Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Wk2: Pulmonary Response to Acute Exercise > Flashcards

Wk2: Pulmonary Response to Acute Exercise Flashcards

1
Q

What is the definition of inspiration?

A
  • during inspiration the diaphragm contracts, flattens, and moves down towards the abdominal cavity.
  • elongation and enlargement of the chest cavity expands air in the lungs, causes its intraplumonic pressure to drop slightly below atmospheric pressure.
  • maximal activate of the inspiratory muscles of healthy individuals produce pressures of 80-140mmHg
  • during inspiration the scalene and external intercostal muscles contract.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to inspiration during exercise?

A
  • inspiration action increases during exercise when the diaphragm descends, the ribs swing upward and the sternum thrusts outward to increase the lateral and anterior diameter of the thorax.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the definition of expiration?

A
  • the passive process of air movement out of the lungs due to:
    1) natural recoil
    2) relaxation of intercostal muscles.
  • sternum and ribs swing down and diaphragm rises towards the thoracic cavity.
  • these movements decrease chest cavity volume and compress alveolar gas so air moves from the respiratory tract to the atmosphere.
  • expiration ends when the compressive force of expiratory muscles ceases and trapulmoic pressure decreases to atmospheric pressure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to expiration during exercise?

A
  • intercostals and abdominal muscles act on the ribs and reduce thoracic dimensions.
  • this makes respiration more rapid and extensive.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is surfactant?

A
  • consists of a lipoprotein mixture of phospholipids, proteins and calcium ions produced by alveolar epithelial cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of surfactant?

A
  • reduced surface tension
  • mixes with fluid that encircles the alveolar chambers.
  • its action interrupts the surrounding water layer, reducing alveolar surface tension to increase overall lung compliance.
  • this effect reduces energy required for alveolar inflation and deflation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the spirometer bell show static lung volumes?

A
  • spirometer bell falls and rise during inhalation and exhalation to provide a record of ventilatory volume and breathing rate.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the definition of total volume?

A
  • air volume moved either during the inspiratory and expiratory phase of each breathing record.
  • at rest 0.4 to 1L of air per breath.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is inspiratory reserve volumes (IRV)?

A
  • after total volume the subject inspires as deeply as possible following normal inspiration.
  • the additional 2.5 to 3.5L volume above inspired tidal air is the IRV.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the expiratory reserve volume (ERV)?

A
  • when normal breathing is reestablished.
  • the subject then continues to exhale and forces as much air as possible from the lungs.
  • 1.0 ro 1.5L for the average man.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is residual ling volume (RLV)?

A

Air remaining in the lungs after exhaling deeply.

  • 0.8L to 1.2L in healthy women
  • 0.9-1.4L in healthy men

RLV increases with age, whereas IRV and ERV decrease proportionally.

a decrease in elasticity of lung tissue components with raging decreases breathing reserve and therefore increases RLV.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

RLV increases from exercise due to…

A
  1. closure of small peripheral airways

2. increase in thoracic blood volume which displaces air preventing exhalation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Forced Vital Capacity (FVC)

A

The total volume of air voluntarily moved in one breath, from full inspiration to maximum expiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the equation for FVC?

A

FVC = TV + ERV + IRV (4-5L in young men)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to static and dynamic lung function with age?

A

it decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the equation for total lung capacity (TLC)?

A

TLC = RLV + FVC.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What factors increase RLV with exercise?

A
  • closure small peripheral airways

- increase in thoracic blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is dynamic lung volume?

A
  • efficient pulmonary ventilation depends on how well an individual sustains high airflow levels rather than air movement in a single breath.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What two factors does dynamic ventilation depend on?

A
  1. maximum SV of the lungs (FVC)

2. speed of moving volume of air (breathing rate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does air velocity depend on?

A
  • the resistance of the respiratory passages to smooth the air flow.
  • stiffness imposed by the mechanical properties of the chest
  • lung tissue to change shape during breathing which is lung compliance.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the definition of lung compliance?

A

-the ability of lungs to expand under pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

FEV - FVC ratio (forced expiratory volume - forced expiratory volume)

A
  • individuals with severe lung disease achieve normal FVC value, therefore to properly assess lung function FEV1/FVC is used to indicate pulmonary expiratory power and overall resistance to airflow.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is maximum ventilatory volume (MVV)?

A
  • evaluates ventilatory capacity (FVC) with rapid deep breathing for 15s.
  • men = 140 to 180L/min + women = 80 to 120L/min
  • expiratory exercise training of the ventilatory muscles improves their strength and endurance.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the effect of ventilatory training in patients with chronic pulmonary disease?

A
  • enhances exercise capacity and decreases physiologic strain.
  • this includes the decrease in feeling of breathlessness and greater self-control of respiratory systems.
25
Q

What are the exercise implications of gender differences in static and dynamic lung function measures?

A
  • adult women have smaller legs and static and dynamic lung function, reduced airway diaper and a smaller diffusion SA then men.
This causes: 
- expiratory flow limitations
- greater respiratory muscle work 
- greater use of voluntary reserve 
(during exercise)
  • during intense exercise this places a large demand on the mechanical constraints of the TV and minute ventilation.
26
Q

What is the relationship between CO2 output and ventilation during moderate exercise?

A
  • PaCO2 is normally well maintained suggesting VA is well matched to increases in VCO2.
  • increase in ventilation occurs with work rate
  • PCO2 levels in the blood remain constant because ventilation is well matched
27
Q

What is the definition of hyperpnoea?

A
  • the appropriate increase in ventilation response to exercise (over breathing)
28
Q

What is Dalton’s Law?

A
  • the molecules each gas in a mixture exert their own partial pressure.
  • the mixture of total pressure = sum of partial pressures
29
Q

What is tracheal air?

A
  • air is completely saturated with water vapour as it enters the nasal cavity and mouth to pass down the respiratory tract.
  • the vapour dilutes the inspired air mixture.
  • the effective PO2 in tracheal air decreases by 10mmHg from 159mmHg.
30
Q

What is alveolar air?

A
  • alveolar air composition differs as CO2 enters the alveoli from the blood and oxygen flows from the lungs.
31
Q

What are the sources of CO2output during exercise?

A

Aerobic substrate catabolism
- Carbohydrates and fatty acids

Bicarbonate buffering

  • Muscle: potassium bicarb, (KHCO3)
  • Blood: sodium bicarb. (NaHCO3)

Pulmonary hyperventilation
- Above lactate threshold (LT)

32
Q

What happens to ventilation above lactate threshold?

A
  • greater increase in CO2 and decrease in PaCO2.
  • ventilatory demands of exercise are increased beyond that required to clear metabolically produced CO2, which in healthy people results in a true hyperventilation and so PaCO2 progressively falls.
  • additional output from the bicarbonate buffering protons
  • increase in ventilation to try and breakdown lactate.
  • CO2 output increases, H+ is used as a buffer and as HCO3 decreases you get a large ventilation increase
33
Q

What happens to VA during low intensity exercise?

A
  • ventilation is largely due to increased VT, via decreased expiratory and inspiratory reserve volumes (IRV & ERV).
34
Q

What happens during high-intensity exercise above LT?

A
  • ERV stabilises and further increases VT and is due to decreased IRV.
  • VD increases bc airways are move listened by more negative intrapleural pressure at larger lung volumes.
  • this is achieved by the repository muscles contracting; greater pressures in the conducting zones to draw air in.
  • the actual dead space fraction of a breath decreases with exercise.
  • any further increase pulmonary and alveolar ventilation is consequent to an increase in breathing rate (fr)
35
Q

What happens during sub maximal exercise above LT?

A
  • ventilation increases rapidly
  • followed by a slower rise toward a steady-sate volume.
  • arterial PO2 and PCO2 are maintained relatively constant during this type of exercise.
36
Q

What is ventilatory threshold?

A
  • when incremental exercise results in a VE up to approximately 50-70% of O2 max; at higher work rates, ventilation begins to rise exponentially. This is the ventilatory threshold.
37
Q

What are the factors of ventilatory control during exercise?

A

Control of the exercise hyperpnoea:
Central command
- Central neurogenesis

Humoral

  • Central (medullary) chemoreception
  • Peripheral (carotid body) chemoreception

Afferent feedback/mechanical receptors

  • Peripheral neurogenesis
  • Cardiogenic drive

– neural impulses originating in the motor cortex may pass through the medulla and spill over, causing an increase in VE that reflects the number of muscle motor units being recruited.

38
Q

What are afferent feedback/mechanical receptors?

A
  • peripheral neurogenesis -> sensory inputs from joints, tendons, and muscle influence the ventilator adjustments throughout exercise.
  • cariogenic drive - neural outflow from the regions of the motor cortex and cortical activation in anticipation of exercise stimulate respiratory neurones in the medulla to initiate the abrupt increase in exercise ventilation.
  • at rest the brainstem and medulla are the main ventilation controllers.
39
Q

What are neural factors?

A
  • accuracy of inspiratory neurones with cell bodies in the medulla govern the respiratory cycle.
  • these activate the diaphragm and intercostals
  • the inspiratory neurones cease firing due to self limitations and inhibitory influence of excitatory neurones.
  • duration and intensity if the cycle respond to the neural centres in the hypothalamus that integrate inputs from the cerebral hemispheres during exercise ventilation adjustments due to mechanical and chemical changes.
40
Q

Where are central chemoreceptors located?

A
  • near the ventral surface of the medulla oblongata
41
Q

What are the central chemoreceptors affected by?

A

changes in PCO2 and pH of the cerebrospinal fluid (CSF).

42
Q

What are the central chemoreceptors protected by? but what about CO2?

A

the blood brain barrier which is impermeable to H+

CO2 is free to diffuse into the CSF.

43
Q

How does the CSF increase ventilation?

A
  • CSF has low protein, and hence low buffering capacity (Sensitive to small changes)
  • an increase in PCO2 or H+ OF THE CSF results in the central chemoreceptors sending afferent input into the respiratory centre to increase ventilation.
  • a small change in PaCO2 causes a large change in H+CSF increasing respiratory drive.
44
Q

Where are peripheral chemoreceptors located?

A
  • in the carotid bodies at the bifurcation of the common carotid arteries
  • the aortic bodies above and below the aortic arch
45
Q

How to peripheral chemoreceptors stimulate increases in ventilation?

A

due to increases in temperature and CO2.

46
Q

What is integrated ventilation? (during sub maximal exercise)

A

the combined and simultaneous effects several chemical and neural stimuli imitate and modulate exercise alveolar ventilation.

47
Q

What are the 3 phases of ventilatory control during sub-maximal exercise?

A

P1 = cortical stimulus plus feedback forma active limbs causes the abrupt increase in ventilation as exercise begins.

P2 = ventilation then rises exponentially to reach a steady state related to exercise demands.

P3 = involves the fine-tuning of steady-sate ventilation through peripheral sensory feedback mechanisms.

48
Q

What are the 3 non chemical factors that augment ventilatory adjustments to exercise?

A
  1. cortical activation in anticipation of exercise and outflow from motor cortex when exercise begins
  2. peripheral sensory input from chemoreceptors and mechanoreceptors in joints and muscles.
  3. increased body temp.
49
Q

What is the function of carotid bodies? (peripheral chemoreceptors)

A
  • monitors the state of arterial blood flow just before it perfuses the brain.
  • sensitive to arterial PO2
  • Highly vascularised, rich capillary network (high amount of blood flow so can easily sense reductions in CO2).
  • High blood flow for their volume and hence have a small (a-v)O2 difference
  • Respond directly to a fall in arterial pH
50
Q

Plasma PCO2 and H+ concentration at Rest

A
  • at rest CO2 pressure in arterial plasma provides the most important respiratory stimulus.
  • small increases in PCO2 trigger large increases in minute ventilation.
  • plasma acidity, which varies with CO2 content, has command over ventilation.
  • a fall in ph signals acidosis and reflects CO2 retention and carbonic acid formation.
  • this causes inspiratory activity to increase to eliminate CO2 and reduce arterial levels of carbonic acid.
51
Q

Is the desire to breath when holding your breath from increase in CO2 or decrease in O2?

A
  • increase in CO2.
52
Q

What is hyperventilation?

A
  • when one consciously increases ventilation above the normal level, before breath holding.
53
Q

How does hyperventilation increase the length of time you can hold your breath?

A
  • as it decreases CO2 concentration in the alveoli so more can move out the blood when holding your breath.
54
Q

Ventilation in steady-state exercise

A

in light to moderate exercise, pulmonary ventilation increases linearly with oxygen consumption so the ventilatory equivalent (VE/VCO2) averages 20 to 25L of air breathed per litre of oxygen.

55
Q

Ventilation in non-steady state exercise

A

ventilation increases disproportionately with increases in oxygen consumption, and the ventilatory equivalent can exceed 35L.

56
Q

How is OBLA formed?

A

a disproportionately sharp rise in minute ventilation during incremental exercise

57
Q

What is the effect of OBLA?

A

provides a sub maximal measure of aerobic fitness that relates to the beginning of anaerobiosis in active muscles.

OBLA occurs with significant metabolic acidosis or severe cardiovascular strain.

58
Q

What are the mechanical considerations for exercise hypernoea?

A
  • large tidal volumes require large changes in intrapleural pressure that can enrich on lung volumes where compliance is reduced, resulting in increased work of breathing.
  • the tachypnoea (high breathing frequency) manifest during exercise above LT, requires expiratory flow rates that may be limited by high compliance of small airways and high expiratory pressures (dynamic compression).
  • in patients of elite athletes this may result in hyperinflation of the lung, reduced tidal volume and respiratory muscle fatigue during high intensity exercise.

Physiology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions