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physiology 4
exam 4
Question | Answer |
---|---|
Trachea has 2 tubes that branch into the ________. | bronchi |
Bronchi branches into ___________. | bronchioles |
Bronchioles branch into __________ ___________. | terminal bronchioles |
Terminal bronchioles branch into _________ ___________. | respiratory bronchioles |
Respiratory bronchioles branch into _______ _______. | alveolar ducts |
Alveolar ducts branch into _________ ________. | alveolar sacs |
Trachea, bronchi, bronchioles, terminal bronchioles = ______________ zone. | conducting |
Respiratory bronchioles, alveolar ducts, alveolar sacs = ______________ zone. | respiratory |
The ___________ contain large amounts of smooth muscle. | bronchioles |
The airways of the respiratory zone contain ____________ (site of gas exchange) and participate in gas exchange wit the blood. | alveoli |
Bronchioles lack or have cartilage? | LACK |
Trachea and bronchi contain cartilaginous rings or lack? | CONTAIN |
The _________ are hollow air sacs that serve as the sites of gas exchange with the blood. | alveoli |
There are _______ million alveoli in the lungs of an adult human. | 300 |
Line the inner walls of the alveoli (main cells). | Type 1 Alveolar cells |
Produce surfactant. | Type 2 Alveolar cells |
Total surface area for gas exchange is the size of a _____ ______. | tennis court |
Gas exchange occurs between air in the _______ and ________ contained within the alveolar walls. | alveoli/capillaries |
Exchange of air between atmosphere and alveoli by BULK FLOW. | ventilation |
Exchange of O2 and CO2 btwn alveolar air and blood in lung capillaries by diffusion. | simple diffusion |
bulk flow occurs from regions of ____ to ____ pressure as determined by changes in thoracic volume. | high to low |
Air flow rate is ________ proportional to the pressure difference between alveolar and atmospheric air. | directly |
Air flow rate is ________ proportional to the resistance to air flow offered by the airways. | inversely |
Changes in air pressure are inversely related to changes in air volume. | Boyle's Law |
Inspiration = _________. | Inhalation |
Expiration = _________. | exhalation |
Composed of one inhalation + one exhalation | Respiratory cycle |
_________ = movement of air into the alveoli | inhalation (inspiration) |
_________ = movement of air out the alveoli | exhalation (expiration) |
Contraction (lowering) of the diaphragm to create negative pressure, pulling air into the lungs | Inhalation |
diaphragm contracts in response to stimulation by the ________ nerves. | phrenic |
Elevation of the ribs _________ from the spine also contributes to expanding the thoracic cavity. | away |
Elevation of the ribs away from the spine is accomplished mainly by contraction of the external _________. | intercostals |
Relaxation of the diaphragm and elastic recoil of the lungs, chest wall, and abdominal structures. | Exhalation |
Exhalation compress the lungs and pushes air out via _______ pressure. | positive |
Contraction of __________ muscles facilitates exhalation during heavy breathing. (pushes the abdominal organs upward against the bottom of the diaphragm, compressing the lungs. | abdominal |
lung compliance = ____________. | stretchability |
The magnitude of the change in lung volume produced by a given change in the transpulmonary pressure. | lung compliance |
Reflects how easily the lungs can stretch. | Lung compliance |
The ________ the lung compliance, the more easily the lungs expand. | greater |
_________ (lung) compliance means that a greater change in pressure must occur to fill the lungs. | low |
1 of 2 determinants of lung compliance that is determined by the thickness of the lung's connective tissue. ________ of the lung tissue. | Elasticity |
One of two determinants of lung compliance = water lining the alveoli exhibits this | Surface tension |
A detergent-like mixture of phospholipids and protein secreted by type 2 alveolar cells that reduces surface tension. | surfactant |
True or False? The lungs wouldn't collapse if the alveoli were lined with pure water. | False - They would! |
Increased lung compliance is the result of loss of elastic recoil in the lung. | Emphysema |
Disease involves destruction of elastic connective tissue and the alveolar walls. | Emphysema |
__________ __________ stimulates elastase release. | cigarette smoking |
Increased compliance = alveoli ________. | destroyed. |
________ compliance = alveoli destroyed. | Increased |
Scarring of the lung = ________ _______. | pulmonary fibrosis. |
Decreased lung compliance is due to an excess of connective tissue fibers in the lung (greater elasticity). | Pulmonary Fibrosis |
As in blood vessels, __________ is by far the most important factor determining resistance to flow. | radius |
Airway resistance is usually very _______. | low |
________ pressure difference can move large volumes of air. | Small |
The _________ resistance to airflow occurs in the medium-sized bronchi and larger bronchioles. | greatest |
Despite their small radius, the _________ bronchioles contribute little total resistance to airflow because of the repetitive branching and parallel arrangement. | terminal |
Elastic fibers attached to the airways pull them open during inhalation, decreasing resistance. | Lateral traction |
Cause changes in resistance during the ventilatory cycle. | Physical factors |
_______ pressure generated by elastic recoil increases airway resistance during exhalation. | positive. |
Positive pressure generated by elastic recoil _______ airway resistance during exhalation. | increases |
Chemical messengers cause bronchodilation and bronchoconstriction. | Chemical factors |
Most common chronic pulmonary disease. | Asthma |
Intermittent of chronic episodes of bronchoconstriction greatly increase airway resistance. | Asthma |
Often associated with inflammatory response to allergens and hyper-responsiveness to intrinsic bronchoconstrictors (e.g. histamine). | Asthma |
Asthma is treated with ____________ drugs. | bronchodilator |
Muscarinic receptor antagonists --> block _______. | ACh |
B2-adrenergic receptor agonists --> mimic _____. | Epi |
Norepinephrine binds to B2-adrenergic receptors (bronchodilation) = __________ innervation. | sympathetic |
_______ exhibits dual innervation of bronchial and bronchiolar smooth muscle. | ANS |
Acetylcholine binds to muscarinic receptors (bronchoconstruction) = ___________ innervation. | parasympathetic |
The volume of air entering the lungs during a single inhalation. | Tidal volume (TV) |
The maximum volume of air that can be inhaled above TV. | Inspiratory Reserve Volume (IRV) |
The volume of air remaining in the lungs at rest, following a normal exhalation of the TV. | Functional Residual Capacity (FRC) |
Maximum volume of air that can be forcibly exhaled below resting TV. | Expiratory Reserve Volume (ERV) |
Volume of air still remaining in the lungs after exhalation of the ERV. | Residual Volume (RV) |
Maximum volume of air that can be exhaled following maximum inspiration. | Vital Capacity (VC) |
Maximum volume of air that can be inhaled after a normal tidal exhalation. | Inspiratory Capacity (IC) |
Maximum volume of air the lungs can hold. | Total Lung Capacity (TLC) |
total rate of ventilation | Minute Ventilation |
T or F? Due to the presence of dead space in the airways and the alveoli, all of the minute ventilation exchanges gas with the blood. | False |
Air in the airways that never reaches the alveoli = volume of the conducting airways (150mL) - volume of fresh entering the alveoli with each inspiration (Vt-Vd) | Anatomical Dead Space (Vd) |
Total volume of fresh air entering the alveoli per minute. | Alveolar ventilation (Va) |
Inspired air that reaches the alveoli, but does not participate in gas exchange with the blood. | Alveolar dead space |
Alveolar dead space is normally ________ by ventilation-perfusion matching. | minimized |
Alveolar dead space is greatly _________ by various kinds of lung disease (e.g., emphysema and pulmonary fibrosis) | increased |
Ratio of CO2 produced to O2 consumed. | Respiratory quotient (RQ) |
In a mixture of gases, the pressure exerted by each gas is independent of the pressure exerted by the other gases present. | Dalton's Law |
The total pressure of the mixture of gases is simply the sum of the individual pressures exerted by each gas (called partial pressures) | Dalton's law |
Atmospheric pressure=________ pressure | Barometric |
The sum of the partial pressures exerted by all the above gases. | Atmospher/Barometric pressure |
Atmospheric pressure is equal to ______ mmHg at sea level. | 760 |
T or F? There is no active transport mechanism for O2 or CO2 (or any other gas). | True |
_________ in the partial pressure of a particular gas (e.g., pO2 and pCO2 gradients) determine the passive net flux of that gas (i.e., the magnitude and direction of gas flux) | differences |
The partial pressure of a gas in atmospheric air is _______ to its fractional concentration times the atmospheric pressure. | equal |
_________ in pO2 and pCO2 determine the direction and magnitude of flux of those gases. | Differences |
Systemic venous blood has _____ pO2 and ________ pCO2. | low/ high |
__________ pO2 determines systemic arterial pO2. | alveolar |
At ___________, O2 leaving the alveoli is = to O2 demand by the body's tissues. | steady-state |
alveolar ventilation exceeds the rate of CO2 production | hyperventilation |
alveolar pCO2 is __________ than normal resting value. | lower |
Hyperventilation: alveolar ventilation is low relative to the rate of CO2 production | hypoventilation |
Hypoventilation: alveolar pCO2 is _________ than normal resting value | higher |
alveolar air flow rate | ventilation |
pulmonary capillary blood flow rate | perfusion |
An even more important cause of hypoxia in diseased lungs is a mismatch between air supply to alveoli (termed ______-________ inequality). | ventilation-perfusion |
_________ occurs in diseased lungs b/c diffusion equilibrium can't be attained (e.g., emphysema, pulmonary fibrosis) | hypoxia |
_________ leaving the pulmonary capillaries is in diffusion equilibrium with alveolar air. | blood |
Local decrease in pulmonary blood pO2 causes ___________, which diverts blood away from a poorly ventilated area. | vasoconstriction |
_______________, which diverts air to areas of the lung with better perfusion. | bronchoconstriction |
_________ disease is accompanied by changes in lung compliance, airway resistance, and/or vascular resistance. These changes result in either __________ air supply or __________ blood supply to alveoli. | lung/decreased/decreased |