Respiratory System - Control Mechanisms
Control mechanisms – Local + CNS
Higher CNS centers (cerebral cortex, limbic system, hypothalamus)-> brain stem -> spinal cord -> respiratory system
To control respiration, what cells should you actually control?
-control skeletal muscles involves in inhalation and exhalation
These cells control respiratory minute volume – how do you control them?
-respiratory minute volume involves the freq. and volume of a respiratory cycle
-motor neurons control skeletal muscle
-both voluntary and involuntary control – from several CNS control centers
how do we know when control is needed/where do the signals originate?
-cognitive input via 5 senses (visual, auditory, olfactory, gustatory, touch)
-sensory input stimulates changes in the CNS control centers -chemoreceptors -baroreceptors -others
Control of respiration
-peripheral and alveolar capillaries maintain balance during gas diffusion bu: -changes in depth and rate of respiration -changes in blood flow and O delivery
-this requires excellent coordination between respiratory and cardiovascular systems
*ventilation (air flow) -> perfusion (blood flow) coupling
1. blood flow toward alveolar capillaries directed toward lung lobules where PO2 levels are relatively high (CO2 levels are low) -alveolar capillaries constrict when PO2 is low -blood is directed to area to pick up O2
2. smooth muscle cells in walls of bronchioles are sensitive to PCO2 -increased PCO2 causes bronchiodilation
-air flow directed toward lobules where PCO2 is high and CO2 is decreased (CO2 is bad)
-these lobules contain CO2 obtained from blood
(decreased PCO2 causes bronchioconstriction)
Local controls – respiratory and cardiovascular systems
-scenario: cells in interstitum are very active, so O2 is being used and PO2 decreases CO2 is being produces (PCO2 increases)
-O2 is good and CO2 is bad so you want to bring in O2 and remove CO2
-to bring in a gas, you open up the tube in which is
Higher CNS centers (cerebral cortex, limbic system, hypothalamus)-> brain stem -> spinal cord -> respiratory system
To control respiration, what cells should you actually control?
-control skeletal muscles involves in inhalation and exhalation
These cells control respiratory minute volume – how do you control them?
-respiratory minute volume involves the freq. and volume of a respiratory cycle
-motor neurons control skeletal muscle
-both voluntary and involuntary control – from several CNS control centers
how do we know when control is needed/where do the signals originate?
-cognitive input via 5 senses (visual, auditory, olfactory, gustatory, touch)
-sensory input stimulates changes in the CNS control centers -chemoreceptors -baroreceptors -others
Control of respiration
-peripheral and alveolar capillaries maintain balance during gas diffusion bu: -changes in depth and rate of respiration -changes in blood flow and O delivery
-this requires excellent coordination between respiratory and cardiovascular systems
*ventilation (air flow) -> perfusion (blood flow) coupling
1. blood flow toward alveolar capillaries directed toward lung lobules where PO2 levels are relatively high (CO2 levels are low) -alveolar capillaries constrict when PO2 is low -blood is directed to area to pick up O2
2. smooth muscle cells in walls of bronchioles are sensitive to PCO2 -increased PCO2 causes bronchiodilation
-air flow directed toward lobules where PCO2 is high and CO2 is decreased (CO2 is bad)
-these lobules contain CO2 obtained from blood
(decreased PCO2 causes bronchioconstriction)
Local controls – respiratory and cardiovascular systems
-scenario: cells in interstitum are very active, so O2 is being used and PO2 decreases CO2 is being produces (PCO2 increases)
-O2 is good and CO2 is bad so you want to bring in O2 and remove CO2
-to bring in a gas, you open up the tube in which is