Term
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Definition
| exchange of gases between the alveoli and pulmonary capillaries |
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Term
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Definition
| exchange of gases between the capillaries and the cells in the tissue |
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Term
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Definition
several layers of elastic tissue and capillaries that surrounds the thorax and lungs
contains pleural fluid
decrease friction between plueral membrane
holds lungs tight against thoracic wall and stretched in a partially inflated state |
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Term
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Definition
subatmospheric (-3mmHg)
prevents lung collapse because it exerts a negative force on the pleural membrane |
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Term
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Definition
oral&nasal cavity
pharynx
larynx
trachea
right and left bronchus
bronchi
bronchioles
alveoli |
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Term
| as move down the air pathway.... |
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Definition
increase in branching
decrease in diameter
cartilage replaced by smooth muscle
epithelium gets thinner
cilia replaced by macrophages
increase in total cross sectional area |
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Term
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Definition
psuedostratified ciliated columnar epithelium
cartilage-maintain open airway and can't collapse
cilia-move mucus & trapped particles to pharynx to be coughed ,sneezed, or swallowed
goblet cells produce mucus |
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Term
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Definition
simple cuboidal epithelium
smooth muscle-changes airway diameter, can collapse
no cilia |
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Term
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Definition
site of gas exchange
3 types of cells: macrophages, type 1 alveolar cells, type 2 alveolar cells
elastic fibers inbetween to create elastic recoil when lung tissue is stretched (smooth muscle would block rapid gas exchange) |
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Term
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Definition
simple squamous epithelium
gas exchange occurs |
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Term
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Definition
secrete surfactant-->
decrease surface tension of fluid within alveoli
keeps alveoli from collapsing
increase compliance (ability of lungs to stretch)
easier to inflate alveoli |
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Term
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Definition
decrease surface tension of fluid within alveoli (separates membrane to increase gas exchange)
keep alveoli from collapsing
makes it easier for the alveoli to inflate following exhalation
increase compliance (ability of the lungs to stretch) |
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Term
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Definition
alveolar wall (squamous epithelium)
capillary wall (endothelial)
with thin basement membranes for easy gas exchange |
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Term
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Definition
how easily the lungs can be stretched
affected by-->
elasticity of lung tissue and thoracic cage
surface tension of alveoli |
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Term
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Definition
poiselle's law R=(length x viscosity)/radius^4
length of system and viscosity of air usually constant
diameter of airway alters resistance
-decrease diameter=bronchoconstriction (parasympathetic or histamine)
-increase diameter=bronchodilation (sympathetic)
-physical obstruction such as mucus or other factors |
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Term
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Definition
gases move from areas of high P to low P
decrease in V=increase in P |
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Term
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Definition
movement of air between the atmosphere and the alveoli
gas movement based on changes in pressure and volume in thoracic cavity
involves inspiration and expiration |
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Term
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Definition
increase in atmospheric P
decrease in thoracic cavity P
contraction of muscles by somatic motor neurons
-diaphragm=lowers thoracic floor
-external intercostals=ribs up and out
air flows into lungs |
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Term
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Definition
contraction of additional muscles to increase thoracic volume/decrease thoracic pressure
-scalenes=ribs upward
-sternocleidomastoids=sternum upward |
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Term
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Definition
decrease atmosphere P
increase lung P
relaxation of inspiratory muscles
elastic recoil of lungs
decrease in thoracic volume/increase thoracic P
air flows out of lungs |
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Term
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Definition
contraction of additional muscles to decrease thoracic volume/increase thoracic pressure
-internal intercostals=ribs inward
-abdominal=ribcage inwards & abdominal organs upward |
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Term
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Definition
normal breathing volume
amt air moved during a single inspiration or expiration
average=500mL |
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Term
| inspiratory reserve volume |
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Definition
| additional volume of air that can be inhaled after a normal inspiration |
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Term
| expiratory reserve volume |
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Definition
| amount of air that can be forcefully exhaled after the end of a normal expiration |
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Term
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Definition
| amount of air left after maximum expiration |
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Term
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Definition
maximum amount of air that can be moved into and out in one breath
TV+IRV+ERV |
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Term
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Definition
maximum amount of air that can be inspired
TV+IRV |
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Term
| functional residual capacity |
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Definition
amount of air left after normal breathing
TV+ERV |
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Term
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Definition
amount of air that can be held by the lungs
TV+IRV+ERV+RV |
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Term
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Definition
total amount of air that moves into and out lungs
PV=breathing rate (breaths/min) x tidal volume (mL/breath) |
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Term
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Definition
amount of fresh air that reaches the alveoli
not all inspired air reaches alveoli=dead space (150mL)
rate and depth of breathing affects AV
-deep breathing/slow breaths=increase in fresh air to alveoli and increase in AV
-shallow breathing/rapid breaths=decrease in fresh air to alveoli and decrease in AV (tidal volume is decreased)
*total pulmonary ventilation is not affected by changes in rate and depth of breathing. always stays the same.
* |
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Term
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Definition
based on partial pressure gradients of gases
solubility in plasma |
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Term
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Definition
alveoli PO2=100mmHg
arterial blood PO2=100mmHg
peripheral tissues PO2venous blood PO2=40mmHg |
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Term
| diffusion of carbon dioxide |
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Definition
peripheral tissues PCO2 >or equal to 46mmHg
venous blood PCO2=46mmHg
alveoli PCO2=40mmHg
arterial blood=40mmHg |
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Term
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Definition
2% dissolved in plasma
98% bound to hemoglobin-->oxyhemoglobin
occurs in arterial blood |
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Term
| oxygen-hemoglobin binding |
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Definition
depends on PO2 in plasma (dictate loading) and PO2 in cells (dictate unloading)
-increase O2 con.=O2 binds/loading
-decrease O2 con.=O2 released/unloading
%saturation of hemoglobin=amt of O2 bound to hemoglobin at a given PO2
Ex: (2 oxygen bound/4max O2 can be bound)x100=50% saturated hemoglobin |
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Term
| oxygen-hemoglobin dissociation curve |
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Definition
x axis= resting cell PO2 mmHg
y axis= % hemoglobin saturation
less than 40mmHg=unloading
@40mmHg=75% saturation
-O2 reserve for cells that have increase in metabolism
>60mmHg=@ least 90% saturation
increase in exercise=increase in hemoglobin saturation because muscles need more oxygen to work |
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Term
| other factors that affect oxygen-hemoglobin binding: temperature |
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Definition
increase temperature=decrease O2 binding
occurs during increase in metabolism |
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Term
| other factors that affect oxygen-hemoglobin binding: PCO2 |
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Definition
increase in PCO2=decrease in O2 binding
occurs during increase in metabolism |
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Term
| other factors that affect oxygen-hemoglobin binding: 2,3-DPG |
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Definition
2,3-DPG increases in hypoxia conditions (high altitude, anemia, extended period of low oxygen)
increase in 2,3-DPG=decrease in O2 binding |
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Term
| other factors that affect oxygen-hemoglobin binding: pH |
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Definition
Bohr Effect
increase in pH=increase in O2 binding
occurs during increase in metabolism |
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Term
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Definition
7% dissolved in plasma
23% bound to hemoglobin-->carboxyhemoglobin
-binds to polypeptide chains
70% bicarbonate ion in plasma
-CO2+H2O+carbonic anhydrase enzyme in RBC <--> H2CO3 <--> H+ + HCO3-
occurs in venous blood |
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Term
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Definition
| Cl- ions enter red blood cells as HCO3- ion leaves to maintain the membrane potential |
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Term
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Definition
quaternary structure, complex protein
4 globular protein chains (2 alpha, 2 beta)
each chain has iron containing heme group
O2 binds to heme group
CO2 binds to protein chains
1 hemoglobin can bind 4 O2 |
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Term
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Definition
medulla and pons (brain stem)
-control basic rhythm of breathing
-forced breathing changes (influenced by other factors) --> emotions and voluntary control
-somatic motor neurons to inspiratory and expiratory muscles |
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Term
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Definition
central-medulla
peripheral-carotid artery and aorta |
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Term
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Definition
medulla
respond to changes in plasma PCO2 (increase)
increase in CO2 and H+ in cerebrospinal fluid stimulates medulla to increase ventilation to decrease PCO2 |
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Term
| peripheral chemoreceptors |
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Definition
carotid artery and aorta
respond to changes in arterial plasma PCO2, PO2, H+
-increase PCO2 and H+
-decrease in PO2 (<60mmHg)
results in increase in ventilation to decrease plasma PCO2 and increase plasma PO2 |
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Term
| irritant receptors in airways |
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Definition
detect inhaled particles or noxious gas
signal CNS to stimulate parasympathetic bronchoconstriction |
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Term
| hering-breur inflation reflex |
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Definition
prevents overinflation of lungs
if tidal volume exceeded normal volume, stretch receptors detect change
stretch receptors signal CNS-->brain stem stops inspiration |
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Term
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Definition
limited conscious control
cannot override chemoreceptor influence
chemoreceptors respond to increase PCO2 and decreased PO2 levels and cause the brain stem to override the cerebrum in the control of breathing and increase ventilation |
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Term
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Definition
| emotions may affect breathing rate and depth |
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Term
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Definition
warmed by body heat
humidify=water from mucosal lining evaporates into incoming air
cleanse=cilia, antibodies in mucus, macrophages filter out/kill foreign material so it does not reach alveoli |
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