Respiratory system Flashcards
(33 cards)
Function of respiratory system
A group of organs that ensures that oxygen is brought in and carbon dioxide is removed from each cell of the body
Four stages of respiration
-Breathing (inspiration and expiration)
-External respiration (exchange of gas between lung and blood)
-Internal respiration (exchange of gas between blood and cells)
-Cellular respiration (energy releasing reactions in cells)
What is breathing
Breathing is the process which air enters and leaves the lungs
What is external respiration
It is the exchange of oxygen and carbon dioxide by the lungs and blood
What are the 2 requirements for respiratory surfaces
- Large respiratory surface: Gas exchange quickly to meet bodies need
- Must be moist: So gas can dissolve
What are the types of respiratory system?
- Outer skin
- Gills
- Trachea
- Lungs
Outer skin
-Breathing is used by process of diffusion
-Transport O2 and CO2 in and out of cells from blood
-Organism must live in a moist environment
Gills
-Extension of folds in the body surfaces that increase the surface area
-Process of diffusion transport gases to blood and cells
-All gill breathers live in aquatic environment
Trachea respiration
-Insects employ a tracheal system
-Internal system of branching respiratory trachea (tubes)
-Trachea connects cells directly to environment for gas exchange (blood not required)
Lungs respiration
-Large animal employ lungs since they can provide more gas exchange
-Lungs contain sacs lined with moist surface (epithelium); these sacs increase surface area
Aquatic gas exchange
-Gill users exchange gas by taking water into mouth and venting over gills
-Dissolved O2 in water diffuses into the blood in the gills
-CO2 dissues out of the blood, across gill and into water
This is called COUNTER-CURRENT system where O2 and CO2 flow down diffusion gradients since blood and water flow in opposite directions
Terrestrial gas exchange
-Breathing is required to move in and out of lungs
-Brain regulates breathing rate and monitors volume of air in lungs
-Diaphragm and intercostal muscles control air pressure in the lungs, thus inhalation and exhalation
Air pressure in lungs (inhalation)
When you breathe in, two main muscles help:
1.Your diaphragm moves down
2.Your rib muscles pull your ribs up and out
This makes your chest space (thoracic cavity) bigger.
Because the space is bigger, the air pressure inside your lungs drops. Now the pressure outside your body is higher than the pressure inside your lungs.
And just like how air rushes into a balloon when you squeeze one side, air rushes into your lungs to fill the space and balance the pressure.
Air pressure in lungs (exhalation)
Expiration (exhale): Is the opposite action. The diaphragm and intercostal muscles relax, reducing volume. The INCREASE in pressure inside force the air out
Respiratory volume terms
1.Tidal volume
2.Inspiratory reserve volume
3. Expiratory reserve volume
4.Vital capacity
5. Residual volume
Tidal volume
volume of air that is inhaled and exhaled in a normal breathing movement (body is at rest)
Inspiratory reserve volume
the additional volume of air that can be taken into the lungs beyond a regular (tidal) inhalation
Expiratory reserve volume
is the additional volume of air that can be forced out of the lungs beyond a regular (tidal) exhalation.
Vital capacity
(total lung volume) is the total volume of gas that can be moved into or out of the lungs.
(TV+IR+ER=VC)
Residual volume
the amount of air that remains in the lungs and passageways even after a full exhalation.
What is the pathway of air into the body?
Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli
What is the function of the alveoli?
Tiny air sacs where gas exchange occurs between air and blood.
What is the diaphragm and what does it do?
A muscle under the lungs that contracts to pull air in (inhalation) and relaxes to push air out (exhalation).
What structures keep the airway clean and moist?
Cilia and mucus in the nasal cavity and trachea.
