Control of lung function Flashcards
(32 cards)
What are the 4 groups/centres in the medulla that regulate breathing
- Dorsal respiratory group
- Ventral respiratory group
- Apneustic centre
- Pneumotaxic centre
What is the function of the dorsal respiratory group?
- Inspiratory centre
- Main controller of Inspiration
- Set the rate
What is the function and features of the Ventral respiratory group?
- Expiratory centre
- inactive during quiet breathing
- inhibit APNEUSTIC centre
What are the features and function of APNEUSTIC centre
- Stimulate activity in dorsal respiratory group
- Inhibited by pulmonary afferents
What are the features and function of the pneumotaxic centre
Inspiratory off switch
Regulates depth and frequency of breathing
How does the centres and groups interact with each other
DRG- inhibits VRG
Pneumotaxic centre- inhibits DRG
VRG- inhibits DRG and inhibits APNEUSTIC centre
Apneustic centre- stimulates DRG
Descirbe the innervation of the respiratory muscles
draw it
Diaphragm- phrenic nerve (C3,4,5)
intercostal nerves- intercostal muscles
pulmonary plexus- lungs
*learn the diagram*
Descirbe the capillary of the blood brain barrier; how is it different from other SIMILAR capillary
Continuous capillaries with TIGHT junction - charged/lipid molecules cannot pass Blood brain barrier
other continuous capillaries have water filled gap junction
Describe how the brain detects the amount of metabolism in th body
High metabolism- high respiration hence high CO2
CO2 is lipid soluble and easily crosses Blood Brain Barrier; into CSF
CO2 combines with H2O to make H+ and HCO3-in CSF
H+ is detected by receptors in Brain (medulla) and send impulses to DRG
What are the different types of receptors in the lungs/airways that are part of pulmonary afferents
Stretch receptors
J-receptors
Irritant receptors
Describe the features, location and function of Irritant receptors
Found within and beneath epithelium cells (nerve endings) in trachea
Lead to cough- forceful expiration against closed glottis with sudden glottal opening and high velocity expulsion of air
Describe the features, location and function of stretch receptors
Found in lobar bronchioles
Activated by Excessive inflation of the lungs
send afferent signals to respiratory centres- inhibits DRG and Apneustic centre
stimulates VRG and Pneumotaxic
Prevents hyper-inflation of the lungs by Inhibiting inspiration and stimulating expiration
Describe the features, location and fucntion of J receptors
- Sensitive to oedema and pulmonary capillary engorgement
- increases breathing frequency
- found next to capillaries
Describe the buffering capacity of blood
The blood has an enormous buffering capacity that can react almost immediately to Imbalances
Has a lot of HCO3-
How do you convert H+ concentration to pH
What is alkalaemia
HIgher than normal pH of blood
What is Acidaemia
Lower than normal blood pH
What is Alkalosis
Descirbe cirucastance that will decrease [H+] and increased pH
What is Acidosis
Describes circumstances tha will increase [H+] and decrease pH
What is needed to correct an acidosis
Alkalosis
How does kidney aid in acid base homeostasis
Changes in H+ and HCO3- retention/secretion in kidneys can stimulate a SLOW compensatory response to increase/decrease pH respectively
How does ventilation aid in acid base homeostasis
Changes in ventilation can stimulate a rapid compensatory response to change CO2 elimination and therefore alter pH
Where are peripheral chemoreceptors found and what respective nerve do they carry sensory information via?
They detect O2 levels unlike the BRAIN that detects CO2
Carotid bodies in aortic arch- near baroreceptors; they carry information via CN IX
AORTIC bodies- via CNX
What are emotional changes to ventilation
Limbic system
Special sensory like ears and eyes. E.g. loud sound or fire shouted will increase breathing rate
