Hematology

Week 1b

What are the two components of blood?

Plasma and formed elements

What do formed elements consist of?

Erythrocytes, leukocytes, and thrombocytes

What is the main component of plasma?

Water, around 90%

What are the non-water components of plasma?

Electrolytes, nutrients, wastes, gases, hormones, and proteins

What are some electrolytes?

Na+, Ca2+, Cl-

What are some kinds of plasma proteins?

Albumins, globulins, clotting factors, and fibrinogen

What is the role of albumins?

Contribute to the osmotic pressure of blood

What is the role of globulins?

Transport of certain substances such as hydrophobic hormones

What helps to buffer pH changes in the blood?

Plasma proteins

What is another name for erythrocytes?

Red blood cells

What makes up the largest part of formed elements?

Erythrocytes

What is the roles of erythrocytes?

The transport or O2 and CO2

What is another name for leukocytes?

White blood cells

How many individual types of leukocytes are there? And how many categories are there?

5 types and 2 categories

What are the roles of leukocytes?

Defensive functions

What is another name for platelets?

Thrombocytes

What is the role of platelets?

Hemostasis

What shape are erythrocytes?

Biconcave discs, cheerios

What do mature erythrocytes lack?

A nucleus and most other organelles

What is the lifespan of an erythrocyte?

Approx. 120 days

What protein is found in erythrocytes that gives blood its red colour?

Hemoglobin

What role does hemoglobin play?

Carries O2 and CO2, also CO

What is the role of heme in hemoglobin?

Responsible for carrying O2 and CO2

How many O2/CO2 molecules can one heme carry?

4 molecules

What makes up the center of a heme and gives blood the red colour?

Fe2

How many heme subunits make on hemoglobin?

4 subunits

What are the 2 leukocyte groups called?

1. Granulocytes

2. Agranulocytes

What are some characteristics of granulocytes?

Large stained granules, lobed nuclei

What are some characteristics of agranulocytes?

No visible granules, non-lobed nuclei

What are the 3 types of granulocytes?

1. Neutrophils

2. Eosinophils

3. Basophils

What are the most common leukocytes?

Neutrophils

What are some characteristics of neutrophils?

Pink/blue stained, nuclei have 3-5 lobes

What is the role of neutrophils?

Phagocytosis, other defenses against bacterial infection, can leave the blood stream

What are some characteristics of eosinophils?

Pink stained, bilobed nuclei

What is the role of eosinophils?

Reduce inflammation, can enter inflamed tissues, common in allergic response, kill certain parasites

What are some characteristics of basophils?

Blue stained, bilobed nuclei

What are the roles of basophils?

Release histamine and heparin, can leave bloodstream, common in allergic response

What are the 2 types of agranulocytes?

1. Lymphocytes

2. Monocytes

What are some characteristics of lymphocytes?

Smallest leukocytes, nucleus fills most of cell, mostly in lymphatic tissues

What are the roles of lymphocytes?

Produce antibodies, other immune response roles

What are some characteristics of monocytes?

Largest leukocytes, have a round blobby shape

What are some roles of monocytes?

Phagocytic, can leave blood stream as macrophages, engulf and breakdown foreign particles then signal immune response

What is hematopoiesis?

The process of blood cell formation

What is another name for hematopoiesis?

Hemopoiesis

From where do all blood cells originate?

Pluripotent stem cells in red bone marrow

What are the other names for pluripotent stem cells?

Hematopoietic stem cells or hemocytoblasts

What 2 cells do pluripotent stem cells make?

Myeloid stem cells and lymphoid stem cells

Into what can myeloid stem cells differentiate?

Erythrocytes, platelets, granulocytes, or monocytes

Into what can lymphoid stem cells differentiate?

Different types of lymphocytes

What helps to regulate the maturation of blood cells from stem cells?

Colony stimulating factors, erythropoietin, testosterone, and thymosins

What can also produce colony stimulating factors in response to specific infections?

Mature lymphocytes and macrophages

What is the role of erythropoietin in blood cell maturation?

Stimulates erythrocyte production

What is the role of testosterone in blood cell maturation?

Helps stimulate erythrocyte production

What is the role of thymosins in blood cell maturation?

Involved in the development of T lymphocytes

What is erythropoiesis?

Formation of erythrocytes

How is erythropoiesis regulated?

Low levels of O2 causes increased erythropoietin (EPO) production which stimulates red marrow to increase erythropoiesis, enough O2 will limit release of EPO

What breaks down hemoglobin?

Spleen, liver, and other lymphatic tissues

What is hemoglobin broken down into?

Amino acids (from globin) and heme (which is then separated in iron and biliverdin)

What are amino acids reused for?

Synthesis of other proteins

What is iron (from heme) reused for?

Transported to red marrow to be made into new erythrocytes

What is biliverdin (from heme) recycled into?

Transported to the liver to be made into bilirubin, eventually ends up in feces and urine