Respiratory Systems (Part 3) Flashcards
What is ventilation?
breathing in air
What is the goal of ventilation?
- get air to the respiratory membranes
- must inflate the lungs
What are the two types of ventilation?
- positive pressure ventilation
- negative pressure ventilation
What is positve pressure ventilation?
push air to lungs
What is negative pressure ventilation?
pulling air to lungs
What type of ventilation do frogs use?
positive pressure breathing
How developed are frog lungs?
poorly developed
What is another way frogs do respiration since they ahve poorly developed lungs?
cutaneous respiration especially when submerged
What is frog body wall musculature like?
they have little body wall musculature
-very small ribs
Describe how frogs push air into lungs?
air pushed into lungs by action of floor of mouth and throat
What helps air flow back out in frogs?
elastic characteristics of lung tissue
How is positive pressure ventilation used in medical situations?
- during anesthesia or decreased brain stimulation (respiration is suppressed)
- when there is paralysis of breathing muscles
- when lung tissue injured or loses elasticity
What kind of ventilation do mammals, birds, and reptiles use?
negative pressure breathing
What happens to the rib cage during negative pressure breathing?
expansion of rib cage
Why does rib cage expand?
increase volume of body cavity housing the lungs which decreases pressure
How does air flow (in lungs, negative pressure breathing)?
from where there is greater pressure to where there is lower
What law describes air flow?
Boyle’s Law
What happens to lungs when air is pulled into them?
lungs inflate
What are the parts of the respiratory cycle?
- inhalation
- exhalation
What is inhalation also called?
inspiration
What is inhalation?
thoracic volume increases
For inhalation to occur, what is contracted?
external intercostal muscles and diaphragm (mammals only)
What does inhalation produce?
negative pressure which draws air into the lungs
What is exhalation also called?
expiration
What is exhalation?
thoracic volume devreases
What is relaxed in order for exhalation to occur?
intercostals and diaphragm (mammals only)
What happens to lungs after exhalation?
return to a less inflated state
What does exhalation do to air?
causes air to flow out
What does the diaphragm do?
separates the coelomic cavity into thoracic and abdominal cavities
How does respiration in birds occur?
in two cycles
What is the first cycle of bird respiration?
- first inhalation and exhalation
- inhaled air moves from trachea into posterior air sacs
- exhaled into the lungs
What is the second cycle of bird respiration?
- second inhalation and exhalation
- air moves from the lungs into anterior air sacs
- exhaled through the traches
Does air mix in bird respiration?
no mixing of “old” and “new” air
When is respiration more or less efficient at higher altitudes?
more
What does each hemoglobin have?
4 heme subunits
What does each heme have at its center?
an Fe (iron)
What can each Fe (iron) do?
reversibly bind to one oxygen molecule
Is oxygen binding to RBC reversable?
yes it reversibly binds
Gases can ____ and _____ between the lungs and circulatory system.
dissolve; diffuse
What occurs between alveoli and capillaries?
gas exchange
What does oxygen diffuse into?
red blood cells
What does carbon dioxide diffuse into?
alveolus
What determines how much oxygen the hemoglobin will carry?
its affinity for oxygen
What is hemoglobin’s affinity for oxygen determined by?
- PO2, where the blood happens to be
- lungs vs tissues
- carbon dioxide level
- blood pH
- body temperature
What happens if your blood pH drops?
oxygen is given up/released by hemoglobin more
What factors shift the curve to the right? (oxygen-hemoglobin dissociation)
- decrease in pH
- increase in temperature
- increase in PCO2
What is the Bohr effect?
describes hemoglobin’s lower affinity for oxygen secondary to increases in the partial pressure of carbon dioxide and/or decreased blood pH
