Ch25: Blood Flashcards
What are the 4 components of blood?
Plasma
Platelets
Red Blood Cells (RBC’s)
White Blood Cells (WBC’s)
Brief description of plasma
-Yellow, liquid part of blood
-Makes up 55% of blood
-Made up of 90% water, 7% proteins and 3% dissolved materials
What are the main plasma proteins?
-Antibodies (produced by WBC’s to bind foreign substances)
-Clotting proteins (form blood clots)
What is serum?
Plasma from which the clotting proteins have been removed
What is the function of plasma?
-To transport dissolved materials like glucose, CO2, hormones etc.
-To transport heat
What are other names for RBC’s?
-Red blood corpuscles
-Erythrocytes
Where are red blood cells produced?
Bone marrow
Describe the structure of RBC’s
-Have a nucleus UNTIL they mature into red blood corpuscles after a few days (No nucleus in maturity)
-No mitochondria
-Very small biconcave discs (for increased surface area to aid diffusion)
What protein do RBC’s contain? Describe this protein
-Contains red protein, haemoglobin
-It combines with oxygen to form oxyhaemoglobin
Describe the life span of a RBC, and the processes by which th ey are broken down.
-RBC’s live for 4 months before being broken down in the liver and spleen
-When they are broken down, the haemoglobin is stored in the liver (and recycled), and the rest of the cell is converted to bile pigments, bilivirdin and bilirubin
-RBC’s are damaged when they change shape to pass through narrow blood vessels
What is the function of RBC’s?
To transport oxygen
What causes anaemia and how can it be treated?
-Caused y lack of haemoglobin or red blood cells
-Treated by iron supplements or iron rich foods like green vegetables, red meat
What does sickle cell anaemia cause?
Causes blood flow to be blocked
What is another name for white blood cells?
Leucocytes
Describe WBC’s
-Made in bone marrow
-Have a nucleus
-Less numerous than red blood cells (700 red : 1 white)
What is the function of white blood cells?
-To defend against and fight infection
What are 2 types of WBC’s?
-Lymphocytes
-Monocytes/macrophages
Lymphocytes:
1. Where are they produced
2. Percentage that they make up
3. Length of time they survive for
4. Description of structure
5. Where are they stored
- Made in bone marrow
- 25%
- 3 months to 10 years
- Large; round nucleus; very little cytoplasm
- Mature in and stored in lymphatic tissue
Monocytes/Macrophages
1. Where are they produced
2. Percentage that they make up
3. Length of time they survive for
4. Description of structure
- Bone Marrow
- 5%
- 6-9 days
- Kidney-shaped nuclei
What is the function of lymphocytes?
To make antibodies
What is the function of monocytes?
-To surround and digest bacteria and viruses in a process called phagocytosis
What is leukemia and how can it be treated?
-A form of cancer in which the WBC’s are produced too rapidly and are immature
-They crowd out other blood cells and may cause anaemia, increased risk of infection and reduced ability to clot
-Treated by radiation or drugs
What is another name for platelets?
Thrombocytes
How are platelets made?
Made in bone marrow from large cells which break into fragments called platelets
What is the fnction of platelets?
-To clot the blood (using a strong platelet plug with stable fibrin mesh)
-This reduces blood loss and stops microorganisms from entering
What is haemophilia?
-The lacking ability to form a clot, leading to excessive bleeding
-Lack of natural clotting factor means only a weak platelet plug can form
-Incomplete fibrin mesh allows the bleeding to continue
How is a blood clot formed? What do blood clots cause?
Formed if vessel walls are damaged, leading it to be blocked
Blood clots are also called a thrombosis
-In the brain, causes stroke
-In the heart, causes heart attack
What are the overall functions of blood?
-Transport food, waste and hormones
-Transport heat
-Transport oxygen
-Defence against disease (WBC’s engulf bacteria, Lymphocytes produce antibodies, platelets clot blood)
What is an antigen?
A chemical marker that can stimulate the production of antibodies
Where are antigens on RBC’s?
Most RBC’s have a carbohydrate/protein molecule on their surface that acts as an antigen
What are the 4 main blood types and how do they differ?
A, B, AB, O
-They differ in the type of antigens they have on their RBC’s, e.g. blood type B has B antigens, therefore has antibodies for A (not compatible with blood type A)
Why are blood groups important?
Important in blood transfusions, because introducing the wrong antigen may cause blood clumping in the receiver
Name the 2 blood grouping systems
-ABO Blood groups
-Rhesus factor
Explain the rhesus factor
-If somebody is Rhesus Positive (RH+), they have an antigen called factor D
-Rh- people will produce antibodies to Factor D
-Rh- blood can be given to a Rh+ person
-Rh+ blood cannot be given to a Rh- person because the Rh- person has antibodies for the Rh+ blood (causes clumping in blood)
Explain how Rhesus factor can impact pregnancy and what can be done to prevent this?
-May lead to problems for a Rh- mother who is pregnant with her Rh+ child
-1st Rh+ baby is born safely
-Any further born Rh+ babies may be anaemic, brain-damaged or stillborn
-Anti-D treatment is used to prevent this
