Anatomy of the chest wall & mechanics of breathing Flashcards
(26 cards)
What is the pressure in the pleural cavity when compared to Patmos ?
Always -ve
What is the pressure in the Alveoli when compared to Patmos ?
Can be +ve or -ve as the person breathes in & out
Is Transpulmonary pressure +ve or -ve ?
Always +ve
What muscles are used for inspiration ?
Diaphragm & external intercostal muscles
What muscles are used for expiration ?
Internal intercostal muscles (forced expiration include abdominal muscles)
What is Boyle’s law ?
That gas will move from an area of high pressure to an area of low pressure.
What is respiratory minute volume ?
The amount of gas inhaled and exhaled from a person’s lungs each minute.
What is the definition of pulmonary ventilation ?
The total air movement in and out of the lungs.
What is the definition of Alveolar ventilation ?
The fresh air that enters the Alveoli & is therefore available for gas exchange.
What is the ‘law of Laplace’ ?
P=2T/r (when T is surface tension & r is Radius of Alveoli)
What is the definition of Compliance ?
Change in volume is relative to the change in pressure.
In what part of the brain is the DRG & the VRG found ?
The medulla
What is the DRG & what is it responsible for with regards to respiration ?
The Dorsal Respiratory Group is found in the Medulla and is responsible for inspiratory muscles via the phrenic and intercostal nerves.
What is the VRG & what is it responsible for with regards to respiration ?
The Ventral Respiratory Group is found in the medulla and is responsible for expiratory muscles and the tongue (stops it from blocking airway)
What type of receptors are the DRG & VRG ?
Central chemo receptors
How does chemicals influence the behavior of these central chemo-receptors ?
When CO2 rises or falls within the blood stream this drop or rise in H ions will be detected within the CSF and the central chemo receptors. This leads to increased or decreased respiratory drive as suitable.
What is the term used to describe plasma with too many H ions ?
Acidosis
What is the term used to describe plasma with too little H ions ?
Alkalosis
Where are the peripheral chemo-receptors found ?
In the Carotid & Aortic bodies
What are these peripheral chemo-receptors responsible for ?
Secondary ventilatory drive
What do peripheral chemo-receptors respond to ?
Changes in H ion levels not solely from CO2 but they also monitor O2 levels
What kind of motor neurons relay the message to the muscles for inspiration and expiration ?
Somatic motor neurons
The lungs and ribs are constantly trying to pull apart, what prevents this ?
The pleural fluid in the pleural cavity
What is the pressure within the pleural cavity ?
-3mmHg (sub-atmospheric)
