Pathophysiology - Infection and Hematologic Alterations

50 vocabulary flashcards covering infectious disease principles, specific pathogens, and hematologic alterations including leukemias, anemias, clotting disorders, and splenic conditions.

Infectious Diseases

Disorders in which tissue damage or dysfunction is produced by a microorganism.

Endemic

Term used to describe a disease that exists all the time in certain communities (for example, malaria in parts of Africa).

Epidemic

An outbreak of a disease that spreads within a certain time frame to people of one or several communities.

Pandemic

A disease outbreak that spreads from being epidemic (a few communities) to being worldwide.

Infection

The presence and multiplication of a living organism on or in the host.

Pathogen

An invading organism that causes harm to the host.

Standard Precautions

Basic infection prevention measures used during every patient interaction, regardless of known or suspected infection status.

Contact Precautions

Infection control measures used when a patient has diarrhea, stool incontinence, draining wounds, uncontrolled secretions, vomiting, skin rashes, or sores.

Droplet Precautions

Infection control measures used for pathogens spread by coughing, sneezing, or talking that travel no more than 3 feet from the infected individual.

Airborne Precautions

Infection control measures used when an individual has a suspected or known infection transmitted via the airborne route (e.g., TB, measles, chickenpox, smallpox).

Incubation Period

The phase during which a pathogen begins active replication but does not yet produce signs and symptoms.

Prodromal Stage

The stage of an infectious disease characterized by the initial appearance of mild signs and symptoms.

Acute Stage

The period of maximum impact of a disease, characterized by very pronounced and specific signs and symptoms.

Convalescent Period

The stage of infection recovery characterized by containment of the pathogen and resolution of signs and symptoms.

Resolution

The total elimination of a pathogen from the body without remaining signs or symptoms.

Fulminant Illness

An illness characterized by an abrupt onset with little or no prodromal stage.

Beta-lactamase

An enzyme produced by mutated microbes that destroys beta-lactam antibiotics by dismantling their beta-lactam ring structure.

MRSA

Methicillin-resistant Staphylococcus aureus; a mutated strain resistant to beta-lactam antibiotics, commonly spread nosocomial or community-acquired.

VRE

Vancomycin-resistant enterococcus; a hospital-associated pathogen resulting from a mutated gene that prevents vancomycin from binding to its cell wall.

Cellulitis

An infection of the dermis and subcutaneous tissue, commonly caused by Staphylococcus aureus penetrating skin breaches.

Botulism

A disease caused by Clostridium botulinum toxin that blocks acetylcholine muscle receptors, leading to descending symmetric paralysis.

Tetanus

A disease caused by Clostridium tetanii exotoxin (tetanospasmin) blocking inhibitory neurotransmitters, causing trismus and tetany.

Rabies

A viral infection transmitted via saliva (often bat bites) that travels via the PNS to the CNS, causing brain inflammation, hydrophobia, and excessive salivation.

Post-Exposure Prophylaxis (PEP)

Rabies treatment that must begin within the first 14 days after exposure, consisting of one dose of rabies immunoglobulin and four doses of rabies vaccine.

Malaria

A protozoal infection transmitted by mosquitoes that reproduces in hepatocytes, infects RBCs, and causes hemolysis leading to high fever, chills, and splenomegaly.

Zika Virus

A mosquito-borne viral infection that can cause mild flu-like symptoms, or severe fetal birth defects such as microencephalopathy if contracted during pregnancy.

Mumps

A viral infection that targets the parotid glands causing swelling and fever, with a primary complication of male infertility.

Rubeola

Also known as 'two-week measles,' a viral disease causing a dense red maculopapular rash spreading from head to body, fever, cough, and conjunctivitis.

Rubella

Also known as 'German measles,' a mild viral infection that poses severe risks of birth defects if contracted during early pregnancy.

Varicella

Also known as 'chicken pox,' a highly contagious viral illness causing fluid-filled vesicles on the trunk that move outward in varying stages of development.

Variola

Also known as 'small pox,' a viral disease causing dense clusters of uniform-stage vesicles starting on the face and extremities moving toward the trunk.

Herpes Zoster

Also known as 'shingles,' a condition where dormant varicella virus reactivates in the nervous system and produces painful skin lesions along a dermatome.

Antigenic Drift or Shift

Mutations in neuraminidase and hemagglutinin proteins on the Type A influenza envelope that produce new viral variants.

Dysentery

Severe infectious diarrhea marked by blood and mucus in the stool due to intestinal mucosal damage caused by bacteria (shigella) or protozoa.

Giardiasis

A protozoal infection from contaminated water that interferes with intestinal fat absorption, producing greasy, frothy, non-bloody diarrhea.

Pseudomembranous Colitis

An antibiotic-associated infection caused by Clostridium difficile overgrowth that leads to severe intestinal inflammation and yellowish membrane-like mucosal debris.

Leukemia

A hematopoietic cancer causing uncontrolled leukocyte proliferation, bone marrow overcrowding, leukocytosis, thrombocytopenia, and anemia.

Multiple Myeloma

A cancer of B-lymphocytes (plasma cells) resulting in overproduced immunoglobulins that infiltrate bone, drive osteoclastic activity, and cause hypercalcemia.

Anemia

A condition characterized by a total circulating RBC count of $\mathbf{< 4\,\text{million}}$ or a decrease in hemoglobin quality/quantity.

Polycythemia

A hematologic disorder characterized by an RBC count $\mathbf{> 6\,\text{million}}$ and a hematocrit $\mathbf{> 52\%}$.

Microcytic Anemia

An anemia characterized by an MCV $\mathbf{< 80}$, occurring when chronic blood loss causes the bone marrow to produce smaller replacement RBCs.

Normocytic Anemia

An anemia characterized by normal RBC size (normal MCV), resulting from acute rapid blood loss or reduced production due to chronic disease.

Macrocytic Anemia

An anemia characterized by an MCV $\mathbf{> 95}$, caused by faulty DNA coding that creates oversized, non-functional RBCs.

Pernicious Anemia

A macrocytic anemia caused by a lack of intrinsic factor from stomach parietal cells, preventing vitamin B12 absorption necessary for DNA synthesis.

Frank Bleeding

Obvious blood loss visible on clinical assessment, including petechiae, purpura, ecchymosis, nosebleeds, or bloody stools.

Idiopathic Thrombocytopenia Purpura (ITP)

An autoimmune disorder where IgG antibodies attack platelets, lowering counts below $\mathbf{100{,}000}$ and causing easy bleeding.

Hemophilia

A group of hereditary (usually X-linked recessive) coagulation factor deficiencies causing spontaneous bleeding or excessive bleeding relative to trauma.

von Willebrand Disease (vWD)

The most common inherited clotting disorder, caused by a defect or deficiency in von Willebrand factor, leading to mild bleeding tendencies.

Splenomegaly

Enlargement of the spleen secondary to increased RBC hemolysis, infection/inflammation, or hematologic malignancies like leukemia.

Hypersplenism

A complication of splenomegaly where trapped blood cells are prematurely destroyed en masse, resulting in pancytopenia.