Pulmonary ventilation – Flashcards

Unlock all answers in this set

Unlock answers
question
Most ATP production: requires O2, produces CO2 as waste called?
answer
cellular respiration
question
The respiratory and cardiovascular systems cooperate to provide O2, remove CO2 to accomplish this, 4 processes must occur collectively called?
answer
respiration
question
Air is moved in and out of the lungs so gases are continuously refreshed is called?
answer
pulmonary ventilation (breathing)
question
- O2 diffuses from the alveoli to the blood (O2 loading) - CO2 diffuses from the blood to the alveoli (CO2 unloading)
answer
external respiration
question
- O2 is transported from the lungs to the tissue cells - CO2 is transported from tissue cells to the lungs
answer
gas transport
question
- cardiovascular system accomplishes this transport
answer
gas transport
question
- O2 diffuses from the blood to the tissue cells (O2 unloading) - CO2 diffuses from tissue cells to blood (CO2 loading)
answer
internal respiration
question
Four Processes of Respiration they are?
answer
1. pulmonary ventilation (breathing) 2. external respiration 3. gas transport 4. internal respiration
question
- functionally, the system consists of two zones they are?
answer
1. the respiratory zone 2. the conducting zone
question
- the actual site of gas exchange
answer
the respiratory zone
question
- composed of: - the respiratory bronchioles, alveolar ducts & alveoli - all microscopic structures
answer
the respiratory zone
question
all other respiratory passageways is called?
answer
the conducting zone
question
- provides rigid conduits for air to reach gas exchange sites is?
answer
the conducting zone
question
cleanses, warms and humidifies incoming air this is?
answer
the conducting zone
question
Each lung is: surrounded by pleurae and connected to the mediastinum by vascular and bronchial attachments: - called the ?
answer
lung root
question
The anterior, lateral and posterior lung surfaces lie in close contact w the ribs: - form the?
answer
costal surface
question
The lungs - concave inferior surface:
answer
base
question
Blood Supply to the Lungs 2 circulations:
answer
- pulmonary and - bronchial
question
Systemic venous blood that is to be oxygenated in the lungs is delivered by?
answer
pulmonary arteries
question
- lie anterior to the main bronchi this is?
answer
pulmonary arteries
question
- and branch profusely along w bronchi this is?
answer
pulmonary arteries
question
- pulmonary arteries finally feed into:
answer
- pulmonary capillary networks
question
- surrounding the alveoli is?
answer
- pulmonary capillary networks
question
- convey freshly oxygenated blood to the heart this is?
answer
- pulmonary veins;
question
The pulmonary circuit is a what type of circulation?
answer
low-pressure, high-volume circulation
question
- lung capillary endothelium is an ideal place for NZs that act on blood such as?
answer
ACE NZs that inactivate prostaglandins
question
Provide oxygenated systemic blood to lung tissue is?
answer
- bronchial arteries
question
Arise from the aorta enter lungs at the hilum run along branching bronchi
answer
- bronchial arteries
question
- provide a high-pressure, low-volume supply - of oxygenated blood to all lung tissues - except alveoli
answer
- bronchial arteries
question
- there are multiple anastomoses between the two circulations - and most venous blood returns to the heart via?
answer
pulmonary veins
question
Innervation of the Lungs - innervated by both branches of?
answer
- ANS - visceral sensory
question
Innervation of the Lungs - Nerve fibers enter each lung through the?
answer
pulmonary plexus on lung root
question
- run along bronchial tubes and blood vessels
answer
pulmonary plexus on lung root
question
Alveoli The walls are composed primarily of (90%): a single layer of squamous epi cells called?
answer
type I alveolar cells
question
Account for most of our lung volume
answer
Alveoli
question
Provide a huge surface area for gas exchange
answer
Alveoli
question
type I alveolar cells surrounded by a ?
answer
flimsy basement membrane
question
Alveoli External surfaces covered w a cobweb of?
answer
pulmonary capillaries
question
The Respiratory Membrane is made up of the?
answer
capillary and alveolar walls
question
Two simple squamous cells w a very thin membrane between them blood flowing by on one side: air on the other this is?
answer
The Respiratory Membrane
question
Scattered among the type I alveolar cells are?
answer
Cuboidal type II alveolar cells
question
Cuboidal type II alveolar cells (10%) these cells secrete?
answer
surfactant
question
- 3 other significant alveolar features they are?
answer
1. they are surrounded by fine elastic fibers 2. open alveolar pores connect adjacent alveoli 3. alveolar macrophages crawl freely
question
Allow equalization of air pressure and provide alternate air routes to alveoli whose bronchi have collapsed in disease this is?
answer
alveolar pores
question
Old dead ones are swept up and away by cilia to pharynx this is?
answer
alveolar macrophages
question
The Pleurae - form a thin, double-layered serosa
answer
- parietal pleura - visceral pleura
question
- covers thoracic wall and superior face of the diaphragm - continues around the heart and between the lungs
answer
- parietal pleura
question
- forming the lateral walls of mediastinal enclosure - snugly enclosing the lung root
answer
- parietal pleura
question
- covers the external lung surface - dipping into and lining its fissures
answer
- visceral pleura
question
pleurae produce?
answer
pleural fluid
question
fills the slit-like pleural cavity between them is?
answer
pleural fluid:
question
- the suction of excess pleural fluid into lymphatics - maintains a slight suction between?
answer
pleural layers
question
contributes to adherence to the thoracic wall this is?
answer
Lung Lymphatic Drainage
question
- inflammation of pleura
answer
Pleurisy
question
Pleurisy- often results from?
answer
pneumonia
question
Pleura become rough, resulting in friction as pleurisy progresses, pleurae may produce?
answer
excessive amounts of fluid
question
- relieves pain but hinders breathing
answer
Pleurisy
question
- general term for fluid accumulation in pleural cavity:
answer
- pleural effusion
question
- other fluids that may leak into pleural cavity include:
answer
blood blood filtrate
question
Pleural Effusion - blood from?
answer
leaked from damaged vessels
question
Pleural Effusion - blood filtrate from?
answer
From lung capillaries with left side congestive heart failure
question
Mechanics of Breathing: Pulmonary Ventilation consists of 2 phases:
answer
- inspiration: - expiration:
question
- inspiration & expiration: - these are mechanical processes that depend upon?
answer
- volume changes in the thoracic cavity
question
Gases always expand to?
answer
fill their container
question
Volume changes lead to?
answer
pressure changes
question
Pressure changes lead to the?
answer
flow of gases
question
- gives the relationship between the pressure and volume of a gas
answer
Boyles Law
question
Boyles Law
answer
- gives the relationship between the pressure and volume of a gas
question
Boyles Law at a constant temperature what occurs?
answer
- the pressure of a gas varies inversely w volume
question
Boyle's Law - gases always fill their container thus in a large container gas molecules will be?
answer
Far apart and the pressure will be low
question
Boyle's Law - if the volume of the container is reduced gas molecules will be?
answer
Forced closer together and the pressure will rise
question
respiratory pressures are always described relative to?
answer
- atmospheric pressure (Patm)
question
- atmospheric pressure (Patm) is described as?
answer
- the pressure exerted by the air surrounding the body - at sea level = 760 mmHg = 1 atm
question
- a negative respiratory pressure indicates:
answer
- the pressure is lower than atmospheric
question
- 4 mmHg =
answer
756 mmHg
question
- 756 mm Hg is know as what in that region?
answer
"absolute pressure"
question
A positive respiratory pressure is what compared to atmospheric?
answer
- is higher than atmospheric
question
Zero respiratory pressure is what to atmospheric?
answer
Equal to atmospheric
question
- is the pressure in the alveoli - it rises and falls with breathing
answer
Alveolar (Intrapulmonary) Pressure (Pa)
question
Alveolar (Intrapulmonary) Pressure (Pa) At the end of respiration, w the glottis open? what is the aveolar pressure?
answer
- alveolar pressure is zero (equal to atmospheric)
question
As are all pressures in the respiratory tree to cause air to flow into alveoli during inspiration: - alveolar pressure must?
answer
fall to below atmospheric (below 0)
question
- pressure in the pleural cavity is?
answer
Pleural (Intrapleural) Pressure (Pip)
question
Pleural (Intrapleural) Pressure (Pip) fluctuates with breathing but pleural pressure is always?
answer
~ 4 mmHg less than alveolar
question
Pleural is always negative relative to?
answer
alveolar (very important that it's always negative)
question
What causes the negative intrapleural pressure?
answer
syphoning of fluid from the pleural cavity by the lymphatics
question
The collapse tendency of the lungs is about how many mmHg?
answer
4 mmHg
question
The pleural pressure must be at least as negative to?
answer
keep the lungs expanded
question
- 2 forces tend to make the lungs collapse
answer
1. natural elasticity of the lungs 2. the surface tension of the alveolar fluid
question
1. natural elasticity of the lungs - tendency to recoil: always assume?
answer
smallest size possible
question
2. the surface tension of the alveolar fluid Molecules of fluid lining alveoli attract each other this produces surface tension that do what?
answer
constantly acts to draw alveoli to smallest size
question
Lung Collapsing Forces are Opposed by?
answer
-Natural elasticity of the chest wall - a force that tends to pull thorax outward - And enlarge the lungs
question
There are opposing forces that exist in the thorax. The net result is a?
answer
negative pleural pressure (Pip)
question
The negative pleural pressure is very important because it?
answer
holds the lungs to the thoracic wall
question
Any condition that equalizes Pip w Pa causes?
answer
immediate lung collapse
question
Atelectasis AKA?
answer
Alveolar Collapse
question
Atelectasis: Alveolar Collapse occurs when?
answer
- bronchiole becomes plugged -chest wound -rupture of the visceral pleura
question
Atelectasis: Alveolar Collapse What happens with alveoli?
answer
the associated alveoli absorb all their air and collapse
question
the difference between alveolar and pleural pressures
answer
Transpulmonary Pressure
question
transpulmonary pressure forumla is?
answer
Pa - Pip
question
what keeps air spaces open (it keeps the lungs from collapsing) at the end of a normal expiration:
answer
transpulmonary pressure
question
Transpulmonary Pressure - 0 - (- 4 mmHg) =
answer
4 mmHg
question
The size of the transpulmonary pressure determines the?
answer
size of the lungs at any time
question
the greater the transpulmonary pressure the
answer
larger the lungs
question
Back to Pulmonary Ventilation: Inspiration The inspiratory muscles contract to cause?
answer
enlarging the thorax
question
The diaphragm contracts moving how? and doing what?
answer
Inferiorly Increasing the height of thorax
question
- external intercostals contract causing?
answer
- lifting ribs increasing diameter of thorax
question
Back to Pulmonary Ventilation: Inspiration - this increases the thoracic volume by?
answer
500mL
question
Expansion of the thorax during inspiration causes?
answer
- stretches the lungs and alveolar volume increases
question
Expansion of the thorax during inspiration stretches the lungs and alveolar volume increases so what happens with alveolar pressure?
answer
alveolar pressure drops - about 1mmHg below atmospheric
question
Anytime alveolar pressure is less than atmospheric what happens with air?
answer
- air rushes into the lungs along its pressure gradient
question
Pleural Pressure during Inspiration - at the beginning of inspiration pleural pressure is what mmHg?
answer
~ - 5 mmHg
question
Pleural Pressure during Inspiration - Then during inspiration expansion of the chest pulls outward on the lungs and creates?
answer
more negative pressure: ~ - 7 mmHg
question
Pleural Pressure during Inspiration - inspiration ends when:
answer
- alveolar pressure equals atmospheric Pa = Patm (or 0 mmHg)
question
During forced inspiration: as in vigorous exercise, some COPDs accessory muscles will do what?
answer
further ? thoracic volume
question
Accessory muscles further ? thoracic volume are?
answer
- scalenes -sternocleidomastoid -pectoralis minor (any muscle that elevates the rib cage)
question
In healthy: quiet expiration is a passive process - that depends on?
answer
lung elasticity
question
Inspiratory muscles relax - the rib cage does what? and the lungs?
answer
descends lungs recoil
question
Expiration - both thoracic and pulmonary volumes decrease this will?
answer
compresses alveoli: - so Pa rises to about 1mmHg above atm
question
Whenever alveolar pressure exceeds atmospheric (Pa ; Patm) the pressure gradient does what?
answer
forces gases out of the lungs
question
- forced expiration is an active process they do what?
answer
- contract abdominals: - internal intercostals:
question
- forced expiration - contract abdominals causes what movement?
answer
- increases intra-abdominal pressure - forcing abdominal organs superiorly
question
- forced expiration - internal intercostals do what movement?
answer
- depress the rib cage
question
Forced expiration - contract abdominals: - internal intercostals: - both do what to thoracic volume?
answer
decrease thoracic volume
question
Physical Factors Influencing Pulmonary Ventilation - inspiratory muscles consume NRG to?
answer
expand the thorax
question
Physical Factors Influencing Pulmonary Ventilation NRG must also be expended to overcome other factors that hinder pulmonary ventilation - such as?
answer
1. airway resistance 2. alveolar surface tension 3. lung compliance
question
Airway Resistance the relationship between?
answer
gas flow (F) pressure (P) resistance (R)
question
Airway Resistance equation is?
answer
- F = ?P/ R
question
The amount of gas flowing into and out of the alveoli is directly proportional to the? or the?
answer
-change in pressure -the pressure gradient between the atmosphere and the alveoli
question
Usually, small changes in the pressure gradient produce?
answer
large changes in volume of air flow (F)
question
the average pressure gradient during normal quiet breathing is how many mmHg?
answer
2mmHg or less
question
The average pressure gradient during normal quiet breathing is ~ 2mmHg or less and that is sufficient to move how many mL of air with each breath?
answer
500 ml of air with each breath
question
gas flow varies inversely with
answer
resistance
question
Gas flow decreases as resistance does what?
answer
increases
question
Airway resistance is usually insignificant because of what issues?
answer
1. airway diameters are huge relative to the low viscosity of air 2. as airways get smaller, there are more branches
question
Airway resistance is usually insignificant because: 1. airway diameters are huge relative to the low viscosity of air 2. as airways get smaller, there are more branches - so the total cross-sectional area is what size?
answer
huge
question
At any gas-liquid boundary molecules of liquid are more strongly attracted to each other than to what?
answer
gas
question
At any gas-liquid boundary molecules of liquid are more strongly attracted to each other than to the gas This unequal attraction produces a state of tension at the liquid surface called?
answer
surface tension
question
draws liquid molecules closer together (contracts them)
answer
Surface tension
question
Water is composed of highly polar molecules and has a very high surface tension. As the major component of the film coating alveolar walls it is always acting to?
answer
reduce alveoli to their smallest size
question
If fluid was pure water, alveoli would collapse between breaths but surfactant (produced by Type II alveolar cells) causes what?
answer
- decreases cohesiveness of water molecules - reduces surface tension of the alveolar fluid
question
Surfactant - Decreases cohesiveness of water molecules - Reduces surface tension of the alveolar fluid This causes?
answer
Less NRG is needed to expand the lungs and discourage alveolar collapse
question
- Fetal lungs don't produce adequate surfactant - until when?
answer
last two months of development
question
- Babies born before that are unable to keep alveoli inflated between breaths - treatment is?
answer
- spray surfactant into airways - use devices that maintain positive airway pressure
question
A measure of the change in lung volume that occurs with a change in transpulmonary pressure this is known as?
answer
Lung Compliance
question
distensibility of the lungs AKA?
answer
Lung Compliance
question
So the more a lung expands for a given rise in transpulmonary pressure how is the compliance?
answer
- the greater its compliance
question
The higher the compliance the easier it is to?
answer
expand the lungs
question
Lung Compliance is determined by 2 factors:
answer
1. distensibility of the lung tissue (generally high if healthy) 2. alveolar surface tension (surfactant keeps this ?)
question
Healthy lungs tend to have what kind of compliance?
answer
high compliance
question
Any decrease in the natural resilience of the lung what is the compliance status?
answer
diminishes compliance
question
Chronic inflammation or infections causes?
answer
fibrosis (scar tissue to replace normal tissue) decreased surfactant secretion
question
decreased surfactant secretion fibrosis What happens with compliance?
answer
-lower lung compliance -more NRG is needed to breathe
question
Factors that reduce thoracic compliance hinder lung expansion such as what?
answer
deformities of thorax ossified costal cartilages
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New