1. Intro to Hematolgy and Basic Formed Element Morphology

Question 1

What are the four basic functions of blood?

Answer 1

1. Major “transportation medium” - blood permeates all organs and tissues
2. Homeostasis - quantity of everything in the blood is regulated in some fashion
3. Buffering
4. Temperature regulation

Question 2

1.8 Blood can be divided into what categories?

Answer 2

1. Formed elements

2. Plasma

Question 3

1.8 What are the three formed elements?

Answer 3

1. RBCs (erythrocytes), WBC (leukocytes), and platelets (thrombocytes)

Question 4

1.9 What does plasma consist of?

Answer 4

1. H2O
2. Solutes
3. Plasma proteins (albumins, globulins, fibrinogen)

Question 5

1.9 Define serum

Answer 5

Plasma minus its clotting factors

Question 6

1.10 What percentage of body weight is blood?

Answer 6

8% body weight (5-6 L males and 4-5 L for females)

- Varies according to overall mass

Question 7

1.11 Is blood at a higher or lower temperature than the rest of the body?

Answer 7

Blood is at a higher temperature than the body (we are a warm blooded species)

Question 8

1.12 What are the three hematocrit states?

Answer 8

1. Normal
2. Anemia (low hematocrit)
3. Polycythemia (high hematocrit)

Question 9

1.13 What is considered the best method for definitely evaluating and identifying immature and abnormal formed element cells?

Answer 9

A blood smear examined by a trained eye

Question 10

1. 14 Describe red blood cells in terms of appearance on a blood smear
   - Shape?
   - Nucleus?
   - Principal functions?

Answer 10

Biconcave shape - increases surface area - center will look lighter than periphery

Lacks a nucleus

Solubilize, exchange, and carry gases; buffering

Question 11

1.15 Because RBC’s lack a nucleus, what functions do they lack that other cells normally have?

Answer 11

1. Cannot make proteins
2. Cannot repair themselves
3. Can’t reproduce
4. Finite lifespan of 90-120 days

Question 12

1. 16 Describe platelets
   - Are they cells?
   - Principal function?

Answer 12

Not really cells - they are fragments of megakaryocytes that break off in the bone marrow before entering the peripheral blood

Formation of platelet plugs, which slow down or stop bleeding (depending on severity) - different than blood clots

Question 13

1. 17 Neutrophils
   - Describe their nucleus
   - Principal function?
   - Granular or aggranular?

Answer 13

Very characteristic nucleus divided into 3-5 lobes which are connected by thin strands of chromatin

Function is primary defense against bacteria and fungi - they are the most frequent white blood cell (~60-70), invade sites of infection, and phagocytize pathogens

Granular

Question 14

1. 20 Eosinophils
   - Nucleus has how many lobes?
   - Granular or aggranular?
   - Principal function?

Answer 14

Nucleus usually has only two lobes - looks like an alien head

Has granules - cytoplasm usually filled with them
- The name eosinophil comes from how the granules strongly stain red or pink when eosin or another dye is used

Function is defense against parasitic infections

Question 15

1. 21 Basophils
   - Nucleus has how many lobes?
   - Granular or aggranular?
   - Principal function?

Answer 15

Nucleus usually has two or three lobes, but they are not well defined and may appear S shaped

Granular - but not as many as eosinophils

Function is to mediate inflammatory reactions, especially those that cause allergy symptoms

Question 16

1. 23 Basophils
   - What are they called after migrating to tissues?
   - What do they release?

Answer 16

Basophils become mast cells when migrating

Histamine is released by basophils and mast cells, causing some of the symptoms of an allergic reaction.

Question 17

1. 24 Monocytes
   - Nucleus shape?
   - What other structure notably appears in the stain?
   - Granules?

Answer 17

Nucleus is C or kidney shaped - single lobe

Golgi apparatus appears in the stain - leaving a light impression known as a “negative image”

Very few, if any granules

Question 18

1. 25 Monocytes
   - What are they called after migrating to tissues?
   - Principal function?

Answer 18

Monocytes become macrophages

Principal function is to kill intracellular microorganisms (certain bacteria, fungi) similar to neutrophils (i.e. phagocytosis)

Question 19

1. 26 Lymphocytes
   - Nucleus shape?
   - Granules?

Answer 19

Round nucleus with very little cytoplasm (nucleus fills up the cell)

Very few, if any granules

Question 20

1. 27 Lymphocytes
   - Two main types?
   - Principal function?

Answer 20

B and T lymphocytes

Function is to identify “non-self” antigens and each one has a specific response to eliminate pathogens with antigens or pathogen-infected cells

Question 21

1. 28 B Lymphocytes

- What do B lymphocytes produce in response to pathogen interaction?

Answer 21

Antibodies, which then attack bacteria and viruses

Question 22

1. 28 T Lymphocytes
   - What do T-helper cells (CD4+ cells) do?
   - What do cytotoxic t cells (CD8+ cells) do?

Answer 22

T-helper cells: Produce chemicals that direct the immune response
Cytotoxic T cells: Produce enzymes which induce the death of pathogen infected cells

Question 23

1. 29 Natural Killer cells
   - What do these lymphocytes play a major role in?
   - Granular or agranular?
   - What proteins do they release?

Answer 23

Play a major role in the rejection of tumors and cells infected by viruses.

They have granules.

They kill cells by releasing small cytoplasmic granules of proteins called perforin and granzyme that cause the target cell to die.