3.1-HOMEOSTASIS Flashcards
What is the function of hemostasis?
Keeps blood in a fluid state and forms a clot to stop bleeding when injury occurs.
What are the two life-threatening consequences of an imbalance in the hemostasis system?
Hemorrhage (uncontrolled bleeding) and thrombosis (pathologic clotting).
What happens if a single plasma procoagulant is absent?
Lifelong anatomic hemorrhage, chronic inflammation, and transfusion dependence.
What is the consequence of lacking a coagulation control protein?
Uncontrolled coagulation, leading to thrombosis, stroke, pulmonary embolism, deep vein thrombosis, and cardiovascular events.
Which three major systems are essential for hemostasis?
Blood vessels, platelets, and plasma proteins.
Why is understanding hemostasis important in a clinical setting?
To interpret lab results and prevent, predict, diagnose, and manage hemostatic diseases.
What does the Greek word ‘hemostasis’ mean?
The stoppage of blood flow.
What are the two main functions of hemostasis?
Forms a barrier to blood loss and maintains blood in a fluid state.
Where does hemostasis primarily occur?
In the vascular system (blood vessels).
What three components are involved in hemostasis?
Vascular vessels, platelets, and coagulation factors.
How do blood vessels respond to injury in hemostasis?
They constrict to decrease blood flow.
What do platelets do in response to blood vessel injury?
Adhere to exposed collagen in the subendothelium and aggregate to form a clot (thrombus).
What are coagulation factors also known as?
Plasma factors or blood factors.
When do coagulation factors become active?
When a clot begins to form.
What is the function of coagulation factors?
They are proteins that help control blood loss and bleeding.
Who is considered the ‘father of medicine’ and what was his observation on blood coagulation?
Hippocrates; he observed that blood congealed as it cooled and bleeding resumed when the skin covering it was removed.
What was Aristotle’s contribution to early coagulation theories?
He noted that blood cooled when removed from the body, which he believed led to decay and congealing.
What was Aristotle and Hippocrates’ collective theory on blood coagulation called?
The cooling theory of blood coagulation.
What was the first recognized coagulation disorder, and when was it identified?
Hemophilia, recognized in the 2nd century A.D.
Who described two male children who died from excessive bleeding after circumcision in the 12th century?
Moses Maimonides.
Who observed clots forming in veins at body temperature in 1627?
Mercurialis.
Who disproved the cooling theory of coagulation, and how?
William Hewson (1770); he demonstrated that clotting originated from the liquid portion of blood, the coagulable lymph, not from the cells.
Who performed the first whole blood clotting time (WBCT) test, and what did he observe?
William Hewson (1780); blood from healthy people clotted in 7 minutes, while some disease states extended clotting time to 15–90 minutes.
When were the first clinical descriptions of hemophilia in families published?
1803
