Why do we respire?
1) Take in oxygen
- drives aerobic cellular respiration
2) Remove carbon dioxide
Why do we need to remove carbon dioxide?
Other roles of Respiratory System?
Even some multicellular organisms are small enough to obtain their O2 by…
…diffusion
Small multicellular organisms which are small enough to obtain their O2 by diffusion tend to be…
…simple animals with flattened or tubular shapes to maximise surface area.
Such as:
- Flatworm
- Planaria
Oxygen diffuses…
…slowly
Because oxygen diffuses slowly, bigger animals including humans cannot…
…obtain oxygen only by diffusion
Larger animals have also evolved …
…transport systems, normally through circulatory systems
Different animals have respiratory systems that differ in:
structure
complexity
What systems have larger animals developed to carry out respiration?
Tracheal systems mainly seen in…
…insects
Gills seen in…
Primitive lungs & book lungs found in…
Lungs seen in…
The respiratory systems (RS) of other animals are often not as …
…efficient as ours
eg - the lungs of frogs
- This places limitations on the performance of other animals compared to mammals
avian lungs are more…
…efficient than ours
Getting O2 to cells can be divided into four main stages:
1) Ventilation
2) Gaseous exchange
3) Transport of gases
4) Entry into/exit from cells
What is ventilation?
the movement of air from the external environment to the respiratory surfaces
What is Gaseous exchange?
the diffusion of O2 and CO2 across the respiratory epithelium into the blood circulatory system
What is Transport of gases?
movement of gas from/to the lungs to/from the tissues (via the heart in humans)
What is entry into/exit from cells?
the diffusion of O2 and CO2 across the cell membrane for cellular resp.
Our Ventilation System is divided into…
…2 main regions
The two main regions of the ventilation system:
Upper and lower respiratory tract.
Whats the Upper Respiratory Tract?
airways of the head and neck, which include the nose, nasal cavity, pharynx (throat) and associated structures