167 - finish Flashcards
Pressure inside a spherical (curved) surface is inversely proportional to its radius
Law of Laplace
This explains why smaller alveoli have higher pressure (more to overcome)
Like blowing up a smaller balloon vs a bigger one
Law of Laplace
P=2T/r
P = pressure T = tension r = radius
Law of Laplace
Premature newborns born before their lungs have the capability of producing surfactant
Without surfactant, alveoli collapse much easier
This causes a reduction in breathing capability
Usually enough production by ~ week 35
Respiratory Distress Syndrome (RDS)
Partial or complete collapse of the lung
Atelectasis
Anything that causes alveoli to collapse
Being ventilated (sometimes even during surgery)
Constrictive pressure (garments, pleural effusions)
Pneumonia
Neuromuscular diseases (unable to take full breath)
Atelectasis
A measure of how much effort is required to stretch the lungs and chest wall
Compliance of the Lungs
lungs and chest wall expand easily
High Compliance
lungs and chest wall resist expansion
Low Compliance
Compliance determined by elasticity and surface tension
Lungs normally have high compliance due to elastic fibers in lung tissue and ____ in surface tension
Surfactant
Walls of airways (especially _____) offer resistance to airflow in and out of lungs
Bronchioles
As lungs expand during inhalation, airway walls are pulled outward, enlarging the ___, decreasing resistance
Lumen
As lungs recoil during exhalation, airway walls return to normal size, shrinking the lumen, increasing ____
Resistance
Airway Resistance:
Also regulated by degree of contraction/relaxation of ____ muscle in walls of airways
smooth
Normal pattern for quiet breathing
Can consist of shallow, deep, or combined breathing
Eupnea
Pattern of shallow (chest) breathing
Upward and outward movement of chest due to contraction of external intercostal muscles
Costal Breathing
Pattern of deep breathing
Consists of outward movement of abdomen due to constriction and descent of diaphragm
Diaphragmatic Breathing
Respirations provide humans with methods for expressing emotions such as:
Laughing
Sighing
Sobbing
Respiratory movements can be modified and controlled during talking and singing
Modified Respiratory Movements
Stimulated by foreign matter in trachea or bronchi irritating mucosal lining/cilia
Epiglottis and glottis close + contraction of expiratory muscles = increased air pressure in lungs
Epiglottis and glottis open rapidly which causes a burst of pressurized air to be expelled quickly
Cough Reflex
Similar to cough reflex
Only difference is that it’s stimulated by irritants in the nasal cavity
Droplets from a sneeze can travel 100mph and as far as 12 ft
Sneeze Reflex
Involuntary, spasmodic contraction of the diaphragm
Usually occurs during inhalation which abruptly closes the glottis which causes the characteristic sound
Hiccup
Apparatus used to measure volume of air exchanged during breathing and the respiratory rate
Spirometer/Respirometer
Spirometer/Respirometer
The record of this is called a ____
Spirogram
Spirogram:
Inhalation is recorded as an ____ deflection
Exhalation is recorded as a ____ deflection
Inhale - Upward
Exhale - Down
Spirometry Values:
Male values are listed as primary
Female values are within parentheses
ladies have the curves
Spirometry slide 181
take a deep breath
At rest, healthy adult averages 12 breaths a minute
Each inhalation and exhalation moves ____mL of air in and out of lungs
500mL
Tidal Volume (Vt)
Volume of one breath – normal 500mL
Minute Volume (MV) Total volume of air inhaled and exhaled each minute
Resp rate x tidal volume
12 breaths/min x 500mL/breath = (6000mL/min or 6 liters/min)
Minute to win it
In typical normal adult, __% of tidal volume (350mL) actually reaches the respiratory zone
70%
The other 30% (150mL) remains in the ___ ___ (nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles)
Conducting Airways
This 30% lies in something called the ___ ___ ___
It cannot be used for gas exchange
Anatomic Dead Space
Alveolar Vent Rate = 70% (resp zone) x breaths/min
AVR = 350mL x 12breaths/min
AVR = 4200mL/min
Volume that actually reaches respiratory zone in one minute
By taking a very deep breath, you bring in additional air
3100mL EXTRA in males,
1900mL EXTRA in females
Even more can be inhaled if it is followed by a forceful exhale
Inspiratory Reserve Volume
Inhale normally (500mL), but exhale forcefully using accessory muscles
Another 1200mL for males, another 700mL for females
The amount over the tidal volume that is exhaled
Expiratory Reserve Volume
The air that cannot be exhaled (or the alveoli would collapse) as well as air left in non-collapsible airways
Cannot be determined by spirometry
Males (~1200mL), Females (~1100mL)
Residual Volume
___ ____ = tidal volume + insp reserve vol
Inspiratory capacity = tidal volume + insp reserve vol
___ ___ ___ = residual volume + expiratory reserve volume
Functional residual capacity = residual volume + expiratory reserve volume
Inspiratory capacity = ___ ___ + insp reserve vol
Tidal Volume
Functional residual capacity = ___ ___ + expiratory reserve volume
Residual Volume
___ ___ = insp reserve vol + tidal vol + expir reserve vol
Vital Capacity
__ __ __ = vital capacity + residual volume
Total Lung Capacity
take a peak at slide 193
Breath of fresh air
Dependent on several factors
Composition of inspired air
Alveolar ventilation
Concentration of dissolved gases in mixed venous blood
Alveolar Air
Atmospheric air is composed of
79% nitrogen
21% oxygen
<1% other gases (ie: carbon dioxide)
Air head
As air is inspired, it warms rapidly to body temperature and becomes saturated with water vapor (humidified)
Composition of alveolar air begins to change when the air hits the ___ ___ and exchanges of oxygen and carbon dioxide begin
Respiratory Zone
Dalton’s Law:
Each gas in a mixture of gases exerts its own pressure as if no other gases were present
The pressures will remain constant (one gas will not compress more to accommodate the others)
The pressure of a gas in a mixture is called its ___ ___
Partial Pressure
Dalton’s Law:
The total pressure is calculated by adding the __ __ of all gases in the mixture
Partial Pressures
Dalton’s Law:
Example – atmospheric pressure (760mmHg)
Atm pres = Pn2 + Po2 + Par + PH2O + PCO2 + Pother gases
Dalton’s Law Math!
Dalton’s Law:
These partial pressures of gases determine the movement of O2 and CO2 between
The atmosphere and lungs
The lungs and blood
The blood and tissue cells
Dalton’s Gas Law
Dalton’s Gas Law:
Each gas moves from a higher partial pressure space to a lower partial pressure space
The higher the partial pressure (or larger gradient), the ___ the gas moves
Faster
The quantity of gas that will dissolve in a liquid is proportional to the partial pressure of the gas and it’s solubility
Henry’s Law
Soda bottle: while unopened, the gas (space) above the liquid is almost pure CO2, after removing the cap the gas escaping (hiss sound) is the CO2…the pressure is now lower in the bottle allowing some of the CO2 that was dissolved in the liquid to come out of solution…this gives the characteristic bubbles you see climbing the walls of the bottle
Henry’s Law for those who don’t read good much
Henry’s Law:
In body fluids, ability for gas to stay in solution (dissolved/solubility) is greater when it’s partial pressure is ___ and when it’s solubility in water is higher
Higher
Henry’s Law:
In comparison, much more CO2 is dissolved in blood plasma as it’s ____ is 24x’s greater than O2
Even though air we breath contains mostly (78.6%) nitrogen, very little is dissolved in blood as it’s ____ is very low
Solubility
Diffusion of O2 from the air in the alveoli to the blood in the pulmonary capillaries
Diffusion of the CO2 from the pulmonary capillaries into the alveoli
External Respiration:
Pulmonary Gas Exchange
Converts deoxygenated blood (from right side of heart) to oxygenated blood (that returns to left side of heart)
External Respiration: Pulmonary gas exchange
Oxygen (O2)
Diffusion continues until the pressures are equal
Alveolar air – PO2 = 100mmHg
Capillary blood – PO2 = 40mmHg
So this means that O2 moves from the ____ to the capillary for transport to the rest of the body
Alveolus
Carbon Dioxide (CO2) Diffusion continues until pressures are equal Capillary blood – PCO2 = 45mmHg
Alveolar air – PCO2 = 40mmHg
So this means that CO2 moves from the ___ to the alveolus to be removed through exhalation
Blood
Systemic Gas Exchange:
Diffusion of O2 from the blood in the capillaries to the tissue cells
Diffusion of the CO2 from the tissue cells to the blood in capillaries
Internal Respiration
Converts oxygenated blood (in the capillaries) to deoxygenated blood (by picking up CO2 from the tissue cells)
Internal Respiration
Oxygen
Diffusion continues until the pressures are equal
Systemic Capillaries – PO2 = 100mmHg
Tissue Cells – PO2 = 40mmHg
So this means that O2 moves from the ___ ___ to the tissue cells
Systemic Capillaries - Internal Respiration
Carbon Dioxide (CO2) Diffusion continues until pressures are equal Tissue Cells – PCO2 = 45mmHg
Systemic Capillaries – PCO2 = 40mmHg
So this means that CO2 moves from the tissue cells to the systemic capillaries for transport to ___
Alveoli
Slide 208 for the external/internal respiration
pictures of air!
exchange that is
The more the surface area, the faster and easier the gas exchange
As many capillaries surround each alveolus, there is ample opportunity for this process to occur
Any pulmonary disorder that decreases the functional surface area, decreases the rate of ___ ___
External Respiration
ex: emphysema
slide 210-smoking is bad mmmk
The respiratory membrane is very thin (0.5 micrometers) so diffusion occurs quickly
Also, the capillaries are so small that RBC’s must pass through them single file
This minimizes the ___ ___ from the alveolar air space to the hemoglobin in RBC’s
Diffusion Distance
Buildup of interstitial fluid in between alveoli or fluid within the alveoli, slows this rate of gas exchange because of the ___ ___
Diffusion Distance
Ex: Pulmonary Edema
also slide 212 - water in the lungs
Oxygen Measurements:
Helps us to understand the relationship of arterial, oxygen saturation to the partial pressure of oxygen in arterial blood
Very important as it relates to disease
Dissociation – detachment, separation
____ – attraction (in this case, O2 to hemoglobin)
Affinity
PaO2- partial pressure of dissolved (free) oxygen in arterial blood (the only oxygen that exerts pressure)
This is measured by an arterial blood draw
SaO2 – measurement of oxygen that is bound to hemoglobin (____) in arterial blood
Saturation
SpO2 – measurement of the oxygen that is bound to ____ peripherally
This is readily measured by a pulse oximeter (why we like to see %’s above 95)
Pulse oximeter uses colorimetric measurements (looks for color)
Hemoglobin
Carbon Monoxide:
CO has much higher affinity for hemoglobin
If oxygen is knocked off hemoglobin, more is dissolved
This will increase our __
PaO2
Carbon Monoxide:
CO has much higher affinity for hemoglobin
If more CO is attached to hemoglobin, less O2 is attached
This reduces the ___
SaO2
Carbon Monoxide:
If you drew labs, this may be misleading
Normal or elevated PaO2
SaO2 will be decreased
SpO2 (measured by pulse oximeter) would pick up on the color it is scanning for because _____ (like oxyhemoglobin) is red in color…would give a falsely normal reading
Carboxyhemoglobin
Draw a serum carboxyhemoglobin level (can be venous)
Treatment is with 100% oxygen to “bump” the __ off of the hemoglobin
Carbon Monoxide (CO)
what about hyperbaric chambers?
Oxygen does not dissolve easily
Only ~1.5% of inhaled O2 is dissolved in __ ____
~98.5% of O2 is bound to hemoglobin in RBC’s
Blood plasma
The 98.5% of O2 bound to ____ is trapped because of the pressure to stay bound
Only the 1.5% can diffuse into tissue unless the pressure changes
Hemoglobin
Most important factor that determines how much O2 is bound to hemoglobin is the ___ ___ of oxygen
Partial Pressure
The higher the PO2, the more O2 combines with partially saturated hemoglobin to make it fully saturated
This is easy in the lungs as the PO2 is higher
The amount remaining by the time it gets to the tissue is much less as PO2 decreases significantly
When this decreases, O2 is offloaded into the tissue
Oxygen transport
This graphical representation depicts the relationship between the % saturation of hemoglobin and PO2 (partial pressure of O2)
slide 223
As PO2 gets higher, the affinity for O2 to bind to hemoglobin gets higher
60-100mmHg PO2 shows almost 90% of affinity for O2 to bind in the lungs
At 40mmHg PO2 reduces affinity to ~75%
At 20mmHg PO2 affinity reduces to 35%
As pressures decreases, oxygen does not want to stay attached to ___
Hemoglobin
Four factors affect the affinity of O2?
- Acidity (pH)
- PCO2
- Temperature
- 2,3-bisphosphoglycerate (BPG)
The changing affinity of hemoglobin for O2 is an example of how ___ ___ adjust body activities to cellular needs
Keep in mind that metabolically active tissues need O2, and that they produce acids, CO2, and heat as wastes
Homeostatic Mechanisms
As pH decreases (more acidic), the affinity for O2 ___, and dissociation occurs more readily
Decreases
A decrease in pH causes the whole curve to shift to the right
This means that at higher PO2, the saturation of hemoglobin is ___ than if the pH were normal
Less
An increase in pH (more ____), the affinity for O2 increases, dissociation is more difficult
Alkalinic
An increase in pH causes whole curve to shift left
This means that at higher PO2, the saturation of hemoglobin is ___ than if the pH were normal
Higher
Effect of pH on affinity of hemoglobin for oxygen
Slide 226
Much like pH because if ___ increases, pH decreases
This then shows the same structure on the dissociation curve as pH
CO2 (PCO2)
As ____ increases, the affinity for O2 to hemoglobin decreases
Similar to the pH and CO2 curves, but wider spread
temperature
Effect of PCO2 on affinity of hemoglobin for oxygen
on slide 228
Temperature effect in graphical format
slide 229
This is a substance found in RBC’s
Formed in RBC’s when they break down glucose to produce ATP (glycolysis)
2,3-bisphosphoglycerate (BPG)
Increased levels of this decrease the affinity for O2 to bind to hemoglobin
The higher the level of ___, the more O2 is unloaded from hemoglobin (into tissues)
2,3-bisphosphoglycerate (BPG)
Under normal conditions, each 100mL of ____ blood contains the equivalent of 53mL of CO2, which is transported in three forms
deoxygenated
Under normal conditions, each 100mL of deoxygenated blood contains the equivalent of 53mL of CO2, which is transported in three forms?
Dissolved CO2
Carbamino compounds
Bicarbonate ions
smallest percentage (~7%), when this reaches the lungs, it is exhaled
Dissolved CO2
23%, combines with amino acids and proteins (hemoglobin is most prevalent protein) so most of this is bound to hemoglobin (carbaminohemoglobin)
Carbamino Compounds
~70% H2CO3 dissociates in presence of carbonic anhydrase into CO2 and H2O – we exhale the CO2
Bicarbonate ions
At rest, ____ of oxygen is used each minute by body cells
During exercise oxygen use increases 15-20 fold in normal healthy adults
___-___mL
In elite endurance athletes, this increases to 30 fold
____ EACH MINUTE!!!
200mL
3,000 - 4,000mL
6,000mL
During ____, the muscles involved are voluntary, but they receive nerve input to make them contract
The absence of this nerve impulse/input is what allows the exhalation to be passive
inspiration
These impulses are sent from clusters of neurons in the medulla oblongata and pons
This widely dispersed group of neurons is collectively called the __ __ which is divided into three areas on the basis of their function
Respiration center
Respiratory center pic
slide 236
The ___ ___ center in the medulla oblongata
Function of this is to control the basic rhythm of respiration
There are inspiration and expiratory areas within the ___ ___ area
Medullary rhythmicity
The ___ ___ in the pons
Helps to coordinate transition between inhalation and exhalation
Major effect is to inhibit the inspiratory area before the lungs become too full with air
Regulates the amount of air that can be taken into the body, each breath
Pneumotaxic center
The apneustic center in the pons:
This area also helps coordinate the transition between inhalation and exhalation
Major effect is to ___ ___, or -_____
prolong inhalation
-or-
provide deep inhalation
This area is inhibited by pulmonary stretch-receptors and also by the pneumotaxic center
The ___ ___ can only provide so much inhalation guidance before the pneumotaxic center takes over
Apneustic center
As the ___ ___ has connections with the respiratory center, we can voluntarily alter our pattern of breathing, or even refuse to breathe at all…for a short time
___ ___ is not needed to continue to breath
As long as brainstem (medulla oblongata and pons) is functioning, you can continue breathing
Cerebral Cortex
Voluntary control is important as it prevents us from inhaling water or irritating gases if exposed
This ability is limited though by the build up of CO2 and H+
When CO2 and H+ increase to a certain level, the ___ ___ is strongly stimulated which overrides the holding of the breath
Inspiratory center
Chemoreceptors:
Certain chemical stimuli modulate how quickly and deeply we breath
O2, H+ and CO2
Chemoreceptors in two locations of the respiratory system monitor levels of these chemicals
Central Chemorecptors
Peripheral Chemoreceptors
located in/near the medulla oblongata
These respond to changes in H+ and CO2 only
Central Chemoreceptors
located in aortic bodies and carotid bodies
These respond to changes in H+, CO2, O2
Peripheral Chemoreceptors
As soon as exercise begins, your heart rate and depth of breathing increase even before changes in PO2, PCO2, and H+ occur
These changes occur from the movement of the joints and muscles in anticipation of changes in the chemical composition..picked up by:
Proprioceptors
other influences on respiration:
Limbic system Temperature Pain Stretching the anal sphinchter muscle Irritation of airways Blood Pressure
Anticipation of activity or emotion stimulates this system which send impulses to inspiratory area
Limbic system
Increase in ___ increases respiration and vice versa
A sudden cold stimulus (polar bear club) causes a temporary apnea
Temperature
Sudden, severe ___ brings a brief apnea
Prolonged somatic ___ increases respirations
Visceral ___ may slow the respiratory rate
Whats your prediction for the fight Clubber…
“Pain”
Increases respiratory rate
Sometimes used to stimulate newborns to breath, also adults who may have stopped breathing
Stretching the anal sphincter
Physical or chemical irritation of pharynx or larynx may bring an immediate cessation of breathing followed by a cough or sneeze
Irritation of the airways
Carotid/aortic baroreceptors detect changes in __ __
Sudden rise in __ __ lowers respiration rate
Drop in __ __ increases respiration rate
Blood Pressure
As we age, chest wall, airways and tissue of respiratory tract become less elastic, which…?
Decreases lung capacity
with Aging:
Vital capacity can decrease by as much as 35% by age 70
Decrease in blood O2
Decrease in alveolar macrophages
Decrease in ciliary action of epithelium
All of this leads to being more susceptible to pneumonia, bronchitis, emphysema, and other pulmonary disorders
