Respiratory System 3 Flashcards
Gas Laws
Gas Laws
Principles that govern movement/diffusion of gas molecules
Boyle’s Law
Gas Laws
Pressure/Volume have an Inverse relationship. Determines air direction during pulmonary ventilation
Partial Pressure
Gas Laws
Pressure exerted by single gas in mixture
Dalton’s Law
Gas Laws
All partial pressures of gases together equal total pressure exerted by gas mixture
Henry’s Law
Gas Laws
At a given temperature, amount of particular gas in solution is directly proportional to partial pressure of that gas above liquid
Po2/Pco2 levels in pulmonary capillaries
External Respiration
Higher Pco2 and lower Po2 than alveolar air
Po2/Pco2 levels during diffusion
External Respiration
Po2 increases and Pco2 decreases
Po2 levels of blood leaving lungs
Internal Respiration
Drops slightly when mixing with capillary blood. Still higher Po2 than IF
Pco2 levels in blood
Internal Respiration
Pco2 levels are higher in IF/tissues than blood
Each 100ml of blood leaving alveoli carries how much oxygen?
Gas Transport in Blood
20 ml
What happens to 20ml of oxygen per 100ml of blood leaving alveoli
Gas Transport in Blood
0.3ml dissolved in plasma and 19.7ml bound to heme units of hemoglobin
Heme unit
Gas Transport in Blood
Contained in the 4 globular proteins of each hemoglobin molecule
Oxyhemoglobin
Gas Transport in Blood
Binding of four oxygen molecules to a hemoglobin molecule
Why carbon monoxide dangerous
Gas Transport in Blood
Can bind to heme units making them unavailable for O2 transport
Hemoglobin saturation
Gas Transport in Blood
Percent of heme units containing bound oxygen at any moment
Oxygen-hemoglobin saturation curve
Gas Transport in Blood
Graph showing hemoglobin saturation at different partial pressures of oxygen
Hemoglobin >90% saturated at what mm Hg
The Oxygen-Hemoglobin Saturation Curve
60 mm hg
Hemoglobin entering systemic circuit is what % saturated
The Oxygen-Hemoglobin Saturation Curve
~97% (95mm hg)
Hemoglobin leaving body tissues is what % saturated
The Oxygen-Hemoglobin Saturation Curve
~75% (40mm hg)
Hemoglobin in blood of active muscle is what % saturated
The Oxygen-Hemoglobin Saturation Curve
~20% (15-20mm hg)
Shift in the curve represents
The Oxygen-Hemoglobin Saturation Curve
Change in affinity for O2 (affinity - how strongly O2 binds)
Shift to the right means
The Oxygen-Hemoglobin Saturation Curve
Oxygen being released more easily from hemoglobin
Shift to the left means
The Oxygen-Hemoglobin Saturation Curve
Oxygen is more tightly bound to hemoglobin
Four things that shift oxygen-hemoglobin saturation curve
The Oxygen-Hemoglobin Saturation Curve
pH changes, temperature changes, changes in partial pressure of CO2, changes in concentration of 2, 3-biphosphoglycerate
Bohr Effect
The Oxygen-Hemoglobin Saturation Curve
Blood pH directly affects hemoglobin saturation
pH decreases
The Oxygen-Hemoglobin Saturation Curve
Saturation curve shifts right
pH increases
The Oxygen-Hemoglobin Saturation Curve
saturation curve shifts to the left
Higher temperature leads to
The Oxygen-Hemoglobin Saturation Curve
hemoglobin release oxygen more easily
Increase Pco2 leads to
The Oxygen-Hemoglobin Saturation Curve
Curve shifting to the right
Byproduct of glycosis
The Oxygen-Hemoglobin Saturation Curve
2, 3-biphosphoglycerate (BPG)
How BPG is made
The Oxygen-Hemoglobin Saturation Curve
RBC’s
BPG in low oxygen areas
The Oxygen-Hemoglobin Saturation Curve
Builds up
BPG can bind deoxyhemoglobin and cause
The Oxygen-Hemoglobin Saturation Curve
O2 from binding to hemoglobin
Fetal hemoglobin affinity for O2
The Oxygen-Hemoglobin Saturation Curve
Higher than adult, can pull more oxygen from mother
Carbon Monoxide affinity for hemoglobin
The Oxygen-Hemoglobin Saturation Curve
Higher than oxygen, can reduce O2 carrying capacity and lead to hypoxia/ monoxide poisoning
Carbon dioxide is generated where and how
Carbon Dioxide Transport
Peripheral tissues by aerobic mechanism
Where carbon dioxide removed
Carbon Dioxide Transport
Lungs
Three ways carbon dioxide transported in blood
Carbon Dioxide Transport
Dissolved in plasma, bound to hemoglobin, converted to bicarbonate
Carbonic anhydrase
Carbon Dioxide Transport
Causes conversion of carbon dioxide to carbonic acid
Carbonic acid dissociates into
Carbon Dioxide Transport
bicarbonate and hydrogen ions
HbH+
Carbon Dioxide Transport
Hydrogen ions binded to Hb and maintain ph
Chloride shift
Carbon Dioxide Transport
Bicarbonate ions leave cell in exchange for chloride ion
Haldane effect
Carbon Dioxide Transport
Deoxygenation of blood increase CO2 carrying ability
Medulla
Respiratory Center
Contains main components for automatic respiration
Pons
Respiratory Center
modifies spontaneous rhythmic discharge of medullary neuron
Medulla Oblongata
Respiratory Center
Contains pacemaker cells which generate contraction cycles of diaphragm
Medullary Respiratory Center contains two rhythmicity centers
Respiratory Center
Dorsal respiratory group, Ventral Respiratory group
Dorsal Respiratory Group
Respiratory Center
Mainly concerned with inspiration
Inspiratory Center of DRG
Respiratory Center
Controls lower motor neurons to primary inspiratory muscles
Ventral Respiratory Group
Respiratory Center
Associated with forced breathing
Pre-potzinger complex
Respiratory Center
Rhythm maker sending input to DRG
Pontine Respiratory Group
Respiratory Center
Transmit nerve impulses to DRG
Pontine Respiratory Group contains which two paired nuclei?
Respiratory Center
Apneustic centers, Pneumotaxic centers
Where are the Apneustic centers and Pneumotaxic centers located
Respiratory Center
pons
Apneustic Centers
Respiratory Center
Promote inhalation by stimulating DRG
Pneumotaxic Centers
Respiratory Center
Inhibit apneustic centers by promoting passive or active exhalation
Cerebral Cortex
Regulation of Respiratory Centers
Voluntarily changes or stops breathing to keep out gases or water
Chemoreceptors
Regulation of Respiratory Centers
Detect chemical changes in blood/csf
Most important factor influencing respiration
Regulation of Respiratory Centers
Pco2
Central Chemoreceptors
Regulation of Respiratory Centers
Located in medulla oblongata Monitor Pco2 and H+ in CSF
Peripheral Chemoreceptors locations
Regulation of Respiratory Centers
Aortic bodies, carotid bodies
Hypercapnia
Regulation of Respiratory Centers
Slight increase in Pco2 - Activates DRG and hyperventilation occurs to expel excess co2
Hypocapnia
Regulation of Respiratory Centers
Decrease in Pco2 - DRG sets its own pace until CO2 accumulates
Hypocapnia common cause
Regulation of Respiratory Centers
hyperventilation
Chemoreceptors decrease in Po2
Regulation of Respiratory Centers
peripheral receptors activate, DRG activates to bring in more O2
Baroreceptors
Regulation of Respiratory Centers
Detect lung expansion in walls of bronchi and bronchioles
Hering-Breuer reflex
Regulation of Respiratory Centers
Baroreceptors activate when Tidal volume > 1500ml. Send inhibitory signal to DRG through vagus nerve
Proprioceptors
Regulation of Respiratory Centers
Ventilation increases even before need for O2 increases
Respiratory Rate
Variations in Ventilation
number of breaths per minute (normal adult 12-18)
Respiratory minute volume
Variations in Ventilation
Volume of air moved per minute
O2 diffusing capacity increased 3x that as rate of rest due to
Respiration in Exercise
more pulmonary capillaries maximally perfused
Abrupt breathing increase due to which 3 neural changes
Proprioception, limbic anticipation, primary motor complex
Gradual increase in breathing with moderate exercise due to which chemical/physical changes
Decreased Po2, Increase Pco2, increased temperature