Respiratory System Flashcards
what are the functions of the respiratory system?
exchange O2 and CO2 b/w environment, blood, and tissues
what is ventilation?
inspiration/expiration
exchange nutrients at capillary level
what is external respiration/gas exchange?
CO2 and O2 b/w lungs and blood
blood and lungs
what is internal respiration/gas exchange?
CO2 and O2 b/w systemic blood and tissues
blood and tissues
what structures are in the upper respiratory system?
nose, larynx, and pharynx
what structures are in the lower respiratory system?
below and including Carina (last ring of trachea b4 bifurcation into 2 main bronchi)
when is the epiglottis up/down?
up at rest, down when swallowing
histology of the trachea mucosa
ciliated pseudostratified epithelium w/goblet cells
histology of the trachea submucosa
connective tissue w/seromucus glands
histology of the trachea adventitia
outermost connective tissue
what makes up the conducting zone? what is the job of the conducting zone?
trachea–> primary bronchi–> bronchi–> bronchioles
ventilation: air in and out
is the right or left bronchi wider and shorter?
right
what makes up the respiration zone? what is it’s role?
begins where terminal bronchioles feed into respiratory bronchioles to alveolar ducts to sacs
respiration-gas exchange
what do the alveoli secrete and what is its role?
surfactant which keeps the sacs open
how many lobes does the left lung have
2 with the heart in the cardiac notch
how many lobes does the right lung have?
3
pulmonary circulation
pulmonary arteries deliver blood from heart to lungs for oxygenation
pulmonary veins carry oxygenated blood to the heart
pulmonary circulation is a ___ pressure, ___ volume system:
low, high
systemic circulation is ___ pressure:
high
bronchial circulation
oxygenated blood to lungs
sympathetic function in the respiratory system
bronchodilation
parasympathetic function in the respiratory system
bronchoconstriction
what is intrapleural pressure?
negative pressure inside- cavity acts like a suction to keep the lungs from collapsing
what is intrapulmonary pressure?
pressure in alveoli sacs
what is transpulmonary pressure?
difference b/w intrapulmonary pressure and intrapleural pressure
what is atelectasis?
plugged bronchioles collapse alveoli
what is a pneumothorax?
air in the pleural cavity
pulmonary ventilation depends on what?
volume changes that lead to pressure changes which lead to gas flow
what is Boyle’s law?
relationship b/w pressure and volume of gas
constant gas+smaller container=increased pressure
inspiration
active-uses muscles
diaphragm contracts down and out
intercostals contract ribs up and out
external intercostals for deep breaths
increased thoracic volume
expiration
quiet=passive
volume decreases
pulmonary pressure > atomospheric pressure=air out
forced=active using obliques and transverse muscles and intercostals
what is lung compliance
stiffness of the lungs
lung compliance in restrictive diseases
low compliance (more energy needed to breathe)
lung compliance in obstructive diseases
high compliance
volume
single
capacity
volumes added together
what is inspiratory reserve?
air forcefully exhaled
what is tidal volume?
resting
about 500 mL
what makes up inspiratory capacity?
inspiratory reserve and tidal volume
what is expiratory reserve volume?
big exhale
what is residual volume?
air that is always left in the lungs even after expiration
what makes up functional residual capacity?
expiratory reserve volume and residual volume
what makes up vital capacity?
inspiratory reserve, tidal volume, and expiratory reserve
what makes up the total lungs volume?
inspiratory reserve, tidal volume, expiratory reserve, and residual volume
what is anatomical dead space?
no contribution to gas exchange
increased TLC, FRC, and RV
COPD
decreased TLC, VC, FRC, and RV
restrictive disease
what is FEV1?
amount of air expelled in 1st second
reduced in COPD
what is a better indication of effective ventilation?
alveolar ventilation rate (AVR): gas in/out of alveoli at a specific time
what is Dalton’s law of partial pressures?
total pressure=sum of pressures of each gas
is the pressure gradient more steep for O2 or CO2? why?
O2 bc CO2 is 10x more soluble in plasma and alveolar fluid than O2
what is perfusion-ventilation coupling?
perfusion:
- blood flow reaching alveoli
- controlled by PO2-arterial diameter
ventilation:
- amount of gas reaching the alveoli
- controlled by PCO2-bronchiole diameter
tissue PO2 is always ___ than arterial PO2 so O2 moves from ____ to ____
lower; blood; tissues
tissue PCO2 is always ____ than arterial PCO2 so CO2 moves from ____ to ____
higher; tissues; blood
oxygen transport
1.5% dissolved in plasma
98.5% loosely bound to hemoglobin in RBCs
oxygen transport with hemoglobin
each hemoglobin has 4 polypeptide chains each w/1 ion containing heme group
hemoglobin can transport 4 O2 molecules
loading and unloading of )2 changes Hg shape
O2 binds and changes the shape to increase affinity
factors influencing hemoglobin saturation
PO2, temp, blood pH, PCO2, BPG (causes O2 release)
what is the oxyhemoglobin dissociation curve?
shows the relationship b/w how much hemoglobin is saturated w/O2 versus how much O2 is dissolved in fluid around hemoglobin
arterial blood
PO2=100mmHg
20 mL O2 per 100 mL blood
98% saturated
increased PO2
venous blood
75% saturated
PO2=40 mmHg
15% volume O2
right shift in oxyhemoglobin dissociation curve
enhanced O2 unloading
decreased O2 affinity
increased temp, H+, PCO2, and BPG
Bohr effect
decreased pH
exercise
left shift in oxyhemoglobin dissociation curve
decreased factors
increased O2 affinity
decreased O2 unloading (holds onto O2)
life sustaining
when BPG increased, oxygen…
decreased
Hg concentration in men
13-18 g/dL
Hg concentration in women
12-16 g/dL
CO2 transport
7-10% dissolved in plasma
20% chemically bound to Hg
70% as bicarbonate ion in plasma
CO2 transport: as bicarbonate ion in plasma
O2 and H2O=carbonic acid
quickly dissociates into bicarbonate and H+ (releases CO2 and H2O)
in lungs anhydrase splits carbonic acid
what is the relationship b/w CO2 and pH?
increased CO2=decreased pH
decreased CO2=increased pH
what is the Haldane effect?
amount of CO2 transported is affected by PO2
decreased PO2 and O2 saturation=increased CO2 can be carried in the blood
encourages in CO2 exchange
CO2 enters blood, increased O2 dissociation from Hg (Bohr effect)
slow shallow breaths lead to ___ CO2 and ___ pH
increased; decreased
rapid deep breaths lead to ___CO2 and ___pH
decreased; increased
carbon monoxide poisoning
Hg has 200x affinity for CO than O2
what are the controls of respiration?
higher brain centers
respiratory centers
COs
O2
what are the higher brain centers that control respiration?
pons and medulla
what affects respiratory centers?
chemical factors-PCO2, PO2, pH
higher brain centers
pulmonary irritant reflex
inflation reflex
what is the influence of CO2 on respiration?
most potent and closely controlled
what is the influence of O2 on respiration?
declining O2 may only have a slight affect on ventilation bc of large O2 reservoir bound to Hg (need to have significant drop to see effects)
when PO2 drops below 60 mmHg it becomes a major stimulus for respiration
hyperventilation leads to ___CO2
decreased
treat by breathing into paper bag to reinhale CO2
