Exam 3

Kallikrein

Catalyzes the conversion of inactive plasminogen into the active molecule plasmin.

Warfarin

Creates a deficiency of reduced vitamin K by blocking Vitmain K epoxide reductase, thereby inhibiting maturation of clotting factors.

What can emboli cause?

Damaging obstructions (infarcts), or death, when they block blood flow.

Fibrous skeleton

Dense, non-conductive tissue, connective tissue between the atria and ventricles.

Athrosclerosis

Develops deep in the walls of the arteries and works its way to the lumen and destroys the overlying endothelium exposing collagen. From the inside. Narrowing of the walls.

Rivaroxaban (Xarelto)

Directly inhibits activated factor X are now available as alternatives to warfarin for some patients. Anticoagulant.

Consumptive coagulopathy (DIC)

Disorder go coagulation system. Potent stimulators trigger platelet aggregation and clotting cascade. As this happens in wide spread regions of the body you will consume your clotting proteins (fibrinogen and platelets) so much that you become deficient. because of descending coagulation you develop thrombocytopenia and an acute deficiency of fibrinogen and your other clotting proteins. Because of that, you start hemorrhaging.

Where does oxygen-rich blood in the left atrium go?

Enters the left ventricle and is pumped into a very large, elastic artery - the aorta.

Where does blood go after the right atrium?

Enters the right ventricle, which pumps it into the pulmonary trunk and pulmonary arteries.

What happens when one has Factor V Leiden?

Facto V becomes over active. Cannot be degraded properly and remains active, promoting coagulation.

The numerous small muscular arteries and arterioles of the systemic circulation presents what?

Greater resistance to blood flow than that in the pulmonary circulation.

How can you get clots in your brain?

Have something going on in the left side of your heart. Atrial fibrillation in the left side. Infarction in the left ventricle.

Two main types of anticoagulants?

Heparin and vitamin K antagonist(warfarin).

What kind of system is the left side, or systemic circulation?

High pressure system.

Vitamin K dependent clotting proteins?

II, VII, IX, X

Warfarin secondary characteristics

Important for preventing blood clot formation in people with atrial fibrillation and to treat venous thrombeombolism.

Largest vessel in the body

Inferior vena cava.

Factor V Leiden

Inherited genetic defect that can lead to abnormal activity of a clotting factor. Found in 5% of caucasian women.

Where does the right ventricle pump blood?

Into the short pulmonary trunk which quickly divides into the right and left pulmonary arteries.

How is Heparin administered? How long does it take to work?

Intravenously. Acts immediately.

Which clotting pathway is stimulated the most by collagen?

Intrinsic factor XII.

What happens to the blood that returns to the left atrium by the way of pulmonary veins?

It is enriched in oxygen and partially depleted of carbon dioxide.

Agents that convert plasminogen to active plasmin?

Kallikrein, Tissue plasminogen activator (TPA), Urokinase, and streptokinase (a bacterial enzyme).

What 2 structures are separated by the aortic semilunar valve?

Left ventricle and ascending aorta.

If you're bed ridden, in which particular vessels are thrombi likely to form?

Legs.

Bicuspid valve

Located between the left atrium and left ventricle, has two flaps. called the mitral valve bc it looks like a bishop's hat or mitre.

Tricuspid valve

Located between the right atrium and the right ventricle, has three flaps.

What kind of system is pulmonary circulation?

Low pressure system.

What can DIC be triggered by?

Obstetrical complication (Amniotic fluid embolism or retained dead fetus), infection (endotoxin, produced in infections with gram-negative bacteria is a potent stimulator of DIC), cancer, transfusion reaction.

Who are given anticoagulants?

Persons with a history of heart attack, stroke, or pulmonary embolism to reduce their clotting tendencies.

Why do birth control pills increase a women's risk to thrombi?

Pills that contain estrogen increase the chemicals needed for blood formation -> increasing risk of blood clots.

Why do clots break down?

Plasminogen became trapped within the clot when if formed; as it is slowly activated, it breaks down the fibrin mesh.

What is the key benefit of atria?

Preventing circulatory inertia and allowing uninterrupted venous flow to the heart.

Auscultation

Process of listening to internal sounds of the body.

Vitamin K

Produced by intestinal bacteria and is also found in leafy green vegetables.

Disseminated Intravascular Coagulation (DIC)

Progressive thrombosis and hemorrhage at the same time. Potent stimulation of coagulation enters the blood and stimulates wide-spread diffuse blood clotting which cen be so severe as to use up available platelets and clotting proteins (resulting in consumptive coagulopathy) so that hemorrhaging may ensue.

How can you monitor warfarin dosages?

Prothrombin time (PT) test

What is the second valve you would encounter when going through the trunk?

Pulmonary semilunar valve

Vitamin k epoxide reductase

Reduces vitamin K back to its active form.

Best treatments of DIC?

Remove the underlying cause. Then low dose of heparin and fresh frozen plasma to replace depleted clotting factors.

Four chambers of the heart

Right and left atria, Left and right ventricles.

What 2 structures are separated by the pulmonary semilunar valves?

Right ventricle and pulmonary trunk

Annuli fibrosi

Rings of connective tissue of the fibrous skeleton around the four heart valves, providing a foundation for the support of the valve flaps.

What would happen if you had one-way valves in the atria?

Severely reduced amount of blood flow.

What is different from the left and right chambers?

Since the left chamber has the hardest job of all, its muscular wall is much thicker than the rights.

Anticoagulant

Substance that prevents blood clotting by suppressing the synthesis or function of clotting factors. Are given to prevent thrombosis and used and drawing and storing blood.

What do the chordae tendineae do?

Support the valves when they are closed.

Second sound (S2)

The 'dub'. Closing of the semilunar valves when the pressure in the ventricles falls below the pressure in the arteries. Relaxation of ventricles. Diastole.

First sound (S1)

The 'lub'. Closing of the AV valves during ventricular contraction. Systole.

What contracts first in the heart?

The atria and then the ventricles.

Systemic circulation consists of what?

The chambers on the left side of the heart and all the names blood vessels that carry blood to the tissues (arteries) and all the named blood vessels that return blood from the tissues (veins) back to the right atrium of the heart. The tissue capillaries included.

What happens a couple days after the bleeding stops? How?

The clot is broken down. TPA is released into the blood very slowly by the damaged endothelium of blood vessels.

As the damaged blood vessel wall is repaired, activated factor XII promotes what?

The conversion of an inactive molecule in plasma into the active form called kallikrein.

The AV valves are passively opened by what? And close when?

The flow of blood. Blood tries to move backwards. The chordae tendinae support the valves when they are closed.

Vitamin K deficiencies from other causes; malabsorption, prolonged antibiotic therapy, or impaired vitamin K metabolism in disease (hepatic failure) leads to what?

The formation if PIVKA's (proteins induced by the absence of vitamin K) which are partially or totally non-gamma carboxylated, affecting the coagulation factors ability to bind to phospholipid.

What happens as the ventricles contract?

The intraventricular pressure rises above the pressure in the atria and pushes the AV valves closed.

Pulmonary circuit

The path of blood from the heart (right ventricle), through the lungs, and back to the heart (left atrium) completes one circuit.

Hypercoagulable state

The person has an abnormal tendency to form clots (thrombi). Can lead to infarctions.

Despite the differences in resistance of the sides of the heart, what must happen?

The rate of blood flow through the systemic circulation must be matched to the flow rate of pulmonary circulation.

What does being bedridden increase?

The risk of a thrombi in the legs and lower extremities because it reduces the blood flow through veins.

What can be a cause, within the body for DIC to occur?

The transformation of diffused fibrin nets can fast-moving RBC's

What happens when the ventricles are relaxed?

The venous return of blood to the atria causes the pressure in the atria to exceed that in the ventricles. The AV nodes therefore open, allowing blood to enter the ventricles.

What happens to action potentials that originate at any point in a mass of myocardial cells, called myocardium?

They an spread to all the cells in the mass that are joined by gap junction. Because of this interconnection, a myocardium behaves a a single functional unit. The heart contains two distinct myocardia; atria and ventricles.

Infarctions

Tissue areas that have a deprived that have a deprived blood flow.

What is vitamin K an essential factor for?

To a hepatic (liver) enzyme, gamma-glutamyl carboxylase, that adds a carboxyl group to glutamic acid residues on factors II (prothrombin) VII, IX, and X.

Poorly oxygenated blood with high levels of CO2 is returned where?

To the right atrium by the superior and inferior vena cava.

Where do thrombi of the legs travel to?

Typically to the lungs. (this is the first capillary bed they encounter after leaving the veins in the leg)

What is the target of warfarin? What does it lead to a deficiency in?

Vitamin K epoxide reductase. II, VII, IX, I

What happens when adding the gamma-carboxyl group to glutamate residues on the immature clotting factors?

Vitamin K is itself iodized.

Embolus

When a thrombus is moved by the blood away from its sit of formation. Any mass of un-desolved material swept away by the flow of blood.

What blood returns to the right atrium?

Whose oxygen content has become partially depleted and show carbon dioxide content has increased as a result of tissue metabolism.

If your atria were not pumping blood at all what would happen? What is the side affect?

You would be fine. you could develop blood clots.

Four essential characteristic of the atria?

1. No atrial inlet valves that interrupt blood flow during atrial systole. 2. The atrial systole contractions are incomplete and thus do not contracct to the extent that would block blood flow from the veins through the atria into the ventricles. During atrial systole, blood not only empties from the atria into the ventricles, but blood continues ti flow uninterrupted from the veins right through the atria into the ventricles. 3. The atrial contractions must be gentle enough so that the force of contraction does not exert significant back pressure that would impede venous flow (there is a slight venous pulsation during atrial systole that can be detected in the jugular veins). 4. The relaxation of the atria must be times so that they relax before the start of each ventricular contraction, to be able to accept venous flow without interruption.

Common venous pressure

5mm Hg in the right atrium. 8 mm Hg in the left atrium. This is enough to prevent backflow.

How much blood is in your ventricles before your atria contracts?

80%

How long does it take for warfarin to become active?

A couple of days because the existing vitamin K-dependent clotting factors must be used up before the anticoagulant effect becomes apparent.

What can liver disease lead to?

A decrease in clotting proteins and increased risk of hemorrhage, such as excessive bruising associated with venipuncture.

The atria and the ventricles each contract as what?

A single unit.

Heart murmurs

Abnormal heart sounds produced by abnormal patterns of blood flow in the heart.

Heart

About the size of a fist, hollow, cone-shaped, divided into four chambers.

Heparin

Activates antithrombin III and combines with and inactivates thrombin.

What does Heparin do?

Activates antithrombin III, a plasma protein that combines with and inactivates thrombin.

Aspirin

Acts by permanently damaging the ability of platelets to clump.

What can embolus consist of?

Air, fat, amniotic fluid, blood clot. Will travel wherever it wants until it hits its first capillary.

Infarct

An area of tissue necrosis that results from such a sudden insufficiency of blood flow.

Pulmonary embolsim

An embolus that lodges in the lungs

Plasmin

An enzyme that digests fibrin into 'split products', thus promoting dissolution of the clot (fibrin degradation product FDP)

Vitamin k reductase is pharmacologically important for what?

As a target of the anticoagulant drug warfarin (coumadin).

Where is the aorta?

Ascends a short distance, makes a U-turn, and then descend through the thoracic (chest) and abdominal cavities.

The contraction of the the papillary muscles happens when compared to the contractions of the muscular walls of the ventricles? What does this do?

At the same time. Serves to keep the flaps of the AV valves tightly closed.

What can happen when the vessel lining is abnormal and serves to stimulate clot formation?

Atherosclerosis, Varicose veins, Phlebitis, Infeciton

What is located between the atria and ventricles?

Atrioventricular (AV) valves

Warfarin (Coumadin)

Blocks the cellular activation of vitamin K. Rat poison. Most common.

Thrombus

Blood clot that obstructs a blood vessle.

Pulmonary arteries

Branch to support blood to the lungs, where gas exchange occurs between the lung capillaries and the air sacs (alvioli) of the lungs.

How are the right and left sides of the heart separated?

By a muscular wall or septum.

How can sodium citrate be reversed?

By adding excess calcium in a test tube or by metabolism of the sodium citrate in the body.

How can the clotting of blood in test tubes be prevented?

By the addition of sodium citrate or ethylenediaminetetracetic acid (EDTA), both of which chelate(bind to) calcium.

What do sodium citrate and EDTA do in prevent blood clotting?

Calcium levels in the blood that can participate in the clotting sequences are lowered, and clotting is inhibited.

Oxygen diffuses from the air to ________ _______, while carbon dioxide diffuses in the _________ direction.

Capillary blood. Opposite direction.