Chapter 7: Principles of Pathophysiology
Topics
● The Cell
● The Regulation of Homeostasis
● The Cardiopulmonary System
● Shock
● Pathophysiology of Other Systems
Introduction to Pathophysiology
● Study of how diseases processes affect function of body
● Undstanding helps you recognize changes patient is going through due to illness or
injury
● Understanding helps you recognize the needs of the body in its most vulnerable state
The Cell
Cell membrane protects and selectively allows water and other substances in and out of the
cell.
Mitochondria convert glucose and other nutrients into adenosine triphosphate (ATP).
Fuel for cell functions
Without ATP, many of the cell’s specialized structures cannot function.
Water and the Cell
Cells need the correct balance of water inside and outside.
● Too little water- Cell dehydrates and dies
● Too much water- Basic cellular function interrupted
Water also affects levels of electrolytes.
Impacts electrical functions
Glucose and the Cell
● Building block for energy
● Supply of insulin must match the body’s glucose requirement
Oxygen and the Cell
● Aerobic metabolism- Cellular functions using oxygen
● Anaerobic metabolism- Cellular functions not using oxygen
Creates much less energy and much more waste.
Body becomes acidic, impairing many body functions.
The Vulnerability of Cells, Organs, and Organ Systems
Many diseases alter the permeability of the membrane.
Ineffective cell membrane can allow substances into the cell that should not be there.
These substances can interfere with the regulation of water.
The Regulation of Homeostasis
, Homeostatsis
Regulated in the brain
Maintained through nervous system feedback and messaging
Key structures are the hypothalamus and medulla oblongata
The Fight or Flight Response
Parasympathetic nervous system:
● “Feed or breed” functions
● Neurotransmitters regulate digestion and reproduction
● Reduces heart rate and blood pressure
Sympathetic nervous system:
● “Fight or flight” situations
● Epinephrine and norepinephrine
● Enhances body’s ability to protect itself
● Increases heart rate and blood pressure
The Cardiopulmonary System
Respiratory and cardiovascular systems work together.
● Bring oxygen into body
● Distribute to cells
● Remove waste products
Any breakdown can result in system failure.
The Airway
Must have an open (patent) airway for system to function
Upper airway obstruction are common.
● Caused by foreign bodies, infection, or trauma
The Lungs
Part of lower airway
Tidal volume- Volume of air moving in and out during each breath cycle
Tidal volume x respiratory rate= minute volume
● Amount of air moved in and out of lungs in one minute
Any decrease in tidal volume or respiratory rate reduces minute volume.
Respiratory dysfunction occurs any time something interferes with minute volume.
Respiratory Dysfunction
Disruption of respiratory control:
● Respirations controlled in brain by the medulla oblongata
● Any even impacting function of the medulla oblongata can affect minute volume
● Infection, drugs, toxins, trauma
Disruption of pressure:
● If a hole is created in the chest wall (thorax), pressures needed for breathing are
disrupted
Topics
● The Cell
● The Regulation of Homeostasis
● The Cardiopulmonary System
● Shock
● Pathophysiology of Other Systems
Introduction to Pathophysiology
● Study of how diseases processes affect function of body
● Undstanding helps you recognize changes patient is going through due to illness or
injury
● Understanding helps you recognize the needs of the body in its most vulnerable state
The Cell
Cell membrane protects and selectively allows water and other substances in and out of the
cell.
Mitochondria convert glucose and other nutrients into adenosine triphosphate (ATP).
Fuel for cell functions
Without ATP, many of the cell’s specialized structures cannot function.
Water and the Cell
Cells need the correct balance of water inside and outside.
● Too little water- Cell dehydrates and dies
● Too much water- Basic cellular function interrupted
Water also affects levels of electrolytes.
Impacts electrical functions
Glucose and the Cell
● Building block for energy
● Supply of insulin must match the body’s glucose requirement
Oxygen and the Cell
● Aerobic metabolism- Cellular functions using oxygen
● Anaerobic metabolism- Cellular functions not using oxygen
Creates much less energy and much more waste.
Body becomes acidic, impairing many body functions.
The Vulnerability of Cells, Organs, and Organ Systems
Many diseases alter the permeability of the membrane.
Ineffective cell membrane can allow substances into the cell that should not be there.
These substances can interfere with the regulation of water.
The Regulation of Homeostasis
, Homeostatsis
Regulated in the brain
Maintained through nervous system feedback and messaging
Key structures are the hypothalamus and medulla oblongata
The Fight or Flight Response
Parasympathetic nervous system:
● “Feed or breed” functions
● Neurotransmitters regulate digestion and reproduction
● Reduces heart rate and blood pressure
Sympathetic nervous system:
● “Fight or flight” situations
● Epinephrine and norepinephrine
● Enhances body’s ability to protect itself
● Increases heart rate and blood pressure
The Cardiopulmonary System
Respiratory and cardiovascular systems work together.
● Bring oxygen into body
● Distribute to cells
● Remove waste products
Any breakdown can result in system failure.
The Airway
Must have an open (patent) airway for system to function
Upper airway obstruction are common.
● Caused by foreign bodies, infection, or trauma
The Lungs
Part of lower airway
Tidal volume- Volume of air moving in and out during each breath cycle
Tidal volume x respiratory rate= minute volume
● Amount of air moved in and out of lungs in one minute
Any decrease in tidal volume or respiratory rate reduces minute volume.
Respiratory dysfunction occurs any time something interferes with minute volume.
Respiratory Dysfunction
Disruption of respiratory control:
● Respirations controlled in brain by the medulla oblongata
● Any even impacting function of the medulla oblongata can affect minute volume
● Infection, drugs, toxins, trauma
Disruption of pressure:
● If a hole is created in the chest wall (thorax), pressures needed for breathing are
disrupted
