Lecture 4 Flashcards
What stimulates the production of platelets
What is the shape of platelets?
Thrombopoietin stimulates the production of platelets.
Plts: disk-shaped cell fragments that play a vital role in blood clotting.
What is haemostasis
Haemostasis is the physiological process
involves multiple interlinked steps
Stoppage of blood flow
Result of a break in a blood vessel
Normal blood flow maintained elsewhere in the circulation
What is primary and secondary hemostasis
Secondary: fibrinogen to fibrin to get blood clot
Primary: platelet plug formation
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What is the typical duration within which blood is supposed to clot?A. 1 to 2 minutes
B. 3 to 6 minutes
C. 6 to 10 minutes
D. 10 to 15 minutes -
When is the clot typically broken down?A. When the endothelium regenerates
B. After tissue repair
C. Immediately after clot formation
D. After 24 hours
What happens to the clot as the endothelium regenerates?
A. The clot is broken down immediately
B. The clot remains until tissue repair is complete
C. The clot is converted into a scar tissue
D. The clot dissolves naturally within 1 minute
Blood usually clots within 3 to 6 minutes
The clot remains as endothelium regenerates
The clot is broken down after tissue repair
Here are two MCQs based on the information provided:
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What is the typical duration within which blood is supposed to clot?A. 1 to 2 minutes
B. 3 to 6 minutes
C. 6 to 10 minutes
D. 10 to 15 minutesAnswer: B. 3 to 6 minutesExplanation: Blood usually clots within 3 to 6 minutes after the initial injury, depending on various factors such as the health of the individual and the nature of the injury. -
When is the clot typically broken down?A. When the endothelium regenerates
B. After tissue repair
C. Immediately after clot formation
D. After 24 hoursAnswer: B. After tissue repairExplanation: The clot is broken down (a process known as fibrinolysis) after tissue repair has occurred, to restore normal blood flow and remove the clot from the healing site.
Here’s the final MCQ based on the provided information:
What happens to the clot as the endothelium regenerates?
A. The clot is broken down immediately
B. The clot remains until tissue repair is complete
C. The clot is converted into a scar tissue
D. The clot dissolves naturally within 1 minute
Answer: B. The clot remains until tissue repair is complete
Explanation: The clot remains at the site of injury to provide a temporary barrier and support for tissue repair. It is only broken down after the tissue repair process is completed.
What percentage of blood loss causes weakness?
Which percentage causes shock?
Large losses of blood have serious consequences
Loss of 15 to 30 percent causes weakness
Loss of over 30 percent causes shock, which can be fatal
Transfusions are the only way to replace blood quickly
Transfused blood must be of the same blood group
How many blood group systems are there?
What determines your blood group?
How many blood groups do we focus on in Ghana?
Determined by RBC antigens that are genetically inherited.
~ 36 blood group systems, with over 400 red cell antigens
Principally ABO, Rh, MNS, P, Kell, Lewis, Kidd, Duffy, etc
We focus on 8 blood groups (comprising of the ABo blood grouping and then the RH factor so we have A pos,A neg,B pos B neg AB pos AB neg O pos O neg)
ABO and Rh: Clinically significant for transfusions.
The most vigorous transfusion reactions
ABO blood groups are based on what?
Based on the presence or absence of two antigens:
Type A
Type B
The lack of these antigens is called type O
Which blood group is the universal donor?
O negative
Which blood group is the universal recipient (state the blood group and whether positive or negative)
AB positive
What antigen does A blood group have?
What about B?
What about AB?
What about O?
What plasma antibodies does A blood group have?
What about B?
What about AB?
What about O?
A- antigen A
B-antigen B
AB-antigen A and B
O- neither A nor B antigens
A- plasma antibodies B
B- plasma antibodies A
AB- neither plasma antibodies A nor B
O- has both A and B
Which blood group is the most common?
Which is the least common?
O is most common (50%)
AB is Less common(2%)
A is 23%
B is 22%
Antigens are present on the surface of the rbc cell while antibodies are in the serum or plasma
When will you say there is a mismatch in Rhesus D blood groups concerning pregnancy?
What about mismatch concerning transfusion reactions
When do we say there is ABO incompatibility?
When do we say there is Rh- incompatibility
When mother has Rh- and the baby is Rh+
This leads to hemolytic disease of the newborn
Also, when Rh+ blood is given to Rh- blood, it’ll cause a transfusion reaction
Hemolytic disease of the newborn (HDN) usually results from incompatibility between the mother’s and baby’s blood types, but the case you mentioned, where an O-negative mother has an O-positive baby, typically does not lead to HDN. Here’s why:
- ABO Compatibility: If both the mother and the baby are of blood group O, there is no ABO incompatibility issue. The problem typically arises when the mother is blood group O and the baby is A, B, or AB, as the mother’s anti-A and anti-B antibodies can cross the placenta and attack the baby’s red blood cells.
- Rh Factor: Hemolytic disease of the newborn is more commonly associated with Rh incompatibility. For HDN to occur due to Rh factor, the mother would need to be Rh-negative and the baby Rh-positive. If the mother is Rh-negative and the baby is Rh-positive, the mother’s immune system can produce anti-Rh antibodies that can cross the placenta and attack the baby’s red blood cells.
In your case:
- O-negative mother with an O-positive baby: Normally, there shouldn’t be an issue since both are blood group O, and Rh factor compatibility usually does not cause problems in this specific scenario. However, if the mother has developed antibodies due to a previous pregnancy or transfusion, it might complicate matters. Generally, the concern is more significant when there is Rh incompatibility. So if this is the second pregnancy and baby has O+ and mother is O-, there will be Rh incompatibility
For preventing HDN, Rh-negative mothers are often given an injection of Rh immunoglobulin (Rho(D) immune globulin) during and after pregnancy to prevent the development of anti-Rh antibodies.
