Platelets are real cells

There are more thrombocytes (150K-400K) than RBC

Thrombocytes circulate for 8-10 days and then are broken down and recycled

What is the function of thrombocytes

This occurs when there is over 400k platelets and excessive clots formed in blood vessels (thrombosis)

This occurs when there is less than 100k platelets which causes excessive internal bleeding...hemorrhagic spots and hematoma in response to minor trauma

Hemopoietic stem cell in red bone marrow divide to form....

Myeloid stem cells (from hemopoietic stem cell) divide to form megakaryoblasts which from megakaryocyte. The cytoplasm breaks up and forms platlets

Platelets are formed from pieces of the cytoplasm of megakaryocyte

Hemostasis stops bleeding and prevents hemorrhage (loss of large amounts of blood) and is done...

In this Hemostasis step (#1), platelets and endothelial layer linning the wall of blood vessels secrete vasoconstrictors that cause vasocontraction of smooth muscle in wall of blood vessels which reduces the opening and reduces blood flow

In this Hemostasis step (#2), Platelets attach to exposed damaged wall of blood vessels which platelets become irregular, larger and stick to each other to form soft mass

In hemostasis #2 Platelet plug formation: this is when platelets attach to the exposed damaged wall of the blood vessels

In hemostasis #2 Platelet plug formation: is when platelets become irregular, large and stick to each other.

In hemostasis #2 Platelet plug formation: a soft mass is formed

In hemostasis #2 Platelet plug formation: release of chemicals such as ADP, prostaglandins, serotonin, enzymes, calciums ions

Platelets do not stick to undamaged blood vessels due to presence of a coating of platelet repellant prostacyclin.

In this Hemostasis step (#3), this is the clot formation

When blood constantly flows in blood vessels --> blood cells and platelets remain suspended due to platelet repellant prostacyclin --> blood does not clot.

What does clot formation require

In the test tube, straw colored liquid separates out and is called serum

Serum = plasma-fibrinogen

But when blood is withdrawn in a test tube or stops flowing

a soluble plasma protein fibrinogen gets converted to insoluble fibrin which form a network and trap blood cells to form a thick dark red mass (clot).

What are the pathways of # 3 Coagulation (of Hemostasis)

In what pathway of # 3 Coagulation (of Hemostasis) are Prothrombinase and Ca2+ convert prothrombin to thrombin. Thrombin and Ca 2+ convert soluble fibrinogen into insoluble fibrin fibers, these fiber trap blood cells and makes a clot

In what pathway of # 3 Coagulation (of Hemostasis) is triggered by damage of the tissue that is outside of the blood vessels (like a cut that leads to bleeding)

In what pathway of # 3 Coagulation (of Hemostasis) is a simpler process and has fewer steps

In what pathway of # 3 Coagulation (of Hemostasis) is a a very rapid process, takes place within 15 seconds of trauma

In what pathway of # 3 Coagulation (of Hemostasis) is initiated by tissue factor (TF) released from damaged tissue and damage wall of the blood vessel...not the blood

In what pathway of # 3 Coagulation (of Hemostasis) damaged tissue releases tissue factors and tissue factors and Ca2+ activate factor X which activates prothrombinase for the final steps

In what pathway of # 3 Coagulation (of Hemostasis) is triggered by the damage to the inside of the blood vessel wall.

In what pathway of # 3 Coagulation (of Hemostasis) is more complex and has more steps

In what pathway of # 3 Coagulation (of Hemostasis) is more a slower process, takes 3-6 minutes

In what pathway of # 3 Coagulation (of Hemostasis) is initiated by the platelet within the blood vessel

In what pathway of # 3 Coagulation (of Hemostasis) platelets come in contact with the damaged wall of the blood vessels --> the platelet factors and Ca2+ activate factor X--> factor X activates prothrombinase for the final steps

Clot is a soluble fibrinogen in blood plasma that converts to a insoluble fibrin and makes a network of fibrin and forms a soft mass...

Hemostasis 3. Coagulation...this is an embolus (clot) lodged in lungs that blocks circulation in lung, causes breathing difficulties

Hemostasis 3. Coagulation...slower blood flow that can cause thrombosis

Hemostasis 3. Coagulation...caused by embolus in blood vessel going to the brain causes paralysis of one side of the body.

Hemostasis 3. Coagulation...excessive bleeding due to extensive injury or lack of clotting.

Hemostasis 3. Coagulation..continued bleeding due to lack of clotting. due to absence of specific clotting factors.

treated with blood transfusion or infusion of factors.

Hemostasis- 3. Coagulation: a clot formed in an unbroken blood vessel….inside the blood vessel

Hemostasis- 3. Coagulation: the process of internal clot formation is

Hemostasis- 3. Coagulation: traveling clot is..

Hemostasis- 3. Coagulation: dissolving an internal clot that is done by an inactive enzyme present in blood plasma: plasmigoen converted to active enzyme plasmin which dissolves the clot

If an external clot is formed closer to body surface --> clot tightens (clot retraction) -->dries to form a scab -->scab eventually falls off --> new skin appears from underneath.

Such clots can detach --> travel within blood to the other body parts --> may block blood vessels --> cause ischemia (decreased blood supply) and necrosis (tissue death) --> leading to multisystem organ failure.

A thrombus inside a blood vessel can drop off

Chemicals that are used to dissolve a clot like plasminogen activator, stroptokinase

Chemicals that prevent clot formation like heparin, warfarin, EDTA are called

Inhibits prostaglandin synthesis, reduces platelet activation and decreases clotting. Reduces risk of unnecessary clot formation, reduces chances of stroke and heart attack