Introduction to Hematology

Question 1

what is the structure of blood? How much blood do we have as adults?

Answer 1

Form of connective tissue
Made up of several different components including cells and plasma
5L of blood..makes up 8% of our body weight

Question 2

What are the functions of blood?

Answer 2

1- supplies oxygen to the body’s cells
2-Supplies nutrients( glucose, AA, fatty acids)
3- Remove wastes ( CO2, urea, and lactic acid and carries these to lungs, kidneys and liver for excretion)
4-Part of the immune system( WBC, Antibody)
5- Coagulation system( coagulation factors and platelets)
6- Regulates body temperature ( produces heat)
7- Transports hormones and other signalling proteins
8-Regulates water content of the tissues

Question 3

What does the cellular portion of the blood contain? What are the functions of these cells?

Answer 3

Erythrocytes( carries oxygen to the cells)
Leukocytes( fights infections
Platelets ( primary hemostasis, platelets bud off of cells, they aren’t cells themselves)

Question 4

What is the life cycle of a red blood cell?

Answer 4

Average lifespan is 110-120 days

Every second you are making 2.4 million blood cells

Question 5

What is the term for the production of red blood cells? Where does it occur in adults/infants? How long does it take?

Answer 5

Erythropoiesis, takes 7 days, occurs in the red bone marrow of the large bones. In the fetus, produced in the liver

Question 6

What hormone drives erythropoiesis? how?

Answer 6

cytokines and growth factors involved

• Erythroietin (EPO)
• This hormone is produced by the kidneys
• Horomone is produces by cells that sense tissue oxygenation relative to an individuals metabolic activity
• Hormone enhances growth and differentiation of erythroid percursors

Question 7

What can an increased amount of reticulocytes tell you? ( What is the normal amount in blood)

Answer 7

can represent hemolysis or RBC destruction

Normally only represent 1% of cells

Question 8

What its the diametre and width of a RBC?

Answer 8

Diameter: 6-8 microns
Width: 3 microns

Question 9

What three things factor in to the ability of RBC to enter small vessels

Answer 9

1- Shape( Biconcave)
2- Membrane properties
3-Cytoplasm viscosity

Question 10

Why is the biconcavity of the RBC important?

Answer 10

High surface area to volume ratio
Extra 43% SA compared to sphere
Aids will deformation to travel in small capillaries
Helps RBC carry more hemoglobins

Question 11

What WBC is increased in acute myeloid leukemia?

Answer 11

myeloblast

Question 12

What cell makes platelets?

Answer 12

Megakaryocytes

Question 13

How hormone regulates platelets/thrombocytes production?

Answer 13

thrombopoietin- a hormone released by liver and kidneys

Question 14

When might you see an increased platelet count?

Answer 14

Acute stress: inflammation and infection

Question 15

How are old platelets removed?

Answer 15

through the spleen

Question 16

What can lead to an increased WBC count?

Answer 16

1- can go up with almost any disease state
2-Goes up with infection and inflammation
3-Medications, esp steroids
4-Hematologic malignancies ( leukemia, lymphoma)

Question 17

What can lead to a decreased in WBC count

Answer 17

• Severe illness can lead to bone marrow suppression
• Medications such as chemotherapy
• Leukaemia and lymphoma can also cause WBC to go down: marrow is packed with malignant cells and can’t produce normal cells
• Low neutrophil count is called febrile neutropenia and is a medical emergency

Question 18

What can a high platelet count be associated with? What is considered high?

Answer 18

Thrombosis( blood clots) ( >1000 x 10^9/L)

Question 19

What can a low platelet count be associated with? What is considered low?

Answer 19

Spontaneous bleeding without trauma(