Respiratory 2

Question 1

Air flows into the lungs (inspiration)
* atmospheric pressure is … than intra-alveolar pressure, and intra-alveolar pressure is … than intrapleural pressure, air flows in

Air flows out of the lungs (Expiration)
* during expiration based on the same principle; pressure within the lungs becomes … than the atmospheric pressure, air is expelled

In general, two muscle groups are used during normal inspiration:
the … and the … muscles

• Additional muscles can be used if a … is required
  When the diaphragm contracts, it moves … toward the abdominal cavity, creating a … thoracic cavity and more space
  for the lungs

Contraction of the external intercostal muscles moves the ribs…, causing the rib cage to …, which … the volume of the thoracic cavity

Answer 1

Air flows into the lungs (inspiration)
* atmospheric pressure is greater than intra-alveolar pressure, and intra-alveolar pressure is greater than intrapleural pressure, air flows in

Air flows out of the lungs (Expiration)
* during expiration based on the same principle; pressure within the lungs becomes greater than the atmospheric pressure, air is expelled

In general, two muscle groups are used during normal inspiration:
the diaphragm and the external intercostal muscles

• Additional muscles can be used if a bigger breath is required
  When the diaphragm contracts, it moves inferiorly toward the
  abdominal cavity, creating a larger thoracic cavity and more space
  for the lungs

Contraction of the external intercostal muscles moves the ribs
upward and outward, causing the rib cage to expand, which
increases the volume of the thoracic cavity

Question 2

The process of normal expiration is …
inspiration is
how do muscles go, and what do lungs do

As a result, the thoracic cavity and lungs … in volume, causing an … in pressure in the thoracic cavity
When the pressure rises above atmospheric pressure, the pressure gradient causes air to leave the lungs

Quiet breathing (eupnea) is a mode of breathing that occurs at … and does not require … the individual
* During quiet breathing, the … and … must contract

Answer 2

The process of normal expiration is passive
inspiration taks energy
The elasticity of the lung tissue causes the lung to recoil, as the diaphragm and intercostal muscles relax

As a result, the thoracic cavity and lungs decrease in volume, causing an increase in pressure in the thoracic cavity
When the pressure rises above atmospheric pressure, the pressure gradient causes air to leave the lungs

Quiet breathing (eupnea) is a mode of breathing that occurs at rest and does not require the cognitive thought of the individual
* During quiet breathing, the diaphragm and external intercostals both must contract

Question 3

Diaphragmatic breathing (… breathing) requires the … to contract

• As the diaphragm relaxes, air … the lungs

Costal breathing (… breathing) requires contraction of the… muscles
* As the … muscles relax, air passively leaves the lungs

Both of these forms of breathing typically require …

Additionally, forced breathing can occur during coughing, exercise or actions that require the active manipulation of breathing, such as singing

• During forced breathing, inspiration and expiration both occur due to…

Forced Inspiration uses the …, … muscles and other accessory muscles
* The accessory muscles lift the thoracic wall, increasing lung volume

Forced expiration contracts the accessory muscles of the … which pushes the diaphragm further into the thorax and forcing more air out
* The … also help to compress the rib cage further reduces thoracic volume

Answer 3

Diaphragmatic breathing (deep breathing) requires the diaphragm to contract

• As the diaphragm relaxes, air passively leaves the lungs

Costal breathing (shallow breathing) requires contraction of the intercostal muscles
* As the intercostal muscles relax, air passively leaves the lungs

Both of these forms of breathing typically require cognitive thought

Additionally, forced breathing can occur during coughing, exercise or actions that require the active manipulation of breathing, such as singing

• During forced breathing, inspiration and expiration both occur due to muscle contractions

Forced Inspiration uses the diaphragm, external intercostal muscles and other accessory muscles
* The accessory muscles lift the thoracic wall, increasing lung volume

Forced expiration contracts the accessory muscles of the abdomen which pushes the diaphragm further into the thorax and forcing more air out
* The internal intercostals also help to compress the rib cage further reduces thoracic volume

Question 4

Tidal volume (TV)
* The amount of air that… (~…ml)

Inspiratory reserve volume (IRV)
* Produced by a …, …

Expiratory reserve volume (ERV)
* Amount of air you can…

Residual volume (RV)
* The air …
* The residual volume makes breathing easier by…

Answer 4

Tidal volume (TV)
* The amount of air that normally enters the lungs during quiet
breathing (~500ml)

Inspiratory reserve volume (IRV)
* Produced by a deep inhalation, beyond a normal tidal inspiration and represents the extra volume that can be brought into the lungs during a forced inspiration

Expiratory reserve volume (ERV)
* Amount of air you can forcefully exhale past a normal tidal expiration

Residual volume (RV)
* The air left in the lungs if you exhale as much air as possible.
* The residual volume makes breathing easier by preventing the alveoli from collapsing. NEVER LEAVES

Question 5

Respiratory capacities are the combination of two or more selected volumes, which further describes the amount of air in the lungs during a given time

Total lung capacity (TLC)
* The….
* TLC is about … ml for men, and about … ml for women

Vital capacity (VC)
* The amount of air….
* Typically, is between … and … ml

Inspiratory capacity (IC)
* the maximum amount of air that can be inhaled… (… and …)

Functional residual capacity (FRC)
* The amount of air … (… and …)

Answer 5

Total lung capacity (TLC)
* The sum of all of the lung volumes (TV, ERV, IRV, and RV), which represents the total amount of air a person can hold in the lungs after a forceful inhalation
* TLC is about 6000 ml for men, and about 4200 ml for women

Vital capacity (VC)
* The amount of air a person can move into or out of his or her lungs, and is the sum of all of the volumes except residual volume (TV, ERV, and IRV)
* Typically, is between 3000 and 5000 ml

Inspiratory capacity (IC)
* the maximum amount of air that can be inhaled past a normal tidal expiration (TV and IRV)

Functional residual capacity (FRC)
* The amount of air that remains in the lung after a normal tidal
expiration (ERV and RV)

Question 6

anatomical or physiological

the respiratory system also contains anatomical dead space, which is air that is…

Alveolar (…) dead space involves air…

Total dead space is the …

Answer 6

ana tomical means cant exchange in that location, no connection
even if air gets down to alveoli, cant get in

the respiratory system also contains anatomical dead space, which is air that is present in the airway that never reaches the alveoli and therefore never participates in gas exchange

Alveolar (physiological) dead space involves air found within alveoli that are unable to function, such as those affected by disease or abnormal blood flow

Total dead space is the anatomical dead space and alveolar dead space together, and represents all of the air in the respiratory system that is not being used in the gas exchange process (~150 ml)

Question 7

Ventilation Control
Respiratory rate is…
It is controlled by the respiratory center located within the … in the brain, which responds primarily to changes in blood …

The medulla oblongata contains the …

The DRG is involved in maintaining a… by stimulating the …
resulting in …

When activity in the DRG ceases, it no longer…

The VRG is involved in …, as the neurons in the VRG stimulate the accessory muscles involved in … to contract, resulting in…

The VRG also stimulates the…

Answer 7

Respiratory rate is the total number of breaths (respiratory cycles) occurring each minute
It is controlled by the respiratory center located within the medulla oblongata in the brain, which responds primarily to changes in blood CO2, O2, and pH levels

The medulla oblongata contains the dorsal respiratory group (DRG) and the ventral respiratory group (VRG)

The DRG is involved in maintaining a constant breathing rhythm by stimulating the diaphragm and intercostal muscles to contract,
resulting in inspiration

When activity in the DRG ceases, it no longer stimulates the diaphragm and intercostals to contract, allowing them to relax, resulting in expiration

The VRG is involved in forced breathing, As the neurons in the VRG stimulate the accessory muscles involved in forced breathing to contract, resulting in forced inspiration(diaphragm, external intercostals)

The VRG also stimulates the accessory muscles to contract in forced expiration(internal intercostals, abs)

Question 8

The second respiratory center of the brain is located within the …

This breathing center helps stimulate and inhibit the neurons in the …
* This provides additional control for the depth of …, particularly for deep breathing
* The inhibition of … neuron activity, allowing …

Answer 8

The second respiratory center of the brain is located within the pons

This breathing center helps stimulate and inhibit the neurons in the DRG
* This provides additional control for the depth of inspiration, particularly for deep breathing
* The inhibition of DRG neuron activity, allowing relaxation after inspiration and results in expiration

Question 9

DRG
when you activate it?
…

inactive?
…

when you want to up regulate inhalation
what gets involved and what happens

forced exhalation
what gets involved and what happens

Answer 9

DRG
when you activate it?
diaphragm contract, internal intercostals, volume increases, pressure decreases, quiet inhalation

inactive?
relax and recoil lungs and thoracic cavity decreases, pushing air out

activate VRG, add in accesory muscles of inhalation, sternocleidomastoid, pec minor

VRG goes up, accessory muscles of exhalation, external obliques, internal intercostals, abs

Question 10

CO2 is a waste product of cellular respiration and can be toxic
and are sensed by chemoreceptors
* Central chemoreceptors are located in the … and …
* Peripheral chemoreceptors is are located in the … and …

PROCESS

• Blood CO2 concentration increases
• This causes bicarbonate buffer system to increase in H+ in the extracellular Leads to a … in pH and triggers the central and peripheral chemoreceptors
• In turn, they stimulate the…
• Allows more … to be expelled, … H+ in the blood and … pH

Answer 10

CO2 is a waste product of cellular respiration and can be toxic
and are sensed by chemoreceptors
* Central chemoreceptors are located in the brain and brainstem
* Peripheral chemoreceptors is are located in the carotid bodies and aortic arch

PROCESS

• Blood CO2 concentration increases
• This causes bicarbonate buffer system to increase in H+ in the extracellular Leads to a decrease in pH and triggers the central and peripheral chemoreceptors
• In turn, they stimulate the respiratory centre to contract the diaphragm and external intercostals to increase the rate and depth of respiration
• Allows more CO2 to be expelled, decreasing H+ in the blood and raises pH

Question 11

low levels of CO2 in the blood cause low levels of H+ (… pH)

Leading to a … in firing rate of the central and peripheral chemoreceptors

In turn causes a … in the stimulation of the respiratory centres leading to a … rate and depth of pulmonary ventilation, producing … breathing

• This allows CO2 to… and … pH

Blood levels of O2 can also influencing respiratory rate by triggering the peripheral chemoreceptors when blood
O2 levels become quite low (<… mmHg or ~3200m altitude)

These low levels of dissolved O2 (not bound to Hb) stimulate the … which in turn activate the … to …
* Occurs irrespective of blood … levels at high altitudes

Answer 11

low levels of CO2 in the blood cause low levels of H+ (increased pH)
Leading to a decrease in firing rate of the central and peripheral chemoreceptors
In turn causes a decrease in the stimulation of the respiratory centres leading to a decreased rate and depth of pulmonary ventilation, producing shallow, slow breathing

• This allows CO2 to build up in the blood and decreases pH

Blood levels of O2 can also influencing respiratory rate by triggering the peripheral chemoreceptors when blood
O2 levels become quite low (<60 mmHg or ~3200m altitude)

These low levels of dissolved O2 (not bound to Hb) stimulate the peripheral chemoreceptors which in turn activate the respiratory centre to increase respiratory activity
* Occurs irrespective of blood CO2 levels at high altitudes

Question 12

Ventilation is also modulated by the Hering- Breuer (Inflation) reflex

what is it?

• Triggered when tidal volume exceeds … ml
• Plays a minimal role during …, but is thought it may provide a…

Answer 12

Ventilation is also modulated by the Hering- Breuer (Inflation) reflex

stretch receptors located in the walls of the bronchi and bronchioles stop inhalation when the lungs are over inflated

• Triggered when tidal volume exceeds 1500 ml
• Plays a minimal role during normal ventilation, but is thought it may provide a protective mechanism during severe exercise

Question 13

Dalton’s law describes the behaviour of nonreactive gases in a gas mixture and states:
* A specific gas type in a mixture exerts its own pressure; thus, the total pressure exerted by a mixture of gases is the sum of the partial pressures of the gases in the mixture

Partial pressure (Px) refers to the pressure of a …within a gas mixture
* In the atmosphere, N2, O2, CO2, H2O all exert their own partial pressure, independent of each other

Total pressure (based on Dalton’s Law) is the…

Henry’s law describes the behavior of gases when… (e.g. …) and states:
* The concentration of gas in a … is directly proportional to the … and …

O2 solubility…
CO2 solubility…

Answer 13

Dalton’s law describes the behaviour of nonreactive gases in a gas mixture and states:
* A specific gas type in a mixture exerts its own pressure; thus, the total pressure exerted by a mixture of gases is the sum of the partial pressures of the gases in the mixture

Partial pressure (Px) refers to the pressure of a single type of gas within a gas mixture
* In the atmosphere, N2, O2, CO2, H2O all exert their own partial pressure, independent of each other

Total pressure (based on Dalton’s Law) is the sum of all the partial pressures of a gas mixture

Henry’s law describes the behavior of gases when they come into contact with a liquid (e.g. blood) and states:
* The concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas

O2 has a low solubility, does not want to go in blood without being carried by something. Hb
CO2 has a very high solubility, carried very well by the blood,

Question 14

Atmospheric and alveoli air differ in absolute composition
* Although in both cases, the relative gas concentration are:
N2 > O2 > H2O > CO2

The difference are:
* Alveolar air also has higher levels of … and lower levels of … as a result of cellular respiration
* Alveolar air has more … (47mmHg) than atmospheric air because the respiratory system…

Additional factors for consideration for gas exchange is the … must occur over and the… available
In most cases, there is a very thin membrane for the gases to cross which is accomplished easily

• However, under clinical conditions such as pneumonia (infection causing … in the alveoli themselves), gas exchange is impaired

Ventilation is the movement of air…
Perfusion is the flow of…

Ventilation is regulated by the …
Perfusion is regulated by the…

Answer 14

The difference are:
* Alveolar air also has higher levels of CO2 and lower levels of O2 as a result of cellular respiration
* Alveolar air has more H2O (47mmHg) than atmospheric air because the respiratory system humidifies the air as it is inhaled

Additional factors for consideration for gas exchange is the distance diffusion must occur over and the surface area available
In most cases, there is a very thin membrane for the gases to cross which is accomplished easily

• However, under clinical conditions such as pneumonia (infection causing fluid build up in the alveoli themselves), gas exchange is
  impaired

Ventilation is the movement of air into and out of the lungs
Perfusion is the flow of blood in the pulmonary capillaries

Ventilation is regulated by the diameter of the airways
Perfusion is regulated by the diameter of the blood vessels

Question 15

The diameter of the bronchioles is sensitive to the…

• Greater CO2 (or Reduced O2) levels in the alveoli causes the bronchioles to… their diameter which allows…
• A reduced blood O2 level will … the pulmonary arteriole and … blood flow to … transit time enabling more …
• In the lungs, where O2 is picked up and CO2 is released at the respiratory membrane (… Respiration)
• At the tissues, where O2 is released and CO2 is picked up (… Respiration)

At both locations gas exchange occurs due to…

Answer 15

The diameter of the bronchioles is sensitive to the partial pressure of CO2 and O2 in the alveoli

• Greater CO2 (or Reduced O2) levels in the alveoli causes the bronchioles to increase their diameter which allows CO2 (and O2) to be exchanged at a greater rate
• A reduced blood O2 level will constrict the pulmonary arteriole and decrease blood flow to increase transit time enabling more gas exchange to occur
• In the lungs, where O2 is picked up and CO2 is released at the respiratory membrane (External Respiration)
• At the tissues, where O2 is released and CO2 is picked up (internal Respiration)

At both locations gas exchange occurs due to simple diffusion

Question 16

External Respiration
The partial pressure of O2 in the alveoli is ~105mmHg, whereas its partial pressure in the capillary blood is ~40 mmHg
* This … pressure gradient causes O2 to…

The partial pressure of CO2 in the alveoli is ~40 mmHg, whereas its partial pressure in the capillary blood is ~45 mmHg
* The high … of CO2 (despite the …) causes CO2 …

MNM

Internal Respiration
The partial pressure of O2 in the tissues is ~40mmHg, whereas its partial pressure in the arterial blood is ~100 mmHg
* This … pressure gradient causes O2 to…

The partial pressure of CO2 in the tissues is ~45 mmHg, whereas its partial pressure in the arterial blood is ~40 mmHg
* The high … of CO2 (despite the…) causes CO2 to…

Answer 16

• This very strong pressure gradient causes O2 to rapidly cross the respiratory membrane and enter the blood

The partial pressure of CO2 in the alveoli is ~40 mmHg, whereas its partial pressure in the capillary blood is ~45 mmHg
* The high solubility of CO2 (despite the small pressure gradient) causes CO2 to rapidly cross the respiratory membrane and enter
the alveoli

MNM

Internal Respiration
The partial pressure of O2 in the tissues is ~40mmHg, whereas its partial pressure in the arterial blood is ~100 mmHg
* This very strong pressure gradient causes O2 to rapidly cross the plasma membrane and enter the tissues

The partial pressure of CO2 in the tissues is ~45 mmHg, whereas its partial pressure in the arterial blood is ~40 mmHg
* The high solubility of CO2 (despite the small pressure gradient) causes CO2 to rapidly cross the plasma membrane and enter the blood