Pathology Exam Review

pathology

study of the nature, cause and condition of disease

pathophysiology

 study of the process of a disease

importance of pathology and pathophysiology to HCP

a firm foundation in anatomy and physiology allows HCP to communicate with other HCP, apply knowledge to image/treat patient, to be able to care and empathize with patient

diagnosis

identification of a specific disease through the evaluation of signs and symptoms, lab tests, imaging tests, etc.

etiology

cause of disease

iatrogenic

disease caused by medical treatment

idiopathic

cause of disease is unknnown

predisposing factors

 susceptibility to disease or indicating a high risk for a disease

precipitating factors

condition/circumstance that triggers an acute episode

prevention

keeping an illness from spreading or infecting

pathogenesis

development of disease

acute

sudden onset of disease or short termed

chronic

often a milder condition but with a longer term

latent/incubation period

initial stage of disease where no clinical signs are present

prodromal period

time during the early development of a disease when one is aware of a change in the body, but signs are **non-specific**

signs

objective indicators of a disease that are obvious to someone else other than the affected individual

symptoms

a collection of signs and symptoms that occur together in characteristic patterns

manifestation of disease

 clinical evidence or effect of a disease

local manifestation

found at site of problem

systemic manifestation

affecting the body as a whole

lesion

structural change or specific **local** change in tissue

biopsy

removal of a small piece of living tissue for microscopic examination to determine diagnosis

autopsy

postmortem examination of the organs and tissues of a body by a pathologist to determine cause of death

remission

during course of disease, the manifestations have ***subsided***

exacerbation

during the course of disease, the signs of the disease have ***increased***

complication

additional or secondary problems that arise after original disease

convalescence or recovery period

period of recovery and return to normal, healthy state

sequelae

potential unwanted outcomes of a primary condition

therapy

treatment measures used to promote recovery or to slow the progress of disease

morbidity

***disease rates*** within a group

mortality

***death rates*** resulting from a particular disease

epidemiology

science of tracking the pattern or the occurrence of disease

incidence

 numbers of new cases noted within a stated period of time

epidemic

large number of cases of an infectious disease within an area

pandemic

 high number of cases in several regions and possibly worldwide

communicable disease

infections that can be spread from one person to another

reportable disease

a disease that ***must*** be reported by the physician to certain designated authorities

atrophy

decrease in size of an organ or body part due to the ***shrinkage in the size of its cells***

causes for atrophy

due to reduced use, insufficient nutrition and aging

hypertrophy

increase in size of an organ/tissue mass due to an ***increase in the size of the existing cells***

causes for hypertrophy

due to increased workload on the organ/body part

hyperplasia

increase in the size of an organ/mass due to an ***increase in the number of cells***

metaplasia

reversible change when one adult cell type is ***replaced*** by another cell type

causes for metaplasia and dysplasia

usually in response to chronic irritation/inflammation/infection or may be a ***precancerous change***

dysplasia

 tissue in which ***cells vary in size and shape***

anaplasia

refers to cells that are ***undifferentiated***

hypoxia

cause of cellular injury in which decrease oxygen in the tissues

causes for hypoxia

* **Ischemia**: decreased blood supply to a part


* Decreased oxygen in ***air*** due to altitude
* Decreased oxygen in ***blood*** due to respiratory disease
* Decreased oxygen carrying capacity of blood due to anemia

mechanical forces

cause of cellular injury in which a trauma leads to a fracture, split or tear in a tissue

temperature extremes

* ***Low intensity heat***: disrupts blood flow and cell membrane
* ***More intense heat***: coagulation of blood vessels ad tissue protein
* ***Cold***: increases blood viscosity and induces vasoconstriction

electrical forces

cause of cellular injury in which there is extensive tissue injury

radiation injury

* ***Ionizing Radiation***: causes ionization of cellular molecules
* Immediate cell death
* Interruption of cell replication
* May cause genetic mutations
* ***Non-ionizing Radiation***: causes vibration which results in thermal energy
* ***Ultraviolet Radiation***: causes sunburn and increased risk of cancer

chemical toxins

* ***Exogenous***: chemicals form the environment cause injury to many body systems
* ***Endogenous***: refers to toxins from inside the body that cannot be excreted due to a metabolic disorder
* ***Drugs***: can overwhelm system and cause massive liver failure

nutritional imbalances

cause of cellular injury in which there are excesses or deficiencies of nutrients

possible outcomes to cellular injury

1. **Reversible:** if factor causing damage is removed quickly the cell maybe able to recover to normal
2. **Irreversible:** if noxious factor remains, damage becomes irreversible and causes cellular death (necrosis)

events after cellular damage

1. Cell nucleus disintegrates
2. Cells undergo "lysis" or "dissolution"
3. Cells release "lysosomal/lytic" enzymes
4. Enzymes can cause inflammation and damage to nearby cells
5. Enzymes can diffuse into blood
* Helpful clues to type of cell damage

infarction

an area of cell death resulting from lack of oxygen and large number of cells die due to significant loss of function

necrosis

death of cells/tissue within a living body

liquefication necrosis

cells liquefy as a result of the enzyme and cystic space is filled with fluid

coagulative necrosis

gray firm mass where cells tend to maintain their outline due to cellular death and decreased oxygen levels

caseous necrosis

 cells transform into soft cheese like center and can bind with calcium

gangrene

infection by microorganisms

treatment for gangrene

in order to stop spread of gangrene, gangrene have to be removed surgically or amputated

dry gangrene

slow occlusion which leads to a loss of blood supply and eventually body part becomes dry, shrinks and turns black

wet gangrene

found in a part containing fluid and exposed to bacteria

gas gangrene

"clostridium" bacteria produces gas bubbles

first line of defense

body doesn't respond specifically mechanical barriers are involved

second line of defense

body doesn't respond specifically and inflammation/phagocytosis occurs

* includes neutrophils and macrophages

third line of defense

body responds specifically and immune system is involved

* B and T cells react to antigen

net hydrostatic pressure

pressure that determines if the fluid, oxygen, electrolytes and nutrients will move out of the capillary and into interstitial fluid or vice versa

inflammation

body's response to tissue injury and non-specific response occurs

causes for inflammation

* **Direct**: cuts or sprains
* **Chemicals**: acids
* Ischemia and infarction
* Allergic reactions
* **Physical Reactions**: burns or radiation
* **Foreign Bodies**: splinters or dirt
* Infection from virus, bacteria or fungi

acute inflammation

almost immediate response to injury

pathophysiology of acute inflammation

1. **Vascular Response**

* Involves the pre-capillary sphincter
* *High* pressure = *high* permeability
* **Vasodilation:** causes redness and heat
* **Capillary Permeability:** causes swelling and edema


2. **Cellular Response**

* Involves the mast cell
* **Mast Cell**: most important activator of the inflammatory response
* Found in tissues
* Stimulated by injury
* Responds to injury by spilling out contents such as histamine and producing various chemicals

leukotrienes and prostaglandins

involved in long term response to inflammation and has a similar effect as histamine

chronic inflammation

inflammation lasting weeks, months or years due to unsuccessful acute response

fibroblasts

produce scar tissue

macrophages

engulf bacteria resulting in pus

granulomatous inflammation

 if the body cannot get rid of the problem easily, body will wall off the problem

serous exudate

local effect of inflammation where there is watery fluid in the tissues

hemorrhagic exudate

local effect of inflammation where there are damaged vessels leading to leakage of blood into tissues

fibrous exudate

local effect of inflammation where there’s an increased fibrinogen in tissue which creates thick and sticky meshwork increasing the risk of scar tissue formation

membranous exudate

local effect of inflammation where puss is found on the mucous membrane

purulent or suppurative exudate

local effect of inflammation where puss, tissue debris, old white blood cells and proteins are found

abscess formation

local effect of inflammation where puss core surrounded by neutrophils and eventually gets walled off

ulcer

local effect of inflammation where site of inflammation is the epithelial tissue

general systemic effects

* Malaise


* Fatigue
* Headache
* Anorexia
* Fever
* Increased number of WBC

leukocytosis

systemic effect of inflammation where there is an increased number of WBC especially neutrophils

leukopenia

systemic effect of inflammation where there is a decreased number of WBC

shift to the left

gives insight about how well body is handling inflammation

5 cardinal signs of inflammation

heat, redness, swelling, pain and loss of function

histamine

involved in immediate response and serves as a chemotaxis factor, which attracts leukocytes to the site of inflammation

nonspecific chronic inflammation

involves macrophages and fibroblasts

lymphadenitis

reaction of lymph nodes to acute or chronic inflammation

drugs used to treat inflammation

ASA, acetaminophen, NSAIDs and prednisone

differential counts

can identify different levels of neutrophils and eosinophils

* increased neutrophils identify bacterial infection
* decreased neutrophils viral infection
* increased eosinophils identify allergic response

increased cell enzymes

helpful in locating site of necrosis

normal capillary exchange

movement of oxygen and nutrients into cell and are not all open

* open only when needed
* precapillary sphincters restrict flow

resolution

type of healing where there is minimal tissue damage and tissue returns to normal in a short period of time

regeneration

type of healing where there is a replacement of injured tissue with cells of the same parenchymal type leaving little to no evidence of injury