Dr Fitz Chapter 13

Which of the following respiratory muscles are activated during quiet (resting) inspiration?

Diaphragm and external intercostals

What muscles contribute to inspiration when they contract?

Diaphragm, sternocleidomastoid, scalenes, external intercostals

Exchange of O2 and CO2 between alveolar air and blood in lung capillaries occur by what?

Diffusion

What are the main components of the medullary respiratory center?

Dorsal respiratory group and ventral respiratory group

Neurons of the ________ respiratory group primarily fire during inspiration, while the neurons of the _______ respiratory group contains expiratory neurons, and fires mainly when large increases in ventilation are required

Dorsal; ventral

When a person breathes a gas mixture that contains CO2

Increased [H+] stimulates both central and peripheral chemoreceptors

What would stimulate peripheral chemoreceptors and result in an increase in ventilation?

Inhaling atmospheric air containing a trace concentration of carbon monoxide; a 10% reduction in the amount of hemoglobin in the blood

Maximum amount of air that can be inhaled after a normal tidal expiration (TV + ERV)

Inspiratory Capacity (IC)

Steps of expiration

Inspiratory muscles stop contracting, chest wall recoils inward and intrapleural pressure increases toward pre-inspiration value, intrapleural pressure increases and transpulmonary pressure decreases back toward pre-inspiration values, lungs recoil toward pre-inspiration size compressing alveolar air, alveolar pressure increases above atmospheric pressure and air flows out of lungs

Amount of air in excess of tidal inspiration that can be inhaled with maximum effort

Inspiratory reserve volume (IRV)

The extremely thin fluid layer that is between membranes surrounding the lungs and lubricates their surfaces is known as the ________ fluid?

Intrapleural

What is an indicator that hypoventilation is occurring?

Systemic arterial PCO2 is above normal

The most important determinant of airway resistance is

The radius of the airways

What consequences would result if inflammation caused a buildup of fluid in the alveoli and interstitial spaces?

The rate of diffusion of gases between the air and the capillaries may be decreased due to the increased resistance to diffusion

The concentration of a gas dissolved in a liquid is directly proportional to what?

The solubility of the gas in the liquid; the partial pressure of the gas

The oxygen-hemoglobin curve at blood PO2 values between 60 - 100 mmHg

There is a plateau in which little change in oxygen saturation occurs

Amount of air inhaled or exhaled in one breath

Tidal Volume (TV)

What are the main adaptive effects of pulmonary arterial blood vessel vasoconstriction and bronchoconstriction?

To supply less blood flow to poorly ventilated areas, to redirect air way from diseased or damaged alveoli

Maximum amount of air the lungs contain (RV + VC)

Total lung capacity (TLC)

Which structures are part of the anatomical dead space?

Trachea, Nose, Bronchi

The conducting zone included the:

Trachea, bronchi, terminal bronchioles

Inspiration occurs when...... (in regards to pressure)

atmospheric pressure is greater than alveolar pressure; alveolar pressure is less than atmospheric pressure

Carbon dioxide combines with water to form carbonic acid, a reaction that catalyzed in the red blood cells by the enzyme __________ _________

carbonic anhydrase

Is the partial pressure of a gas directly or indirectly proportional to it concentration?

directly

The _________ intercostal muscles are activated during inspiration

external

When the diaphragm muscle contracts it...

flattens from its dome shape and enlarges the thorax

The number of polypeptide subunits that make up a molecule of hemoglobin in what?

four

If other factors remain the same, decreasing ventilation will _________ alveolar PCO2.

increase

In the absence of other changes, what would increase the PO2 in the alveoli?

increasing the rate of alveolar ventilation; increasing the PO2 of atmospheric (inspired) air

The hydrostatic pressure responsible for causing the lungs and thoracic wall to move in and out together during normal breathing is the what?

intrapleural pressure

What is the physiological dead space?

it is the anatomical and alveolar dead space combined

Airways and alveoli contain immune cells called ____ that engulf and destroy inhaled particles and bacteria

macrophages

Central chemoreceptors are located within the region of the central nervous system called the what?

medulla

A decrease in arterial H+ concentration caused by something other than a change in arterial PCO2 is called?

metabolic alkalosis

As blood flows through pulmonary capillaries there is a net diffusion of oxygen where?

net diffusion of oxygen into the blood and carbon dioxide out of the blood

When the PO2 of arterial blood decreases significantly, the _______ chemoreceptors stimulate ventilation

peripheral

The ____ is a structure posterior to the oral cavity that is a common pathway for food moving toward the esophagus and air moving toward the larynx

pharynx

Major components of pulmonary surfactant

phospholipids, proteins

Motor neurons within the _______ nerves innervate and activate the diaphragm muscle

phrenic

The sum of the anatomical and alveolar dead spaces in known as the _______ dead space

physiological

The sum of the anatomical and alveolar dead spaces is known as the _____ dead space?

physiological

Muscles of respiration are composed of what?

skeletal muscles

The apparatus used in pulmonary function tests to measure lung volumes and capacities is called a what?

spirometer

What are two main determinants of lung compliance?

the surface tension at the air-water interfaces within the lungs; the amount and distensibility of connective tissues making up the lung tissue

What two factors work together to create the subatmospheric intrapleural pressure when a person is resting quietly at the end of an unforced expiration with muscles relaxed and no air flowing?

the tendency of the chest wall to expand due to elastic recoil, the tendency of the lungs to collapse due to elastic recoil

What would decrease the compliance of the lungs?

thickening of the connective tissues present in the lungs

T/F: In a closed system, the pressure of a gas and the volume of its container are inversely proportional.

true

(tidal volume - dead space) x respiratory rate =

alveolar ventilation

Tiny, hollow air sacs within the lungs that are principally responsible for gas exchange are called

alveoli

What structures are present in all parts of the pulmonary system categorized as the respiratory zone?

alveoli

What reduces the oxygen saturation of hemoglobin at a given PO2?

an increase in 2,3 DPG

Afferent neural activity from peripheral chemoreceptors is stimulated by what?

an increase in arterial [H+], a decrease in arterial PO2

The most important inputs to the medullary respiratory neurons come from chemoreceptors called the ______ and ______ bodies

aortic and carotid

What structure would air flow through next after passing the nose?

Pharynx

The partial pressure of O2 in pulmonary venous blood

100 mgHg

Total milliliters of oxygen normally delivered by systemic arterial blood each minute

1000

The partial pressure of O2 in alveolar air

105 mmHg

Milliliters of oxygen normally bound to hemoglobin in 1 liter of systemic arterial blood

197

total milliliters of oxygen dissolved and bound to hemoglobin in 1 liter of systemic arterial blood

200

Milliliters of oxygen normally dissolved in 1 liter of systemic arterial blood

3

The partial pressure of O2 in the pulmonary artery blood

40 mmHg

The partial pressure of CO2 in pulmonary artery blood

46 mmHg

typical cardiac output in liters per minute

5

The partial pressure of O2 in mitochondria

5 mmHG

What is the minute ventilation of a person who takes a breath every 5 seconds and has a tidal volume of 500 mL?

6000 mL

RBCs have an average diameter of approximately _______, and the thickness of the barrier separating alveolar air from pulmonary capillary blood is approximately ________.

7 micrometers; 0.2 micrometers

At the typical atmospheric pressure found at sea level, a jar containing 10% oxygen would have an oxygen partial pressure of _______ mmHg

76

The tiny air sacs of the lung which mediate gas exchange with the blood are called what?

Alveoli

What does the arterial PCO2 most directly influence?

Arterial pH

The physical principle stating that gas pressure in a closed space increases as its volume decreases is know as what?

Boyle's law

Transport of O2 and CO2 through pulmonary and systemic circulation occurs how?

Bulk flow

What chemoreceptors are located within the medulla oblongata?

Central

According to ________ law, the total pressure of a gas mixture is equal to the sum of the partial pressure of individual gases in the mixture

Dalton's

The movement of air from the alveoli to the external environment during breathing is called ________ and movement from the atmosphere into the alveoli is called ______

Exhalation; inhalation

Amount of air in excess of tidal expiration that can be exhaled with maximum effort

Expiratory reserve volume (ERV)

Proper equation for calculating the bulk flow of air out of the lungs (F = flow, Palv = alveolar pressure, Patm= atmospheric pressure, R = resistance)

F = (Palv - Patm)/R

T/F: During exercise, active exhalation occurs by reversing the direction of action potentials along neurons to the inspiratory muscles.

False

T/F: If a liquid is exposed to two different gases having the same partial pressures, at equilibrium the concentration of gases in the liquid will always be identical

False

T/F: Minute ventilation and alveolar ventilation always increase and decrease in proportion to each other

False

Amount of air remaining in the lungs after a normal tidal expiration (RV + ERV)

Functional residual capacity (FRC)

What is a function of the conducting zone of the respiratory system?

Has cilia, mucus, and macrophages that help defend against microbes and foreign matter that enter the system; participates in the production of sounds for communication with others; warms and moistens inhaled air; regulates airway resistance by varying the contraction of smooth muscle in the walls

A ventilation rate that removes CO2 from the body faster than it is produced is known as what?

Hyperventilation

The acid-base disorder that involves an increase in arterial H+ concentration caused by something other than elevated PCO2 is known as what?

Metabolic acidosis

What = tidal volume x respiratory rate

Minute Ventilation

What are parts of the upper airway system?

Mouth, Larynx, Pharynx, Nose

Which respiratory system structures aid in the trapping and clearing of inhaled particles present in inspired air?

Nasal hair, epithelial cell cilia, macrophages, mucus

Equation for Boyle's law?

P1V1 = P2V2

What is this the order of: Erythrocyte intracellular fluid in systemic arterioles; plasma of systemic capillaries; tissue interstitial fluid; inside tissue cell mitochondria

PO2 in descending order

Amount of air remaining in the lungs after maximum expiration; keeps alveoli inflated between breaths and mixes with fresh air on next inspiration

Residual Volume (RV)

The respiratory zone of the respiratory system includes

Respiratory bronchioles, alveolar sacs, alveolar ducts

Hyperventilation can lead to a reduction in CO2, a clinical condition known as respiratory ________________

alkalosis

What are three determinants of alveolar PO2?

The PO2 of the atmospheric air; the rate of alveolar ventilation; the rate of total-body oxygen consumption

The pressure of a gas within a closed, rigid-walled container depends on what two things?

The concentration of the gas and the temperature of the gas

Which portion of the oxygen-hemoglobin dissociation curve provides a safety factor that maintains arterial oxygen saturation in situations where hypoventilation occurs?

The plateau portion of the curve, from 60-100 mmHg

What is the exchange of air between atmosphere and alveoli by bulk flow?

Ventilation

List the 5 steps of respiration in the order that they appear when a molecule of oxygen from the environment is used by the body

Ventilation; gas exchange between lungs and pulmonary capillary blood; gas transport in the blood; gas exchange between systemic capillary blood and tissues; cellular respiration

The respiratory rhythms generator known as the pre-Botzinger complex is located in the upper portion of the __________ respiratory group

Ventral

The maximal amount of air that can be expired after a maximal inspiration is called what?

Vital Capacity

The sum of the expiratory reserve volume, tidal volume, and inspiratory reserve volume is equal to what?

Vital Capacity

Amount of air that can be exhaled with maximum effort after maximum inspiration (ERV + TV + IRV); used to assess strength of thoracic muscles as well as pulmonary function

Vital Capacity (VC)