Respiratory System Flashcards
Main function of respiratory system
Supply O2 to tissues, remove CO2
components of respiratory system
upper-nose, nasal cavity, pharynx
lower- larynx, trachea, bronchi, lungs
functional divisions
conducting zone and respiratory zone
function of conducting zone
cleanses, humidifies, warms air and ducts
respiratory zone function
site of gas exchange, aveoli, bronchioles
conducting zone parts
nasal cavity, nasal conchae, pharynx, larynx, trachea, carnia
nasal conchae
increase mucosal surface which provides more mucous interaction with turbulent air and traps more dust particles
olfactory mucosa
lines superior region of the nasal cavity where olfactory receptors are located
respiratory mucosa
lines the rest of nasal cavity
epithelium of respiratory mucosa
pseudostratified columnar epithelium with scattred goblet cells
epithelia
ciliated and cause waves of mucos toward throat for swallowing
if the cilia is cold
the nose drips
if nose becomes red
blood vessel engorge with blood to warm air
paranasal sinus
surround nasal cavity and warms and moistens air to produce mucus that drains into nasal cavity
parts of the nasal cavity
nasal conchane, olfactory mucosa, respiratory mucosa, epithelelia
pharynx
connects the nasal cavity to the larynx and esophagus, 5”
3 divisions of the pharynx
nasopharynx, oropharynx, laryngopharynx
nasopharynx
posterior to nasal cavity, only an airway lined with ciliated pseudostratified epithelium, tonsils and closed off during swallowing
oropharynx
posterior to oral cavity, both food and air so stratified squamous
larygopharynx
posterior to epiglottis, continous with esophagus, both food and air so stratified squamous
larynx
attached to hyoid, on top of trachea, behind laryngeal prominence, epithelium is ciliated pseudostratified
functions of larynx
open airway, ensures air and food go into correct channels and voice production
voice production
vocal folds are elastic fibers that make sound when air rushes over them
higher pitch
shorter vocal folds, vibrate faster
lower pitch
longer vocal folds, vibrate slower
valsalva’s maneuver
vocal folds act as sphincter and close off trachea, occurs when we cough, sneeze, gag, vomit
process of valsalvas manuever
glottis closes-abdominal muscles contract-pressure rises
Trachea
decends into mediatimun dividing into two bronchi
walls of trachea
mucosa, submucosa, adventita
mucosa
pseudostratfied ciliated epithelia with goblet cells, cilia propel debreis
submucosa
CT, lots of serous and mucos glands
Adventita
CT, reinforced by hyaline cartilage, stretches during inhalation, recoils during exhalation
carnia
last piece of tracheal cartilage before it splits
right main bronchus is ___ than the left
shorter and wider
how does the bronchus divide
into secondary broncus-tertiary bronchi-bronchioles
as bronchi get smaller
cartilage disappears, epithelium becomes cuboidal, mucous production decreases
Respiratory zone
begins where terminal bronchioles feed into respiratory bronchioles to aveolar ducts to aveolar sacs to aveoli
aveoli
type 1 and 2 cells, pores, macrophages
external surface of aveoli
covered by capallaries and elastic fibers
type 1 cells
single layered squamous epithelial cells
type 2 cells
cuboidal cells, secrete surfacant onto epithelium
surfactant
interupts polar force of H2O that coats aveolar walls to decrease surface tension
aveolar pores
equalize air pressure
macrophages
crawl freely on surface to keep aveoli sterile
Respiratory membrane
aveolar membrane and basal lamina and capillary membrane
apex of lung
beneath clavicle
base of lung
sits on diaphragm
hilum of lung
medial surface through which blood vessels, lymphatic, and nerves, bronchi enter and exit
Segments of right lung
10
segments of left lung
8-10
what serves each segment
tertiary bronchus, pulmonary art and vein, bronchial artery, nerves, lymphatic vessel
what sections each lung
CT into pyramid shaped bronchopulmonary segments
CT walls help..
confine spread or disease
lung lobules
smallest visile subdivision
stroma
rest of lung tissue, mainly elastic CT
blood supply of lungs
pulmonary, bronchial
pulmonary circulation
deoxygenated blood for oxygenation in pulmonary capillaries, returns via pulmonary veins
pressure and volume in pulmonary
low pressure, high volume
bronchial circulation
provides oxygenated blood to lung tissue except aveoli
steps of bronchial circulation
bronchial arteries branch from aorta, enter hilum, and run along bronchi to deliver oxygenated blood to lung tissue
what returns bronchial blood to heart
many anastomes between bronchial and pulmonary, blood returns to heart via pulmonary
nerve supply
afferent and efferent
afferent nerves
visceral sensory to the brain, pain
efferent nerves
para, bronchial constriction
sym-bronchia dilation
pleurae
double layered serosa membrane, parietal and visceral, secrete fluid in cavity
parietal pleurae
covers thoracic wall
visceral pleura
covers lungs
pleurisy
lack of fluid in pleura
daltons law
the total pressure exerted by air is the sum of the pressures of each of the gasses in the air
pressure in the lunch
760 mm Hg
nitrogen pressure
597
oxygen pressure
159
CO2 pressure
0.3 mm Hg
H2O pressure
3.7 mm Hg
intraoulmonary pressure
pressure in the alveoli, flucuates
intrapleural pressure
pressure in the pleura pressure, always negative
why is intrapleural pressure negative
because the pleural cavity is sealed but the two serosal membranes are trying to seperate from each other
Ventilating the lungs
when the volume of the air in thoracic cavity changes
pressure___ when you inhale, pressure ___ when you exhale
decrease, increases
boyle’s law
PV=PV
as pressure decreases, volume increases
as pressure increases, volume decreases
inspiration
pressure in lung must decrease, therefore volume must increase
causes of volume of lunch increasing
diaphragm contracts and moves down and flattens, external intercostal muscles contract, lift ribs up
inspiration decreases ___ and ___
intrapulmonary and intrapleural
expiration
pressure in lungs must increase, therefore volume decreases
causes of volume decreasing
diaphragm relaxes and move upwards, external intercostal muscles relax
expiration increases ____ and ___
intrapulmonary and intrapleaural
factors influencing ventilation
airway resistance, aveolar tension forces, lung compliance
airway resistance
the wider the lumen, the lower the resistance
fisrt part of conducting zone resistance
bronchi has a wide lumen and extensive branching so the resistance is very low
medium sized bronchi
greatest resistance
smallest bronchi
diffusion is main driving force so resistance is not an issue
bronchoconstriction
para, gettting smaller
bronchodialation
sym, gettingbigger
aveolar tension forces
forces want to collapse the alveoli due to high surface tension of water which is reduced by surfacant
lung compliance
stretchiness, the ease which lungs can expand, reduce by fibrosis
respiratory voumes
tidal volume, inspiratory reserve, expiratory reserve, residual volume
tidal volume
volume of air inhaled then exhaled during quiet breathing, 500 ml
inspratory reserve volume
what you can inhale above 500
expiratory reserve volume
what you can blow out over 500
residual volume
what is always left inside your lungs
inspiratory capacity
volume of air inhaled after tidal
functional residual capacit
volume of air remaining in lungs after tidal exhalation
vital capacity
the volume of exchangeable air
total lung capacity
sum of all four
spirometer
can measure the rate at which air enters and exits the lung, show respirator function
forced vital capacity
measures how quickly the vital capacity can be expelled
forced expiratory capacity
the amount of air expelled during specific time intervales
minute ventilation
the amount of air that flows in and our of the respiratory system per minute
quiet breathing
500 ml/breath at 12 breaths/min
during vigrous exercise
200 l/min
alveolar ventilation rate
more accurate measurement takes into account the air that remains in the conducting zone
AVR equation
AVR= frequency X TV(dead space)
What do we inhale into the lungs
PO2=160
PCO2= 0.3
what goes into the alveoli
PO2= 104
PCO2= 40
Oxygen in lungs
O2 diffuses from alveoli into pulmonary capillaries, and returned to the heart
PO2 in alveoli
104 mm Hg
PO2 entering the capillaries
100 mm Hg
Carbon dioxide in the lungs
CO2 diffuses from the blood into the alveoli
PCO2 in the blood
45 mm Hg
PCO2 entering the alveoli
40mm Hg
Oxygen in the tissues
O2 diffuses from blood into the tissue cells, then blood leaves tissues to go back to alveoli
PO2 in arteries
100 mm Hg
PO2 blood leaves the tissues
less then 40 mm Hg
Carbon Dioxide in the tissues
CO2 diffuses from the tissues into the blood and is going back to the alveoli
PCO2 in the tissues
less then 45 mmHG
PCO2 leaving the tissues
45 mm Hg
ventilation
air flow
perfusion
blood flow
ventilation-perfusion coupling
ventilation-perfusion must be matched to ensure that the blood leaving the lungs fully oxygenated
low ventilation
low Po2 and high PCO2, terminal arterioles constrict and blood is redirected, bronchioels dilate to allow CO2 to be exhaled more easily
high ventilation
high PO2 and low PCO2, terminal arterioles dilate and increase blood flow; O2 goes into lungs easier and bronchiles constrict
oxyhemoglobin
O2 binds to hemoglobin
Deoxyhemoglobin
HHb is reduced hemoglobin, no O2
When PO2 is 104, how saturated is the HB?
100% saturated
what happens as blood flows through systemic capillaries?
the Hb drops 25% of O2
at 40 mmHg, what happens with Hb
first O2 is droped
what changes Hb affinity for O2?
temp, blood, pH, PCO2
when temp increases…what happens to Hb affinity
affinity decreases so O2 offloads before PO2 reaches 40 mmHg, curve shifts right
When temp decreases, what happens to Hb affinity?
When temp decreases, affinity increases so O2 offloads after 40 mmHg, curve shifts left
When PCO2 or pH is increased, what happens to Hb affinitiy?
affinity decreases, offloads before 40, curve shifts right
When PCO2 or pH is decreased, what happens to Hb affinitiy?
affinity increases, so offloads after 40, shifts left
3 ways of carbon dioxide transport
dissolved in plasma- 7-10%
bound to Hb-carbamino 20%
in plasma as bicarbonate-70%
equation of bicarbonate
CO2 + H2O <–> H2CO3 <—> H + HCO3
chloride shift
HCO3 diffuses out of RBC, so Cl replaces the negative charge in the plasma
enzyme of bicarbonate
carbonic anhydrase
carbaminohemoglobin
CO2 + Hb —-> HbCO2
Blood pH buffers
buffered by Hb or other proteins
what happens if H ions levels rise
ions will combine with HCO3 to make H2CO3, this removes H and normalizes pH
what happens if H levels drop
ions will be produced when H2CO3 dissociates into HCO3 + H
what effect does shallow breathing have
increased CO2–> increased H2CO3—> decreased pH of blood —> acidosis
acidosis
pH of 7.2
what effec does deep or rapid breathing have?
decreased CO2 —> decreased H2CO3 —> increased pH of blood—-> alkalosis
alkalosis
pH 7.6
Control of respiration
medullary respiratory centers, pontine, VRG and DRG
VRG
ventral respiratory group
when inspiratory neurons fire, the VRG,…
EPSP are sent along the phernic and intercostal nerves
external intercostal muscles and diaphragm contract
thorax explands
air moves in
when expiratory neurons fire the VRG…
IPSP along the phernic and intercostal nerves stop
External intercostals and diaphragm relax
thorax reduces in volume
air moves out
DRG
dorsal respiratory group, integrates input from stretch and chemo Rs and send to VRG
nromal respiratory rhythm
12-15 times/min
inhalation time
2 s
exhalation time
3 s
eupnea
normal rate and rhythm
apnea
not breathing
orthopnea
inability to breath lying down
cheyne-stokes breathing
abnormal breathing pattern just before death
VRG suppressants
sleeping pills, morphine, alcohol
Pontine Respiratory centers
pons, modify the acticity of medullary neurons, smooth out transition from inhalation to exhalation
what transmits pulses to VRG
Pontine respiratory group, fine tunes rhythm generated during vocalization, sleep, exercise
chemical factors
levels CO2, O2, H, detected by chemoreceptors
what is the most potent chemical for control of respiration?
CO2
hypercapnia
high levels of CO2
What happens if CO2 levels rise too high?
H2CO3 dissociates, H ions excite central chemo R in medulla, hyperventilation that flushes out excess CO2
how does PO2 influence breathing
indirectly by changing peripheral chemo R sensitiviity to PCO2
Herring-Breuer inflation reflex
protective mechanism that prevents excess stretching of lungs, when baroreceptors in visceral pleurae send impulses to medulla, inspiration is stopped
hypothalmic
emotion, pain, temp
cortical
exert conscious contol, cerebral motor neurons bypass medulla
chronic obstructive pulmonary disease
irrevisable dyspnea, coughing, respiratory acidosis and hypoxemia
emphysema
breakdown of alveolar walls
chronic bronchitis
distinguesd by excessive mucos production and inflamed bronchi
