Unit 3: Respiratory

nasal cavity

hollow space behind nose

The c-shaped rings that support the trachea are composed of what type of tissue?

hyaline cartilage

The central chemoreceptors are located ___.

in the brainstem

lobes

large regions of lungs

thyroid cartilage ("adam's apple")

largest hyaline cartilage of larynx; covered by part of thyroid gland; more pronounced in males

The ___ is the main structure located between the laryngopharynx and the trachea.

larynx

pleural cavity

small space between pleurae containing lubricating serous fluid

bronchioles

smaller branches of airways

A right main bronchus branches into ___.

three lobar bronchi, each extending into one of the three right lobes.

Label the structures of the upper respiratory system

Hard palate Nasopharynx Uvula Soft palate Nasal septum Choana

The role of the dorsal respiratory group (DRG):

adjusts respiratory rate based on stimuli from peripheral chemoreceptors.

laryngopharynx

air and food passageway

oropharynx

air and food passageway

nasopharynx

air passageway only

larynx

airway enlargement superior to trachea; voicebox

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

diaphragm

Contractions of the ___ results in increased depth of the thoracic cavity and contractions of the ___ widens the thoracic cavity.

diaphragm external intercostals

bronchial tree

branched airways extending throughout lungs

COPDs are almost always caused by ___.

cigarette smoke

Within the respiratory system passageway is the ___ where there is only airflow and no gas exchange.

conducting division

vocal folds

consists of two sets of folds

nasal septum

divides nasal cavity into right and left portions

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

dorsal

The epithelial lining of the respiratory tubes includes occasional ___ which secrete protective mucus that catches dust and potential pathogens.

goblet cells

Which of these occurs during exhalation?

lung volumes decrease and intrapulmonary pressure increases

Pharynx

often called throat

CHemoreceptors in the carotid and aortic bodies are called ___ chemoreceptors.

peripheral

A narrow potential space called the ___ is located between the two pleurae and contains pleural fluid secreted by these membranes.

pleural cavity

The ___ are not anatomically connected together.

pleural memebranes.

lobules

smallest visible subdivisions of a lung

Respiratory volumes can be measured by using an instrument called a ___

spirometer

Oxygen unloading occurs at the ___. This process causes a(n) ___ in the oxygen partial pressure of the blood leaving this region.

tissues decrease

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

vocal folds (true vocal cords)

vibrate when exhaling to produce sounds

A ___ adheres to the surface of each lung, including the fissures between the lobes.

visceral pleura

Which term refers to the layer of serous membrane that covers the lung surface?

visceral pleura

artenoid cartilages

vocal cords attached to these small cartilages

Increases respiration:

-A decrease in the pH of the CSF -Stimulation of proprioceptors in skeletal muscles -Stimulation of the dorsal respiratory group -Stimulation of pain receptors

Decreases respiration:

-Activation of irritant receptors in the airway -Stimulation of stretch receptors in the lungs

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

-adjusts respiratory rate based on stimuli from limbic system or cerebral cortex

The peripheral chemoreceptors detect changes in which of the following?

-blood pH -blood oxygen saturation -blood CO2 saturation

Processes that would occur in Alveolar capillaries

-carbonic acid in RBCs converts back to carbon dioxide and water -Carbon dioxide diffuses from the blood -Oxygen is diffusing into the blood -Decreasing carbon dioxide levels decrease the levels of HHb

What occurs during the "chloride shift" in red blood cells?

-chloride ions are transported into the RBC -bicarbonate ions are transported out of the RBC

Peripheral chemoreceptors trigger an increase in ventilation in response to which of the following?

-high levels of blood CO2

Which factors that would decrease the affinity of hemoglobin for oxygen?

-increased biphosphoglycerate production by RBCs -increased temperature

Which two factors facilitate systemic unloading of oxygen from hemoglobin in the peripheral tissues?

-lower PO2 in tissue fluid -binding of protons to hemoglobin (hemoglobin unloads more oxygen at higher temperatures) (O2 diffuses in and out of the blood according to the PO2 gradient. There is no active transport of O2)

Which best describes what happens during exhalation?

-the diaphragm relaxes, intrapulmonary pressure increases, air flows out (thoracic volume decreases)

What is the correct calculation for vital capacity?

-tidal volume plus expiratory reserve volume plus inspiratory reserve volume

Which are functions of the larynx?

-to keep food and drink out of the airway -to produce sound

According to this graph, how much of the oxygen bound to hemoglobin is released into the tissues as the blood flows through the systemic capillaries?

22%

An average tidal volume is about ___ mL of air.

500

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

6000

If intrapulmonary pressure was 760 mm Hg, what would you expect the intrapleural pressure to be?

756 mm Hg

According to the graph, hemoglobin becomes fully saturated with oxygen at what PO2?

90 mmHg

Processes that would occur in Systemic capillaries

-Chloride ion shifts into the RBC -Carbon dioxide binds to plasma proteins -Carbonic anhydrase is increasing the amount of carbonic acid -Carbon dioxide is diffusing into the blood

fissures

-horizontal (only in right lung) -oblique (both lungs)

What is the partial pressure of oxygen that is found in the systemic tissues?

40 mmHG (78% saturation)

Which of the following is not involved in inspiration?

Elastic recoil of the lungs.

Muscles of Inspiration: Internal Intercostals (intercartilaginous part)

Origin: Superior border of inferior costal cartilages Insertion: Inferior border of superior costal cartilages Inspiration action: Assists in elevating ribs

This air the remains within the respiratory system passageway is said to be in the ___.

anatomic dead space. The average volume of anatomic dead apace is 150ml.

Breathing is critical to our survival. Pulmonary ventilation is the physiologic process of air entering and exiting the lungs. Since air flows from a high to a low pressure, both inspiration and expiration depend upon pressure gradients. The weight of the air surrounding us creates atmospheric pressure. Since atmospheric pressure remains constant at a given location, our ability to move air into the lungs depends upon intrapulmonary pressure being lower than atmospheric pressure. In contrast, air won't move out of the lungs until the intrapulmonary pressure rises higher than the ambient atmospheric pressure. Intrapulmonary pressure varies as a result of changes in thoracic volume. Decreases in thoracic volume cause increases in the intrapulmonary pressure. In contrast, increases in thoracic volume result in decreases in intrapulmonary pressure. These thoracic volume changes depend upon the actions of respiratory muscles such as the diaphragm and external intercostals.

Air flow into the lungs depends upon a pressure gradient: Pulmonary ventilation occurs as air moves into and out of the lungs. The directional movement of air during both the inspiration and expiration processes follows a pressure gradient, moving from a higher to a lower pressure. Transpulmonary pressure is dynamic, but is always positive: Transpulmonary pressure is the difference between the intrapulmonary pressure found within the lungs and the intrapleural pressure found in the pleura surrounding the lungs. (intrapulmonary - pleural = transpulmonary) The transpulmonary pressure helps the lungs expand in the thoracic cavity during inspiration. Although the pleural pressure changes slightly throughout inhalation and exhalation, it continually remains more negative than atmospheric pressure, and is always negative in comparison to the intrapulmonary pressure. Intrapulmonary pressure is variable, changing with conditions: Boyle's law is described as the inverse relationship between volume and pressure where as volume increases, pressure decreases and vice versa. The intrapulmonary pressure, or pressure inside the lungs, changes in response to the changes in the volume of the lungs. Lung volume changes in response to changes in the overall thoracic cavity volume. This occurs in response to the contraction and/or relaxation of the inspiratory muscles - the diaphragm and external intercostals. When these muscles contract they increase the overall thoracic volume and in turn increase the lung volume. For air to move into the lungs the intrapulmonary pressure must be less than atmospheric, or negative in comparison.

Define expiratory reserve volume (ERV):

Amount of air in excess of tidal volume that can be exhaled with maximum effort. Typical volume: 1,200 mL

Define Inspiratory reserve volume (IRV):

Amount of air in excess of tidal volume that can be inhaled with maximum effort. Typical volume: 3,000 mL

Define Functional Residual Capacity (FRC):

Amount of air remaining in the lungs after a normal tidal expiration. Calculated (FRC = RV + ERV) Typical value: 2,500 mL

Carbon dioxide is transported in different forms in the blood. What is the most common form?

Bicarbonate ion

Which explains why the oxyhemoglobin dissociation curve is nonlinear (S-shaped)?

Binding of the first oxygen molecule to hemoglobin facilitates the binding of additional oxygen, so the midportion of the curve becomes steeper.

Air enters the lungs during inspiration and exits the lungs during expiration based upon characteristics of ___.

Boyle's law. The pressure of a gas is inversely proportional to its volume, assuming a constant temperature.

Oxygen is unloaded in the body tissues because the affinity of hemoglobin for oxygen is lower in the systemic capillaries (compared to its affinity in the alveolar capillaries). Which factor contributes to this?

CO2 produced in the peripheral tissues leads to increased H+ concentration.

___ are a group of lung diseases (asthma, chronic bronchitis, and emphysema) that result in long-term obstruction of airflow and substantially reduced pulmonary ventilation.

COPDs

Hemoglobin and carbon dioxide form which of the following?

Carbaminohemoglobin

What are the four predominant components of inspired air?

Carbon dioxide Water vapor Nitrogen Oxygen

Select two examples of chronic obstructive pulmonary disease:

Chronic bronchitis Emphysema

Which term refers to hemoglobin that is not transporting oxygen?

Deoxyhemoglobin

Which is a degenerative lung disease characterized by a breakdown of alveoli and diminishing surface area available for gas exchange?

Emphysema

Label the anterior view of the larynx.

Epiglottis Cricothyroid ligament Cricoid cartilage Thyroid cartilage Thyrohyoid membrane Laryngeal prominence

As the diaphragm relaxes, it is depressed (moves inferiorly)

False (the diaphragm is elevated as it relaxes and the length of the thoracic cavity decreases)

Larger bronchial tubes possess supportive cartilaginous rings and plates so that they do not collapse during breathing. Smooth muscle composes part of the walls of these bronchial tubes.

If the smooth muscle of these tubes relaxes, the air passages dilate, which allows a greater volume of air movement. If the smooth muscle of the respiratory tube contracts, a reduced volume of oxygen enters the lungs.

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

Label the structures of the upper respiratory system.

Larynx Epiglottis Oropharynx Vocal fold Laryngopharynx Trachea

Define Inspirational capacity (IC):

Maximum amount of air that can be inhaled after a normal tidal expiration. Calculated: (IC = TV + IRV) Typical value: 3,500 mL

Define Total lung capacity (TLC):

Maximum amount of air the lungs can contain. Calculated: (TLC = RV + VC) Typical value: 6,000mL

Which best describes ventilation?

Movement of air in and out of the lungs via inhalation and exhalation

Correctly label the components of the respiratory system

Nasal cavity Posterior nasal aperture Larynx Hard palate Epiglottis Nostril Pharynx

Which gas has the greatest partial pressure in inspired air?

Nitrogen

Muscles of (forced) expiration: External oblique

Origin: Anterior surfaces of ribs 5-12 Insertion: Anterior iliac crest and linea alba by aponeurosis Expiration action: Compresses abdominal contents, helping to raise diaphragm

Muscles of inspiration: External intercostals

Origin: Inferior border of superior rib Insertion: Superior border of inferior rib Inspiration action: Elevates ribs; this expands thoracic cavity during inspiration

Muscles of inspiration: Sternocleidomastoid

Origin: Manubrium of sternum and medial clavicle Insertion: Mastoid process of temporal bone Inspiration action: Elevates sternum

Muscles of (forced) expiration: Rectus abdominis

Origin: Pubic crest and pubic symphysis Insertion: Xiphoid process of sternum and costal cartilages of ribs 5-7 Expiration action: Compresses inferior ribs and abdominal contents, helping to raise diaphragm

Muscles of Inspiration: Pectoralis minor

Origin: Sternal ends of ribs 3-5 Insertion: Coracoid process of scapula Inspiration action: Elevates ribs 3-5

Muscles of (forced) expiration: Internal intercostals (interosseous part)

Origin: Superior border of inferior rib Insertion: Inferior border of superior rib Expiration action: Depresses ribs; this compresses thoracic cavity during forced expiration

Muscles of Inspiration: Scalenes

Origin: Transverse processes of cervical vertebrae C2-C6 Insertion: Ribs 1 and 2 Inspiration action: Elevates ribs 1 and 2

Muscles of inspiration: Diaphragm:

Origin: costal cartilages and ribs 7-12, xiphoid process, and lumbar vertebrae Insertion: Central tendon of diaphragm Inspiration action: Flattens (descends) during contraction; this expands thoracic cavity and compresses abdominal viscera during inspiration

Oxygen from the lungs has to be transported by the blood in order to be utilized by the systemic cells. This movement is directed by the partial pressure gradient found between these environments. Oxygen is predominantly carried in the blood bound to hemoglobin molecules found within the red blood cells. As blood flows through systemic capillaries, oxygen dissociates from the hemoglobin, diffuses into the plasma, moves into the interstitial fluid across the capillary wall, and ultimately enters the systemic cells. This process is referred to as oxygen unloading. The systemic tissues utilize this steady supply of oxygen from the blood to produce ATP through aerobic cellular respiration. Because these tissue cells continually use the ATP they produce, the partial pressure of oxygen perpetually remains low within the systemic cells.

Oxygen that is picked up in the blood at the lungs gets dropped off at the tissues. The partial pressure of oxygen is the lowest within the tissues. The pressure gradient drives the movement of the oxygen out of the capillaries and into the tissues ultimately increasing the partial pressure of oxygen within the tissues and decreasing it within the capillaries. Increased metabolic activity of the tissues results in greater oxygen demand. This stimulates increased oxygen release from hemoglobin, and increases the diffusion rate of oxygen into tissues. The steep slope region of the oxygen-hemoglobin dissociation curve occurs because relatively small changes in blood oxygen partial pressures result in large changes in Hb saturation levels. The partial pressure of carbon dioxide, blood pH, temperature, and levels of 2,3 BPG also influence the saturation level of hemoglobin. For example, a decrease in pH, known as the Bohr Effect, shifts the oxygen-dissociation curve to the right, reducing hemoglobin's affinity for oxygen. This allows for increased unloading of oxygen at the tissues.

Which term is used to describe hemoglobin with only one molecule of oxygen bound to it?

Oxyhemoglobin

Label the anterior view of the lower respiratory tract.

Right lung Cardiac notch Visceral pleura Horizontal fissure Parietal pleura Left lung

Correctly label the components of the respiratory system.

Segmental bronchus Pleural cavity Diaphragm Trachea Left main bronchus Right lung Lobar bronchus

Label the anterior view of the lower respiratory tract.

Segmental bronchus Upper lobe of left lung Right main bronchus Left main bronchus Trachea Upper lobe of right lung

The role of the ventral respiratory group (VRG):

Sets basal respiratory rate.

Define Vital Capacity (VC):

The amount of air that can be inhaled and then exhaled with maximum effort; the deepest possible breath. Calculated: (VC = ERV + TV + IRV) Typical value: 4,700 mL

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.

Breathing, or pulmonary ventilation, involves the movement of air from outside the body through the bronchial tree and into the alveoli and the reversal of this air movement to allow gas (oxygen and carbon dioxide) exchange between air and blood.

These movements are caused by muscle contractions.

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

Tidal volume typical volume: 500mL

Which of these calculated volumes typically has the greatest value?

Total lung capacity

What are considered principal organs of the respiratory system?

Trachea Lungs Larynx Pharynx (nose, bronchi)

During inspiration thoracic cavity volume increases.

True

True or false: The chloride shift allows RBCs to continue to produce carbonic acid.

True Carbonic acid formed in the cell dissociates to form bicarbonate. RBCs pump out bicarbonate in exchange for chloride (the chloride shift). Exporting bicarbonate keeps the pathway working.

True or false: Evidence suggests that ventilation increases more quickly in response to high levels of CO2 than it does to low levels of O2 in the blood.

True. Arterial PCO2 has a strong influence on respiratory rate, both directly and indirectly through the production of H+

The action of the cilia creates ___.

a current of mucus that moves any entrapped debris away from the lungs toward the pharynx which helps prevent respiratory infections. The mucus with any entrapped particles is normally swallowed.

An increase in volume causes

a decrease in pressure

The right lung has ___ lobes; the left lung has ___ lobes.

a. 3; 3 b. 2; 2 c. 3; 2 d. 2; 3

A normal resting breathing rate is about ___ breaths per minute.

a. 5-10 b. 12-15 c. 16-20 d. 21-30

Tidal volume is estimated to be about ___.

a. 500 mL b. 1,200 mL c. 3,600 mL d. 4,800 mL

The contraction of the diaphragm increases the size of the thoracic cavity.

a. True b. False

The epiglottic cartilage is composed of hyaline cartilage.

a. True b. False

Vital capacities gradually decrease as a person continues to age.

a. True b. False

Vital capacity is the total of tidal volume, expiratory reserve volume, and residual volume.

a. True b. False

Which of the following airway tubes would have the smallest lumens?

a. alveolar ducts b. segmental bronchi c. lobar bronchi d. main bronchi

The size of the thoracic cavity is increased by the contraction of all of the following muscles except the ___.

a. diaphragm b. external intercostals c. pectoralis minor d. external oblique

The ___ is the most inferior cartilage of the larynx

a. epiglottis b. cricoid cartilage c. thyroid cartilage d. corniculate cartilage

A ___ is an instrument to measure air volumes during breathing.

a. flow meter b. spirometer c. lung function model d. capacity meter

Paranasal sinuses are within the following bones except the

a. maxillary bones b. mandible c. frontal bone d. sphenoid bone

Which of the following structures increases the surface area and air turbulence the most during breathing?

a. nasal meatuses b. nasal septum c. nasal conchae d. nares (nostrils)

The ___ adheres to the surface of the lung

a. pericardium b. pleural cavity c. parietal pleura d. visceral pleura

The alveoli are composed of

a. simple squamous epithelium b. hyaline cartilage c. smooth muscle d. epithelium with cilia

The ___ is the maximum volume of air that can be exhaled after taking the deepest breath possible.

a. tidal volume b. expiratory reserve volume c. vital capacity d. total lung capacity

What is the role of the dorsal respiratory group?

adjusts respiratory rate based on stimuli from peripheral chemoreceptors

nasal meatuses

air passageways along nasal conchae

paranasal sinuses

air-filled spaces that open into nasal cavity; lined with mucus membranes: - maxillary sinus - frontal sinus - ethmoidal sinus - sphenoidal sinus

Which term refers to the exchange of gases across the respiratory membrane?

alveolar gas exchange

Gas exchange between the air and the blood occurs in which of the following?

alveoli

Most of the surface area for gas exchange within the respiratory system is found within the many ___ of the lungs.

alveoli

Contraction of the diaphragm and external intercostal muscles results in ___ in the thoracic volume, which, results in ___ of the intrapulmonary pressure.

an increase a decrease

right and left main (primary) bronchi

arise from trachea

Where does systemic gas exchange occur?

at the capillary networks of the tissues

Most carbon dioxide in the blood is transported in the form of ___ dissolved in the plasma.

bicarbonate

segmental (tertiary) bronchi

branches of lobar bronchi into segments of lung

lobar (secondary) bronchi

branches of main bronchi into lobes of lungs

Which best describes the supportive structures of the trachea?

c-shaped rings composed of hyaline cartilage (overlapping plates of cartilage support the secondary and tertiary bronchi, but not the trachea.

Identify all the forms in which carbon dioxide is transported in the blood.

carbaminohemoglobin dissolved gas bicarbonate ion

Numerous epithelial cells possess ___ that extend into the the mucus.

cilia

cricoid cartilage

complete ring of hyaline cartilage of inferior larynx

Lung tissue is not ___.

contractile. The only muscle in the lungs is smooth muscle in the bronchi and bronchioles. This muscle adjusts speed of airflow into the lungs, but does not create airflow.

epiglottis

covers part of larynx opening during swallowing

Hemoglobin that is not bound to oxygen is called ___.

deoxyhemoglobin

Which term refers to hemoglobin that is not transporting any oxygen?

deoxyhemoglobin

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

dorsal (The ventral respiratory group does not receive any direct inputs from peripheral receptors)

epiglottic cartilage

elastic cartilage supporting epiglottis

A combination of synergistic contractions of the sternocleidomastoid, scalenes, pectoralis minor, and the intercartilaginous part of the internal intercostals ___.

elevate the sternum and rib cage.

Long term inhalation of cigarette smoke often leads to ___, a COPD that is characterized by a loss of alveolar surface area.

emphysema

___ is aided by contractions of the internal intercostals (interosseous part), rectus abdominis, and external oblique, and from the elastic recoil f stretched tissues.

expiration.

Naris (nostril)

external opening into nasal cavity

The exchange of oxygen and carbon dioxide in the lungs is called

external respiration

During ___ the interosseous part of the internal intercostals depresses the rib cage, narrowing the thoracic cavity.

forced expiration

thyrohyoid ligament

hangs inferiorly from hyoid bone

The ___ of the lung represents an area where a main bronchus and a major blood vessel are located.

hilum

nasal conchae

increase surface area and air turbulence during breathing

When the diaphragm contracts, thoracic volume ___.

increases. And intrapulmonary pressure decreases, allowing air to flow into the lungs.

The size of the thoracic cavity during ___ is increased by contractions of the diaphragm, external intercostals, internal intercostals (intercartilaginous part), pectoralis minor, sternocleidomastoid, and scalenes.

inspiration

The size of the thoracic cavity increases during ___ upon contractions of inspiration muscle.

inspiration

Which two muscles (or muscle groups) are primarily responsible for resting (non-forced) inspiration?

intercostals diaphragm

The exchange of oxygen and carbon dioxide in the tissues is called

internal respiration

inferior (lower) lobe

located in both lung

superior (upper) lobe

located in both lungs

lung

location of external respiration between alveoli and blood capillaries

Intrapleural pressure is always:

lower than both the atmospheric and intrapulmonary pressure. This negative intrapleural pressure helps keep the lungs from collapsing.

The pleural fluid is a serous fluid that serves as ___.

lubrication during breathing movements, and due to the surface tension, it resists separation of the pleurae.

Alveolar gas exchange occurs in the ___. This type of exchange is the opposite of ___ gas exchange. As hemoglobin loads ___, its affinity for H+ declines. Hydrogen ions then dissociate from the hemoglobin and bind with ___ ions. The reaction of H+ and bicarbonate ___ the hydration reaction and generates free carbon dioxide.

lungs systemic oxygen bicarbonate reverses

hilum of lung

medial indentation where main bronchus, blood vessels, and nerves enter lung

Which best defines alveolar gas exchange?

movement of oxygen and carbon dioxide across the respiratory membrane

middle lobe

only in right lobe

A ___ covers the internal surface of the thoracic wall and the superior surface of the diaphragm.

parietal pleura

The layer of serous membrane called the parietal ___ lines the thoracic cavity.

pleura

The pleural cavity is normally air-tight. During ___, air enters the pleural cavity and leads to lung collapse.

pneumothorax

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

pontine

Baroreceptors detect changes in ___.

pressure (BP)

Besides keeping food out of the airway, the larynx is also responsible for which of the following?

producing speech

A decrease in temperature ___ oxygen binding to hemoglobin and suppresses oxygen unloading, therefore increasing affinity.

promotes

Biphosphoglycerate ___ oxygen unloading by the RBCs. A decrease in BPG would increase the infinity of hemoglobin for oxygen.

promotes

The contractions of the rectus abdominis and the external oblique compress the abdominal viscera, forcing the diaphragm to ascend, and thus ___ the size of the thoracic cavity.

reducing

The nose, pharynx, larynx, trachea, bronchi, and lungs are the principal organs of which system?

respiratory

The volumes of air that move into and out of the lungs during various phases of breathing are called ___.

respiratory (pulmonary) volumes and capacities. A volume is a single measurement, whereas capacity represents two or more combined volumes.

Respiratory capacities can be determined by using various combinations of ___

respiratory volumes. The values obtained vary with a person's age, sex, height, weight, stress, and physical fitness.

The relationship between hemoglobin ___ and PO2 is shown by an oxyhemoglobin dissociation curve. At low PO2, the curve ___ slowly. When the curve rises, there is a rapid increase in ___ loading. When the first heme group binds a molecule of oxygen, ___ changes conformation to accept a second oxygen. Eventually, at high PO2 levels, the hemoglobin approaches 100% saturation and can not ___ more oxygen.

saturation rises oxygen hemoglobin load

The ___ muscles act as respiratory synergists.

scalene & erector spinae

parietal pleura

serous membrane on inside of thoracic wall and superior surface of diaphragm

visceral pleura

serous membrane on surface of lung

corniculate cartilages

small cartilages superior to srtenoid cartilages

cuneiform cartilages

support soft tissues inferior to the epiglottis

Which term refers to the exchange of gases (O2 and CO2) that occurs in the capillary networks between the blood and the body's cells?

systemic gas exchange

The respiratory division which is ___, includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and the alveoli (most important part).

the area where gas exchange occurs

During volume changes in the thoracic cavity, what is primarily responsible for changes in length?

the diaphragm

During exhalation:

the diaphragm relaxes which decreases the volume of the lungs and increases intrapulmonary pressure.

The intercostal muscles contribute to:

the enlargement and contraction of the thoracic cage, and produce about 1/3 of pulmonary air flow.

The conducting division includes ___

the nasal cavity, pharynx, larynx, trachea, bronchi, and major bronchioles.

Breathing (pulmonary ventilation) involves:

the nose, nasal cavity, paranasal sinuses, pharynx, larynx, trachea, and bronchial tree, all serving as passageways for gases into and out of the lungs.

The central chemoreceptors respond to ___.

the pH of CSF.

pneumotaxic center is another name for

the pontine respiratory group

Systemic gas exchange is ___

the process of gas exchange between the blood and the tissues.

The tidal volume is:

the volume of air taken in or out in a normal breath. average is 500ml is moved in through the nose and mouth and through the conducting and respiratory divisions to the alveoli. A certain amount of that air never reaches the alveoli, instead in remains within the respiratory passageway.

A left main bronchus branches into ___.

two lobar bronchi, each extending into a left lobe.

vestibular folds (false vocal cords)

upper folds but do not produce sound

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

ventral

glottis

vocal folds and opening between them

Elevation of the ribs increases thoracic cavity ___.

width

trachea

windpipe anterior to esophagus