Pathophysiology Flashcards
What happens if homeostasis is disrupted and the body is unable to componsate
damage, disease, or death
what are diseases
disruptions of the physiological functions
what is trauma
physical disruption of physiologic function
What is respiratory compromise
the inability of the body to move gases effectively
what are the potential affects of respiratory compromise
hypoxia and hypercarbia
what is hypoxia
decreased level of oxygen in the body
what is hypercarbia
elevated levels of CO2 in the body
What two processes can be compromised in a state of respiratory compromise
ventilation and respiration
what can cause ventilation to be comprised in a state of respiratory compromise
blocked airway, impairment of muscles of breathing, airway is obstructed physiologically, drug overdose, trauma to chest wall, and allergic reaction
what can compromise respiration in a state of respiratory compromise
composition of ambient air, high altitudes, transport of gases(across alveoli, to tissues), and the ventilation/perfusion ration
what can affect airway patency
anything: solid objects, fluid and closure due to swelling, anything that prevents adequate breathing
What is required to expand the thorax during inspiration
energy
what might impair respiration
paralysis, fatigue, or damage to the chest wall
what separates the chest wall from the lungs
pleural space
what happens if air enters the pleural space
the lungs will collapse
what part of the body regulates ventilations
brain stem
why is CO2 able to be sensed by the body both directly and indirectly
it is an acid
what happens when there are elevated acids in the blood
hyperventilation
What might happen if there is trauma to the brain
damage of regulatory centers(if damaged can’t regulate ventilation)
what has the most profound effect on respiration
air composition
what happens to your oxygen level at higher altitudes
there is less air pressure and therefore oxygenation will decrease
what happens when toxic gases interact with hemoglobin
damage, they prevent hemoglobin from carrying O2 and instead act as antagonists
In what event is oxygen consumed and replaced with other gases
fires
How do gases travel across the alveolar wall
diffusion
How does diffusion take place
Gases move from high concentration to low concentration; CO2 highly concentrated in blood and therefore enters alveoli to be released into the atmosphere and O2 is highly concentrated in the alveoli and enters the blood to be transported back to the heart and then throughout the body
What happens if their is fluid in the alveolar wall
gas movement is impaired
Why do only the alveoli exchange gas
Trachea, bronchi, and bronchioles are too thick
What is the volume of the trachea, bronchioles, and bronchi referred to as
dead space
What is the formula for alveolar ventilation
tidal volume - dead space = alveolar ventilation
What is the formula used to calculate minute ventilation
tidal volume x rate = minute ventilation
what does minute ventilation refer to
the quantity of air available for O2 and CO2 exchange
what happens when we have a low tidal volume and slow rate
reduced oxygenation
what two kinds of breaths are considered adequate
deep & slow n fast & normal
what kind of breathe is inadequate for oxygenation
fast & shallow
Why are fast & shallow breaths inadequate
dead space
Where is ventilation the greatest
Top of the lungs
Define ventilation
Movement of air into the lungs
Define perfusion
circulation of blood through the lungs
Where is perfusion the greatest
bottom of the lungs
What are the appreciations for Ventilation & Perfusion
V and Q
Under what circumstances will V=0
if there is an airway obstruction
why does an airway obstruction prevent ventilation
no gas exchange will be able to occur in the alveoli with the blood
Under what circumstance will Q=0
if there is a blockage of a blood vessel
Why will a blood vessel blockage prevent adequate perfusion
No blood will circulate through the capillaries for gas exchange
What is a key sign of inadequate breathing
Labored breathing or increased respiratory effort
What are other signs or symptoms of inadequate breathing
Pale, cool, clammy skin, Nasal flaring or pursed lips, and Tripod position
What are the effects of respiratory compromise on the body
Hint: there are 5
- Oxygen levels fall and CO2 levels rise
- Respiratory rate increases
- Blood becomes more acidic
- Brain sends commands to the body to breathe
- Cells move from aerobic to anaerobic metabolism
What is the perfusion triangle made up of
Pump, pipes, and volume
What is the pump referring to in the perfusion triangle
Effectiveness of the heart
What are the pipes referring to in the perfusion triangle
Vessel size and resistance
What is volume referring to in the perfusion triangle
Blood volume and RBCs
When respiratory effort increases what happens to the size of the thoracic cavity
The thoracic cavity increases
What is stroke volume
The amount of blood pumped from the left ventricle of the heart per beat
What causes stroke volume to increase
Preload and contractility
What is preload
The amount of the blood in the heart at the beginning of a contraction
What is contractility
How hard the heart beats; based on how the heart contracts during a beat
What causes stroke volume to decrease
Afterload
What is afterload
Afterload is the resistance in the blood vessels against blood flow
True/False: Afterload is estimated by blood pressure
True
What happens to blood pressure if afterload is high
blood pressure is also high
What is cardiac output
Amount of blood moved in one minute
How do you calculate cardiac output
Stroke volume x heart rate
What happens to the heart beat when under the influence of the sympathetic nervous system
Stronger contractions, faster heart rate, shorter heartbeats
What happens to the stroke volume when the heart rate is high
note: fast heart rate= shorter beats
stroke volume decreases
what happens in the body when the heartbeat is under control of the parasympathetic nervous system
reduces contractility and slows heart rate
what increases when the heart rate slows down
preload
how does increased preload and reduced contractility affect stroke volume
stroke volume increases
What happens to the cardiac output when the heart rate is too fast or too slow
cardiac output decreases: reason why balance between parasympathetic and sympathetic nervous system is crucial for our survival
when stroke volume increases what happens to the afterload
afterload increases and so does resistance of blood flow
What will affect the hearts ability to contract
damage caused by disease or trauma
What rhythmic disturbances compromise cardiac output
heart rate too fast or too slow, irregular breathing, and fibrillation
What controls blood vessel diameter
vessels
What adjusts blood vessel diameter
hormones
what happens when you reduce the diameter of blood vessels
resistance and pressure increases
How does our body increase blood pressure
constricting the blood vessels to compensate for blood loss
how does our body decrease blood pressure
inappropriate dilation of the blood vessels
If one experiences trauma to the blood vessels, causing blood loss, what will happen to the blood pressure
blood pressure will decrease (& blood vessels will constrict)
Maintenance of circulation is dependent on what
adequate blood volume
What happens to the body when greater than 10% of the blood volume is lost
shock
What percentage of blood loss must occur for it to be considered fatal
40%
What will happen to the blood if there are too few RBCs
there will not be enough oxygen
Is blood pressure a sign of adequate perfusion
Yes
How do we calculate blood pressure
Cardiac output x resistance
What is systolic blood pressure a measure of
the maximum pressure during cardiac contraction
What is diastolic blood pressure a measure of
minimum pressure during cardiac relaxation
What other measure is used to indicate perfusion
MAP; mean arterial pressure
What is mean arterial pressure
average arterial pressure during systolic and diastolic
How does one calculate MAP
(Heart Rate x Stroke Volume) x Systemic Vascular Resistance(SVR) OR Cardiac Output x SVR
reminder: CO= SV x HR
What part of the nervous system controls circulation
Autonomic Nervous System(ANS)
What value must MAP be greater than to prevent shock
65; but average is 70 to 100
What is systemic vascular resistance
the resistance that must be overcome to pump blood into the rest of the body
How does our body maintain blood volume
movement of fluid in and out of the capillaries
What happens when hydrostatic pressure is greater than plasma oncotic pressure
fluid leaves the capillary
what happens when hydrostatic pressure is less than plasma oncotic pressure
fluid enters the capillaries
What receptors help us maintain blood pressure
baroreceptors
How happens when pressure is sensed to be low
vessels constrict which increases resistance and heart rate
what happens when pressure is sensed to be high
signals to dilate vessels are sent which reduces resistance and decreases heart rate
When does shock occurs
organs and tissues don’t receive enough oxygen
what happens when oxygen delivery is impaired
hypoxia
What effects does shock have on the body
1.) oxygen to the tissues decreases
2.) cells engage in anaerobic metabolism
3.) metabolic acidosis ensues
4.) baroreceptors initiate release of epinephrine and norepinephrine
5.) heart rate increases
6.) interstitial fluid moves into capillaries
what happens to cellular metabolism when there is inadequate oxygen
cells will create energy through anaerobic metabolism
What happens when cells are forced to utilize anaerobic metabolism
1.) metabolic acidosis
2.) requires more energy
3.) decreased ability of blood to effectively carry oxygen to the cells
4.) decreased functioning of oxygen within the cells
5.) brain cells can’t use alternative fuels- can cause them to die due to lack of glucose
6.) cellular injury- this can only be fixed if tissue perfusion is restored, if not, no treatment will help
