➔ Pathophysiology
◆ Physiology of altered health
● Patho: from Greek pathos meaning “suffering, disease”
● Physiology: from ancient greek, physis, meaning “nature,
origin,” and logia, meaning study of
◆ Study of structural and functional changes in cells, tissues and organs of the
body that cause pr are caused by disease
➔ Disease
◆ A part, organ or system of the body that is manifested by signs or symptoms
➔ Why should nurses study pathophysiology?
◆ To ask questions and find answers
◆ Nurses need to ask questions and find answers when we meet patients
➔ We need to ask the questions:
◆ What causes diseases in our patients
◆ How do diseases alter our patients normal physiology
◆ Why do our patients get certain signs and symptoms
◆ How do our patients influence the course of disease
◆ How does each disease cause complications
◆ Which complications are associated with which disease?
➔ How is pathophysiology different for doctors than nurses?
◆ MD approach uses treatments of medicine and surgery to repair or acute disease
◆ RN approach deals with the experience of the person with disease, signs
and symptoms, comfort and function
➔ BELL: Components of the disease process
◆ Etiology
● What caused the disease
● “High water pressure burst a pipe”
◆ Pathogenesis
● The story of the development, or path, of the disease
● Pattern of tissue changes
◆ Clinical manifestations
● Morphological (shape) changes that show disease is present
● “Morphing” is a shape change
● Signs and symptoms (objective and subjective)
◆ Diagnosis
● Name that problem, the reason as to why the patient is
coming to the hospital
◆ Clinical course
● How the disease progresses from the time it starts
● Can be acute, chronic, or terminal
➔ Pathophysiology
◆ Pathogenesis
, ● Etiology
● Mechanism of disease
◆ Clinical manifestations
● Signs
● Symptoms
◆ Diagnosis
◆ Treatment and care
➔ BELL: Epidemiology measures
◆ Incidence = number of individuals who develop a specific disease
during a particular time period
◆ Prevalence = proportion of a population who have a specific
characteristic in a given time period
◆ Morbidity = rate of disease in a population
◆ Mortality = number of deaths in a population unit per time
➔ Influences on disease
◆ Genetics
◆ Age
◆ Lifestyle and more
➔ Impacts to systems
◆ Metabolic
◆ Hematologic
◆ Pulmonary
◆ Cardiovascular
◆ Hormonal
◆ Gastrointestinal
◆ Neurological
◆ Musculoskeletal
◆ Immune
◆ Renal
➔ BELL Physiologic aging
◆ Senescence = Cells progressive loss of the ability to replicate over time
◆ Loss of physiologic reserve = decreased ability to age and adapt to
physiologic stresses, younger people heal faster
◆ Multicausality = Internal processes and influences from the
environment cause senescent cell changes, multiple factors
affecting progression of disease
➔ BELL theories of aging
◆ Programmed aging of the cell
● Ex: ovary undergoing apoptosis after 55 years (menopause)
● Telomere shortening theory
○ Telomere is an area of nucleotide sequences at the
end of a chromosome, which shortening with aging
○ Replication will not occur over time for older people
○ Telomere rays can replace them
, ◆ Damaged based theory of aging
● Means that as we age our cells will get damaged more and more
from the environment
● Makes aging worse
● The damage will impact the DA as well which will lead
to error in metabolism and protein functions which can
cause cell death
◆ Free radical accumulation theory
● Really reactive, trying to find molecules that can bind because
they have one free electron (and want to become stable)
● Can damage other cells after they bind
● Smoking will cause more free radicals in our body
● Free radicals contain a free electron with chemically
instability and a strong affinity to bind to other molecules
◆ Immunosenescence: losing biological ability
● The nature mechanism and vaccinations
● Older people will have a bad immune system
● Leaked innate and adaptive immune systems
Chapter 2: Cell adaptation and inflammation
➔ When injured, cells can:
◆ Adaptive changes
● Homeostasis (dynamic steady state)
● Maladaptive changes (can develop into a disease)
◆ Cell injury or cell death can occur in circumstances of overwhelming insult
➔ BELL cellular adaptation
◆ 5 different types of cell adaptation:
◆ Change in size or number
● Hyperplasia
○ Increase in cell number
○ Ex: breast enlargement when pregnant, scar tissue
○ Usually returns back to normal
● Hypertrophy
○ Increase in cell size
○ Lower quality of blood
● Atrophy
○ Decrease in cell size
◆ Change in cell
type
● Metaplasia
○ Reversible replacement of one mature cell type by
another less mature cell type
○ Ex: GERD/Barrett’s esophagus
● Dysplasia
○ Deranged cellular growth, a PRE-cancerous condition
, ○ It can become neoplasia (means new growth = cancer cells)
➔ Causes of cell injury
◆ Hypoxic cell injury
● Hypoxia: not enough oxygen/blood supply → cells cannot survive
○ Reduced blood supply → cells become injured
● Causes ischemia
● Anemia → infection
◆ Free radical injury (oxidative stress)
● Exogenous: from environment
● endogenous
◆ Physical agents of injury (ex: knife)
◆ Chemical injury: based on medication
◆ Infectious agent injury: bacteria, fungi, etc
◆ Injurious immunological reactions: normal things that help our body
protect itself from foreign invaders
◆ Genetic defects: some effects RNA & DNA
● Can cause cellular & nutritional cell injury
◆ Nutritional imbalances
➔ BELL free radicals and reactive oxygen species
◆ Free radical is an electrically uncharged atom or group of atoms
that has an unpaired electron
● Unstable molecules
● Highly reactive meaning they can react with most close molecules
● Become a threat to cells when cells are deprived of oxygen
◆ Formation of free radicals
● Normal respiration, radiation, chemicals, inflammation, metals
◆ Oxidative stress occurs when ROS overwhelms endogenous antioxidant system
★ Smoking is a good example of exogenous free radical
➔ BELL free radicals
◆ Free radicals oxidize cell structures and can be called oxidants
◆ They disrupt the integrity of the cell membrane and damage
organelles and DNA, causing cell dysfunction
● If someone is healthy, their normal cells remove the free
radicals -- if they are unhealthy, it's an issue
◆ The body has natural free radical “scavengers” or natural antioxidants that
destroy these destructive molecules
◆ Antioxidants such as vitamins A E C and beta-carotene counteract free radicals
➔ Cell death
◆ Apoptosis (dropping off) can be normal (as patients who are older aged)
● Active process of cellular self-destruction called programmed cell death
● Both normal and pathological tissue changes