Basic Concepts of Pathophysiology

Define Physiology

The study of functions & processes that occur in body, mostly the NORMAL processes

Define Pathophysiology

The study of the underlying changes in body physiology that result from disease or injury 

What is an example of Pathophysiology?

physiologic amenorrhea versus pathophysiological amenorrhea

What is an example of Pathophysiology?

physiologic albuminuria versus pathophysiological albuminuria

Define Homeostasis

maintenance of constant conditions in the body’s internal environment

What must cells constantly have?

Nutrients, H2O, O2, and exist in narrow pH & temperature range

Define Compensation

The return to homeostasis after being challenged by a stressor

Other words for compensation

Adaptation, healing, etc.

How is compensation achieved?

By the body’s use of control mechanisms

Provide an example of compensatory response to “normal” daily-life stressors

When exposed to an elevated external temperature (Texas summer) or heavy exercise  body temperature rises. The hypothalamus senses the elevated core temperature and sends a signal to the skin to produce sweat heat loss occurs through evaporation. Dilation of the superficial blood vessels also occurs  as “heated blood” circulates from the core to the periphery  heat loss occurs through radiation (heat removed from body into surrounding air).

Provide an example of compensatory response to pathologic stressors

 if you’ve lost a lot of blood (massive bleeding) or water (dehydration), the body uses certain compensatory techniques to keep remaining fluid volume circulating as effectively as possible (temporary measures until the cause of the problem gets fixed)

Define Decompensation

The failure to compensate, adapt, heal, etc. 

How does decompensation occur?

If the body is unable to appropriately meet the challenge of stressors-- for example, if  the control mechanisms are “exhausted”-- compensation can deteriorate either rapidly or slowly into decompensation

Define Disease

A harmful condition of the body (and/or mind)

Define Disorder

A disturbance in the healthiness of the body

Define Syndrome

A collection of symptoms

What are the terms leading up to a disease

risk factors and precipitating factor

Define risk factors

factors that or contribute to and/or increase probability that a disease will occur  …”setting the stage” 

Provide an example for risk factors

heredity, age, ethnicity, lifestyle (smoking, eating habits, etc), environment

Define precipitating factor

a condition or event that triggers a pathologic event or disorder …. the “kick-off”

Provide an example for precipitating factor

an asthma attack can be precipitated by exertion

What are the terms relating to causes of a disease

etiology, idiopathic, iatrogenic problem, and nosocomial problems

Define etiology

the cause of a disease; includes all factors that contribute to development of disease

Provide examples of etiology

• AIDS: HIV (human immunodeficiency virus)

• rheumatic heart disease: autoimmune reaction 

• TB (tuberculosis): mycobacterium 

Define idiopathic

disease with unidentifiable cause

Define iatrogenic problem

occurs as result of medical treatment

Provide an example for iatrogenic problem

if kidney failure is due to improper use of antibiotics prescribed by a healthcare provider you could say “the etiology of the kidney failure was iatrogenic.”

Define nosocomial problems

result as consequence of being in hospital environment

Provide an example for nosocomial problems

urinary tract infection is called a nosocomial infection if it developed while patient was in the hospital

What are the terms relating to course of a disease

Clinical manifestations and Prognosis

Define clinical manifestations

the demonstration of the presence of a sign and/or symptom of a disease

Define Sign

manifestations that can be objectively identified by a trained observer

Define Symptoms

subjective manifestations that can only be reported by the person experiencing them-- pain, nausea, fatigue

Define local S&S

some S&S are local: redness, swelling, heat, rash, & lymphadenopathy in a particular area

Define systemic S&S

others are systemic, such as fever, urticaria (hives), malaise (“I feel dragged out” or “awful all over”), systemic lymphadenopathy

Define acute S&S

fairly rapid appearance of S&S of dz (over a day to several days); usually last only a short time

Provide an example of acute S&S

The patient had an acute URI (upper respiratory infection) that resolved within a few days.

Define chronic S&S

develop more slowly; S&S are often insidious and last longer and/or wax and wane over months or years.

Define remissions

periods when S&S disappear or diminish significantly (wane) (chronic S&S )

Define exacerbations

periods when S&S become worse or more severe (wax); exacerbate—to provoke, to make worse. (chronic S&S)

Provide an example of exacerbations

The patient had an exacerbation of his chronic asthma and had to go to the hospital

What are the terms relating to location of manifestations

central and peripheral (or periphery)

Define central

usually refers to problem, situation, etc, that is occurring towards the center, or “core,” of the body

What is often used when referring to essential organ systems like brain, heart, lungs, kidneys?

Central

Fill in the blank. When someone loses a lot of blood, the body shunts most of the remaining blood away from non-essential areas such as gut, hands, feet, so that the essential organs are oxygenated—ie, most of the volume of blood ends up circulating __________.

Centrally

Fill in the blank. The more central an area or problem is, the more _________ to the core it is

Proximal

Provide an example for the term proximal

the arm was fractured proximal to the elbow

Define peripheral (or periphery)

refers to problem, situation, etc, that is occurring towards the outer parts of the body, away from core

Provide an example for peripheral (or periphery)

if we lose a lot of blood, the blood vessels of the periphery often constrict so that not a lot of blood can circulate into those areas (mainly arms & legs)

• thus there is more blood going to central areas such as the heart, brain, lungs, and kidneys—blood has been shunted to those areas

• this is why sometimes a sign of shock is cool, pale extremities.

Fill in the blank. The more peripheral an area or problem is, or further away from the core of the body, the more ______ it is.

Distal

Provide an example for the term distal

distal to the blood clot in the left coronary artery, the tissue lost oxygenation & died

Define Prognosis

the predicted outcome of a disease based on certain factors

Fill in the blank. ________ is the usual course of that particular disease AKA the likely course of a disease or ailment.

Prognosis

What are the characteristics used to find the prognosis?

An individual’s characteristics such as age and the presence of comorbidities

How does age affect the prognosis?

patients at either end of age spectrum --infants & the elderly are at higher risk for a poor prognosis due to immature or “worn out” immune systems, respectively

How does the presence of comorbidities affect the prognosis?

two or more coexisting medical conditions; this increases chance of poor prognosis

Provide an example for the presence of comorbidities

The patient’s comorbidities of heart disease and lung disease contributed to his poor prognosis in recovering from pneumonia

What is the term that relates to the aftermath of a disease.

Sequela

Define Sequela

any abnormal condition that follows and is the result of disease, injury, or treatment; synonym = complications

What is another way the term sequela is used?

occasionally the term is used as simply “outcome,”

Provide an example for a positive sequela

Getting pneumonia made the patient stop smoking

What is a possible sequela for chicken pox?

Shingles

What is a possible sequela for a stroke?

loss of sensation AKA hemiparesis