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Chapter 23- Respiratory System

provides the means for gas exchange necessary for living cells.
Describe the functions of the respiratory system.
1.Air Passageway. The respiratory tract is a passageway for air between the external environment and the alveoli (air sacs) of the lungs
2.Site for the Exchange of Oxygen and Carbon Dioxide. A thin barrier between the alveoli and the pulmonary capillaries provides the site for exchange of oxygen and carbon dioxide. Oxygen diffuses from the alveoli into the blood, while carbon dioxide diffuses from the blood into the alveoli.
3.Detection of Odors. Olfactory receptors located in the superior regions of the nasal cavity detect odors as air moves across them.
4.Sound Production. The vocal cords of the larynx (voice box) vibrate as air moves across them to produce sound; these sounds then resonate in upper respiratory structures.
1 Know the two structural regions of the respiratory system.
What structures are found in each?
1.upper respiratory tract -nose, nasal cavity, and pharynx
2.lower respiratory tract -larynx, trachea, bronchi, bronchioles (including terminal and respiratory bronchioles), alveolar ducts, and alveoli
1. Know the two functional regions of the respiratory system.
2.What structures are found in each?
1.conducting zones- passageways from the nose to the end of the terminal bronchioles.
2. respiratory zones-bronchioles, alveolar ducts, and alveoli
What is the function of the conducting zones
Passageways that serve primarily to transport or conduct air
what is the function of the respiratory zone.
Structures that participate in gas exchange with the blood
mucosa (or mucous membrane).
what the respiratory passageway that is exposed to the external environment is lined internally by
How does the epithelium of the respiratory tract change as you move from the nasal cavity to the alveoli
The epithelium becomes progressively thinner from the nasal cavity to the alveoli; it changes from pseudostratified ciliated columnar to simple ciliated columnar to simple cuboidal to simple squamous
1.Know the function of goblet cells.
2.What is the function of their secretions?
1.Goblet cells and mucous glands
produce mucus that bathes exposed
What is mucin and what is its function?
a protein that increases viscosity of mucus to more effectively trap inhaled dust, dirt particles, microorganisms, and pollen.
What other substances are found in this secretion?
The secretions also contain specific substances to help defend the body against microbes, including lysozyme (an antibacterial enzyme), defensins (antimicrobial proteins), and immunoglobulin A (antibodies).
What is sputum?
When mucus mixes with saliva and materials it entraps, it may be coughed up as a viscous substance
Describe the function of the nose
is the main conducting passageway for inhaled air
It a paired openings lead into the pharynx.
Because the conchae help produce turbulence in the inhaled air,
conchae partition the nasal cavity into separate air passages (or "valleys)
vibrissae of the nasal vestibule
to trap large particulates.
olfactory region.
Airborne molecules that dissolve in the mucus covering the olfactory epithelium stimulate olfactory receptors to detect different odors
1.why are nosebleeds common
2.what relationship does this region have with the nasolacrimal duct?
1.Nosebleeds (epistaxis) common due to the large numbers of superficial vessels .
both the vast distribution of blood vessels and their superficial location (just deep to the epithelium).
2. nasolacrimal drain lacrimal secretions from the surface of each eye into the respiratory region of the nasal cavity
What is the primary function of the nasal cavity and how does it achieve this?
A primary function of the nasal cavity is to condition the air (which means to warm, cleanse, and humidify the air) as it enters the respiratory tract.
1. The air is warmed to body temperature by the extensive array of blood vessels within the nasal cavity lining.
2.The air is cleansed as inhaled microbes, dust, and other foreign material become trapped in the mucus covering the inner lining of the respiratory tract. Cilia then "sweep" the mucus and its trapped contents towards the pharynx to be swallowed.
3.The air is also humidified as it passes through the moist environment of the nasal passageway.
1.Describe the function of the paranasal sinuses.
2.What is their connection with the respiratory system?
1. sinuses are spaces within the skull bones and named for the specific skull bones in which they are housed.
2. Ducts connect all sinuses to the nasal cavity.
3 .The mucus, with its trapped particulate matter, is swept from each paranasal sinus into the nasal cavity and then into the pharynx, where it is swallowed.
Describe the function of the pharynx. What is the common name?
1. Air is conducted along its entire length, and both air and food along its inferior portions.
-contribute to both the flexibility and distensibility needed to accommodate swallowed food, and help force these materials into the esophagus.

2. throat,
Describe the functions of the larynx.
1.Serves as a passageway for air.
2.Prevents ingested materials from entering the respiratory tract by covering
3.Produces sound for speech.
4.Assists in increasing pressure in the abdominal cavity.
5.Participates in both a sneeze and cough reflex
What is the common name of the larynx
voice box,
know the laryngeal prominence and why it is generally larger in males
This protuberance is generally larger in males because (1) the laryngeal inlet is narrower in males (90 degrees) than in females (120 degrees), and (2) it enlarges at puberty due to testosterone-induced growth.
function of the true and false vocal cords (or vocal folds and vestibular folds)
1. True(vocal folds) -they produce sound when air passes between them.
2. False(vestibular) -they have no function in sound production, but serve to protect the vocal folds.
How is sound produced?
when vocal folds begin to vibrate.
What is meant by the range, pitch, and loudness of sound?
1.range of a voice (be it soprano or bass) is determined by the length and thickness of the vocal folds.
2. Pitch - the frequency of sound waves.
3.Loudness depends on the force of the air passing across the vocal cords.
How are different vocal ranges produced and why do males and females differ?
1.Males generally have longer and thicker folds than do females, and thus males produce sounds that are in a lower range.
2. Different vocal ranges are produced by thickness and length of the vocal cord
How are different pitches produced?
Pitch is determined by the amount of tension or tautness on the vocal folds
1. increase the tension on the vocal folds cause it vibrate more when air pass and produce higher sound
2.the less taut the vocal folds, the less they vibrate, and the lower the pitch of the sound.
How are a scream, normal voice, and whisper achieved?
Scream- A lot of air forced through the rima glottidis produces a loud sound.
Normal voice - little air produces a soft sound.
Whisper-only the most posterior portion of the rima glottidis is open, and the vocal folds do not vibrate. all the same pitch
What structures are used for articulation and how do they affect speech?
the structures of the lips, teeth, and tongue that help form different sounds.
Describe the functions of the trachea. What is the common name?
2.Flexible, slightly rigid, tubular organ
shape and function of the tracheal cartilage rings
C-shaped "rings" hyaline cartilage called
These rings reinforce and provide some rigidity to the tracheal wall to ensure that the trachea remains open (patent) at all times,
What is the function of the trachealis muscle?
1.allows for distension during swallowing of food through the esophagus.
2.They contract during coughing helping to dislodge material (foreign objects or food) from the air passageway
What is a tracheotomy and why would it be performed?
1.An incision is made in the trachea to facilitate breathing
2.Performed when an airway is blocked or respiratory ventilation is compromised
function of the cilia and how it works with mucus to protect the respiratory tract.
Cillia located in the mucosal epithelium move mucus with dust, microbes and other partciles toward the larynx and the pharynx where it may be swallowed or expelled
the components of the bronchial tree
the main, lobar, and segmental bronchi ,bronchioles,
Terminal bronchioles-last part of conducting zone
and respiratory bronchioles-first part of respiratory zone
Know the function of the cartilage found on the main bronchi.
hyaline cartilage support the walls of the main bronchi to ensure that they remain open
How does the diameter and amount of cartilage change as you go down the bronchial tree in the main bronchi
Diameter and the amount of cartilage decrease as you go down
How are bronchioles different in terms of cartilage and smooth muscle?
1.bronchioles have no cartilage in their walls compare to bronchi
2..bronchioles thicker layer of smooth muscle than do bronchi
Contraction of smooth muscle narrows the diameter of the bronchiole
and decreases the amount of air passing through the bronchial tree.
Expansion of the diameter of the bronchiole from relexation of the smooth muscle and
increases the amount of air passing through the bronchial tree.
Know the components of the respiratory zone.
being composed of respiratory bronchioles, alveolar ducts, and alveoli.
What type of epithelium is found in the alveoli and why?
simple squamous epithelium because it is thinner and it helps facilitating gas diffusion between the alveolus and pulmonary capillaries.
Describe alveolar pores and know their function.
Openings in their walls and Provide for collateral ventilation
What surrounds each alveolus and why?
pulmonary(blood) capillaries it help facilitate gas exchange.
What is the function of the elastic fibers found here in the alveolus
help the lungs contract and expand
Know the two cells types of the alveolar wall
simple squamous alveolar type I cell, and the cuboidal-shaped alveolar type II cell
Why are alveoli prone to collapsing?
internal surface of alveoli formed by type I cells is moist creating high surface tension.
What is produced by the type II cells to prevent collasping from happening?
pulmonary surfactant- it coats the internal surfaced during expiration
What is the function of the alveolar macrophage?
engulf any microorganisms or particulate material that reach the alveoli.
Describe the structure of the respiratory membrane
alveolar epithelium and its basement membrane
capillary epithelium and its basement membrane
basement membrane are fused
What is the function of this respiratory membrane and why is it imperative that it is thin?
is the thin barrier that oxygen and carbon dioxide diffuse across during gas exchange between the alveoli and the blood in the pulmonary capillaries.
Which way does oxygen and CO2 flow across this respiratory membrane?
-Oxygen diffuses from alveolus into capillaries
•erythrocytes become oxygenated
-Carbon dioxide diffuses from blood to alveolus
•expired to external environmen
Describe the location of the lungs.
within the thoracic cavity on either side of the mediastinum, the median region that houses the heart.
What provides the protection for the lungs?
thoracic cage
Know how the right and left lung differ in shape and why.
-right lung is larger and wider than the left lung
left lung -smaller than the right lung because the heart projects into the left side of the thoracic cavity
Understand how portions of the lung can become diseased while other portions can remain healthy
Both lungs (left and right ) are partitioned into self-contained bronchopulmonary segments each supplied by a segmental bronchus-
-so doctors can remove damage segment
pulmonary circulation
What vessels are found in each
what is the function, and what do they supply?
1. Pulmonary circulation replenishes oxygen and eliminates carbon dioxide
2. -Pulmonary arteries carry deoxygenated blood to pulmonary capillaries
-Blood is reoxygenated
-Blood enters pulmonary venules and veins, returns to left
the bronchial circulation.
What vessels are found in each, what is the function, and what do they supply?
Bronchial circulation transports oxygenated blood to bronchi and bronchioles
-Bronchial arteries branch off the descending aorta, divide to form capillaries
-Bronchial veins collect venous blood
-Some drains into the pulmonary veins
•makes pulmonary veins slightly less oxygenated than blood leaving the pulmonary capillaries
-Alveoli exchange respiratory gases directly with air
function of the lymph vessels and lymph nodes located in the lungs
1. lymph vessels - remove excess fluid from the lungs
2. Lymph nodes - collect carbon, dust particles, and pollutants that were not "swept out" by cilia lining the respiratory tract
Describe the effect of sympathetic and parasympathetic innervation
-sympathetic innervation primarily causes bronchodilation.
-parasympathetic innervation - stimulates bronchoconstriction
Know the two pleural membranes surrounding the lungs and where each of these are found.
1. visceral pleura - cover the outer surface of the lung
2. parietal pleura - inner surface of the thoracic wall
Why are the lungs considered "compartmentalized" and how is this beneficial?
each lung is enclosed in a separate visceral pleural membrane,
helps limit spread of infections.
Where is the pleural cavity located? What is found here and what is the function?
1. Located between the visceral and parietal serous membrane layers.
2. oily, serous fluid a lubricant, ensuring the pleural surfaces slide by each other with minimal friction during breathing.
Know the properties that keep the lungs inflated.
-expanding properties of the chest wall,
-the recoiling properties of the lungs,
-the anatomic arrangement of the pleural cavity between chest wall and lungs.
what causes the lungs to cling to the chest wall.
surface tension caused by the serous fluid within the pleural cavity.
What is the function of the elastic connective tissue in the lungs?
recoil, which causes the lungs to exhibit a inward pull.
expand- cause outward pull
What effect do the elastic connective tissue have in the pleural cavity
create a vacuum or "suction" within the pleural cavity.
1.Define intrapleural pressure and intrapulmonary pressure.
2.How do these to pressures keep the lungs inflated?
3.What happens is these two pressures are equal?
-Intrapleural - lower pressure outside the lung
-intrapulmonary- higher pressure inside the lungs,
-difference in pressure keeps the lungs inflated.
-the lungs deflate
exchange of respiratory gases (oxygen and carbon dioxide) between the atmosphere and the tissue cells of the body—
pulmonary ventilation
movement of respiratory gases between the atmosphere and the alveoli of the lungs
alveolar gas exchange
(external respiration)—exchange of respiratory gases between the alveoli and the blood
gas transport
transport of respiratory gases within the blood between the lungs and systemic cells of the body
systemic gas exchange.
(internal respiration)—exchange of respiratory gases between the blood and systemic cells of the body
know the movement of oxygen and carbon dioxide between the atmosphere and systemic cells.
Know the two cyclic phases of breathing (or pulmonary ventilation) and their definitions.
1.inspiration, also called inhalation, which brings air into the lungs and
2.expiration, also called exhalation, which forces air out of the lungs.
Define quiet and forced breathing.
1.Quiet breathing is the rhythmic breathing that occurs at rest;
2.forced breathing is vigorous breathing that accompanies exercise or hard exertion.
Know the general steps involved in breathing
oStimulus: The nervous system must stimulate the skeletal muscles involved in breathing. If there is no stimulus from the nervous system, breathing will not occur.
oVolume Change: The skeletal muscle will contract or relax because of the stimulus from the nervous system. When the muscles contract or relax, the volume of the thoracic cavity will change.
oPressure Change: When the volume of the thoracic cavity changes, this will change pressure in the thoracic cavity. This creates a gradient between the atmosphere and the lungs.
oAir Movement: This difference in pressure between the atmosphere and the lungs will cause air to move- either in or out of the lungs. Air moves down a pressure gradient (moves from high to low pressure).
quiet breathing muscles
skeletal muscles involved in normal rhythmic breathing that occurs at rest
diaphragm - floor of the thoracic cavity
external intercostals-elevatest the ribs
forced inspiration muscles
used during a deep inspiration, such as occurs during heavy exercise or prior to "holding a long note" while singing.
sternocleidomastoid, lifts the ribs cage
scalenes, elevated the ribs
pectoralis minor -elevated the ribs
serratus posterior superior -lifts the ribs cage
erector spinae.- extends the verbebral colum
-superior location relative to the thoracic cavity
forced expiration muscles
contract during a hard expiration, for example, when one blows up a balloon or coughs
-internal intercostals,
-abdominal muscles,
-transversus thoracis,
-serratus posterior
What are "accessory muscles of breathing"?
muscles of forced inspiration and forced expiration
three dimensions of volume changes in the thoracic cavity.
vertically, laterally, and in an anterior-posterior direction
What causes the vertical volume change
movement of the diaphragm as it contracts and relaxes
what happens when the diaphragm contracts and relaxes
Relaxed- forms rounded floor and dome shaped-decreased thoracic cavity
Contracts- increase the thoracic cavity and central position flatten and moves inferiorly
How are the movements of the diaphragm different in quiet and forced breathing?
Quiet- small changes in the movement of the diaphragm
Forced- large changes in the movement of diaphragm because of contraction of the abdominal muscles.
What causes the lateral volume change?
How does the volume change in the thoracic cavity?
as the rib cage is elevated and the thoracic cavity widens, or as the rib cage depresses and thoracic cavity narrows
What causes the anterior-posterior volume change? How does the volume change in the thoracic cavity?
As the inferior portion of the sternum moves anterior and then posteriorly.
inferior portion of the sternum moves anterior thoracic cavity expends.
-inferior portion of the sternum moves posteriorly thoracic cavity compress
Define Boyle's Law and know the formula for Boyle's Law
constant temperature, the pressure (P) of a gas decreases if the volume (V) of the container increases= p1v1= p2v2
What type of relationship do volume and pressure have?
inverse relationship
How do changes in volume cause changes in pressure
Increase in volume cause a decrease in pressure-
Decrease in volume cause increase in pressure
Know how an air pressure gradient occurs.
force per unit area is greater in one place than in another.
How does air move along a pressure gradient?
air moves from the region of higher pressure to the region of lower pressure until the pressure in the two regions becomes equal.
Define atmosphere and atmospheric pressure
1. atmosphere is the air in the environment that surrounds us.
2.Atmospheric pressure is the pressure (weight) gases in the air exert in the environment.
What is the value for atmospheric pressure at sea level? How does this change with an increase in altitude?
760mm- it increase
Does Atmospheric pressure change in the context of breathing.
1.Define alveolar volume.
2. What is its associated pressure?
3. How does this pressure change?
1. collective volume of the alveoli within the lungs
2. intrapulmonary pressure (higher pressure inside the lungs)
3.fluctuates with breathing and may be higher, lower, or the same as atmospheric pressure
What causes this pressure change (remember Boyle's Law!)? What happens to the pressure gradient and air movement?
1. Volume changes
2. establishes a pressure gradient between the atmosphere and the thoracic cavity that determines the direction of airflow.
3. Volume increase and preasure decrease causing air moving into the lungs during inspiration.
Quiet Breathing-Inspiration:-contracting is active
How do intrapulmonary pressure and atmospheric pressure correspond at the start of inspiration?
They are both at 760 mm(equal)
Quiet Breathing-Inspiration:
What muscles are stimulated and how do they change the volume of the thoracic cavity (and in turn alveolar volume)?
1. diaphragm muscles are stimulated
2. Thoracic cavity volume increases and alveolar volume increase
Quiet Breathing-Inspiration:
What happens to the intrapulmonary pressure? How does this correspond to atmospheric pressure (what is the gradient?)?
1.The intrapulmonary pressure decreases from 760 to 759 mm
2. gradient is the pressure difference
Quiet Breathing-Inspiration:
How does air move because of the gradient? What causes the air to stop moving? What is tidal volume?
1. air moves down the pressure gradient from the environment
2.when intrapulmonary pressure is once again equal to atmospheric pressure.
3.volume of air that moves from the atmosphere into the lungs during a single breath in quiet breathing
Quiet Breathing-Expiration:
How do intrapulmonary pressure and atmospheric pressure correspond at the start of expiration?
They are equal 760
Quiet Breathing-Expiration:
What happens to the muscles and how do they change the volume of the thoracic cavity?
How does the recoil of the thoracic wall affect alveolar volume?
1. diaphragm and external intercostals muscles relax and decrease the volume of thoracic cavity
2.the alveolar volume decreases because the lungs are pulled inward by the recoil of elastic connective tissue in the lungs
Quiet Breathing-Expiration:
What happens to the intrapulmonary pressure? How does this correspond to atmospheric pressure (what is the gradient?)?
Pressure increase and intrapulmonary pressure is more than the atmospheric pressure
2. intrapulmonary pressure is 761
3. gradient different= +1
Quiet Breathing-Expiration:
How does air move because of the gradient? What causes the air to stop moving?
1.air is forced out of the alveoli into the atmosphere
2. When intrapulmonary pressure is equal to the atmospheric pressure
Forced Breathing:
both forced inspiration and forced expiration are active processes, meaning that additional muscles are required to contract
Quiet Breathing
Quiet inspiration is an active process because the muscles used contract. However, quiet expiration is a passive process because no muscles are contracting.
Forced Breathing:
How does the addition of extra muscles affect the volume and pressure changes?
There is a larger volume and pressure change
Know where the nuclei are located that controls the skeletal muscles of breathing.
What are the two centers that make up the respiratory center and where are these located?
1.medullary respiratory center within the medulla oblongata
2.pontine respiratory center (also called the pneumotaxic center) within the pons.
Medullary respiratory center:
1.What is the function of the VRG and DRG and where are these located?
1.The VRG initiates neural impulses for inspiration and expiration; -ventrolateral region of the medulla
2. DRG relay inputs into VRG-dorsomedial region of the medulla
What do these axons eventually form?
phrenic nerves -innervate the diaphragm
intercostal nerves -innervate the intercostal muscles
What do the inspiratory neurons stimulate and what is the effect?
Action potentials it cause both the diaphragm and external intercostal muscles to contract causing an increase in thoracic cavity volume.
What happens when the inspiratory neurons are inhibited (what causes the inhibition?)?
1.inspiratory impulses cease and muscle are relax and thoracic cavity volume is decrease
Inhibition is cause by VRG neurons and the pontine respiratory group
Pontine respiratory center: What is the function of this center?
provide for a smooth transition between inspiration and expiration by sending impulses to the VRG.
average respiratory rate in the pontine
average respiratory rate of 12 times per minute.
1. 2 seconds inspiration
and 3 second expiration
The average range for the rate of quiet breathing is generally between 12 and 15 times per minute
Altering Breathing Rate and Depth: Where are sensory impulses sent when receptors are stimulated?
How does this eventually change breathing rate and depth?
1. DRG
2. Rate-Rate is changed by altering the amount of time spent in both inspiration and expiration
3. Depth-Depth is change by the stimulation of accessory muscles, which results in greater thoracic volume changes
The levels of respiratory gases are given as partial pressures
higher the partial pressure for a gas, the greater its concentration.
What are the internal chemoreceptors,
include both central chemoreceptors and peripheral chemoreceptors.
central chemoreceptors
1. Where is it located
2. what do they monitor
3.How does each of these affect breathing rate and depth?
1.ventrolateral surface of the medulla.
2. only pH changes of CSF induced by changes(increase) in blood Pco2
3.Respiration rate and depth are increased
peripheral chemoreceptors.
1. Where is it located
2. what do they monitor
3.How does each of these affect breathing rate and depth?
1.within the walls of specific blood vessels.
---(carotid bodies and aortic bodies )
2.detect changes in arterial blood.
3.increase or decrease in rate and depth
What is the most important stimulus affecting breathing rate and depth and why?
Why is this detected quicker in the CSF?
blood Pco2. The respiratory center is very sensitive to changes in carbon dioxide levels;-small increase can double breathing rate
2. the CSF lacks proteins to buffer the gain or loss of H+
Where are proprioceptors and baroreceptors (for the lungs) found
1.proprioceptors- within joints and muscles
2. baroreceptors- visceral pleura and bronchiole smooth muscle
How do proprioceptors stimulate a change in breathing rate and depth?
By increasing the body movement will stimulate a change
What is the function of the barorecptors?
initiate a reflex to prevent overstretching of the lungs by inhibiting inspiration activities
What is the inhalation (or Hering-Breuer) reflex? What does this protect?
protects the lungs from damage due to overinflation.
? How do the baroreceptors here work in inhalation reflex (and what cranial nerve is used?)?
baroreceptors send sensory impulses through the vagus nerves to the respiratory center to shut off inspiration activity
What is the function of coughing and sneezing and what is involved with these reflexes?
1.exaggerated intake of breath,
2. closure of the larynx and contraction of abdominal muscles, followed by an explosive blast of exhaled air when the vocal cords open abruptly.
What higher brain centers influence breathing rate and how?
1.hypothalamus, limbic system, and cerebral cortex
2. The hypothalamus increases the breathing rate if the body is warm and decreases it if the body is cold
3. The limbic system alters the breathing rate in response to emotions and emotional memories
4. Cerebral cortex controls voluntary changes in our breathing pattern for various activities, such as talking, singing, breath-holding, performing the Valsalva maneuver, and other actions.
Nervous Control of Breathing Versus Nervous Control of the Respiratory Center:
How does the innervation for breathing and anatomic structure of the respiratory system differ?
What parts of the brain control each
1.Respiratory system- innervated by the axons of lower motor neurons of the autonomic nervous system and controlled by brainstem nuclei.
2.Breathing - composed of skeletal muscle tissue, are innervated by axons of the lower motor neurons of the somatic nervous system.
3.brainstem and the cerebral cortex
Define airflow.
amount of air that moves into and out of the lungs with each breath.
What two factors determine the efficiency of airflow and how?
(1) the pressure gradient established between atmospheric pressure and intrapulmonary pressure,
2) the resistance that occurs due to conditions within the airways, lungs, and chest wall.
What formula expresses airflow?
F = flow, ΔP = difference in pressure between atmosphere (atm) and the intrapulmonary pressure within the alveoli (alv), and R = resistance.

How is airflow related to pressure gradient and resistance?
1.flow is directly related to the pressure gradient
2.inversely related to resistance
For pressure gradient, how can the airflow be altered?
It can be changed by altering the volume of the thoracic cavity
What is resistance
1.all the factors that make it more difficult to move air from the atmosphere through the respiratory passageway into the alveoli.
what are the three ways resistance can be altered?
(1) a decrease in elasticity of the chest wall and lungs,
(2) a change in the bronchiole diameter or the size of the passageway through which air moves, and
(3) the collapse of alveoli.
How does a decrease in elasticity affect resistance?
increase in resistance
What are some ways elasticity can be decreased?
(1) an individual has vertebral column malformation, such as scoliosis;
(2) arthritis develops within the thoracic cage; or (3) elastic connective tissue in the lungs is replaced with inflexible scar tissue, which occurs with pulmonary fibrosis.
How does brochoconstriction and brochodilation affect resistance? What are some causes of brochoconstriction and brochodilation?
1.Resistance increases with bronchoconstriction
which are cause by parasympathetic stimulation, histamine release, or exposure to cold.
2.Resistance decreases with bronchodilation caused by sympathetic stimulation and the subsequent release of epinephrine from the adrenal medulla, or with external administration of epinephrine.
What can cause alveoli to collapse and how does this affect resistance? Why is this more important in premature infants?
1. lack of pulmonary surfactant , it increases resistance
2.premature infants are unable to produce sufficient pulmonary surfactant
What is ARDS?
acute respiratory distress syndrome (ARDS).
when premature infants experience greater resistance to airflow.
Define compliance.
the ease with which the lungs and chest wall expand.
What factors affect compliance? How does this relate to lung expansion?
1.surface tension and elasticity of the chest wall and lung are factors that affect compliance
2. the easier the lung expansion, the greater the compliance
1.How can respiratory diseases (such as asthma and pulmonary fibrosis) affect resistance?
2.How does this affect energy expenditure does this affect individuals with breathing disorders?
1.increase resistance to airflow
2.greater amount of the body's metabolic energy must be spent on breathing
3. They can become exhausted simply from breathing.
Define alveolar ventilation
-The amount of air that reaches the alveoli and is available for gas exchange per minute
-pulmonary ventilation may also refer to the amount of air that is moved between the atmosphere and alveoli in 1 minute
How are pulmonary ventilation represented in mathematical form and what are the normal values?
pulmonary ventilation -normal value = 500ml per breath
Tidal volume(amount of air per breath) *Respiration rate(number of breath per minute)
How are alveolar ventilation represented in mathematical form and what are the normal values?
(Tidal volume - anatomic dead space ) * respiration rate
What is anatomic dead space and why is this taken into consideration when calculating alveolar ventilation?
1.collective space, where there is no exchange of respiratory gases,
2. when air is moved from the atmosphere into the respiratory tract, a portion of it remains in the conducting zone
Why is deep breathing more effective at increasing alveolar ventilation?
Because you have to overcome anatomic dead space only once
Define physiologic dead space. How does this differ from anatomic dead space
1. The difference in volume of air available for gas exchange
2. in healthy individual there should be no difference
3. anatomic dead space plus any loss of alveoli = physiologic dead space
How can respiratory volumes and capacities be used as a diagnostic tool?
-variation is significant enough to be used as a diagnostic tool for determining the health of an individual's respiratory system.
Define tidal volume
amount of air per breath
amount of air inhaled or exhaled per breath during quiet breathing
Inspiratory reserve volume (IRV) is the amount of air that can be forcibly inhaled beyond the tidal volume (after a normal inspiration). I
RV is a measure of lung compliance.
Expiratory reserve volume (ERV) is the amount that can be forcibly exhaled beyond the tidal volume (after a normal expiration).
ERV is a measure of lung and chest wall elasticity.
How is FEV used to diagnose individuals with emphysema
-Forced expiratory volume (FEV) is the percentage of the vital capacity that can be expelled in a specific period of time.
1.inspiring as much air as possible and then expelling the air from the lungs as quickly as possible.
2.Individuals with decreased ability to expire (have decreased FEV)
alveolar and systemic gas exchange.
Alveolar - The movement of these gases between blood in pulmonary capillaries and the alveoli of the lungs
systemic - the movement of respiratory gases between blood in systemic capillaries and systemic cells
Define partial pressure
the pressure exerted by each gas within a mixture of
gases and is measured in mm Hg
Know how partial pressure is written
it is written with a P followed by the symbol for the gas.
An example partial pressure for oxygen is written as PO2.
know how partial pressure is found for each gas
determined by multiplying the total pressure exerted by the gas mixture by the percent of the specific gas of interest
Total pressure * % of gas = Partial pressure of that gas
What are all of the gases found in the environment?
nitrogen (N2), oxygen (O2), carbon dioxide (CO2), water vapor (H2O),
How does each of these contribute to the total atmospheric pressure (this is defined in Dalton's Law- know this definition)?
total pressure in a mixture of gases is equal to the sum of all of the individual partial pressures.
When these partial pressures are added together, their sum must equal the total atmospheric pressure
which gas has the highest percentage, the second highest the specific partial pressures (in mmHg)
nitrogen (N2), oxygen (O2), water vapor (H2O), carbon dioxide (CO2)
What is a partial pressure gradient?
when the partial pressure for a specific gas is
higher in one region of the respiratory system than in another
How does partial pressure gradient affect gas movement?
the gas moves from the region of its higher partial pressure to the region of its lower partial pressure, and it may continue to move until the partial pressures in the two regions become
What are the two relevant partial pressures in the body and where are the relevant locations?
PO2 and PCO2 within alveoli in the lungs, systemic cells, and in circulating blood
In the Alveoli: Why is the partial pressure of gases in the alveoli different from that of the atmosphere?
(1) air from the environment mixes with the air remaining in
the anatomic dead space in the respiratory tract
(2) oxygen diffuses out of the alveoli into the blood, and
carbon dioxide diffuses from the blood into the alveoli;
(3) more water vapor is present within the alveoli
because of the higher humidity there
What is the the final alveolar partial pressures
PO2= 104
PCO2 = 40
In the Systemic Cells: What causes the partial pressure in the systemic cells?
activities of cellular respiration
Cells use oxygen during cellular respiration and produce carbon
know the systemic cells partial pressures at resting condition
At rest- PO2 = 40 and PCO2 = 45
In Circulating Blood: Why do these partial pressures change?
How do these differ in the lung and systemic capillaries?
the blood change continuously as the blood flows through the lung capillaries,
alveoli and systemic ells are relatively constant values
Gas Solubility and Henry's Law: Define Henry's Law (use the example of carbon dioxide gas in a soda to understand this).
which states that at a given temperature, the solubility of a gas in a liquid (i.e., how much gas can either enter or leave the liquid) is
dependent upon
(1) the partial pressure of the gas in the air and
(2) the solubility coefficient of the gas in the liquid.
If the partial pressure of gases changes, how does this affect the amount of gas that enters a liquid?
the amount of the gas that enters the liquid changes
Define solubility coefficient.
the volume of gas that dissolves in a specified volume of liquid at a given temperature and pressure
Which gas has the highest solubility in water (and which one is second and third)?
1.Carbon dioxide 2. oxygen 3. Nitrogen
How does the solubility coefficient affect how easily a gas will go into a solution?
gases with low solubility coefficients require larger pressure gradients to "push" the gas into the liquid- does not dissolve easier
Alveolar Gas Exchange (External Respiration)
Which way does oxygen move and why?
Which way does carbon dioxide move and why?
oxygen moves from alveoli to blood because the PO2 in alveoli is 104 and the blood entering has PO2 of 40. so oxygen diffuses from the alveoli to the pulmonary capillaries because of partial prssure gradient.
carbon dioxide move from blood to alveoli
because alveoli is 40 mm and blood entering is 45
What factors affect the efficiency of gas diffusion?
dependent upon anatomic features of the respiratory membrane, this include both its large surface area and minimal thickness
? What is ventilation-perfusion coupling
This inherent ability of bronchioles to regulate airflow and arterioles to regulate blood flow simultaneously
What can alter ventilation and how?
1. Means to deliver air

altered by changes in bronchodilation and bronchoconstriction
Bronchioles dilate in response
to an increase in PCO2, whereas they constrict in response to a decrease in PCO2.
d-increase in PCO2
What can alter perfusion and how?
1. means to deliver blood
altered by changes in pulmonary arteriole dilation and pulmonary arteriole constriction
arterioles dilate in response to either an increase in PO2 or a decrease in PCO2, whereas they constrict in response to either a decrease in PO2 or an increase in PCO2.

d-increase in PCO2
Know the difference between external and internal respiration.
External is inside the respiration system
Internal is outside the respiration system
Which way does oxygen move and why? Which way does carbon dioxide move and why?
1 Oxygen moves blood from (B-A) blood in the systemic capillaris to the systemic cells
(outside oxygen 95 is higher than inside oxgyen 40)- diffues out
2. Carbon dixode moves from the systemic cells to the systemic capillaris because inside level of 45 is higher than outside level of 40
-diffues down
. Why does oxygen decrease from 104 mmHg leaving the pulmonary capillaries to 95 mmHg entering the system tissues?
The input of deoxygenated blood accounts for the decrease in PO2
gas transport.
Gas transport is the movement of respiratory gases within
the blood between the lungs and systemic cells.
how oxygen is transported
dissolved in plasma or attached to hemoglobin
Know the percentage of oxygen that is dissolved in plasma. Why is this so small?
1. only less the 2 percent are dissolved in plasma
2. Because the solubility coefficent is low therefore it is hard to dissolves
Know the percentage of oxygen that is attached to hemoglobin. What exactly is it attached to?
1. 98 percent are attached to hemoglobin
2. It is attached to Iron within the hemoglobin
Oxygen bound to hemoglobin(HbO2)
Hemoglobin without bound oxygen (HHB)
three ways carbon dioxide is transported in the blood and the percentage of each.
(1) CO2 dissolved in plasma -7%
(2) CO2 attached to globin portion of hemoglobin,- 23%
(3) as bicarbonate (HCO3−) dissolved in plasma - 70%
Why is more CO2 dissolved in plasma than oxygen?
Because CO2 have a higher solubility coefficiet of ..57- making it easy to dissolve in liquid
What part of hemoglobin does CO2 attach to
The amine groups(-NH2)
Know the three substances that hemoglobin transports and where they are attached.
(1) oxygen attached to iron,
(2)carbon dioxide bound to the globin
(3) hydrogen ions bound to the globin
What happens to the hemoglobin molecule when one of these substances are bound or released and how does this affect the other two substances?
-that the binding or release of one substance causes a conformational change that temporarily alters the shape of the hemoglobin molecule.
-This change influences the ability of hemoglobin to bind or
release the other two substances.
How many oxygen molecules can one hemoglobin carry and how does this affect the "percent O2 saturation of hemoglobin"?
1. Carry 4
2. It becomes 100% saturated because all of the iron sites are occupied by oxygen
How does Po2 affect hemoglobin saturation and how?
As the PO2 increases the hemoglobin saturation increases- making it easier for additional O2 molecule to bind to any available iron
What is the cooperative binding effect?
The increase in the ease of oxygen binding
What is an oxygen-hemoglobin saturation curve
it relates the PO2 and percent O2 saturation of hemoglobin
. How does the graph differ when looking at Po2 from 20 mmHg to 40 mmHg compared to when Po2 is at 60 mmHg?
Large changes in percents O2 saturation of hemoglobin as PO2 changes from 0 to 60.
After 60, the percents O2 changes is small because hemoglobin become over 90% saturated
percent O2 saturation of hemoglobin
The amount of oxygen bound to hemoglobin is
expressed as the
How doesPO2 and percent O2 saturation of hemoglobin change in high altitude
Increase in high attitude , decrease alveolar PO2 this will cause the hemoglobin saturation to decrease
(PO2- 81-elevation of 5000 feet- Hemogloin 95%
PO2- 65- elevation of 9000 feet- hemoglobin 91%
*** as PO2 decreases, elevation level raises
What is altitude sickness?
The adverse physiologic effects from a decrease in alveolar PO2
What might happen if an individual is given pure oxygen?
Little would be gain because a person hemoglbin is 98% saturated
What percentage of oxygen is actually released to the cells?
20-25 percent
What is oxygen reserve and what is its function?
When would the oxygen reserve be used?
The amount of oxygen that remains bound to the hemoglobin after passing through the systemic capillaries.
-provides a means for additional oxygen to be delivered
to systemic cells under increased metabolic demands, such as occurs during exercise
How does an increase in temperature affect oxygen release?
More oxygen is released as temperature increase
How does H+ affect oxygen release (how is this H+ produced?
1. It cause additional oxygen to be release
2. Produced with Carbon dixoide enter erythrocytes and binds to the globin protein in hemoglobin
How does the presence of 2,3-BPG affect oxygen release and where is 2,3-BPG produced?
It cause release of additional oxygen as blood moves through systemic capillaries
2,3-BPg is produced in alternative (gllycolytic) metabolic pathway within erythrocytes
How does CO2 binding affect oxygen release?
It also release of more oxygen from hemoglobin
Describe the Haldane effect
the more oxygen that is released from
hemoglobin, the more carbon dioxide that binds to it—
Understand what it means when the curve "shifts right" or "shifts left".
In what pH and temperature conditions would the curve shift left or right?
1. Shifts right- Factors that bring about a decrease in oxygen affinity
(e.g, increase in temperature, increase in H+) to hemoglobin and the additional release of oxygen
2. Shifts left - the variables that bring about an increase in oxygen
affinity to hemoglobin (e.g., decrease in temperature, decrease in H+) result in release of less oxygen
breathing rate or depth that is increased above the body's demand- faster breathing
decrease breathing
blood PCO2 decreases below normal levels
Lower amounts of carbon dioxide diffuse from the blood into the alveoli. This causes blood PCO2 to
breathing that is either too slow
breathing too shallow
alkalosis and acidosis
1. acidosis - acidemia, is an arterial blood pH reading below
2. alkalosis.- alkalemia, is an arterial blood pH reading above 7.45
Lower amounts of oxygen diffuse from the alveoli into the blood, and blood PO2 decreases. This is a
Know the causes of hyperventilation (either involuntary or voluntary).
How does this affect Po2 and Pco2 in the alveoli as well as the partial pressure gradients?
How does this affect the blood and how can this cause hypocapnia?
1. Cause by anxiety, panic or ascending to a high altitude(breath faster to compensate for lower oxygen levels)- involuntary
2. voluntary- when you consciously inspire and expire excessively at an advance rate.
3.Po2 levels increase and PCO2 levels decreases and the partial pressure gradients increase
4. additional oxygen does not enter the blood and carbon dioxides leaves the blood to enter alveoli due to steeper PCO2. this cause blood PCO2 to decrease below normal levels.
What physiological affects does low Pco2 have on blood vessels, specifically in the brain?
How can this eventually lead to respiratory alkalosis?
Low blood PCO2 causes vasoconstriction of blood vessels and decrease of oxygen delivery to the brain
-This can lead to repiratory alkalosis because it results in decrease in blood H+ and increase in blood pH
What are some symptoms of hyperventilation?
How does breathing rate return to normal?
How does breathing into a paper bag help?
1.feeling faint or dizzy, numbness, tingling of the
mouth and fingertips, muscular cramps, and tetany. If hyperventilation is prolonged, it can cause disorientation, loss of consciousness, coma, and possibly death
2.returns to a normal level once the individual loses consciousness.
3. this action is thought to slow the loss of CO2.(breathing into paper bag)
Know the causes of hypoventilation.
Causes of hypoventilation are
varied and include airway obstruction, pneumonia, brainstem injury, obesity (which restricts lung expansion),
and any other condition that interferes with pulmonary ventilation or alveolar gas exchange
How does hypoventilation affect Po2 and Pco2 in the alveoli as well as the partial pressure gradients?
Oxygen level decrease and carbon dioxide levels increases.
Smaller partial pressure gradient increase
How does hypoventilation affect the blood and how can this cause hypercapnia and hypoxia?
1. Lower oxygen amount decrease PCO2 is cause hypercapina
2. Lower carbon dioxide this cause increase in PO2 called hypoxia
What physiological affects does low Po2 have, specifically with cellular respiration? during hypoventilation
Low blood oxygen levels may result in insufficient oxygen delivery to systemic cells, with a subsequent
decrease in aerobic cellular respiration
What affects does Pco2 have and how can this eventually lead to respiratory acidosis? during hypoventilation
Decrease in Oxygen and increase in PCO2 results in increase in Blood H concentration and decrease blood pH
How does breathing rate return to normal? Is it possible to hold your breath until you die and why? during hypoventilation
NO - you can not hold your breath
The accumulation of CO2 in the blood stimulates chemoreceptors to stimulate inspiration before or after loss of consciousness—but always before the brain suffers damage from lack of
Describe what happens to breathing depth and rate during vigorous exercise.
Breathing depth increases while breathing rate remains the same.
Define hyperpnea
Deeper breathing but not fast - dept increase and rate is constant
How does oxygen and carbon dioxide change due to an increase in cellular respiration and how is it that Po2 and Pco2 remain relative the same despite the changes due to cellular respiration? during exercise
O2 and CO2 increase and PO2 and PCO2 remains constant because the deeper breathing , increased cardiac output and increased blood flow are able to deliver the additional o

This occurs
because deeper breathing, increased cardiac output, and increased blood flow are able to deliver the
additional oxygen needed and eliminate the greater amount of carbon dioxide produced (i.e., supply increases
to meet demand). Thus, blood PO2 and PCO2 levels are not thought to be the stimuli that cause breathing to
change because they remain relatively constant during exercise.