Chapter 18 Respiratory System Part 3 Flashcards
Which of the following statements is true?
A. During inhalation, the thoracic cavity gets smaller
B. During exhalation the thoracic cavity gets bigger
C. During inhalation, the thoracic cavity gets bigger
D. During inhalation, the thoracic cavity stay the same
C. During inhalation, the thoracic cavity gets bigger
A patient has a respiratory rate of 20 breaths/minute, tidal volume of 300mL and an estimated anatomic dead space of 100mL. What is her Va (alveolar ventilation)?
A. 4000mL
B. 8000mL
C. 400mL
D. 800mL
Va=(20(300-100))
Va=4000mL
A. 400mL
What is oxygen transport?
- Oxygen is transported by red blood cells
- Binds to the heme group of hemoglobin (~98.5%)
- Hemoglobin unloads oxygen when partial pressure of O2 in surrounding tissue is lower than blood
What is carbon dioxide transport?
- Carbon dioxide
- Waste produce from cellular respiration (synthesis of ATP)
- Transported in blood as carbonic acid and bicarbonate
- Relates to pH of blood (related to the concentration of H+)
- More Acidic - Higher Protons
- More Basic - Lower Protons
Carbonic Acid equation is reversible?
A. True
B. False
A. True
Hense the double arrows
What happens when carbon dioxide becomes to high or low?
- In situations where carbon dioxide becomes too high, the equation proceeds to the right
- Produces hydrogen ions, lowers pH
- Called hypercapnia (too much carbon dioxide) and results in….
- Acidosis (acidic blood), Less than 7.35
- In situations where carbon dioxide is too low, the equation proceeds to the left
- Decreases hydrogen ions, raises pH
- Called hypocapnia (too little carbon dioxide) and results in…
- Alkalosis (basic blood), greater than 7.45
- OXYGEN AND CARBON DIOXIDE CONCENTRATIONS CAN ALTER RESPIRATORY RATE
What do you do to get rid of carbon dioxide from the blood stream?
Exhalation
How is respiratory rate controlled?
- Afferent, interneurons and efferent neurons
- Afferent neurons supply sensory input
- Interneurons integrate sensory input at respiratory centers in brain
- Located in the pons and medulla (four different centers that work together)
- Work together to set the pace of respiration (involuntary)
- Efferent neurons cause a response
- Altered respiratory rate
- These neurons are visceral motor
Visceral - organs of the chest (heart, blood vessles, lungs, digestive organs, bladder)
Somatic - skin, muscles, bones, joints
Motor - voluntary movement (muscle contractions)
Sensory - sends information
Visceral - organs of the chest (heart, blood vessles, lungs, digestive organs, bladder)
Somatic - skin, muscles, bones, joints
Motor - voluntary movement (muscle contractions)
Sensory - sends information
What do afferent neurons include?
- Higher brain centers (cortex)
- Emotions (eg. anxiety)
- Conscious control
- Stretch receptors in lungs
- Prevent over inflation of lungs
- Irritant receptors in lungs
- Tell brain to increase respiratory rate to get irritants out!
- Proprioceptors
- Tell brain to increase respiratory rate to remove CO2 during high muscle activity (CO2 is a waste from muscle activity)
- Chemoreceptors
- Detect oxygen (peripheral) or CO(central) of blood
- Alters respiratory rate to maintain oxygen levels and pH
What are the two different chemoreceptors for afferent neurons?
- Central chemoreceptors
- Monitor CO2 levels and pH\
- When CO2 levels rise (pH lowers) they increase action potentials
- Peripheral chemoreceptors
- Monitor O2
- When levels drop, they increase action potentials
Where are the interneuron and efferent neurons located and what are they
What are two different neurons that are located in the brain centers
- Inspiratory Neurons
- Used in “quiet” or normal breathing
- Interneurons synapse with motor neurons of skeletal muscles
- Cause contraction of diaphragm and rib muscles inhalation
- Exhalation is passive
- More action potentials per time from interneurons in brain center increases respiratory rate (altered by sensory input)
- Expiratory Neurons
- Used in “forced” or active breathing
- Interneurons synapse with motor neurons of skeletal muscles
- Cause contraction of accessory rib muscles and abs forcing exhalation
- Rhythm is created between inspiratory and expiratory during forced breathing (one type is sending action potential, other is at rest)
What are the effecs of carbon dioxide?
- Imagine a situation where carbon dioxide increases in the bloodstream
- Ex. Intense exercise produces more waste (CO2)
- Blood becomes acidic.
- High levels of carbon dioxide hypercapnia
- Blood will become more acidic respiratory acidosis
- Central chemoreceptors increase action potentials
- Cause interneurons to increases respiratory rate
- Removing excess CO2 pushes reaction back to the left CO2 (expired) + H2O H2CO3 HCO3- + H+
- Reduces blood carbon dioxide levels
What are the effects of hydrogen?
- Imagine a situation where carbon dioxide decreases in the bloodstream (hyperventilation)
- This will cause the equation to shift to the left
- Low levels of carbon dioxide hypocapnia
- Blood will become more alkaline respiratory alkalosis
- Chemoreceptors decrease rate of action potentials
- Decrease respiratory rate by interneurons
- Cause CO2 to build up and pushes reaction back to the right
- Reduces blood alkalinity
What do cardiocascular centers include?
- Cardiovascular center includes cardiac and vasomotor
- Cardiac centers
- Proprioceptors
- Baroreceptors
- Chemoreceptors
- Vasomotor center
- Baroreceptors
- Chemoreceptors
*Blue dots represent chemoreceptors
Blood has to get to the lungs to unload carbon dioxide. Logically, what should happen when this waste builds up in the blood?
A. Slow the movement of blood through body
B. Speed the movement of blood through body
C. Not change movement
B. Speed the movement of blood through body
- When pH of the blood becomes too acidic, chemoreceptor cells increase the rate of action potentials to brain
- Vasomotor and cardiac centers increase sympathetic action
- Vasoconstriction, increase in heart rate
