EXCHANGE AND TRANSPORT Flashcards
What is the surface area to volume ration for small animals?
high surface area to volume ratio
What is the surface area to volume ratio for large animals?
low surface area to volume ratio.
What is the equation for the surface area to volume ratio?
SA
SAV =
V
What makes a good exchange surface?
plentiful blood supply, large surface area to volume ratio, thin epithelium, good ventilation.
What are some features of gas exchange that aid passive and active transport?
increasing the surface area and having specialized exchange surfaces (flattened shape) (external or internal), thin separating surface (maximize diffusion rate), large concentration gradient.
What is an example of exchange surface?
Root hair cells - increased surface area facilitates gas exchange.
Red blood cells - bioconcave shape increases surface area.
\What are ways to maximize the rate of exchange?
large surface area, moist surface, diffusion gradients, permeable to oxygen and carbon dioxide, short diffusion path
How are leaves adapted for gas exchange?
Usually thin (high surface area to volume ratio), Large moist gas exchange surfaces of spongy mesophyll, Intercellular air spaces of spongy mesophyll for diffusion in leaf, stomata allow respiratory gases to diffuse.
How are mammals adapted for gas exchange?
The alveolar wall is the area of gas exchange, squamous endothelial cells are thin and so have a very short diffusion distance, the lungs have a surface area 30 times larger then the rest of the body, steep concentration gradients produced by ventilation in the lungs.
Describe inspiration?
(breathing in) External intercostal muscles contract, ribs are pulled upwards and outwards, diaphragm muscle contracts, pressure differential causes air to rush into lungs.
Describe expiration?
(breathing out) External intercostal muscles relax, ribs go down and inward, diaphragm returns to dome shape, thorax pressure is larger than that of the atmosphere, air is forced out of lungs.
What are the effects of smoking on the lungs?
Tar in carcinogenetic, causing lung cancer (cells divide uncontrollably and make a tumor, at a certain size it can damage airways.
Emphysema, irritation from tar damages alveolar lining so lung surface area is reduced so there is less diffusion.
Bronchitis, inflammation of bronchial tubes reduces air flow in and out of lungs, tar paralyses cilia which aid mucus removal.
