Lesson 4: The Pulmonary System Flashcards
Cellular Respiration
exchange of gases at the tissue level (between blood and tissues)
Pulmonary Ventilation
exchange of gases between the alveoli and capillaries (at the lung level)
Gas exchange is the delivery of ____ to and removal of ______ from the tissue
oxygen; CO2
What is the primary function of the pulmonary system?
Gas exchange
Three parts of the upper respiratory tract:
Nasal cavity/mouth
Pharynx (epiglottis)
Larynx (voicebox)
Five parts of the lower respiratory tract
Trachea (windpipe)
Primary Bronchi
Bronchioles
Alveoli
Pulmonary capillaries
Elastic, thin-walled membranuous sacs
Alveoli
Why are the alveoli so thin and so multitudinous?
To allow for ease of diffusion (gas exchange)
True or false: The alveoli lie alongside a complex capillary bed for blood/gas exchange
True
Diseases that affect the elasticity of the lungs
Emphysema
Hyperfibrosis
The lungs provide the _____ for gas exchange that separates blood from the surrounding alveolar gas
surface
How many lobes on the R lung?
3
How many lobes on the L lung?
2
General process of gas exchange in the lungs?
O2 travels from alveolar air to alveolar capillary blood
CO2 travels from blood to alveolar air to be expired
Both occur through diffusion across the alveolar/capillary barrier
Lipoprotein mixture of phospholipids, proteins, and calcium ions
Surfactant
Surfactant increases/decreases surface tension caused by fluid and gas interaction in the alveoli
increases
True or false: Premature babies may not have developed enough surfactant to breath on their own.
True
Reducing the _____ ____ allows the alveoli to expand more efficiently (thanks, surfactant!)
surface tension
Where is the conducting zone?
The trachea and terminal bronchioles
Does gas exchange in the conducting zone?
Nope! It’s an ANATOMIC DEAD SPACE
What is the area of gas exchange called?
Respiratory Zone
Where is the respiratory zone?
respiratory bronchioles, alveolar ducts, and alveoli
Can the lung muscles contract themselves?
No, man. The lungs aren’t even muscles, c’mon.
The diaphragm is the muscular partition that separates the ____ and ______ _____
lungs; abdominal cavities
What is the major ventilatory muscle?
Diaphragm
The diaphragm won which “best ____ of the year” awards for skeletal muscles?
Mitochondrial volume/density
Oxidative capacity of muscle fibers
Aerobic capacity
Steps of Inspiration from a mechanical standpoint
1.) Diaphragm contracts and flattens
2.) Moves downward toward the abdominal cavity
3.) External intercostal muscles contract and lift the ribs
4.) Intrapulmonic pressure decreases below the atmosphere
5.) Allows air to flow into lungs
Steps of expiration from a mechanical standpoint:
1.) Diaphragm relaxes
2.) Lifts towards the thoracic cavity
3.) External intercostals relax and return the ribs to initial position
4.) Intrapulmonic pressure reduces to the atmospheric pressure
5.) Air is expired by the lungs
6.) Mainly a passive process of muscular relaxation at rest
Tell me about the mechanics of ventilation when expiration occurs during exercise.
Intercostal and abdominal muscles work forcefully on the ribs to reduce thoracic volume and make exhalation more rapid and extensive
Why most the muscles become more active when expiring during exercise?
Anaerobic systems; need more to be pushed out
Do the lungs move actively or passively?
Passively
What structures related to breathing may adapt with training?
Diaphragm, abdominal muscles, intercostal muscles
(not hypertrophy; more just aerobic ability)
Volume inspired or expired per breath
Tidal Volume
Maximum inspiration at end of tidal inspiration
Inspiratory Reserve Volume
Maximum expiration at end of tidal expiration
Expiratory Reserve Volume
What is the average value of TV?
600mL for Men; 500mL for women
Volume in lungs after maximum inspiration
Total Lung Capacity (TLC)
Volume in lungs after maximum expiration
Residual lung volume
Maximum volume expired after maximum inspiration
Forced Vital Capacity
Maximum volume inspiration following tidal expiration
Inspiratory Capacity
Volume in lungs after tidal expiration
Functional residual capacity
Average value for total lung capacity:
6000mL for men; 4200mL for women
Can you train to improve your total lung capacity?
No. Your lungs are the size they are.
How are static lung volumes measured?
Pulmonary function testing
Forced Expiratory Volume 1
Volume of gas that can be exhaled in 1 second after a maximal inspiration
Maximum Voluntary Ventilation
Evaluated ventilatory capacity with rapid and deep breathing for 15 seconds
What does FEV determine?
The ability of the lungs to recoil after a maximum expiration
True or false: Like other components of the aerobic system, regular endurance activity stimulates large increases in the functional capacity of the pulmonary system
FALSE
Lung volume is set by your ______ _____ ____
thoracic cavity size
Normal breathing rate at rest:
12-20 breaths per minute
What happens to your breathing during exercise?
Breathing rate increases
TV increases
Do TV and breathing rate increase incrementally with exercise intensity?
Yeah
Alveolar ventilation
The portion of inspired air reaching the alveoli and participating in gas exchange
Anatomic Dead Space
Air that fills the upper airways but never travels further for actual alveolar ventilation
Physiologic dead space
Alveoli not function appropriately in gas exchange
What causes physiologic dead space?
Underperfusion of blood (hemorrhage)
Inadequate ventilation relative to alveolar surface
Which type of dead space is normal?
Anatomic Dead space
How do you calculate minute ventilation?
breathing rate x tidal volume
Pulmonary f
the volume of air breathed each minute
increase in pulmonary ventilation that exceeds the oxygen consumption and carbon dioxide needs of metabolism
Hyperventilation
What is the stimulus for hyperventilation?
CO2 increase provides the stimulus to breathe
An inordinate shortness of breath or subjective distress in breathing
Dyspnea
Transient periods of cessation of breathing
Apnea
Forced exhalation against a closed glottis while maximally activating the expiratory muscles
Valsalva Maneuver
What is the glottis?
narrowest part of the larynx through which air passes into the trachea
What happens to the circulatory system during the valsalva maneuver
Reduction in venous return to the heart due to increased intrathoracic pressure that collapses low pressure veins
Physiologic consequences of performing the Valsalva Maneuver:
Dizziness
Seeing spots
passing out
dramatic drop in BP
What is the recommended breathing pattern during strength training?
maintain a constant flow of expiration during contraction and inspiration during relaxation
Partial pressure
individual pressure of a gas within a particular mixture of gases
How do you calculate partial pressure?
percentage concentration of a specific gas x total pressure of gas mixture
True or false: Partial pressures remain constant, regardless of environment and location in the body
False; partial pressures can vary based on environment and location in the body
Another word for the outside or surrounding air is ______
ambient
Ambient air is composed mostly of ______
nitrogen
Air saturates with water vapor after entering the nasal cavity/mouth and down the respiratory tract
Tracheal air
Tell me something about tracheal air
WARM and WET
What is the point of tracheal air’s existence?
Dilutes the gas mixture somewhat and causes a reduction in O2 partial pressure
Partial pressure O2 of tracheal air
149 mmHg
Compared to ambient air, alveolar air has more ______ and less _____
CO2; O2
What is Henry’s Law?
Gases dissolve in liquids in proportion to their partial pressures, depending on their solubility in the specific fluids and depending on the temperature.
What two factors determine diffusion into a liquid?
The pressure differential between the gas above the fluid and the gas dissolved in the fluid
The solubility of the gas in the fluid
(Henry’s Law)
Pressure Differential
The pressure difference between alveolar and pulmonary blood gas creates the driving force for gas diffusion across the pulmonary membrane
For two different gases of identical pressures, the _______ of the gas determines the number of molecules that will move into the fluid
solubility
The greater solubility, the more/fewer molecules that will move into the liquid
more
CO2 has a greater ______ than O2, but O2 will have a greater ________
solubility; pressure differential
True or false: Exchange of gases between the lungs/blood and gas movement at the tissue level occurs passively through diffusion and pressure gradients
True
Gases will move from areas of_____ __ ___ pressure
high to low
What two ways does blood carry oxygen?
1) In physical solution dissolved in plasma of the blood
2) In loose combination with Hemoglobin within the red blood cell
O2 is relatively ________ in water making its concentration high/low in bodily fluids
insoluble; low
Most of the oxygen in the blood is carried by the plasma/hemoglobin
hemoglobin
What is hemoglobin?
iron-containing globular protein contained within the red blood cells that carries O2
decrease in number of red blood cells or hemoglobin
Anemia
Pulmonary symptoms of anemia
Fatigue
Light-headedness
Dyspnea
What kind of anemia is particularly prevalent among endurance athletes?
iron-deficiency
Tell me about iron-deficiency anemia
Reduction in iron content of the blood significantly limits O2 carrying capacity in regards to hemoglobin
O2 dissociation from hemoglobin increases/decreases with increased blood acidity and temperature.
increases
The Bohr Effect
A shift both downward and to the right of the oxyhemoglobin dissociation curve due to increases in acidity and/or temperature in the blood
When is an instance when an increase in body temperature and acidity levels happen?
Aerobic exercise
As exercise intensity increases and more heat, CO2, and acidity increases, more O2 _________
is able to be extracted by muscle tissue
An attraction or force between particles that causes them to combine, as the attraction between an antigen and an antibody.\
Affinity
the difference between the oxygen content of the arterial blood and mixed-venous blood
Arteriovenous Oxygen Difference (a-vO2) difference
The greater the a-VO2 difference, the greater the driving force for ______ (will move from high to low pressure)
oxygen delivery
If you are training for a bike race, you should probably bike a lot so that the metabolic changes will occur specific to that.
Big brain there, buddy
CO2 transport in the blood
1) A small amount of physical solution in plasma as free carbon dioxide
~ 5% of carbon dioxide formed during energy metabolism travels in physical solution
2) As plasma bicarbonate
~ 60-80% of the total carbon dioxide exists as plasma bicarbonate
3) Carbon Dioxide transport as carbamino compounds
~ 20% is carried on the hemoglobin as a carbamino compound
3 Ventilation regulation factors
Neural
Humoral
Chemoreceptors
_______ ______ within the medulla (in brain) govern the normal respiratory cycle and activate the diaphragm and intercostal muscles
Inspiratory Neurons
Inspiratory neurons will cease firing based on _______ or ______
self-limitations; inhibitory effects of expiratory neurons
What exerts the greatest control of pulmonary ventilation at rest?
The chemical state of blood
Peripheral chemoreceptors are the primary site to detect _____ ______
arterial hypoxia
Where are the PO2 and peripheral chemoreceptors located?
Located in the Aorta and carotid arteries before the brain
At rest, _______ _____ ____ ______ provides the most important respiratory stimulus
CO2 pressure in arterial plasma
Small changes in the CO2 pressure in arterial plasma trigger large increases in ______ _____
minute ventilation
A drop in __ (increase in _____) of the blood will cause an increase in inspiratory activity varies directly with CO2 accumulation
pH; acidity
3 factors of Regulation of Ventilation During Physical Activity
1.) Chemical mechanisms
2.) Non-chemical mechanisms
3.) Integrated Regulation
During light and moderate activity, ___ __________ and ____ _______ closely match pulmonary ventilation
O2 consumption; CO2 production
With strenuous/vigorous exercise, there is likely added ______, ___, and the coinciding increase in ______, which leads to an additional stimulus to increase breathing
lactate; CO2; acidity
Neural/chemical changes will occur more quickly than neural/chemical changes
neural; chemical
Neural outflow from the motor cortex and activation in anticipation of activity stimulate an abrupt increase in ventilation
Ye
Neural factors of regulating ventilation during exercise
Motor Cortex
Peripheral Sensors (fine-tune)
True or False: sensory input from joints, muscles, and tendons stimulate a respiratory response (similar to our proprioceptors we learned about previously)
True
During light-to-moderate activity ventilation ______ _____ with O2 usage and CO2 production
increases linearly
When you reach your pulmonary threshold, minute ventilation at this point increases mainly through ____ ______
tidal volume
At progressively more intense submaximal effort, minute ventilation increases sharply upward and disproportionate to O2 consumption
the point where pulmonary ventilation increases disproportionately relative to increases in O2 consumption
Pulmonary Threshold
The “excess ventilation” during intense exercise comes from ______
CO2 released from lactate buffering with greater glycolysis
What does our breathing rate increase with exercise?
To get rid of the CO2!!!!!!!!
True or false: O2 requirement of breathing remains relatively small at rest and light to moderate activity
True
O2 requirement of breathing increases to up to __% of the total blood flow required to maintain breathing with maximal exercise
15
What tissues related to breathing may require this additional blood flow with maximal exercise?
How is the energy cost of breathing affected in COPD?
Inadequate ventilation and gas exchange
