157 terms

Respiratory system- Chapter 22

pulmonary ventilation
movement of air in and out of the lungs
external respiration
gas exchange that occurs in lungs between air and blood
internal respiration
gas exchange that occurs at cell membranes between the blood and body cells
transport of respiratory gases
transport of oxygen and carbon dioxide between lungs and other body tissues via blood
cellular respiration
chemical reactions in which cells use oxygen and produce carbon dioxide in the breakdown of glucose (or other molecules) to release energy, some of which is stored in ATP and available for cells to use
conducting zone
interconnecting system of respiratory passageways that carries air to and from sites of gas exchange in the lungs
terminal bronchioles
The conducting zone ends at the ________
warm, humidify, filter
Conduction zone structures _____, ______, and ______ incoming air
respiratory zone
interconnecting system of respiratory passageways in which gas exchange occurs
respiratory bronchioles
The respiratory zone starts at the ______
Where does most of the gas exchange occur in the lungs?
coarse hairs just insigne the external nares that screen out larger debris (dust particles, lint, pollen, etc.)
nasal septum
a vertical partician that divides the nasal cavity into left and right sides
superior, middle, inferior nasal conchae
medial projections from the lateral walls of the nasal cavity that divide it into groove like passageways; they increase surface area and air turbulence in nasal cavity
ethmoid, sphenoid, hard palate, soft palate
The nasal cavity is separated from the cranial cavity by the ______ and ______ bones, and anteriorly from the oral cavity by the ______ (supported by maxillary and palatine bone, and posteriorly by the ______ (muscular, not supported by bone)
internal nares
openings between nasal cavity and pharynx
pseudostratified ciliated columnar, goblet
The nasal cavity is lined with ___________ epithelium containing many ____ cells
warms, moistens, filters, smells, resonant chamber
Nasal cavity functions:
1. _____ air radiating from blood vessel near surface of mucous membrane
2. _____ air by evaporation of water from mucus on mucous membrane surface (and from water that drains into nasal cavity in tears
3. ______ air by trapping particles of debris in mucus layer and conveying them by action of cilia to pharynx where debris ladened mucus is swallowed or spit out
4. ______ air and aids in taste discrimination via olfactory receptors
5. act as ________, along with paranasal sinuses, oral cavity, and pharynx, to affect voice quality and gives voice its individual characteristics
paranasal sinuses
mucous membrane-lined sinuses continuous within maxillary, frontal, ethmoid, and sphenoid bones (named after them ) that open into the nasal cavity
nasal cavity
The mucous membrane of the paranasal sinuses is continuous with that of the ______, and also aids in the warming and moistening of the air
paranasal sinuses, sinus headache
__________ are prone to infection due to poor drainage into the nasal cavity (resulting from human's erect posture) and when their mucous membranes are swollen with infection or allergic reaction, drainage may be totally blocked-pressure builds up- resulting in a painful ______
paranasal sinuses
_________ reduce the weight of the skull, and act as a resonant chamber along with the nasal cavity, oral cavity, and pharynx
common passageway for both respiratory and digestive systems; in respiratory system, connects nasal cavity to larynx and in digestive system, connects oral cavity to esophagus
most superior portion of pharynx extending from just posterior of the nasal cavity (connected with it via internal nares) to the plane of the soft palate
The _______ is lined with mucous membrane of pseudo stratified ciliated columnar epithelium, cilia of which move debris-ladened mucus down the pharynx; It also usually conducts only air
______ tubes that open on lateral walls allow for pressure equalization on either side of the tympanic membrane (eardrum), and connects the nasopharynx with the middle ear
pharyngeal tonsil (adenoid)
mass of lymphatic tissue embedded in superior portion of nasopharynx posterior wall
middle portion of pharynx extending from the plane of soft palate to epiglottis
piece of cartilage that when food is swallowed, covers the glottis
opening to the larynx
The _______ is the part of the pharynx that conducts both air and food
palatine tonsils
pair of lymphatic tissue masses embedded int he lateral walls of the oropharynx
lingual tonsil
mass of lymphatic tissue at the base of the tongue
most inferior portion of the pharynx extending from the epiglottis to the point where the larynx and esophagus diverge; joins the esophagus posteriorly and larynx anteriorly
The _____ is lined with a mucous membrane of stratified squamous epithelium and conducts both air and food
air passageway that connects the pharynx to the trachea and lies anterior to the 4th and 6th vertebrae
The ______ is composed of 9 pieces of cartilage connected by ligaments and membranes
thyroid cartilage
single shield-shaped cartilage (consists of two fused pieces) that forms the anterior wall of the larynx, and is visible as a projection in the anterior neck
thyroid cartilage
______ is larger in males than in females due to growth stimulation by male sex hormones
laryngeal prominence
anterior, medial projection from thyroid cartilage
cricoid cartilage
single ring of cartilage that forms the inferior wall of the larynx and attaches to the trachea inferiorly; most of the inferior part of the larynx, thus a landmark for doing a tracheotomy
spoon-shaped elastic cartilage with its "handle" anchored on the anterior rim of thyroid cartilage, and its other end covering the glottis when swallowing occurs
cough reflex
If a substance other than air enters the larynx, ______ is initiated to expel it, unless person is unconscious
arytenoid, corniculate, cuneiform
____, _____, and _____ are smaller paired cartilages that form part of the lateral and posterior walls of larynx
vocal folds, arytenoid cartilage, thyroid cartilage
pair of ligaments composed of elastic fibers covered with stratified squamous epithelium that vibrate, producing sounds when air passes over them; attach to ________ which also attach to muscles, enabling their movement; at the other end, they are anchored to _______
Sounds are converted into words by changing the shape of the _____ and oral cavity, using the tongue and lips
Pitch of vocal sound is controlled by changing the tension of the vocal cords; greater tension = ______ pitch
air, louder
Loudness of vocal sound is controlled by the force of ____ passing over the vocal cords; stronger force= ______ sound
vestibular folds
pairs of folds in the mucous membrane superior to true vocal cords that are not involved in sound production, but when folds brought together, aid in breath-holding and in helping to keep substances out of the trachea
stratified squamous, pseudostratified ciliated columnar, goblet cells
The portion of the larynx superior to the true vocal cords is lined with _______ epithelium, while that inferior to the cords is lined with ________ epithelium containing mucus secreting _______; cilia here move debris-laden mucus up toward the pharynx
pharynx, trachea, trachea, sounds, air
Larynx function:
1. carry air between the ____ and _____
2. prevent foreign objects from entering the ____
3. produce ______
4. filter _____
flexible, cylindrical tube anterior to esophagus, and extending from the larynx to there it divides into the left and right primary bronchi
pseudostratified ciliated columnar, filter, moisten
The trachea is lined with ________ epithelium containing mucus secreting goblet cells, and as in the larynx, cilia moves mucus up toward the pharynx; Thus the trachea serves to ____ and _____ air
The ______ has 16-20 C-shaped pieces of cartilage embedded in the wall to keep it from collapsing
trachealis muscle
smooth muscle that connects the open posterior part of the C-shaped cartilages, which along with some connective tissue adjacent to the esophagus, allow it to expand anteriorly when food passes through it (by partially collapsing the trachea
trachealis muscle
Contraction of the ________ reduces the diameter of the trachea, causing more forceful expulsion of air when coughing
bronchi, bronchioles
system of branching tubes that carry air between the trachea and alveoli
right and left primary bronchi; right primary bronchi, left primary bronchi
formed by the division of the trachea; the ______ is shorter, wider, and more vertical than the ________, and thus more likely to be the site in which a foreign object lodges
pseudostratified ciliated columnar epithelium
primary bronchi lined with _______ (filters and moistens air) and supported by incomplete rings of cartilage
secondary (lobar) bronchi, 3, 2
branches from the primary bronchi within the lungs and enter the lobes of the lungs ( ____ lobes in right lung; _____ in left lung)
tertiary (segmental) bronchi
branches of the secondary bronchi that enter segments within the lobes of the lungs
bronchi divide into smaller bronchi which eventually divide into ______- natural air passages less than 1mm in diameter
terminal bronchioles
Bronchioles, in turn divide into even smaller ones, and eventually into _______- those less than .5mm in diameter
respiratory bronchioles
smallest bronchioles that branch off the terminal bronchioles; scattered alveoli extend from their walls; continuous with alveolar ducts
alveoli, 64
Many ______ protrude from the walls of alveolar ducts which lead into ____ alveolar sacs-terminal grape like clusters of alveoli
cartilage, smooth muscle, smooth muscle, thins, terminal, respiratory
Changes occur in walls as respiratory passages become smaller:
1. the amount of _____ in walls decreases. Elastic fibers occur only in walls of bronchi and bronchioles
2. Amount of ______ in walls increases with the decrease in size of passages. There is a complete layer of circularly arranged _____ in the walls of bronchioles
3. Epithelial lining _____. Epithelium changes from pseudo stratified ciliated columnar to simple cuboidal in _____ bronchioles, and to simple squamous in ______ bronchioles and beyond
There are about ____ million alveoli in an adult lung which greatly increases surface area for gas exchange to 70m squared
simple squamous
The walls of alveoli are composed of ______ epithelium and thin elastic basement membrane secreted by it
pulmonary, simple squamous
Alveoli are surrounded by a dense network of _______ capillaries with walls composed of a basement membrane and ________ epithelium which which gas exchange occurs
type I, type II, type I
Alveolar epithelium consists of _______ alveolar cells, which are simple squamous epithelium cells and ______ alveolar cells which are scattered among the layer of _____ cells that secrete alveolar fluid
alveolar fluid
______ keeps alveolar cells moist, and contains a surfactant
substance to lower surface tension of a liquid, which helps keep wet walls of alveoli from sticking together and collapsing the alveoli
elastic fibers, alveolar pores
Alveoli are surrounded by fine _______ (as walls of respiratory passageways) and have ______- small openings between adjacent alveoli that allow equalization of pressure throughout the lung and provide alternate route into alveoli
alveoli pores
small openings between adjacent alveoli that allow equalization of pressure throughout the lung and provide an alternate route into alveoli
alveolar macrophages
(dust cells) wandering macrophages occurring inside the alveoli that remove inhaled debris, including microorganisms
respiratory muscles
muscles involved in breathing
inspiratory muscles
muscles involved in normal inspiration
diaphragm, external intercostals
what are the inspiratory muscles?
expiratory muscles
The _______ are to a lesser extent involved in breathing
expiratory muscles
The ______ are involved in forced expiration
abdominal wall muscles, internal intercostals
The expiratory muscles are ____ and _____
respiratory, trachea
The lungs are contained within sealed thoracic cavity formed by ______ muscles and rib cage. The ______ is the only natural opening of the thoracic cavity to the outside.
horizontally positioned, dome-shaped muscle that forms the floor of the thoracic cavity
external intercostal muscles
muscles laying between ribs that together with rib cage form sides and top of thoracic cavity
double-layered serous membrane that surrounds and protects each lung
parietal pleura
outer layer of pleural membrane that lines the wall of the thoracic cavity, including each lung
visceral pleura
inner layer of pleura membrane that covers external surface of lungs
pleural cavity
narrow space between the parietal and visceral pleura filled with pleural fluid
pleural fluid
lubricating fluid secreted by both membrane layers that reduces friction between them as they move during breathing; also causes parietal and visceral pleura to adhere to each other, so when the wall of the thoracic cavity moves, lungs move with it
intrapleural pressure
pressure within the pleural cavity; normally slightly less than both intrapulmonary (intra-alveolar) pressure and atmospheric pressure
inflammation of the pleura due to underproduction of pleural fluid resulting in sharp pain when parietal and visceral pleura move across one another
overproduction of pleural fluid can also cause _______ (though less painful) and by putting pressure on lungs, can interfere with breathing
air filling pleural cavity, usually a result of puncture of thoracic wall, allowing air to rush in and equalize pressure that may collapse the lung; it can be reversed by closing the wound in the chest wall and sucking air out of pleural cavity
In ________, the diaphragm contracts, moving inferiorly and the external intercostal muscles contract moving the rib cage superiorly and outward
The movements of ______ increase the size and volume of the thoracic cavity which also expands the lungs and increases their volume (since the lungs are stretchy due to elastic fibers within them, and are attached to the chest wall via pleura and thus move with it)
In inspiration, as lungs expand, air pressure within them _______, causing air pressure in the lungs to be lower than atmospheric pressure, so air rushes in to equalize pressure
Boyle's law
the pressure of a gas varies inversely with its volume if temperature is constant
air flows into lungs that are already expanded; it does not cause them to expand
In _______, the diaphragm relaxes, moving superiorly and the external intercostal muscles relax, moving the rib cage interiorly and inward
size, volume
The movements of expiration decrease the size and volume of the thoracic cavity, causing the lungs to decrease in ______ and _____
A decrease in the volume of the lungs leads to _____ in air pressure above that of atmospheric air pressure, so air rushes out to equalize the pressure
Contraction of abdominal wall muscles forces abdominal organs superiorly against diaphragm, pushing it ______, and contraction of internal intercostal muscles pull rib cage inferiorly and inward.

These movements expel air from the lungs more forcefully and quickly
tidal volume
the volume of air moved in and out of lungs with each breath during normal quiet breathing
inspiratory reserve volume
volume of air that can be forcibly inhaled beyond tidal volume
expiratory reserve volume
volume of the air that can be forcible exhaled beyond normal tidal volume
residual volume
volume of air that remains in the lungs even after the most forceful exhalation; amount of air remaining in lungs at all times that keeps alveoli partially inflated
inspiratory capacity
total amount of air that can be inhaled after tidal exhalation
formula for inspiratory capacity
functional residual capacity
total amount of air remaining in lungs after tidal exhalation
formula for functional reserve capacity
vital capacity
maximum amount of air that can be exhaled after the deepest possible inhalation; total amount of air that can be moved in and out of the lungs
formula for vital capacity
total lung capacity
total of all respiratory volumes; total volume of air that lungs can hold
formula for total lung capacity
anatomical dead space
volume of respiratory passages (trachea, bronchi, to terminal bronchioles) where no gas exchange occurs; volume of the air that does not reach the alveoli and thus not available for gas exchange- 150 ml
alveolar dead space
volume of air in nonfunctional alveoli (due to alveolar collapse or obstruction)
total dead space
anatomical dead space+alveolar dead space. In a healthy young adult, alveolar dead space is usually negligible, so 150ml
alveolar ventilation rate
volume of new atmospheric air moved into alveoli and available for gas exchange during a given time; AVR(ml/min)= TV-Total dead space (ml) x breathing rate (breaths/min)
AVR=TV-Total Dead Space X breathing rate
Formula for alveolar ventilation rate
increasing the volume of inspiration _____ AVR more than does increasing breathing rate since anatomical dead space is constant in the same person
Slower deeper breaths are _____ effective ventilation than rapid shallow breaths
External respiration
______ is gas exchange in lungs; O2 diffuses across alveolar and capillary walls from alveoli into blood since O2 concentration in alveoli is greater than that in blood; CO2 diffuses across the alveolar and capillary walls in the opposite direction since CO2 concentration in blood is greater than in the alveoli
internal respiration
______ is gas exchange in other tissues; O2 in systemic capillaries diffuses across capillary walls and cell membrane from blood into cells, since O2 concentration is greater in blood than in cells; CO2 diffuses across cell membranes and across capillary walls from cells to blood since CO2 concentration is greater in cells than in blood
Dalton's law of partial pressures
the total pressure of gas mixture is equal to the sum of pressures that each gas in the mixture would exert independently (as if other gases not present)
partial pressure
the pressure exerted by each gas in the mixture= the product of total pressure of gas mixture x its percentage total
Po2 ______ as pressure decreases with higher altitude
Since the amount of gas in the blood is directly proportional to its partial pressure (since blood temp is relatively constant), as Po2 decreases, the O2 concentration in blood _______
Since O2 is not very soluble in water, only 1.5% of O2 carried by blood is dissolved in plasma (mostly water); ____% of O2 carried is bound to hemoglobin
oxygen loading
when hemoglobin combines with O2
HHb- when oxygen combines with hemoglobin
Ah Hb molecule is fully _______ with all 4 of its Heme Groups are bound to )- bound to all for Iron atoms in heme group
An Hb is partially ______ when 1, 2, or 3 O2 are bound to it. Percentage of Hb saturation= amount of O2 bound to Hb
O2, acidity, CO2, BPG
HB saturation with O2 affected by
1. Partial pressure of _____ (Po2)
2. _______
3. Partial pressure of _____ (Pco2)
4. Temperature
5. Amount of _____ in blood
O2 loading
High Po2 promotes ________, so Hb binds with more O2
The higher the _____, the less O2 released from Hb to surrounding tissues (as in capillaries around alveoli)
Hb's affinity for O2 _____ the more acidic the environment (higher H+ concentration), so more O2 is released to the surrounding tissues
Hb's decreased affinity for )2 due to a change in its 3 dimensional shape
unloading, more
High Pco2 promotes O2 _____ by increasing the acidity, so _____ O2 is released to surrounding tissues
carbonic acid, carbonic anhydrase
As CO2 is taken up by the blood, much of it is converted to H2CO3 (________), calatlysed by an enzyme in RBCs, ________, which increases H+ ion concentration
unloading, decreases
Increasing temperature also promotes O2 ______, since heat changes the Hb's 3 dimensional structure, _____ its affinity for )2
BPG, unloading, reducing
(2, 3-Biphosphaglycerate)- a substance produced by RBCs when they breakdown glucose in glycolysis that enhances O2 ________ by combining with HB, ____ its affinity for O2
Increase in BPG, which results in an increase in RBC metabolic rate, results in _____ O2 released by Hb into tissues
Hb, Po2, fever
Factors that increase RBC metabolic rate:
1. Low ____ concentration (anemia)
2. Low _____ (high altitudes)
3. ______ (increase in temperature)
4. Certain hormones (thyroxine, human growth hormone, epinephrine, norepinephrine, testosterone
thyroxine, epinephrine, norepinephrine, human growth hormone, testosterone
Hormones that increase RBC metabolic rate:
heat, CO2, Po2
Actively metabolizing cells generate and release _____ and _____, and have a lower _____, all of which enhance O2 unloading in their vicinity
bicarbonate ions (HCO3), Hb, plasma
CO2 is transported in blood from tissue cells to lungs in 3 forms:
1. as _______ in plasma. Most CO2 is transported in this form
2. Chemically bound to _____ in RBCs. Less CO2 transported in this form. CO2 combines with amino acids of _____ portion.
3. CO2 dissolved in ______. Least CO2 transported in this form
also called acidemia; condition in which pH of extracellular fluid is lower than normal (blood pH below 7.35)
respiratory acidosis, carbonic acid
results from hypoventilation or any condition that interferes with breathing or gas exchange; when the rate of CO2 generation exceeds its excretion in lungs= high H2CO3 (_______) production and decrease in pH
injury, airway, respiratory
Hypoventilation usually due to
1. disease or pathological condition
2. depression of respiratory centers in the brain due to _____ or drug overdose
3. ______ obstruction
4. dysfunction of ____ muscles
depression, inhibiting
The main physiological effect of acidosis is _______ of central nervous system by _______ synaptic transmission
Blood pH less than ____ = severe CNS depression resulting in disorientation, coma, death
also known as alkalemia; condition in which pH of extracellular fluid is higher than normal
respiratory alkalosis
results from hyperventilation, when pH increased by decrease in H2CO3 concentration due to drop in CO2 level
carbonic acid
H2CO3 is
O2, injury, aspirin
Hyperventilation usually due to
1. ______ deficiency
2. lung disease or pathological conditions (pneumonia, asthma)
3. brain tumor or ____ (including cerebrovascular accident-stroke)
4. ____ overdose
Main physiological effect of alkalosis is _____ of CNS and peripheral nerves resulting in repetitive conduction of impulses by nerves (even in absence of normal stimuli) causing extreme nervousness, muscle spasms, and muscle tetany
convulsions, death
Blood pH greater than 7.8 results in ____ and ____ due to respiratory arrest