Breathing control Flashcards
What generates rhythm breathing?
Pre-Botzinger complex
Pacemaker cells in superior ventral respiratory group
What adjusts inspiration and increases breathing intensity?
Pneumotaxic centre
Inhibit apneustic centre- allow expiration
What does increased innervation of pneumotaxic area lead to?
Shallower ventilation
Increased frequency
Inhibit apneustic centre allow expiration
What is the function of dorsal respiratory group? (where situated)
Medulla
Inspiratory neurones- stimulate diaphragm and externa intercostals
Where are the neurones that stimulate diaphragm and external intercostals located?
Dorsal respiratory group
Medulla
What is responsible for forced inspiration and expiration?
Ventral respiratory group
Stimulate accessory musccles of ventilation
Inhibit apneustic centre
What is responsible for inspiration? Apneustic center stimulates DRG (inspiratory center) and causes inspiration (Apneusis = Prolonged inspiratory gasps). Pneumotaxic center (Nucleus parabrachialis and Kolliker fuse nucleus) and CN 10 inhibit Apneustic center to limit inspiration (volume) and increase the rate of respiration
Apneustic centre
What is responsible for increasing rate respiration and limit inspiration?
Pneumotaxic centre and C10
Inhibit apneustic centre- limit inspiration
- increase rate respiration
What nerves control respiratory groups?
CN IX and X
What else can respiratory rates?
Opiods- depress respiratory drive
Amphetimines- stimulate
What is valie minute/ventilation?
7.5L/min
Large resp reserve- increase 30L/min
What are three types of pulmonary recerptors and function?
Slowly adapting- smooth muscle, inhibit inspiration response
stretch
Rapidly adapting- respond change volume, irritants, deep
breathing
Juxtapulmonary- respond irritants, IF
What stimulates deep breathing/coughing?
Rapidly adapting stretch receptors
What effect do juxtapulmonary receptors have?
Respond irritants
Broncoconstriction
Rapid, shallow breathing
Reduced CO
Where are chemoreceptors found?
Bifurcation carotid arteries
Aortic arch
Pontomedullary junction brainstem
What are two types of chemoreceptors?
Central and peripheral
What do central receptors respond to?
How?
High CO2 in cells, H+ can’t cross BBB
CO2 moves combine water form carbonic
Dissociates H+
High H+ stimulates pneumotaxic centre
Stimulates Dorsal Respiratory Group
Increase freq action potentials
Increase ventilation
Decrease CO2
What is high and low pressure CO2 called?
Low- hypocapnia
High- hypercapnia
What drive respiration?
CO2
What do peripheral chemoreceptors respond to?
Main pO2
pH
pCO2
What lvl will peripheral chemoreceptors respond highly at to O2?
Below 60mmHg
What causes changes pH detected by peripheral chemoreceptors?
Metabolic acids- ketones
What do decrease O2 lvls below 60mmHg cause?
O2 low
Type 1 Glomus cell- close K+ channels
High H+ (high CO2) inhibit K+
Potassium accumulate cell
Cell more positive- activate calcium channels
Calcium into cell- dopamine release
Dopamine act nerve terminals
Connected to aortic (CN10) and carotid (CN9)
Increased breathing
What cranial nerves innervate aortic and carotid body?
Aortic- CN10
Carotid- CN9
What does prolonged hypoxia cause?
Type 2 sustentacular cells differentiate type 1
Increase AP firing
Stimulate ventilation
What does prolonged hypoxia cause?
Type 2 sustentacular cells differentiate type 1
Increase AP firing
Stimulate ventilation
Anatomy resp
Anatomy resp
