Lecture Connect 15 - Ventilation and Control

Which type of lung disorder decreases pulmonary compliance and thereby decreases vital capacity?

Restrictive

True or false: When the diaphragm contracts and lung volume increases, intrapulmonary pressure drops.

TRUE: When lung volume increases, intrapulmonary pressure drops. This will pull air into the lungs.

Which of these calculated volumes typically has the greatest value?

Total lung capacity

True or false: The anatomical dead space is subtracted from tidal volume when calculating the alveolar ventilation rate.

True

Pulmonary compliance is reduced in which of the following?

Tuberculosis patients

How is the functional residual capacity calculated?

Residual volume + expiratory reserve volume (RV + ERV)

Which term refers to one complete breath, in and out?

Respiratory cycle

The lungs of premature infants often develop respiratory distress syndrome. Why do these infants experience alveolar sac collapse?

Surfactant is not produced yet in adequate quantities.

Which muscle (or muscle group) aids the diaphragm as a synergist during resting respiration?

Internal and external intercostals

How is inspiratory capacity calculated?

Tidal volume plus inspiratory reserve volume

A normal residual volume would be ______ mL of air.

1200

How much air is in the anatomic dead space?

150mL

A normal functional residual capacity would be ______ mL of air.

2500

A normal inspiratory reserve volume would be ______ mL of air.

3000

An average tidal volume is about ______ mL of air.

500

A normal total lung capacity would be ______ mL of air.

6000

What is the role of the pontine (pneumotaxic) respiratory group?

Adjusts respiratory rate based on stimuli from limbic system or cerebral cortex

What is the role of the dorsal respiratory group?

Adjusts respiratory rate based on stimuli from peripheral chemoreceptors

Which term refers to the conducting zones of the respiratory system because they are incapable of gas exchange?

Anatomical dead space

Which are examples of obstructive lung disorders?

Asthma Chronic bronchitis

Why does air flow into the lungs during inspiration?

Atmospheric pressure is greater than intrapulmonary pressure, and air flows toward the lower pressure area.

Where are the respiratory control centers located?

Brainstem

You place an empty, sealed plastic bottle in the freezer. When you remove the bottle 4 hours later it has collapsed. This is an example of which gas law?

Charles's Law

Which two factors contribute most to airflow resistance?

Diameter of the bronchioles Lung compliance

Which two muscles (or muscle groups) are primarily responsible for resting (non-forced) inspiration? Choose two answers from the list below.

Diaphragm Intercostals

Which term refers to relaxed, quiet breathing?

Eupnea

True or false: Intrapleural pressure is always greater than atmospheric pressure.

FALSE: Intrapleural pressure is always slightly negative relative to atmospheric pressure. If intrapleural pressure were greater than atmospheric pressure, the lungs would collapse.

True or false: The residual volume may be exhaled with a forceful expiration.

FALSE: The residual volume is the air remaining after a maximum voluntary expiration. It cannot be exhaled.

True or false: Asthma is an example of a restrictive lung disorder.

False: Restrictive disorders reduce pulmonary compliance, limiting the amount the lungs can be inflated. Obstructive disorders (such as asthma) interfere with airflow by narrowing or blocking the airway.

Which respiratory volume takes into consideration the rate at which air is exhaled?

Forced expiratory volume

As the thoracic cavity expands, the visceral pleura clings to the parietal pleura, and the surface of the lung is pulled outward. Why does this increase in lung volume cause inspiration?

Intrapulmonary pressure is temporarily lower than atmospheric pressure.

Exposure to smog and dust can lead to coughing and bronchoconstriction. Which type of respiratory receptors initiate this response?

Irritant receptors

Which of these occurs during exhalation?

Lung volumes decrease and intrapulmonary pressure increases.

Which locations contain the brainstem respiratory centers?

Medulla oblongata Pons

Central chemoreceptors

Oxygen level, carbon dioxide level, and pH of the blood

Which includes all of the regions of the airway incapable of gas exchange, including both conducting zones and respiratory zones that have been damaged by disease?

Physiological dead space

Which is often increased in individuals with pulmonary disease?

Physiological dead space

Which term describes the ease with which lung tissue expands during breathing?

Pulmonary compliance

An inactive person, unconscious of their respiratory rate, is performing which type of breathing?

Quiet

Which process is facilitated by the elastic components of the lungs and bronchial tree?

Quiet exhalation

What is the correct formula for calculating total lung capacity?

Residual volume+vital capacity

Which decreases surface tension in the fluids of the alveoli?

Surfactant

Which best describes the expiratory reserve volume (ERV)?

The amount of air that may be exhaled over the tidal volume

Why do the lungs expand along with the thoracic cage during inspiration?

The cohesion of water causes the visceral pleura to cling to the parietal pleura.

Which best describes what happens during exhalation?

The diaphragm relaxes, intrapulmonary pressure increases, air flows out

What is the intrapleural pressure?

The pressure in the fluid-filled space between the parietal and visceral pleurae

Boyle's Law states which of the following?

The pressure of a given quantity of gas is inversely proportional to its volume at a constant temperature.

Ambient (outside) air at 22O C is inhaled. The gases are warmed to body temperature (37.5O C) by the time they reach the alveoli of the lungs. According to Charles's law, what will happen to the volume of the inhaled air?

The volume will increase.

How do the elastic components of the lungs and bronchial tree help conserve energy?

They facilitate recoil during exhalation.

The amount of air inhaled and exhaled during quiet breathing matches

Tidal volume

Which term refers to the amount of air inhaled and exhaled during one cycle of quiet breathing?

Tidal volume

Which component of the respiratory center is responsible for setting the basal respiratory rate and providing output to the muscles of respiration?

Ventral respiratory group

The central ______ in the brainstem are neurons that sense changes in the pH of the cerebrospinal fluid.

chemoreceptors

The ______ respiratory group receives input from chemoreceptors and adjusts the respiratory rate accordingly.

dorsal

Movement of air out of the lungs is called ______.

expiration

Central chemoreceptors in the brain stem that are involved in respiratory control respond most directly to changes in which of the following?

pH

Chemoreceptors in the carotid and aortic bodies are called ______ chemoreceptors.

peripheral

A(n) ______ is a clinical condition characterized by the presence of air in the pleural cavity.

pneumothorax

The amount of air remaining in the lungs after a forced expiration

residual volume

_________ receptors respond to the degree of inflation of the lungs/alveoli.

stretch

The ______ respiratory group sets the basal respiratory rate which may then be adjusted by commands from the pontine and/or dorsal respiratory groups.

ventral

The sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume is the __________ capacity.

vital

Which muscles are used for inspiration?

External intercostals, sternocleidomastoid, scalenes

Which term refers to the volume of air (or percentage of the vital capacity) that can be exhaled in a specific amount of time?

Forced expiratory volume

What is the correct calculation for vital capacity?

Tidal volume plus expiratory reserve volume plus inspiratory reserve volume

The amount of air that can be exhaled in a given time interval. matches

forced expiratory volume

The sum of the tidal and inspiratory reserve volumes is a measure of the _______ capacity

inspiratory

________ volume is the volume of air inhaled or exhaled during a respiratory cycle.

tidal

Which equation represents the alveolar ventilation rate?

(volume of air inhaled - dead space) x (respiratory rate)

Which muscle (or muscle group) is the prime mover of respiration, producing about two-thirds of pulmonary airflow?

Diaphragm

The amount of air that may be exhaled over the tidal volume matches

expiratory reserve volume

The ______ respiratory group adjusts the respiratory rate based on stimuli from the limbic system or cerebral cortex.

pontine

Which term refers to the volume of air remaining in lungs after maximum exhalation?

residual volume

As the volume of a closed container decreases, the pressure of the gas within it increases. This is an example of which gas law?

Boyle's Law

The ______ reserve volume represents the maximum amount of air that may be inhaled after the tidal volume.

inspiratory

The peripheral chemoreceptors detect changes in which of the following?

Blood oxygen saturation Blood pH Blood carbon dioxide saturation

Airway resistance in the lungs is usually controlled by changing the diameter of which of the following?

Bronchioles

The expiratory (E) neurons of the ventral respiratory group (VRG) do which of the following?

Inhibit the inspiratory (I) neurons