Basics Flashcards
Pathology Definition
Study of biological causes and process of disease
Disease Definition and Types
Structural or functional change that is harmful to the organism
Organic Disease
Functional Disease
Organic Disease
Disease associated w/ structural changes
Ex: cancer, viral/bacterial infection resulting in cell death
Cancer = tumor = structural changes
Viral/Bacterial infection = kills cells = structural change
Functional Disease
Disease associated w/ change in tissue/organ function
Ex: irritable bowel disorder, GERD
Pathology’s Importance in Allied Health Professions
Allied health practitioners are typically the first in line of medical care
An understanding of the pathology of injury and illness allows the allied health practitioner to identify injury and illness and make appropriate referrals and appropriately treat the injury or illness
Signs
Observable indication of pathology
Symptoms
Abnormal function, appearance or sensation experienced by the pt.
Diagnosis
Identification of a specific injury or illness as determined by medical examination
Prognosis
Prediction of the course of a condition
Sequela
A condition following and resulting from a disease or injury
Ex: pneumonia from COVID
Syndrome
Group of symptoms and signs commonly associated with a particular disease or injury (things you would expect from a disease/injury)
Causes of Pathology: Predisposing Factors
Condition or situation that may make the person more susceptible to injury or illness
- Age (compromised immune
systems)
~ Newborn (haven’t been
exposed yet)
~ Elderly (not as strong
anymore)
- Sex
- Genetics
~ Defective genes are passed
along by the parents (sickle
cell)
~ Gene mutation (cancer)
Causes of Pathology: Exogenous Causes
Cause from outside the body
- Physical
~ Extreme heat/cold
~ Electricity
~ Atmospheric pressure change
~ Radiation
~ Direct trauma
- Chemical
~ Poisoning
~ Drug reaction
- Microbiologic (infection can result
in cell death and/or dysfunction)
~ Virus
~ Bacteria
~ Fungus
~ Parasite
Causes of Pathology: Endogenous Causes
Cause is from inside the body
- Vascular
~ Obstructed blood flow
(stroke, DVT, heart attack)
~ Hemorrhage (stroke)
- Immunologic
~ Autoimmunity (body's own
immune systems causes
disease)
~ Allergy
~ Immune deficiency
- Metabolic (abnormalities involving
regulation of lipid, carbohydrate,
protein, minerals, vitamins, fluid)
~ Type 2 diabetes
Causes of Pathology: Idiopathic
Cause of the disease is unkown
Principles of Diagnosis: Physical Exam
- Observation, palpation, listening, smelling for signs of illness
- Comprehensive, but focus on the part of the body affected by the disease
Principles of Diagnosis: History
History of current illness
- Details concerning severity, time
of onset and characteristics of
pts. symptoms
Past medical history
- Info on past disease
~ General health
~ Correlation to present disease
Family history
Social history
- Habits
~ Exercise
~ Tobacco use
~ Alcohol use
~ Drug use
- Occupation
Principles of Diagnosis: Lab Testing
(“Special Tests”)
- Imaging
- Blood
- Urine
Body’s Response to Pathology
Inflammation
- Natural physiological changes
- Fluid, chemicals and cells are
brought to the area to:
~ Limit injury
~ Remove debris
~ Prepare for healing
~ Rid of infectious organisms
- Occurs in somewhat predictable
phases
~ Phases are progressive, but
overlap one another
Triggers for Inflammation
- Necrosis
~ Cell death - Degeneration
~ Sublethal cell injury - Exposure to allergen/pathogen
~ Triggers immune system
Signs and Symptoms of Inflammation
- Pain
~ Caused by damage to nerve endings
and release of histamine,
prostaglandin, serotonin and
bradykinin. - Redness & Heat
~ Caused by the increased blood flow
and vasodilation. - Swelling
~ Caused by plasma/exudate
movement. - Loss of Function
~ Caused by swelling, pain and/or
neurological damage.
Fever Production
- PGE2 is produced through the COX pathway.
- PGE2 triggers the hypothalamus to increase body temperature by:
~ Increasing Metabolism (causes more
heat)
~ Vasoconstriction in extremities
(blood goes to core and increases
heat)
~ Inducing shivering (muscle
contraction causes increase in heat) - Fever occurs naturally to try and kill off bacteria because bacteria doesn’t like high temps
Infection
- Disease caused by microorganism (viral, bacterial, fungal or parasitic) invasion.
- Transmission Methods
~ Direct Contact
> Contact with skin or mucous
membranes.
> Contact with sputum and
discharges from respiratory
system.
Transmission Methods: Indirect Contact
- Contact w/ surfaces that have been contaminated (bedding, clothes, etc.)
- Contaminates
~ Blood
~ Sputum and discharges from
respiratory system
~ Feces or urine
~ Saliva
Transmission Methods: Airborne
- Pathogens carried in evaporated residue of human discharges
- Pathogens carried in dust from contaminated bedding or soil
Transmission Methods: Vector
- Pathogens carried on or in another organism that’s not infected
- Mosquito bites infected host and bites an uninfected host
Stages of Disease: Incubation
Period between initial infection and the appearance of signs and symptoms of disease
Stages of Disease: Prodromal
- Short interval after incubation
- Develop non-specific symptoms (due to inflammatory response)
~ Fever
~ Headache
~ Aches and pains - Disease is contagious
Stages of Disease: Acme
- Specific signs and symptoms of the disease develop and peak
- Highly contagious!
Stages of Disease: Convalescence
- Symptoms subside
- Host regains normal functioning
- Disease can still be contagious
Defenses Against Infection: Structural
- Unbroken Skin
- Nasal Hairs
- Respiratory Cilia
- Respiratory Mucous
Defenses Against Infection: Chemical
- Lysozyme
~ Enzyme found in tears, saliva, and
lymphocytes
~ Dissolves walls of bacteria - Interferon
~ Protein found throughout body
~ Produced by leukocytes
~ Interferes w/ virus production
Defenses Against Infection: Cellular Defense/Lymphatic System
- Runs Parallel to the Venous System
- Widely Distributed
~ Lymph Nodes
~ Spleen
~ Liver
~ Thymus
~ Bone Marrow - Removes wastes
Non-Specific Cells Associated with Defense: Macrophages
- Monocytes and Neutrophils
- Originate from the bone marrow.
- Activated when cells are damaged to ingest the pathogens or debris.
Acquired Immunity
- Cell Mediated Immunity
~ Specialized lymphocytes that attack
and destroy foreign material
(bacteria, virus, parasites, fungus) - Humoral Immunity
~ Production of anti-bodies that work
to eliminate foreign material
Antigen
- Protein or sugar on the surface of cells
- Identifies cell type
- Identifies whether a cell is foreign
Cell Associated with Defense: T-Lymphocytes
- Produced by the thymus
- Have receptors on their cell membrane to recognize specific antigens
T-Lymphocytes: Regulators
- One Type secretes proteins to activate effector T-cells and B-lymphocytes (helpers)
- Second type secretes protein to inhibit excessive immune system response (suppressors)
T-Lymphocytes: Effector
- One type attacks and kills cells infected with bacteria or virus (killers)
- Second type accumulates at site of infection to attract and activate macrophages (neutrophils and monocytes)
Cells Associated with Defense: B-Lymphocytes
- Produced by the bone marrow
- Produce antibodies for specific antigens
~ Plasma protein
~ Destroys or disables pathogens
Antigen/Antibody Reaction
- Pathogen enters the body
- Antigens on the surface of the pathogen identify it as foreign
- Specific B-lymphocytes produce specific antibodies against the pathogen
- Antibodies bind to the antigen
~ Interfere with the pathogens ability to
attach to cells
~ Coat pathogens to ease ingestion by
macrophages
~ Attract proteins and enzymes that can
damage the pathogen
(Antibodies keep pathogens from attacking cells, attract other cells to eat it, and or kill it)
Immune Reaction Characteristics: Specificity
- On antibody T-cell will react specifically to the antigen that induced its formation
- Will not react with other antigens
Immune Reaction Characteristics: Memory
Once an immunological response has taken place in reaction to a specific pathogen the system can produce the correct antibody T-cells more rapidly and in larger amounts in reaction to later exposure to the pathogen
Immune Reaction Characteristics: Tolerance
The lymphatic system will not initiate an immunological response to the body’s own antigens
Natural Killer Cells
- Lymphocytes that target virus infected cells and cancer cells
~ Don’t require the presence of foreign
antigens or specific antibodies for
activation
~ Activated by proteins secreted by T-
lymphocytes
~ Fast response
Vaccine
- Introduction to antigen/proteins of infection causing bacteria or virus
~ Dead or inactive bacterial or viral
material injected
~ Triggers cells to produce foreign
proteins - Takes advantage of the “memory” characteristic of the immune system
- Can cause some prodromal symptoms, but doesn’t cause infection
~ Natural inflammatory response
causes symptoms
What is a Drug?
- Chemical demonstrated to be effective for preventing or treating a disease.
- Drug Development
~ Prove effectiveness of chemical
already known to have a therapeutic
effect.
> Aspirin/Salicylic Acid -
Chemical identified in willow
tree bark used for thousands
of years for pain and headache
~ Design a chemical from scratch for a
specific purpose.
~ Identify unpredicted effects of drugs
intended for another use.
> Viagra/Sildenafil - First
developed to treat
hypertension and angina
pectoris (chest pain).
Drug Safety
- Prior to 1962 there was a less stringent process for evaluating the safety of drugs to protect the public.
~ Manufacturers could sell a new drug
if the Food and Drug Administration
(FDA) did not act within 60 days to
prevent its marketing.
~ Did not have to prove effectiveness
and only safety if FDA asked for it. - A drug used to relieve morning sickness (Kevadon/Thalidomide) and used mostly in foreign countries was causing significant birth defects.
~ Drug distributed to 1200 US
physicians.
~ 17 births of deformed infants tied to
Kevadon in the US.
~ The Kefauver-Harris Amendment
was approved in 1962 leading to the
process now in place for drug
approval.
FDA Process
- FDA reviews and approves all new drugs before they’re available to the public
- Process involves two main steps:
~ Preclinical Testing
> Testing on animals to confirm the
desired effects of the chemical
biological systems
~ Clinical Trials (testing on humans)
> Confirm desired effects in human
physiology
> Effectiveness on healthy persons
and pts.
> Identify adverse and long term
effects
Other FDA Processes
- Evaluate drugs made before 1962
~ Mostly for effectiveness - Recall drugs that are unsafe or potentially unsafe
~ Class 1: Possibility that there’s a
serious threat to consumer health
~ Class 2: May cause a temporary
health problem
~ Class 3: Not likely to cause a health
hazard (usually a labeling error)
Drug Classifications
- Nonprescription/Over the Counter (OTC)
- Prescription
- Controlled Substances
~ Controlled due to abuse potential
and poor safety profile, at least
theoretically
OTC
- Does not require a prescription
- Usually lower dosage compared to prescription drugs
- Often contain multiple active ingredients
~ Pt. usually has multiple things going
on and companies target
Prescription Drugs
- Have greater potential for adverse effects than OTC drugs.
- Medical supervision required.
~ Monitor Effectiveness
~ Monitor for interactions with other
drugs. (pt may be unaware of
dangers with combining drugs) - Used for a restricted amount of time.
Controlled Substances (illegal or prescription)
- Have abuse or safety concerns.
~ Manufacture, distribution, and use
are more restricted. - Also referred to as scheduled
substances.
~ Schedule 1
> High abuse potential.
> No accepted medical use
> Ilegal drugs like heroin, LSD
~ Schedule 2
> High abuse potential.
> Accepted medical uses.
~ Schedule 3 - Lower abuse potential
than schedule Il.
~ Schedule 4 - Lower abuse potential
than schedule III.
~ Schedule 5 - Lowest abuse potential
(cough medicine).
Generic Name
- Usually the drugs chemical name or a shortened version of it
- Drugs official assigned name
- Only one generic name for each drug
- Ex: Acetaminophen is the generic name for Tylenol
Trade/Brand Name
- Name assigned by a manufacturer
- Only one trade name can be assigned by the original developer until the drug patent has expired (20 years) then other companies can assign a trade name
Generic vs. Trade Name
- Generic drugs and name brand drugs are identical as far as active ingredients
~ Companies producing generic drugs
must show that the drug is equivalent
to the original trade name product
~ Generic and name brand drugs differ
only in price and packaging
> Low price is the main motivator
of the consumer
> Companies new to the
manufacturing of the drug didn’t
have to do initial testing
Sharing Prescription Drugs is Bad
- Illegal
- Prescription medications are dispensed in a specific amount for treatment of a specific condition
~ Pt. focus on symptoms
> Different conditions can have
similar symptoms - Allergic reaction
~ NSAIDs
~ Antibiotics - Transfer infection with ophthalmic intranasal administration
