CH 6: Principles of Pathophysiology Flashcards
What are the chemical components of inhaled air?
79% nitrogen, 21% oxygen
What is tidal volume?
The volume of air moved in one cycle of breathing.
Measured in mL.
What is minute volume?
The amount of air breathed in during each respiration X number of breaths/minute.
What is dead air space?
Air that occupies space between mouth and alveoli but that does not actually reach the area of gas exchange.
What is the seat of respiratory control?
Medulla oblongata
What can interfere with the medulla oblongata?
Stroke
Infection
Toxins / drugs
Brain trauma / intracranial pressure
How is ventilation activated?
Changing pressures in the thorax.
What is the chief culprit of lung tissue disruption?
Trauma
Can also be: medical problems (congestive heart failure, sepsis)
What is the result of lung tissue disruption?
Low oxygen (hypoxia) and high carbon dioxide levels (hypercapnia)
What are chemoreceptors?
Chemical sensors in the brain and blood vessels that identify changing levels of O2 and CO2
What is the liquid portion of the blood?
Plasma
How does blood transport oxygen?
By binding the oxygen to the hemoglobin in red blood cells.
ALSO
By dissolving in plasma (lesser extent)
What is plasma oncotic pressure?
The pull exerted by large proteins in the plasma that tends to PULL water from the body INTO the bloodstream.
What is hydrostatic pressure?
Pressure within a blood vessel that tends to PUSH water OUT of the vessel.
The most common blood dysfunctions occur because of what?
Inadequate blood volume - BLEEDING/DEHYDRATION
What are stretch receptors?
Sensors in blood vessels that identify internal pressure
What role does the autonomic nervous system play in vessel diameter?
Sympathetic nervous system - fight/flight: constricts vessels
Parasympathetic nervous system - vessels relax
What is stroke volume?
The amount of blood ejected from the heart in one contraction.
What is preload?
The amount of blood returned to the heart prior to the contraction. Ie, how much it is filled.
What is cardiac output?
The amount of blood ejected from the heart in 1 minute. (heart rate X stroke volume)
What are the two types of heart dysfunctions?
Mechanical or electrical
What is a V/Q match?
Ventilation/perfusion match.
The alveoli are supplied with enough air and the air is matched with sufficient blood in pulmonary capillaries to permit optimum exchange of O2 and CO2.
How much of the body is made up of water?
60%
Where in the body do you find water and in what proportions?
Intracellular - 70%
Intravascular - 5%
Interstitial - 25%
What is edema?
Swelling associated with the movement of water.
What is hypersensitivity?
An exaggerated response by the immune system to a particular substance.
