type identifies whether a person has the Rh antigen or not
If they have it, they are Rh+, if they don't they are Rh-
85% of the population has the Rh antigen (Rh+).
People do not normally have antibodies to the Rh antigen in their plasma
Rh- people can develop anti-Rh antibody if they are ever exposed to Rh+ blood
-This is because they don't have the antigen and it is foreign to them.
True or false
99% of blood transfusions are just red blood cells
True
it is very rare for a person to receive whole blood.
Transfusion
RBCs from a donor are given to a needy recipient
-When receiving blood, the patient doesn't want to see any antigens they haven't seen before, or any that they have antibodies for, or the newly transfused RBCs will be flagged for destruction by the immune system.
-Giving the wrong type of blood can cause the patient to develop a fever, go into shock, result in acute renal failure.
Universal Donor
Blood type O
there are no A or B antigens on the RBCs
There aren't any A or B antigens to react with
Universal recipient
Blood type AB
don't have any A or B antibodies in their plasma.
See obj. 18 p.724
Hemolytic disease of the newborn (HDN)
caused by a blood incompatibility between a fetus and an expectant mother.
The mother is producing an antibody against the antigens on her child's RBc
Normally a babies blood never mixes wqith a mother's
if there are any antigens the mother doesn't recognize as hers, she can make an antibody against it.
Throughout the pregnancy, a mother is transferring antibody to the fetus to protect against the disease.
As long as these antibodies are not targeting baby's cells, this relationship works great.
What is the most serious cause of HDN?
An incompatibility with Rh
The problem arises if :
-Dad is Rh+
-Mom is Rh-
-baby is Rh+, due to the genetics inherited from the father.
how can you avoid RH incompatibility?
Mother's who are Rh- are given an injection of Rhogam
Rhogam is commercially produced anti-Rh
This flags any Rh+ cells in the mother, from the baby, to be destroyed before the mother's immune system can produce its own anti-Rh
see obj.19 p.725
Lymphatic system
a system throughout the body made up of lymphatic vessels and supporting organs that drain excess interstitial fluid, transport dietary lipids, and facilitate immune responses.
What is included in the Lymphatic system?
Lymphatic capillaries
Lymphatic vessels
Lymphatic nodes
Lymphatic trunks
Lymphatic ducts
Primary lymphatic organs (bone marrow and thymus gland)
secondary lymphatic organs and tissues (spleen)
Lymphatic vessels
carry lymphatic fluid (lymph) one way, from the tissue, back to the blood stream.
Lymphatic capillaries
Lymph vessels start out as these
they are located throughout the body in the interstitial spaces
They have overlapping endothelium that allows interstitial fluid in, but not out
if pressure in the interstitial space is high, fluid flows in; of it is low, the flaps close and fluid doesn't enter
As _________ _________ converge, they form larger lymphatic vessels. Lymphatic vessels have _____ walls and ______ to encourage ____-____ fluid movements.
lymphatic capillaries, thin, valves, one-way
Lymph nodes
are present at intervals along the lymphatic vessels
They provide an opportunity for the lymphatic fluid to come into contact with the immune system
The immune system gets a continuous flow of info about what is taking place in the body.