Exchange Surfaces Flashcards
Types of epithelial tissue found in the lungs
Squamous/ pavement tissue
Ciliated epithelium tissue
How are the alveoli efficient for gas exchange
Small giving high SA:V ratio which allows diffusion to happen quickly
Cell membranes are extremely thin giving a short diffusion distance
elastic tissues allows alveoli to stretch as air is drawn in, giving greater volume in the alveoli
Number of alveoli
Maintain concentration gradient
How does Squamous epithelium improve efficiency of gaseous exchange
Very thin red due/shorter diffusion disatance allows quick diffusion
Important enough of good ventilation in the lungs
Removes o2
Why do large multicellular animals need transport systems
They cannot rely on diffusion to get all the nutrients, minerals and water that they need.
Tissues and cells are too thick therefore the diffusion distances are too great and the SA:V is too small
Removes waste products
How does smoking cause smokers cough
Causes the cilia to stop beating
Causes goblet cells to produce more mucus
This mucus does not get moved up to the mouth to be expelled due to the cilia not beating therefore the cough is the only way to expel it
Other problems due to smokers cough
-damages alveoli reducing vital capacity
-narrows airways such as bronchioles
Dirt and bacteria is more likely to reach the stomach
How does refreshing the air in the air sacs help maintain a steep diffusion gradient
By refreshing air it all the o2 to diffuse into the passing blood stream keeping the steep concentration gradient
Removal of blood
Who do different cells and tissues in the mammalian gas exchange system enable effective exchange of gasses
Elastic recoil of alveoli
Epithelium cells - short diffusion distance
Surfactants- reduce surface tension
Blood supply- o2 diffuses into keeping gradient steep
Diagram and intercostal muscles
Cartilage keeps airways open
Goblet cells produce mucus to stop dirt
Outline the mechanism of inspiration
Dome shape diaphragm contracts, flattering and lowering
External intercostal muscles contract moving the ribs up and out
Increases volume in thorax
Pressure decrease
Pressure lower the atmospheric
Air rushes in
Why should a person using the spirometer wear a nose clip
So they do not accidentally exhale through the nose offsetting the measurement
To ensure all air is breathed from the chamber
Need for exchange surfaces in multicellular animals
High metabolic activity, meaning oxygen demands and co2 production is high
3 features of an efficient exchange surfaces
Increased SA -bigger area for diffusion, overcomes the limitations of the SA:V ratio of larger organisms.- root hair cells
Thin layers - short diffusion distance- alveoli
Good blood supply- keeps conc gradient steep as substances are constantly removed from the exchange surface.
Expiration
Muscles of the diaphragm relax , so it moves up into the domed shape
External intercostal muscles relax so ribs move down and in
Elastic fibres in alveoli of lungs return to normal length
This decreases volume
Increase in pressure, above atmospheric pressure
Air is forced out
Use of internal intercostal muscles
Forced exhalation
Pulls ribs down hard and fast
Abdominal muscles contract forcing the diaphragm up to increase pressure
