Mechanisms of Disease

Pathology

study of disease

Disease

Abnormal function that threatens well being

Signs

Objective adnormality; can be seen or measured

Symptom

subjective abnormality, pt statement

Syndrome

Collection of s&s with a common cause

acute

sudden onset of s/s, persist short time and disappear

chronic

develops slowly; and last a long time (maybe for life)

Idiopathic

disease with undetermined causes (unknown etiology)

Etiology

the study of the causative factors of a disease

Communicable

transmits from 1 person to another

Epidemiology

The study of disease occurrence, distribution, and transmission. They study

the causal and coincidental relationships when examining outbreaks and transmission

morbidity

disease rates in a specific population

mortality

#of deaths caused by specific diseases

Pathogenesis

actual pattern of a diseases development

Remission

reversal or lessening of s/s

Latent stage

hidden stage, organism establishes itself in pt, no signs are evident

Incubation

latent stage in an infectious disease

Endemic

disease native to a local region

epidemic

affects many people at the same time

pandemic

widespread epidemic; global

factors that affect spread of disease

age, gender, nutrition, socioeconomics, sanitation, infectious agents

Pathophysicology

study of underlying physiologic processes associated w/ disease. usually involved a disturbance of homeostasis

Categories of disease mechanisms

Genetics, pathogens, tumors and cancer, physical/ chemical agents, malnutrition, autoimmune, inflammation, degeneration

Genetics

• mutated genes

• Abnormal protein production/ function resulting in absent or disruptive functioning

• causes for many disease

• Ex: hemophilia, down syndrome

Pathogens

• disease causing microorganisms

• organisms that cause damage to the cells, tissues, organs systems and/or the body as a whole

• Include: bacteria, fungus, virus

tumors and cancer

• Abnormal cell growth and/or division

• causes a wide variety of physiologic disturbance

• neoplasm: abnormal tissue growth

physical/ chemical agents

• cause a variety of pathologies

• toxic chemicals, cold/ heat, mechanical injuries, radiation

• ex: lacerations, burns, contusions, fx, poisoning, hearing impairment etc

malnutrition

• insufficient or unbalanced intake of nutrients resulting in many disease states

• ex: night blindness, rickets, anemia

autoimmune

• own immune system attacks itself due to an over reaction or malfunction of immune response

• ex: ulcerative colitis, rheumatoid arthritis

inflammation

• abnormal inflammatory response results in disease

• inflammation is protective can cause disease if it occurs at inappropriate times

• ex: asthma

degenerations

• normally, this occurs with aging but can occur any time

• unknown causes for premature issue breakdown

• ex: DJD

risk factors

predisposing conditions that make the development of disease more likely, not a cause of disease but rather contributes to the likelihood of developing a disease, many can be controlled or eliminated

• genes

• age

• lifestyle

• stress

• environment

• preexisting conditions

prevention and control

Key to preventing many diseases is to prevent entrance into the human body and control spread from 1 to another

spread of pathogens

• person to person contact

• Environmental contact

• Opportunistic invasion

• Transmission by vector

Vaccine

killed or attenuated pathogen stimulates immunity

antibiotics

compounds produced by living organisms that kill or inhibit bacteria

antivirals

synthetic drugs that do not stop infections but inhibit viral reproduction and, slow down the progression of the viral disease.

Tumors/ cancer

neoplasm: abnormal cell growth; tumor

can be distinct or diffusely spread

benign vs malignant

benign

• localized

• encapsulated

• grow slowly

• no metastasis

• usually not life threatening

• differentiated cells

benign epithelial tumors

• papilloma: Wart, corn, polyp

• Adenoma: of glandular tissue

• Nevus: pigmented lesion; mole

benign conn tiss tumors

• Lipoma: inv adipose tiss

• Osteoma: inv bone tiss

• Chondroma: inv cartilage tiss

malignant

• Not encapsulated

• Can metastasize via blood or lymph

• Rapid growth

• Undifferentiated cells

• Life threatening

malignant epithelial tumors

• AKA carcinomas

• Melanoma: inv melanocytes

• Adenocarcinoma: malignancy of glandular

  tiss

malignant conn tiss tumors

• AKA sarcoma

• Lymphoma: inv lymph tiss

• Osteosarcoma: inv bone tiss

• Myeloma: inv bone marrow

• Fibrosarcoma: inv fibrous conn tiss

  (ex:tendons)

other cancers

• neuroblastoma: inv nervous tiss

• can be labeled according to general location

  • stomach, colon, breast, lung

CA causes

• genetics

• carcinogen exposure and environment

• age

• pathogens (virus)

CA warning signs

• Unusual Bleeding

• Sore that doesn’t heal

• Change in wart/mole

• Lump/thickening

• Cough/hoarseness

• Chronic indigestion

• Change in bowel/bladder habits

• Bone pain

Neoplasm

abnormal cell growth/ uncontrolled division

hyperplasia

too many cells

anaplasia

prod of abnormal undiff cells

diagnosing CA

• self exam

• imaging

• biopsy

• blood testing

CA prognosis

• Staging: I-IV; classification based on size and extent of spread

• Grading: (A-D); assessment of what the tumor is likely to do based on the degreemof cell abnormality

• Also extent of lymph node and other organs involved

CA TX

• surgery

• radiation

• chemotherapy

• laser therapy

• immunotherapy

CA Tx complications

• Cachexia: appetite and wt loss and generalized weakness

• Death: may occur as a tx complication or secondary infection

Inflammatory response

• Protective response to irritant/injury

• Processes that attempt to minimize injury and maintain homeostasis

signs of inflammation

• redness

• swelling

• heat

• pain

Types of inflammation

• Acute: immediate protective response

• Chronic: ongoing. Causes tissue damage. Due to malfunction of immune sys or pathogen exposure

• Localized: isolated to a specific area

• Systemic: affects entire body

inflammation mediators

• Compounds released when cells are damaged

• Cause a series of events following an injury

• Kinins, prostoglandins, histamine

MEMORIZE TIME

The graph on the slideshow page 50 on inflammatory response

Inflammatory exudate

• Fluid that accumulates in inflamed tiss

• Blood prot move into tiss spaces, clot and form a capsule @ inj site preventing spread of irritant

• Slowly removed by lymph vess

• Pus is inflamm exudate thick w/ WBCs, pathogens, debris

fever

• Systemic response

• Inflamm med or irritant reset thermostat

• Inc temp kills/inhibits pathogen and may enhance immune response

• Peds: may dev very high fever w/ inf

• Geriatrics: decreased fever resp which may impair ability to resist inf or dx illness

Meds to tx inflamm

• ASA: disrupts the synthesis of

  prostoglandins

• Antihistamine: blocks histamine

Tissue repair

• Regeneration: new cells formed that have similar structure and function

• Replacement: new cells differ = scar