chapter 23 part 2 Flashcards
ventilation
- definition
- atmospheric pressure
air will flow from high pressure areas to low pressure areas
-760 mmHg
before inspiration: interpleural pressure
- always negative or positive
- what does this do
- ___mmHg
- negative
- keeps lungs open
- 759 mmHg (-1 mmHg)
Before inspiration: interpulmonary pressure
760 mmHg
Inspiration
- chest width
- chest depth
- chest vol
- according to boyle law
- interpleural pressure
- air pressure is ___ than outside than in so air flows __
- increase
- increase
- increase
- increase in vol = decrease in pressure
- 759 mmHg (-1 mmHg)
- higher; in
end inspiration
air pressure inside = air pressure outside
expiration
- chest width
- chest depth
- chest vol
- according to boyles law
- intrapulmonary pressure
- air pressure is ___ inside than out, so air will flow __
- decrease
- decrease
- decrease
- decrease in vol = increase in pressure
- 761 mmHg (+1 mmHg)
- higher, out
gas exchange
- where does it occur
- what is it due to
occurs across the respiratory membrane and across capillary walls between blood and other tissues
-due to pressure gradients
dalton’s law of partial pressure
- total pressure of a gas mixture is…
- partial pressure
- atmospheric pressure
- the sum of the pressures exerted by each gas
- pressure exerted by a single gas in a mixture
- pN2 + pO2 + pCO2 + pH2O = P
formula for partial pressure
Partial pressure of gas A = total atmospheric pressure due to all gases X % of atmospheric pressure composed of gas A
Room air
- pO2
- pCO2
- 160 mmHg
- 0.3 mmHg
gas exchange between alveolus and alveolar capillary
- pO2 = 40; pCO2 = 45
- pO2 = 100; pCO2 = 40; alveolar air contains more ___
- pO2 = 100; pCO2 = 40
- deoxygenated blood coming from pulmonary circuit
- incoming air mixes with air remaining in the lungs after last breath; contains more CO2 and less O2 room air
- oxygenated blood goes to left side of the heart and systemic circuit
when does blood equalibrate with alveolar air
when pO2 = 100 and pCO2 = 40
interstitial fluid and systemic capillary
- pO2 = 95; pCO2 = 40
- pO2 = 40; pCO2 = 45
- pO2 = 40; pCO2 = 45
- systemic capillary carrying oxygenated blood
- cells consumes O2 and produce CO2 (increase in CO2 and decrease in O2 in tissues)
- deoxygenated blood in systemic capillary
when does blood equalibrate with the tissues
pO2 = 40 and pCO2 = 45
5 principles affecting the efficiency of gas exchange
- differences in partial pressure across the respiratory membrane are substantial
- distances involved are short (~0.5 um)
- Gases are lipid soluable
- total surface area is large
- blood flow and airflow are coordinated
greater the distance=
the faster the rate of gas exchange
what can easily diffuse across plasma membrane
gases because they are lipid soluable
large surface area =
more efficient gas exchange
what do blood flow and airflow play a role in
maximizing efficiency of both pulmonary ventilation and pulmonary circulation
oxygen
- 100 ml of blood contains ___ ml of O2; %
- ___ is dissolved in plasma
- ___ are bound to hemoglobin
- 20; 20%
- ~1.5%
- ~98.5%
hemoglobin saturation
- definition
- formula
- what will determine the direction of the reaction
- % of heme units containing bound to O2
- Hb+O2 ->
hemoglobin
- pO2 = 100 mmHg
- pO2 = 70 mmHg
- pO2 = 40 mmHg
- pO2 = 20 mmHg
- pO2 = 10 mmHg
- pO2 = 0 mmHg
- 99%
- 98%
- 75%
- 35%
- 10%
- 0%
the oxygen-hemoglobin saturation curve
- definition
- ___% of Hb is
- ___% represents
- is all O2 released in tissues; what does this generate
- change in pO2 produces
graph that relates the saturation of Hb to pO2
- 75%, oxyhemoglobin in the tissues
- 25%; O2 that has been released in tissues
- no; a reserve of O2
- large changes in amount of O2 released from Hb
hemoglobin undergoes what
-what does this promote
a change in shape each time it binds an O2
-the binding of additional O2
3 factors that shift O2 + Hb saturation curve to the right
-what does this allow
- decrease in blood pH (more acidic)
- Increase in pO2
- Increase in temp
- allows Hb to release O2 more rapidly (makes it easier to unload O2)
Carbon dioxide
- where does it come from
- 3 fates
- generated by cellular metabolism
- ~70% is converted to a molecule of carbonic acid
- ~23% bound to the protein portion of Hb molecules
- ~7% dissolved in blood plasma
- ~70% is converted to a molecule of carbonic acid
carbonic anhydrase in RBC
- formula
CO2 + H2O (H2CO3) H+ + HCO3-
most of the CO2 is transported as
bicarbonate ions (HCO3-)
Respiration
- definition
- cellular rates of absorption =
- restoration of equilibrium
- capillary rates of delivery and removal
respiratory centers in the brain
-2
- voluntary and involuntary
- medulla oblongata
- pons
- medulla oblongata
medulla oblongata
-2 groups
- dorsal respiratory group (DRG)
2. ventral respiratory group (VRG)
dorsal respiratory group
- type of center
- active when
inspiration center
-active every breathing cycle
ventral respiratory group
- type of center
- active when
- expiration center
- active only during forced breathing
when does alternate inhibition occur
between neurons involved in inhalation and exhalation
quiet breathing
-6 steps
- dorsal respiratory group active (fires action potentials)
- Inspiratory muscles contract
- inspiration occurs
- dorsal respiratory group inhibited
- inspiratory muscles contract
- passive expiration occurs
forced breathing
-6 steps
- VRG inhibited; DRG active
- inspiratory muscles contract and expiratory muscles relax
- inspiration occurs
- DRG inhibited; VRG active
- inspiratory muscles relax and expiratory muscles contract
- active expiration occurs
pons
- 2 centers
- function
- apneustic
- pneumotaxic
- regulate rate and depth of repiration
pneumotaxic center of the pons
- definition
- favors what
inhibits apneustic center
-favors exhalation
apneustic center of the pons
-definition
stimulates the DRG
-favors inhalation
respiratory rhythmicity centers
- 2
- function
- DRG
- VRG
- DRG
- establish the basic pace and depth of respiration
pneumotaxic center modifies that pace:
- increased activity
- decreased activity
- increases pace of respiration by shortening the duration of inhalation
- decreases pace of respiration and increases depth of respiration
3 factors that affect breathing
- carbon dioxide
- pO2
- pH
carbon dioxide
- 2 factors
- high plasma CO2
- low plasma CO2
high plasma CO2
- known as
- cause
- 8 steps
- hypercapnia
- hypoventilation
- homeostasis disturbed: increased pCO2
- stimulation of arterial chemoreceptors and increase in pCO2 in CSF
- increased stimulation of CNS chemoreceptors
- increased respiratory centers
- increased respiratory rate and depth
- increased CO2 elimination in lungs
- decreased pCO2
- homeostatsis restored
- homeostasis disturbed: increased pCO2
hypercapnia
- definition
- what do you have to do to reverse is
- increase pCO2 of arterial blood
- increase breathing
low plasma CO2
- known as
- cause
- 8 steps
- hypocapnia
- hyperventilation
- homeostasis disturbed: decreased pCO2
- inhibition of arterial chemoreceptors and decreased pCO2 in CSF
- decreased stimulation of CNS chemoreceptors
- decreased respiratory centers
- decreased rate and depth of respiration
- decreased CO2 elimination in lungs
- homeostasis restored
- homeostasis disturbed: decreased pCO2
hypocapnia
- definition
- what do you need to do to reverse it
- low pCO2 of arterial blood
- decrease breathing
factors that affect breathing:
-high or low pO2
low blood oxygen (hypoxia)
hypoxia
- function
- must see a ____ before effect is seen
- stimulates chemoreceptors in carotid bodies = respiratory rate and depth
- drop of 40%
factors the affect breathing:
- high or low pH
low plasma pH
low plasma pH affecting breathing
- increased or decreased concentration of ____
- formula
- decreased pH =
- increased pH =
- increased; hydrogen ion
- CO2 + H2O H+ + HCO3-
- increased pCO2 = increased respiratory rate and depth
- decreased pCO2 = decreased respiratory rate and depth
what is the main factor that controls breathing
-a change in pCO2 of ____ is enough to ___
- CO2 concentration in blood
- ~10%; double respiratory rate (even is pO2 is normal)
7 additional factors affecting rate and depth of repiration
- higher centers of the brain
- stretch receptors of the lungs
- irritant receptors
- receptors in muscles and joints
- central chemoreceptors
- peripheral chemoreceptors
- other receptors (ex. pain) and emotional stimuli acting through the hypothalamus
additional factors affecting rate and depth of respiration: higher centers of the brain
- inhibit or activate respiratory centers
- voluntary or involuntary control over breathing
- ex
- voluntary
- emotions such as anger and fear and singing
additional factors affecting rate and depth of respiration: stretch receptors in the lungs
- inhibit or activate respiratory centers
- type of reflex
- function
- inhibit
- hering-breuer reflex
- prevents over expansion and inhibits inspiration
additional factors affecting rate and depth of respiration: irritant receptors
- inhibit or activate respiratory centers
- definition
- function
- inhibits
- toxic chemicals or vapors
- increases coughing and sneezing
additional factors affecting rate and depth of respiration: receptors in muscles and joints
- inhibit or activate respiratory centers
- defintion
- activate
- anticipation of exercise with increase respiration rate
additional factors affecting rate and depth of respiration: central chemoreceptors
- inhibit or activate respiratory centers
- location
- function
- activates
- medulla oblongata
- increase CO2 and increase H+
additional factors affecting rate and depth of respiration: peripheral chemoreceptors
- inhibit or activate respiratory centers
- function
- activate
- decrease O2, increase CO2 and increase H+
additional factors affecting rate and depth of respiration: other receptors
- inhibit or activate respiratory centers
- function
- both
- increase respiratory rate = fever and chronic pain
