respiratory system physiology (5b) Flashcards
what are the four events of respiration
pulmonary ventilation: breathing
external respiration: gas exchange in the lungs
internal respiration: gas exchange in the body
respiratory gas transport: gas transport via the bloodstream
what is boules law
P=1/V
what are the types of pressure in the respiratory system
intrapulmonary pressure: pressure inside alveoli
intrapleural pressure: pressure inside the pleural cavity
atmospheric pressure: pressure of the outside air
how is the intrapleural pressure related to the others
intrapleural pressure must always be lower than the others
what are the muscles involved in breathing
external intercostal muscles and diaphragm
do muscles contract or relax when breathing in
muscles contract when breathing in and relax when breathing out
breathing in causes the ribs to stretch laterally
breathing out causes the ribs to be pushed back in laterally
what is the mechanism of inhalation
requires energy
muscles contract
intrapulmonary volume increases
gas pressure decreases
air flows in until intrapulmonary pressure equals atmospheric pressure
what is the mechanism of exhalation
muscles relax
intrapulmonary volume decreases
gas pressure increases
gas flows out to equalize pressure
can expiration be caused by contracting muscles
yes forced expiration can be caused by contracting the muscles
occurs when bronchioles are obstructed
what is the relationship between lung volume and intrapulmonary pressure
as the lung volume increases the pressure decreases
what is atelectasis
when the intrapleural pressure equals atmospheric pressure
results in the collapse and recoil of the lungs
caused by air entering the pleural cavity (tear in pleura)
what are the terms associated with respiratory volumes and capacities
tidal volume
inspiratory reserve volume
expiratory reserve volume
residual volume
vital capacity
what is tidal volume
normal breathing
500 mL of air is moved in and out with each breath
what is inspiratory reserve volume
amount of air that can be taken in forcibly over tidal volume
what is expiratory reserve volume
amount of air that can be forcibly exhaled after tidal expiration
what is residual volume
air left in the lung after exhaling
can’t be exhale voluntarily
allows gas exchange to be continuous
what is vital capacity
total amount of exchangeable air
women: 3.1 L
men: 4.8 L
does coughing, sneezing, crying, laughing, yawning and hiccuping take energy
yes
where does external respiration occur
exchange occurs between alveoli and alveolar capillaries
where does internal respiration occur
exchange of gases between systemic capillaries and tissue cells
what is the formula for blood’s buffer system
HCO3^- + H^+ -> H2CO3 -> CO2 + H2O
HCO3- : bicarbonate ion
H2CO3: carbonic acid
how is oxygen transported in the blood
it travels attached to hemoglobin and forms oxyhemoglobin (HbO2)
what is CO2 transported in the blood as
as bicarbonate ions to prevent blood from becoming too acidic
small amounts are carried inside red blood cells (different binding sites than oxygen)
what is eupnea
normal respiratory rate (12-15 respiration/min)
what is hyperpnea and what causes it
increased respiratory rate
due to exercise
what is the pathway of neural breathing control
- stimulus: CO2 levels increase in blood = drop in CSF pH, O2 sensors in aorta senses drop in O2 levels
- afferent impulses are sent to the medulla oblongata through the vagus nerve and the glossopharyngeal nerve
- breathing control centers integrate: pons centers, medulla centers (VRG, DRG)
- efferent impulses are sent using the phrenic and intercostal nerves to trigger contractions in the diaphragm and intercostal muscles
characteristics of the VRG
ventral respiratory group
pacemaker, sets the rhythm of breathing
sends impulses to excite intercostal muscles and diaphragm
characteristics of the DRG
dorsal respiratory group
integrates information from stretch receptors and chemoreceptors and modifies the rhythm set by the VRG accordingly
characteristics of the pontine respiratory centers
transmits impulses to the VRG
fine tunes breathing rhythm during activities like singing, sleeping and exercise
what are central chemoreceptors in the brain stimulated by
by the concentration of H+ in CSF (high CO2=low pH=high H+)
what are peripheral chemoreceptors stimulated by
oxygen and H+ levels in the blood
what are peripheral chemoreceptors in active muscles stimulated by
H+ from lactic acid
what other factors affect the respiratory depth and rate
increased body temperature
exercise
talking
coughing
conscious control
emotions (hypothalamus can override the breathing centers)
what is the result of blood acidosis
low pH = high CO2
hyperventilation (deep and rapid breathing) so more CO2 is lost than produced
what is the result of blood alkalosis
pH high = low CO2
hypoventilation (shallow and slow breathing) to have more CO2 produced than lost
