Respiratory Physiology Flashcards
What is quite breathing
Quite breathing is made in volume of air we breath in and out naturally = tidal volume
Tidal volume in healthy adult is 500 mL of gaz per movement
When we inhale and retain what volume do we reach ?
Total lungs’ capacity
Do we expulse all the air from the lungs when we exhale ?
No, there is a residual volume
Is the respiratory system an external or an internal organ ?
External organ
What are the functions of the respiratory system ?
- provide oxygen to the body tissues
- remove carbon dioxyde
- help maintenant pH balance of the blood
- sensing odors
- voice production
- defense against the pathogens
- pulmonary ventilation
- gaz exchange between air and blood
- transportation of gases to tissue
- gaz exchange between the blood and tissues
What is systemic respiration ?
It’s the exchange of O2 and CO2 between atmosphere and organs
What is pulmonary ventilation ?
Inspiration and expiration
What is the connexion between respiration and ventilation ?
Aerobic respiration requires O2
O2 is provided by the gaz exchanges provoked by ventilation
Which parts of the NS control the ventilation ?
Mainly neurons in the reticular formation of the pons and medulla
The medulla sets the ventilation rhythm and the pons influences and modifies the activity of the medullary neurons
What are the 2 neurons’ clusters essential to ventilation ? Where are they located ?
In the medulla oblongata
- dorsal respiratory group
- ventral respiratory group
What is the function of the ventral respiratory group of neuron influencing the ventilation ?
- rhythm generative and integrative center
- when inspiratory neurons fire : impulses travel along the phrenic and intercostal nerves to excite the diaphragm and external intercostal muscles. As a result, the thorax expands and air rushes into the lungs
- when expiratory neurons fire : inspiratory signal is inhibited and expiration happens passively as the inspiratory muscles relax and the lungs recoil.
What is the function of the dorsal respiratory group of nerves influencing ventilation ?
They integrate peripheral sensory inputs and modify the rhythm generated by the ventral respiratory group of nerves.
What is the role of pontine respiratory centers ?
They influence and modify the activity of medullary neurons
They smooth out the transition between inspiration and expiration
They modify and fine-tune the breathing rhythm generated by the ventral respiratory group during specific activities such as vocalization, sleep and exercise.
What are the chemical factors influencing volume and frequencies of ventilation ?
- changing volume of O2, CO2 in the arterial blood
- chemoreceptors in the brain stem : central chemoreceptors located in the brain stem and peripheral chemoreceptors located in aortic arch and carotid artery.
What are the neural controls exerted on ventilation ?
- hypothalamic controls acting through hypothalamus and the rest of the limbic system, triggered by strong emotions and pain and impact the respiratory rate and depth.
- cortical controls is a volitional control over the rate and depth of our breath
What vessel brings deoxygenated blood to the alveoli ?
The pulmonary artery
In which part of the internal airways do gaz exchange take place ?
In the respiratory zone composed of respiratory bronchi, alveolar ducts and alveoli
What happens when the diaphragm contracts ?
It moves downward to become flat. The rib cage expends.
What is the atmospheric pressure ?
The pressure exerted by gaz present in the air
Pn = 78%
PO2 = 21%
Pother gaz = 1%
Atmospheric pressure = 760 mmHg at sea level
What is the relation between atmospheric pressure and intrapulmonary pressure during inspiration ?
Patm > Palv
What is the relation between atmospheric pressure and intrapulmonary pressure during expiration ?
Palv > Patm
What happens to pressure in alveoli when inhalation takes place ?
Pressure in the alveoli drops
What happens to pressure in the alveoli when the exhalation takes place ?
Pressure rises
What is the relation between atmospheric pressure and intra pulmonary pressure during pause ?
They equalize
What adjective can describe the pressure in the pleural cavity ?
Subatmoshperic
What happens to the pressure in the pleural cavity during inhalation / exhalation ?
Pressure drops during inhalation
Pressure rises during exhalation
Why is the pleural pressure negative ?
- tendency of thorax to expend outwards
- tendency of lungs to recoil inward
To what is equal trans pulmonary pressure ? What will cause its increase ?
P alv - P ip
The alveoli expand
What is the pressure gradient during breathing ?
During each breath, the pressure gradient moves 0, 5 liter into and out of the lungs
What is the relation between the pleural pressure and alveolar pressure at rest ? What is the relation between both at the end of inspiration ?
It’s the same