Hemostasis platelet involves vascular spasm, platelet plug formation, and blood coagulation

platelet plug formation

- collagen exposed - platelet activation 1st activation - cell adhesion molecules - make sticky ( stick to collagen) 2nd activation - release granules (ADP, Ca++, thromboxanne)

Coagulation Phase

1. Begins 30 seconds or more after an injury 2. Coagulation: blood clotting 3. A cascade reaction or chain reaction form 3 pathways: a. Extrinsic pathway: begins in the vessel wall, and outside the bloodstream b. Intrinsic pathway: begins with circulating proenzymes within the bloodstream. c. Common pathway: where extrinsic and intrinsic pathways converge.

clotting factors

13 factors in roman numeral - numbering is based on discovery - factor #6 is obsolete/no longer used - factor 3,4,6 Not formed in liver - All other factors formed in liver - Factor 2,7,9,10 Vitamin K dependent

clot

CHECKPOINT A sample of bone marrow has unusually few megakaryocytes. What body process would you expect to be impaired as a result? A decreased number of megakaryocytes would interfere with the blood's ability to ____ properly, because fewer megakaryocytes would produce fewer platelets.

intrinsic

CHECKPOINT Unless chemically treated, blood will coagulate in a test tube. This clotting process begins when Factor XII becomes activated. Which clotting pathway is involved in this process? The activation of Factor XII initiates the _______ pathway.

increase

CHECKPOINT Vitamin K is fat soluble, and some dietary fat is required for its absorption. How could a diet of fruit juice and water have an effect on blood clotting? Fruit juice and water do not contain fats, which are required for vitamin K absorption, leading to a vitamin K deficiency. This would lead to a decreased production of several clotting factors— most notably, proihrombin. As a result, clotting time would _______.

Factor 8

Hemophilia deficient in _______, bleed alot and could die.

vascular

Hemostasis consists of three phases: 1. ______ phase 2. platelet phase 3. coagulation phase

platelet

Hemostasis consists of three phases: 1. vascular phase 2. ______ phase 3. coagulation phase

coagulation

Hemostasis consists of three phases: 1. vascular phase 2. platelet phase 3. ________ phase

Coagulation

The Coagulation Phase ________, or blood clotting, involves a complex sequence of steps leading to the conversion of circulating fibrinogen into the insoluble protein fibrin

cascade

The Coagulation Phase -Clotting Factors Many of the proteins are proenzymes, which, when converted to active enzymes, direct essential reactions in the clotting response. The activation of one proenzyme commonly creates an enzyme that activates a second proenzyme, and so on in a chain reaction, or _______, a domino effect..

procoagulants

The Coagulation Phase -Clotting Factors Normal blood clotting depends on the presence of clotting factors, or _________, in the plasma

vascular spasm

The Vascular Phase Cutting the wall of a blood vessel triggers a contraction in the smooth muscle fibers of the vessel wall. This local contraction of the vessel is a _______, which decreases the diameter of the vessel at the site of injury. Such a constriction can slow or even stop the loss of blood through the wall of a small vessel. The ____________ lasts about 30 minutes, a period called the vascular phase of hemostasis.

common

The _______ pathway begins when enzymes from either the extrinsic or intrinsic pathway activate Factor X, forming the enzyme prothrombinase.

platelet plug

The attachment of platelets to exposed surfaces is called platelet adhesion. As more and more platelets arrive, they begin sticking to one another as well. This process, called platelet aggregation, forms a _______ that may close the break in the vessel wall if the damage is not severe or the vessel is relatively small. Platelet aggregation begins within 15 seconds after an injury occurs.

platelet phase

The attachment of platelets to sticky endothelial* surfaces, to the basal lamina, and to exposed collagen fibers marks the start of the ________ of hemostasis**. * is the thin layer of cells that lines the interior surface of blood vessels and lymphatic vessels,[1] forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. ** is a process which causes bleeding to stop, meaning to keep blood within a damaged blood vessel (the opposite of hemostasis is hemorrhage)

calcium

____ is in every pathway.

intrinsic

____ pathway (inside) 1. Collagen exposed 2. Activate platelets & Factor 12(XII) 3. Factor 12 activates 11 (XI) 4. 11 activates 9 5. Ca++ activates 8

extrinsic

____ pathway (outside) 1. Tissue Damage 2. When Tissue Factor (TF) released activates Clot Factor 7(VII) 3. Together form complex (Factor 7, Tissue form complex) 4. Common pathway

common

_____ pathway: 1 .Prothrombinase converts the proenzyme prothrombin into the enzyme thrombin. 2. Thrombin then completes the clotting process by converting fibrinogen, a soluble plasma protein, to insoluble strands of fibrin. CLASS NOTES: ? Thrombin activates factor 13 (XIII) | coverts fibrin --> fibrogen | Fibers attach to each other & clot link to each other | Fibrins

hemophilia

is a rare bleeding disorder in which the blood doesn't clot normally.

aspirin

prevents platelets from sticking.

Hemostasis

the cessation of bleeding ( the stopping of bleeding )