Introduction to Pathophysiology Flashcards
Define homeostasis
Preservation of a constant internal environment in a changing external environment.
What areas will we see pathologies due to the inability to maintain homeostasis?
Pathologies will be seen with:
- Thermoregulation
- Energy balance
- Serum glucose
- Osmoregulation
- Acid-base balance
- Blood volume
Define pathology.
The structural and functional changes in the body caused by disease or trauma.
Define pathophysiology
The study of disordered physiological processes associated with disease or injury.
What does etiology mean?
Cause(s) of a disease.
What does pathogenesis mean?
Mechanism(s) that result in the presenting signs and symptoms.
What does morphology mean in regards to pathophysiology?
Study of form and structure.
Describe a sign of disease/injury.
Any objective evidence of a disease.
Describe a symptom of disease/injury.
Changes detected or sensed by the patient.
Ex: stomach-ache, low back pain, fatigue, chest pain
What are 4 signs used to screen for melanoma?
- Asymmetry
- Border
- Color
- Diameter
What does subclinical mean?
Not sever enough to present definite or readily observable symptoms.
Ex: Covid-19 subclinical for 3 days before symptoms are shown
What does sequela(e) mean?
A condition that is the consequence of a previous disease or injury.
Define what a complication is.
A medical problem that occurs during a disease, or after a procedure or treatment has been completed.
Define resolution.
Reduction in the severity of a pathological state.
Define an illness.
Deviation from a healthy state. Has a broader, more generic and less ominous meaning than disease; tends to be acute or short term.
Define a disease.
Biological or psychological alteration that results in organ/system dysfunction; tends to be chronic.
*Can occur without perceiving the presence of an illness.
Describe what classifies an acute disease.
Rapid onset with short duration; usually self limiting; and can usually anticipate full recovery with full resolution.
Describe what classifies a chronic disease.
Often results in a permanent impairment, or physical/ cognitive impairment; Often require special rehabilitation and/or long term management; and may fluctuate in intensity.
Describe atrophy.
A decrease in size secondary to loss of cell substances or cell number. It can result in a smaller organ/tissue.
*atrophy does not imply cells are dead, but that they have reduced capacity/numbers
Describe hypertrophy.
An increase in the size of cells/organ. Can be physiologic or pathologic.
Give an example of physiologic versus pathologic hypertrophy.
Physiologic = muscle growth
Pathologic = cardiomyopathy secondary to long standing HTN.
Describe hyperplasia.
An increase in cell number/organ size.
What are two types of hyperplasia?
Hormonal hyperplasia = driven by hormones
Compensatory hyperplasia = driven by tissue loss or damage.
Describe metaplasia.
When one adult cell type is replaced by another adult cell type. Arises through genetic reprogramming.
Define dysplasia.
The presence/development of abnormal cells within a tissue or organ.
Give an example of macroscopic and microscopic dysplasia.
Macroscopic = hip dysplasia
Microscopic dysplasia = cancers
Cellular consequences of and insult or injury are dependent on what 4 things?
- Type of insult
- Status of cells at time of insult
- Adaptability of cells
- Genetic makeup of cells
Describe ischemia.
When blood flow is below minimum necessary to maintain cell homeostasis.
Define hypoxia/anoxia.
Deficiency or absence of oxygen.
What causes hypoxia?
- Obstruction in moving air to lungs
- Inadequate movement of O2 from lung to blood
- Inadequate transport of O2
- Inability to utilize O2 at tissue level to fuel cell processes.
Describe what exotoxins and endotoxins are when talking about bacteria.
Exotoxin = when bacteria invade tissue and then is released into the surroundings.
Endotoxins = remain within the bacteria and are released upon cell death.
Define sepsis.
The presence of microorganisms or their toxins in the blood.
What is septic shock?
When there is endothelial cell damage, reduced blood volume, or maldistribution of blood flow that results in cardiovascular collapse or shock.
Describe what an aberrant immune reaction is.
An overly aggressive inflammatory response.
What are physical factors that cause cell injury?
- Trauma
2. Extreme environmental factors (cold, heat, radiation)
What are chemical factors that cause cell injury?
- Chemicals can directly injure/kill cells
- Chemical can have metabolites that injure/kill cells
- Chemical can generate reactive oxygen species
What are the consequences of reversible cell injury?
A mild injury leads to sub lethal alterations/injury and inflammation in the affected cells with recovery resulting in a return to pre-injury state.
What are the consequences of chronic cells injury? What must the cells do?
An occurrence of a sublethal stress over a period of time leads the cell to adapt, allowing it to function in an altered environment.
Example: atrophy, hypertrophy, hyperplasia, metaplasia
What is irreversible cell death synonymous with?
Cell death.
What state of cell injury do physical therapy interventions influence?
The reversible cell injury state.
Which state of cell injury leads to decrease in function?
Chronic cell injury.
What is apoptosis?
The identification and removal of dead cells. Is a natural well regulated, controlled, and useful process.
“cellular housekeeping”
What type of cells clean up the process of apoptosis?
Phagocytes
What is a necrosis?
A form of tissue injury that results in cell death within living tissue.
Describe what causes necrotic tissue and what happens when it is activated.
- Is caused by factors external to the cell or tissue, such as infection, toxins, or trauma
- results in the unregulated digestion of cell component
- results in an uncontrolled release of products of cell death into the extracellular space
- initiates an inflammatory response.
What is a classic example of necrosis?
Gangrene.
*Happens because normal housekeeping does not occur after cell death, which results in accumulation of the decomposing cell debris.
What are the phases of the tissue repair scale and what kind of time scale does each phase follow?
- Bleeding = hours to days
- Inflammation = hours to weeks
- Proliferation = days to months
- Remodeling = weeks to years
