Hematology - Review Flashcards
What are the five hematology drugs?
- Anticoagulants
- Antiplatelets
- Thrombolytics
- Hemostatics
- Antimalarials
What is the only fluid tissue in the human body?
Blood
What makes blood a connective tissue?
Fibrinogen
What are the living cells in the blood?
Formed elements
What are the non-living components of blood?
Plasma
What are cell fragments?
Thrombocytes
What two things make up the formed elements?
- Cells (Erythrocytes and Leukocytes)
- Cell fragments (Thrombocytes)
Name three characteristics of platelets.
- Small cell fragments
- Membrane-enclosed packets of cytoplasm
- Contain enzymes and clotting factors
Plasma makes up what percentage of whole blood volume?
What percentage of this is water?
- 55%
- 90%
Name some substances dissolved in plasma.
What is the most important in terms of pharmacology?
- Nutrients
- Salts
- Respiratory gases
- Hormones
- Plasma proteins - most important
- Waste products
What are the three kinds of plasma proteins? Which is the most abundant?
- Albumin - most abundant (60%)
- Globulins
- Fibrinogen
Which plasma protein is responsible for clotting?
Fibrinogen
Where are the majority of plasma proteins synthesized?
Liver (90%)
If you have a liver disorder, the synthesis of two things might be affected. What are these two things?
What will this cause a problem with?
- Fibrinogen / Vitamin K
- Clotting
How long do thrombocytes circulate for?
What removes them from the blood?
- 9-12 days
- removed by phagocytes
What is the normal platelet count?
150,000 - 500,000 in each µl of blood
What cell are thrombocytes derived from?
Where are these formed?
- Megakaryocytes
- Bone marrow
What are the five main functions of blood?
- Regulation of pH and ion composition of interstitial fluid
- Defense against toxins and pathogens
- Stabilization of body temperature
- Transportation of nutrients, hormones, wastes, and dissolved gasses
- Restriction of fluid losses at injury sites
What are the steps in homeostatis?
- Blood-vessel injury causes vasospasm (constriction)
- Platelets are attracted to and adhere to injured area
- Aggregation of platelets forms plug
- Formation of insoluble fibrin strand
- Final product of fibrin clot that stops blood loss
Normal clotting occurs in how many minutes?
Six
What happens when damaged vessel endothelium stimulates platelets?
Platelet adhesion
What are the two pathways leading to the clotting cascade?
- Intinsic pathway / contact activation pathway
- Extrinic pathway
What is the intrinsic pathway in response to?
Abnormal vessel wall in the absence of tissue injury.
In what homestatic pathway does prothromin convert to thrombin to seal off the system?
Both! (Intrinsic and Extrinsic)
This is where they become the common pathway.
What hemostatic process is clot formation in response to tissue injury?
Extrinsic pathway
Name the three broad categories of chatecteristics contributing to thrombosis?
What “triad” is this called?
- Blood flow abnormalities
- Contact surface
- Clotting component
Part of Virchow’s Triad
What does hemostasis halt?
Bleeding
What are the three overlapping phases of hemostasis?
- Vascular phase
- Platelet phase
- Coagulation phase
In step one of hemostatis (vascular spasms), what do platelets release at the site of injury?
Serotonin
In step one of hemostatis (vascular spasms), what does serotonin do to the smooth muscles lining the blood vessel?
Spasm
In step one of hemostatis (vascular spasms), the spasms narrow the opening at blood vessel. What does this cause?
Decreased blood loss
In step two of hemostasis (platelet plug formation), platelets pile up to form what?
Platelet plug
In step three of hemostatis (coagulation), the injured tissues around severed blood vessels release what?
Thromboplastin
What triggers the clotting cascade (specifically)?
When thromboplastin combines with plasma clotting factor.
List the steps in the clotting cascade.
- Prothromin activator results from both pathways.
- Prothrombin activator converts prothrombin to thrombin
- Thrombin combines with fibrinogen
- Hair-like fibring created
- Fibrin forms a meshwork
How many coagulating factors are there?
13
What happens to the clot after the tissue is repaired?
It is broken down
What are two functions of clot retraction and removal?
- Reduces the size of the damaged area
- Makes it easier for tissue to repair
