Exam 2

from PAL keys

All organisms have what?

Unique protective mechanisms

What do an organisms unique protective mechanisms promote?

Survival

What are the two types of protective mechanisms in humans?

Innate and accquired

What are the human defense systems like?

Highly evolved and highly developed

What is an analogy for the human lines of defense?

A castle

In the castle analogy of immunity, what makes up the first line of defense like the moat, walls, and drawbridge?

Skin, sequestered tissue, flora

In the castle analogy of immunity, what makes up the second line of defense like cannonballs?

Inflammatory response

Does the inflammatory response have a specific target?

No

In the castle analogy of immunity, what makes up the third line of defense like one-on-one combat with an enemy?

Specific immunity with memory

In what time frame do innate defenses work?

Immediately

Innate immunity includes which lines of defense?

First and second

What is the purpose of first line defenses?

To prevent pathogens from entering the body

What are the three types of first line defenses?

Physical, chemical, flora

What are examples of physical first line defenses?

Skin and mucous membranes

What are examples of chemical first line defenses?

Sweat, saliva, cerumen

How do normal flora contribute to first line defenses?

By inhibiting certain microbes from taking up residence

When is the second line of defense activated?

When the first line of defense has been breached

What occurs during a second line activation?

Phagocytes are activated and inflammatory and febrile responses are initiated

What magnifies second line activation?

Circulating plasma proteins

What are the three cascades involved in the amplification of the second line of defense?

Complement, kinin, clotting

What does the second line of defense also involve?

Granulocytes

Which granulocytes are mainly associated with the second line?

Basophils, neutrophils, eosinophils, and monocytes

Which granulocyte serves as the “cleanup crew”?

Macrophages

How is granulocyte activity monitored in relation to the second line?

With a CBC

What is the third line of defense?

Specific immunity

What does the third line of defense do?

Remembers the intruder and acts faster on any subsequent encounter

What does the third line of defense have that the first and second lines don’t?

Specific activation and specific effectiveness to a specific intruder

How does the third line of defense work?

Lymphocytes interact with antigens

What does the third line of defense involve?

T and B lymphocytes

What are the two major divisions of the third line of defense?

Antibody-mediated (humoral) and cell-mediated

What do all stem cells start as and where do they start?

Pluripotent cells in the bone marrow

What is a pluripotent cell?

A cell capable of developing into any type of circulating cell needed

What type of cells pass through lymphoid tissue to mature into immunocompetent B and T cells?

Lymphoid cells

What does the lymphoid line also produce?

Natural killer cells

What do natural killer cells do?

Roam the body tissues detecting anything abnormal

Myeloid cells include what?

Erythrocytes, megakaryocytes, and granulocytes

Which cell types are granulocytes?

Neutrophils, basophils, eosinophils, and mast cells

What other cell type does the myeloid line include?

Monocytes

What do monocytes become?

Macrophages

When do monocytes become macrophages?

When they migrate into body tissues

What can monocytes differentiate into?

Dendritic cells

When do monocytes differentiate into dendritic cells?

Under inflammatory conditions

Where does hematopoiesis begin?

In the bone marrow

What cell type is the beginning of hematopoiesis?

Pluripotent cells

What initiates hematopoiesis?

Growth factors reaching the bone marrow stimulating the production of more circulating cells

What is the stimulating factor for leukocytes?

Colony stimulating factors (CSF)

What is the stimulating factor for megakaryocytes, platelets, and thrombocytes?

Thrombopoietin

Where is thrombopoietin produced?

Liver

What is the stimulating factor for erythrocytes?

Erythropoietin (EPO)

Where is erythropoietin produced?

Kidneys

What are platelets?

Fragmented megakaryocytes

What are thrombocytes?

Platelets

What is the mnemonic for WBC differential?

Never Let Monkeys Eat Bananas

What percent of WBC differential is neutrophils?

60%

What percent of WBC differential is lymphocytes?

30%

What percent of WBC differential is monocytes?

6%

What percent of WBC differential is eosinophils?

3%

What percent of WBC differential is basophils?

1%

What are the suffixes -cytosis, -philia, and -cythemia associated with?

Abnormally high counts

What is leukocytosis?

Abnormally high overall WBC count

What is leukocytosis commonly associated with?

General inflammatory and infection response

What is neutrophilia?

An increase in neutrophils

What is neutrophilia commonly associated with?

Infection

What is eosinophilia?

An increase in eosinophils

What is eosinophilia commonly associated with?

Allergies and parasitic infections

What is basophilia?

An increase in basophils

What is basophilia commonly associated with?

Leukemia

How common is basophilia?

Very rare

What is lymphocytosis?

An increase in lymphocytes

What is lymphocytosis commonly associated with?

Viral infection

What is leukocythemia?

An extremely high WBC count

What is leukocythemia commonly associated with?

Malignancy like leukemia or lymphoma

What is leukopenia?

A low total WBC

What is neutropenia?

A low neutrophil count

Is leukopenia or neutropenia more common?

Neutropenia

What are common causes of neutropenia?

Immunosuppresive medications, autoimmune disorders, bone marrow failure

What is the primary concern with neutropenic patients?

Infection

What are the primary neutropenic precautions?

Hand hygiene, limited visitors, no children, assessment for s/sx of infection, temperature monitoring q4h, daily CBC

What is inflammation?

A protective mechanism

How is inflammation protective?

By isolating an injury, diluting toxins, and destroying invasive microbes

What are the four cells involved in inflammation?

Endothelial cells, mast cells, platelets, and WBCs

How are endothelial cells involved in inflammation?

By releasing inflammatory mediators when injured

What do the inflammatory mediators released by endothelium do?

Regulate the migration of WBCs from circulation into injured tissue

What cells are the circulating counterparts to mast cells?

Basophils

What is the role of mast cells in inflammation?

To release histamine

How to mast cells release histamine?

Via degranulation

What role to platelets play in inflammation?

When activated they release mediators to attract more platelets

Which WBC arrives first to inflammation?

Neutrophils

What causes purulent exudate from inflammation?

The action of phagocytes and removal of debris by neutrophil

What are bands?

Immature neutrophils

What do macrophages release?

Cytokins

What is the role of macrophages in inflammation?

To clean up behind neutrophils

What is the role of eosinophils in inflammation?

Allergic reactions and acting as neutrophils for parasites

What is the role of basophils in inflammation?

Releasing histamine

What is a shift to the left?

An increase in the number of bands in circulation

What causes a shift to the left?

An acute inflammatory response

What is used to mediate the degree and duration of inflammatory reactions?

Cellular receptors on inflammatory cells

Where are inflammatory mediators derived from?

Plasma or cells

Which type of inflammatory mediators are the most common?

Cell-derived

Which cells can cell-derived inflammatory mediators be derived from?

Mast cells, endothelial cells, macrophages, leukocytes, lymphocytes