RBC WBC Lymph Disorders, Infections, Inflammation & Immunity

Granulocytes

WBC produced in bone marrow and contain small granules that release enzymes to fight infection

Neutrophils

Primary pathogen-fighting cells

Eosinophils

Help control allergic responses; fight parasites

Basophils

Blood cells; release heparin, histamine, and other inflammatory mediators

Mast cells

Tissue cells; release heparin. histamine, and other inflammatory meditators; involved in allergic reactions

Agranulocytes

WBC lacking prominent, visible granules in the cytoplasm

B cells (B lymphocytes)

Produce antibodies

T-helper cells

CD4+ - Activate immune response

Cytotoxic T cells

CD8+ - Cell-mediated immunity

Natural killer cells

kill abnormal or antigenic cells

Monocytes

Circulate in blood and can develop into macrophages

Macrophages

Perform phagocytosis, present antigens, and release inflammatory mediators

Myeloid Stem Cell

Gives rise to granulocytes (neutrophils, eosinophils, and basophils) and monocytes

Lymphoid Stem cell

Gives rise to lymphocytes (T cells, B cells, and NKC

Leukopenia

Decreased number of circulating WBCs

Neutropenia

Decreased neutrophils, increasing infection risk

Agranulocytosis

Severe granulocyte deficiency, particularly neutrophils

Aplastic Anemia

Bone marrow failure, resulting in reduced blood cell production

Infectious mononucleosis

Viral illness commonly affecting lymphocytes

HIV

Viral infection that targets immune cells, particularly CD4+ T cells

Myeloid neoplasm

Group of blood cancers that start in the bone marrow when stem cells grow and divide in an abnormal way

Lymphoid neoplasm

Group of blood cancers that start when B-cells, T-cells, or NKC mutate, multiple out of control, and form tumors or crowd the blood & bone marrow

ALL

Acute lymphoblastic leukemia - acute, lymphoid origin

AML

Acute myeloid leukemia - acute, myeloid origin

CLL

Chronic lymphocytic leukemia - chronic, lymphoid origin

CML

Chronic myeloid leukemia - chronic, myeloid origin

Leukemia

Malignant disorder of blood-forming cells that produce abnormal blood cells

Malignant cells

• Proliferate rapidly

• Survive longer than normal

• Crowd out healthy cells in marrow

• Infiltrate widely

Hodgkin lymphoma

• Associated with Reed-sternberg cells

• Associated with malignant b cells

• Forms masses in lymph nodes

• EASIER TO TREAT

Non-hodgkin lymphoma

• Includes numerous b cells and t cell lymphomas

• can involve b cells and t cells

• classified into different types and grades - DIFFICULT TO TREAT

Reed Sternberg cells

Myeloma

Malignancy involving abnormal plasma cells derived from B lymphocytes

Findings with Myeloma

• abnormal antibody production

• immune suppression

• increased blood viscosity from abnormal proteins

• organ involvement

• increased osteoclast activity → breaks down bone

Host

An organism that provides a place for another organism to live

Infection

Invasion and multiplication of microorganisms in the body

Colonization

Microorganisms are present without necessarily causing disease

Microflora

Microorgansims normally living in or on the body

Commensalism

One organism benefits; the other is unaffected

Mutualism

Both organisms benefit

Parasitism

One organism benefits while the host is harmed

Pathogen

A microorganism capable of causing disease

Virulence

The degree of disease-causing ability of a pathogen

Opportunistic Pathogen

Cause disease when defenses are weakened or it enters an unusual location

Saprophyte

Organism that obtains nutrients from dead or decaying matter

Prions

• No genome

• Small, modified, inspection proteins

• Abnormally shaped versions of own proteins

• Can bind together and damage other cells

• Cause degenerative diseases in CNS

Viruses

• Protein coat surrounding nucleic acid core

• Some have envelopes

• DNA/RNA

• Cannot reproduce without a host

• Host cell’s normal metabolic activity makes new viruses

Bacteria

• Prokaryotic

• Contain RNA/DNA

• Produce biofilm

• Cytoplasmic mem

• Use hosts for food and shelter

• Live in colonies

• Classified by genus & species

• Described by: morphological appearance, oxygen dependence, staining

Mycoplasmas

Very small bacteria that lack cell walls

Rickettsiae / Chlamydiae

Bacteria that require living host cells to reproduce

Fungi

Has cell walls, but different from bacteria and requires much cooler temperature than “normal” core body temp

Protozoa

Unicellular, complete cellular components & nucleus

Helminths

Wormlike parasites, depend on and reproduce in host

Arthropods

Includes vectors of infectious disease (ticks, mosquitos, flies, and ectoparasites, infects by direct contact or eggs on host (maggots, mites, lice, fleas)

Adhesion factors

Allow pathogens to attach to host cell

Evasion factors

Help pathogens avoid immune defenses

Invasion factors

Help pathogens enter or spread through tissue

Incubation period

Begins when the pathogen enters the body, pathogen starts multiplying, the patient typically has no symptoms yet

Prodromal period

First signs and symptoms begin, symptoms are mild/unspecific, pathogen continues multiplying (early warning signs)

Acute period

Symptoms become more severe and specific to infection, illness may reach peak, immune system actively fights the pathogen

Convalescent period

Symptoms begin improving, body recovers from the infection, tissue repair and healing occur

Clinical threshold

The point at which illness becomes clinically apparent

Subclinical disease

Infection occurs, but symptoms are absent or not clinically apparent

Critical threshold

A level of severe illness associated with potentially life-threatening complications

Inflammation

Nonspecific protective response to tissue injury or infection (minimize effects of injury/infection, remove damage tissue, generate new tissue, and facilitate healing

What are the signs of inflammation?

Rubor, tumor, calor, dolor

Endothelial cells

Permeability allows for outflow of plasma cells

Vascular stage of acute inflammation

Blood vessels dilate and become more permeable

Mediators of the vasodilation

Histamine & nitric oxide

Mediators of permeability

Histamine,bradykinin, leukotrienes

Cellular stage of acute inflammation

White blood cells move from the blood into injured tissue

What are the plasma derived inflammatory mediators?

Kinis, coagulation & fibrinolysis proteins, complement system

Localized inflammation

Redness, edema, heat, tenderness, loss of function

Systemic inflammation

Fever, increased catabolism, negative nitrogen balance, increased ESR, leukocytosis

Pyrogen

Triggers inflammatory signals that produces elevation in body temperature

Fever in children are usually?

Higher

Fevers in elderly are usually?

Lower

What causes redness in inflammatory process?

Prostaglandins & leukotrienes