Packet 8 - Circulatory Function Part 2 (4) Flashcards
II Mechanics of breathing
Gas Exchange
Transport of oxygen/carbon dioxide across alveolar capillary membrane. Influenced by partial pressure of the gas, surface area, and thickness of membrane.
a. ) Ventilation
b. ) Perfusion
c. ) Diffusion
c.) Diffusion
Transport of oxygen/carbon dioxide across alveolar capillary membrane. Influenced by partial pressure of the gas, surface area, and thickness of membrane.
Gas Exchange
Move venous blood through pulmonary capillaries adjacent to alveoli.
a. ) Ventilation
b. ) Perfusion
c. ) Diffusion
b.) Perfusion
Move venous blood through pulmonary capillaries adjacent to alveoli.
Gas Exchange
Movement of air into and out of alveoli.
a. ) Ventilation
b. ) Perfusion
c. ) Diffusion
a.) Ventilation
Movement of air into and out of alveoli.
Occurs when areas of the lungs are perfused, but not ventilated. Blood is being pushed from the venous circulation to the arterial circulation without it being oxygenated first.
a. ) dead air space
b. ) shunt
b.) shunt
Blood is being shunted from the venous circulation to the arterial circulation without it being oxygenated first.
P/C factors: collapse of alveoli; airway obstruction; decrease in chest expansion; depression of respiratory center
blood, no oxygen
Occurs when areas of the lungs are ventilated, but not perfused. Blood is occluded/blocked, but air is present. Since there is no blood, gas exchange does not occur.
a. ) dead air space
b. ) shunt
a.) dead air space
Occurs when areas of the lungs are ventilated, but not perfused. Blood is occluded/blocked, but air is present. Since there is no blood, gas exchange does not occur.
P/C factors: Thromboembolism (pulmonary embolism); severe vasoconstriction
oxygen, no blood
Diffusion
If there is a decrease in surface area, what happens to diffusion?
Decrease in surface area → decrease in diffusion
Diffusion
If there is an increase in surface area, what happens to diffusion?
increase in surface area → increase in diffusion
Diffusion
If there is an increase in the thickness of the membrane, what happens to diffusion?
increase in thickness of membrane → decrease in diffusion
Diffusion
If there is a decrease in the thickness of the membrane, what happens to diffusion?
decrease in thickness of membrane → increase in diffusion
Oxygen Transport
Oxygen is found in blood in two forms: in a dissolved state and in combination with hemoglobin in RBC. When oxygen is in its dissolved state, oxygen dissolves in plasma as it moves into and out of RBCs, and is represented by ______.
a. ) PaO2
b. ) SaO2
a.) PaO2
Dissolved state
oxygen dissolves in plasma as it moves into and out of RBCs, and is represented by PaO2
Only 1% of oxygen is in this state
Oxygen Transport
Oxygen is found in blood in two forms: in a dissolved state and in combination with hemoglobin in RBCs. When oxygen is found in combination with hemoglobin in RBCs, and it is represented by ______.
a. ) PaO2
b. ) SaO2
b.) SaO2
in combination with hemoglobin in RBCs
- 98-99% of oxygen is carried this way*
- Measures % of Hgb that is carrying oxygen*
Oxygen Transport
Oxygen bound to hemoglobin cannot be used in tissue metabolism, it must be released in order to be used.
When PO2 gets to _____ mm Hg, Hgb releases oxygen.
When PO2 gets to 60 mm Hg, Hgb releases oxygen.
Oxygen Transport
Oxygen bound to hemoglobin cannot be used in tissue metabolism, it must be released in order to be used.
A ______ occurs in conditions that favor oxygen binding.
(Hgb affinity for oxygen increases → PO2 has to drop lower to trigger oxygen release, occurs when tissues don’t need as much oxygen)
a. ) shift to the left
b. ) shift to the right
shift to the right
A shift to the right occurs in conditions that favor oxygen binding.
Hgb affinity for oxygen increases
PO2 has to drop lower to trigger oxygen release, occurs when tissues don’t need as much oxygen)
Oxygen Transport
Oxygen bound to hemoglobin cannot be used in tissue metabolism, it must be released in order to be used.
A ______ occurs in conditions that favor oxygen release.
(Hgb affinity for oxygen decreases → PO2 does not have to drop as low to trigger oxygen release, occurs when tissues need more oxygen)
a. ) shift to the left
b. ) shift to the right
shift to the left
A shift to the left occurs in conditions that favor oxygen release.
Hgb affinity for oxygen decreases
PO2 does not have to drop as low to trigger oxygen release, occurs when tissues need more oxygen
Regulation / Control of Breathing through nervous system
Controls the diameter of airways.
a. ) Respiratory Center
b. ) Autonomic Nervous System
Autonomic Nervous System
Controls the diameter of airways.
Two Components of ANS:
- ) Sympathetic Stimulation (fight or flight / bronchodilation)
- ) Parasympathetic Stimulation (bronchoconstriction)
Regulation / Control of Breathing through nervous system
Provides continuous input to muscles that control respiration.
a. ) Respiratory Center
b. ) Autonomic Nervous System
Respiratory Center
Provides continuous input to muscles that control respiration.
Located in pons and medulla.
Main control center
Two components of Respiratory Center:
- ) Automatic Regulation - chemoreceptors & lung receptors
- ) Volutary Regulation
Regulation / Control of Breathing through nervous system
The respiratory center is located in the pons and medulla (brain stem). Automatic regulation is controlled by chemoreceptors and lung receptors. ______ monitor blood levels of oxygen, carbon dioxide, and pH.
a. ) chemoreceptors
b. ) lung receptors
Chemoreceptors
monitor blood levels of oxygen, carbon dioxide, and pH.
Regulation / Control of Breathing through nervous system
The respiratory center is located in the pons and medulla (brain stem). Automatic regulation is controlled by chemoreceptors and lung receptors. ______ monitor changes in airway pressure/stretch, lung inflation, lung congestion, etc.
a. ) chemoreceptors
b. ) lung receptors
Lung Receptors
monitor changes in airway pressure/stretch, lung inflation, lung congestion, etc.
