week 6 - disorders of the respiratory system Flashcards
What are the 3 functions of the respiratory system?
- Breathing
- exchange of O2 and CO2
- Speech production
What is external respiration>?
exchange of gases across membrane of the lungs
Gas exchange at pulmonary capillaries
Ventilation occurs
what is ventilation?
exchange of air between lungs and atmosphere
What is internal respiration?
exchange of gases from blood into organs and tissues
gas exchange at cellular level
as all cells need oxygen for metabolism and need to remove carbon dioxide
What areas are part of the upper respiratory tract?
Nose and naval cavity - air in, smell
Pharynx - carries food and air to oesophagus
Larynx - breathing, prevents against breathing in food
What is the function of the upper respiratory tract?
moistens/warms incoming air
filters incoming air
passageway fir respiration
What areas are part of the lower respiratory tract?
Larynx - maintains open airway, routes food and air
Trachea - transports air to and from the lungs
Broinchi - branch into the lungs
Lungs - transport air to the alveoli for gas exchange
Describe the bronchi in more detail?
Consist of cartilage rings and smooth muscle
They divide into bronchioles
They stop at the alveoli
What is pleura?
The pleura covers the lung:
Parietal pleura - inner
Pleural cavity - middle
Visceral pleura - outer
The pleura lubricarte fluid
What is the diaphragm?
It is a muscle which separates the chest and the abdomen
Innervated (supplied with nerves) by phrenic nerve
Describe the alveoli/
They are air sacs in the lungs.
Their membranes are one cell thick and are surrounded by capillaries for efficient gaseous exchange
What are properties of the alveoli for efficient gas exchange?
Large surface area
Good blood supply
Short diffusion. pathway
Moist surfaces - the liquid on the surface of alveoli dissolves gases and facilitates diffusion
Describe gas exchange in brief?
Oxygen moves from lungs to the bloodstream while carbon dioxide passes from the bloodstream top the lungs
What is the partial pressure gradient?
Where a gas diffuses from a higher pressure to a lower pressure down the gradient
What are the 2 phases of the respiratory cycle?
Inspiration
Expiration
Describe the process of inspiration (breathing in)?
external intercostal muscles contract - so ribs move up and out
Diaphragm contracts and flattens
Chest cavity/wall and lungs expand as ribs expand
Lung volume increases - causing air pressure to fall so air can flow in
Describe the process of expiration (breathing out)?
external intercostal muscles relax - so ribs return back to normal
the diaphragm relaxes
chest cavity and lungs contract as ribs return back to normal
Lung volume decreases - causing air pressure to rise so air can flow out
How is breathing regulated via the central nervous system/
- Respiratory centre in MO establishes basic breathing pattern
- Chemoreceptors - monitor CO2, O2, H+ levels
- Medulla - sensitive to H+ in CSF resulting from co2 in blood
- Carotid/aortic bodies sensitive to co2, Ph, o2
- Conscious control in the brain
What is physiologic dead space (Vd) - a type of breathing measurement?
volume of air in respiratory zone that does not take part in gas exchange
What is tidal volume (Vt) - a type of breathing measurement?
The amount of air in and out of the lungs with each respiratory cycle (1 breath, expiration and inspiration)
What is respiratory rate (f) - type of breathing measurement?
Amount of breathes per minute
How can you calculate minute volume (Ve) (L/min) - a type of breathing measurement?
(Vt x f)
What is alveolar ventilation (Va) - a type of breathing measurement?
And how do you calculate it?
it is the amount of air that reaches the alveoli
Calculate it by (Vt-Vd) x f
What does Vd/Vt calculate/
the portion of Vt that does not exchange
What are the 3 ways to measure lung function?
Pulmonary function tests
Lung volumes and vital capacity
Gas transfer test
What is tidal volume (Vt) - a measurement of lung function?
Amount of air inhaled/exhaled during normal breathing
