Topic 4: The Respiration Flashcards
What is the primary function of the respiratory system?
obtain OXYGEN, eliminate CARBON DIOXIDE
What are other important functions besides respiration of the respiratory system? (5)
- filters, warms and moistens incoming air
- maintains blood pH
- produces sound
- assists in olfaction
- helps return blood to the heart
What is Dalton’s Law of Partial Pressures?
gases move independently down their partial pressure gradients, from higher to lower pressure
What is the expression for partial pressure?
partial pressure exerted by each gas in a mixture equals the total pressure times the fractional composition of that gas in the mixture
What is the partial pressures in atmosphere?
- nitrogen (597.4 mmHg)
- oxygen (158.8 mmHg)
- carbon dioxide (0.3 mmHg)
- other gases (3.5 mmHg)
Total: 760.0 mmHg
How do fish breathe underwater?
fish gills use a countercurrent exchange system, where blood flows in the opposite direction to water passing over the gils; blood is always less saturated with O2 than the water meets
What are the two aspects to respiration?
- external respiration
- internal respiration
What happens during external respiration? (3)
- ventilation or gas exchange between the atmosphere and alveoli in the lungs
- exchange of O2 and CO2 between air in the alveoli and the blood
- transport of O2 and Co2 between the lungs and the tissues
What happens during internal respiration?
exchange of O2 and CO2 between the blood and the tissues
What are the two anatomical (and functional) divisions of the respiratory system?
- upper respiratory tract
- lower respiratory tract
What organs makeup the upper respiratory tract?
- nose
- pharynx
- larynx
What is the function of the upper respiratory tract?
warms, moistens and filters air
What organs makeup the lower respiratory tract?
- trachea
- bronchi
- bronchioles
- lungs
What is the function of the lower respiratory tract?
allows oxygen to enter the blood and carbon dioxide to leave the blood
What is the structure of the trachea?
- 5 inch tube that connects the larynx to the bronchial tree
- muscular walls are embedded with 16 to 20 “C”-shaped pieces of cartilage
What happens during tracheotomy?
the trachea is opened between two “C” rings to bypass the larynx and allow access to the lungs
What is the bronchial tree?
- the trachea splits into two primary bronchi, which lead to each lung
- the primary bronchi(s) divide into secondary bronchi
- branching continues, leading to smaller and smaller tubes (tertiary, bronchioles, terminal)
How large are the lungs?
fill the rib cage, extending from the diaphragm to the collar bone
What is the difference between the right and left lung?
- the right lung is shorter and wider and has three lobes
- the left lung is thinner, has two lobes and the cardiac notch
What is the pleural sac?
a thin sac that allows the lungs to expand and contract without tearing the delicate respiratory tissues
What are the two types of pleural sacs?
- visceral pleura
- parietal pleura
What is the visceral pleura?
stuck to the lungs
What is the parietal pleura?
stuck to the thoracic wall (ribs)
What is intrapleural fluid?
secreted by surfaces of the pleura that lubricates pleural surfaces
What is pleurisy?
inflammation of the pleural sac
Where are the lungs locates?
in the fairly rigid thoracic cavity
What is the difference between the lungs and thoracic cavity?
lungs are smaller than the thoracic cavity but are very elastic and are slightly stretched under normal conditions
What happens to the lungs in slight negative pressure?
the intrapleural space “glues” the outside of the lung to the inside of the thoracic pressure
What is the pressure of the alveoli?
760 mmHg
What is the pressure of the thoracic cavity?
760 mmHg
What is the pressure of the pleural sac?
756 mm
Why are lungs stuck to visceral pleural?
the transmural pressure gradient across the lung wall
Why is the thoracic cavity stuck to the parietal pleura?
the transmural pressure gradient across the thoracic wall