Natalie - Control of Breathing Flashcards
What are the two aspects of respiratory control
Involuntary
Voluntary
Which control is used most of the time
Involuntary control used most often
Why is involuntary control used most open
Its most efficient way to breath
In general what happens when we exert conscious control
Breathing changes
What three things does voluntary control of respiratory rate depend on?
Conscious and unconscious thought
Emotional state
Anticipation
How does conscious and unconscious thought affect respiratory rate?
(2)
e.g. rage or fear
Affect respiratory rate by stimulating centres in the hypothalamus
How can emotional state affect respiratory rate
Depression can slow down RR
How can anticipation affect RR?
If anticipating strenuous exercise
This can cause automatic increase in RR, along with increased cardiac output by sympathetic stimulation
How much control do you have over voluntary breathing
Breathing cannot be consciously suppressed
Can only hold your breath until you lose consciousness then brain takes over
What are the central controllers of the brain
Pons
Medulla
Explain the pathway of control
(3)
Information from various sensors is fed to the central controller
The output of which goes to the respiratory muscles
By changing ventilation, the respiratory muscles reduce negative feedback of the sensors
What are the five receptors of the lung?
Chemoreceptors
Baroreceptors
Stretch receptors
Sensations
Physical or chemical stimuli
What are chemoreceptors
Receptors sensitive to the PCO2, pH or PO2 of the blood or cerebro-spinal fluid
What are baroreceptors
Receptors that detect changes in blood pressure in aortic or carotid sinuses
What are stretch receptors
Receptors that respond to changes in the volume of the lungs and prevent overstretch
How do sensations act as sensors
Sensations of pain, changes in body temperature or abnormal gut sensations
How do physical or chemical stimuli act as sensors
Physical or chemical stimuli in the nasal cavity, larynx or bronchial tree
What does the medulla oblongata do?
Sets pace of breathing
What centres are found in the medulla oblongata?
Respiratory rhythmicity centers
What does the pons do?
Controls breathing pattern (inhalation and exhalation)
What centres are found in the pons?
Apneustic and pneumotaxic centers