PhysiologyLesson 5 of 6 in the course The Cardiovascular System: Blood

Hemostasis: Platelet Plug, Coagulation, Clot Removal, and Disorders

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

Save course
Lesson progress
0 / 5

Your progress is kept in this browser only.Sign up to save it

Summary

Hemostasis is the body's response to damage in a blood vessel. This lesson introduces its first two steps: narrowing the injured vessel and forming a temporary platelet plug.

When a vessel is cut, punctured, or otherwise damaged, smooth muscle in its wall contracts. This response, called vascular spasm or vasoconstriction, narrows the vessel and reduces blood flow through the injured area. Circular smooth muscle layers constrict the vessel; in larger vessels, longitudinal muscle layers can also pull the vessel back into surrounding tissue.

All flashcards

What is thrombocytopenia?
An abnormally low platelet count that can impair platelet-plug formation and increase bleeding.
Which clotting-factor deficiencies cause hemophilia A and B?
Hemophilia A involves factor VIII deficiency; hemophilia B involves factor IX deficiency.
What is thrombocytosis?
An excessive platelet count that may contribute to excessive clot formation.
How does aspirin affect platelet aggregation?
It inhibits platelet aggregation, but can increase the risk of ulcers and bleeding complications.
How does tissue plasminogen activator (tPA) promote clot breakdown?
It promotes conversion of plasminogen into plasmin, which breaks down fibrin.

Quiz questions

  1. Which factors and substance initiate the extrinsic pathway and help it activate factor X?Answer: Tissue factor, factor VII, and calcium.
  2. Which sequence of clotting factors leads the intrinsic pathway to activate factor X?Answer: Factors XII, XI, IX, and VIII.
  3. What does thrombin do in the common coagulation pathway?Answer: It converts soluble fibrinogen into insoluble fibrin.
  4. What is vitamin K needed for in blood coagulation?Answer: It is needed by the liver to produce several clotting factors.
  5. What is the difference between an embolus and an embolism?Answer: An embolus is a traveling clot fragment; an embolism is the resulting vessel blockage.

Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

More in Physiology

All Physiology lessons
PhysiologyHormonal Regulation of Renal Fluid, Vascular, and Mineral Balance5 flashcards · 5 quiz questions · 4 gamesPlay free →PhysiologyExercise Hyperpnea and High-Altitude Oxygen Adaptation5 flashcards · 4 quiz questions · 4 gamesPlay free →PhysiologyCardiac Cycle and Heart Sounds: Valve Timing, ECG, and Auscultation5 flashcards · 5 quiz questions · 4 gamesPlay free →PhysiologyEndocrine Hormone Signaling and Major Gland Functions5 flashcards · 5 quiz questions · 4 gamesPlay free →PhysiologyEmbryonic Origins and Age-Related Changes in Endocrine Function5 flashcards · 5 quiz questions · 4 gamesPlay free →PhysiologyFemale Reproductive System: Anatomy, Cycles, and Lifespan Changes5 flashcards · 5 quiz questions · 4 gamesPlay free →