131106outline7 - Note that affinity is higher than for Hb...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Biol. 1311 9/13/06 - Hemoglobin’s “commute” The red arrows are not diffusion (fig 44-1) Open versus closed circulatory systems Open systems have low flow and may not even be primarily there for gas exchange Closed systems have high flow rates and are always involved in gas exchange Typical open design (fig 44-14) Trachea in insects are air capillaries (no eq. fig) A bit more on tracheal organization (no eq fig) Note how far into body cavity they extend Fig 44-7 shows ventilation of trachea during flight Experiment plus anatomy also shows that hemoglobin isn’t needed At least not for O 2 delivery Not all trachea are ventilated, but they still work (no eq. fig) So why is it that some organisms with open circulatory systems have hemoglobin? O 2 solubility is still low A reservoir of O 2 means that it doesn’t always have to diffuse in. Our own muscles have a similar protein Myoglobin stays but acts as a local O 2 “bank” Mb = myoglobin – (no eq. fig)
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Note that affinity is higher than for Hb what are the consequences? Back to moving O 2 (no eq. fig) The design of a closed system close to our hearts (no eq. fig) Most vasculature is like a closed pipe (fig 44.15b) Contrast to capillary structure (44.15a) Capillaries arent really closed (fig 44.16) Seeing osmosis as a force may take some imagination How does this help with gas exchange? Holes in capillaries are called fenestrations (no eq. fig) On to the pump: Low pressure system has single chamber (fig 44-14) Two chambers required for higher pressure (detail of Fig 44.17) Two circuits means higher delivery rate to tissues (fig 44.17) Another phylogeny to appreciate Flow paths through the 2 circuits (fig 44-18) What gets pumped where (fig 44-19) What pressures are generated when (fig 44-20) Relate this figure to what hemoglobin is doing (Fig 44-23)...
View Full Document

This note was uploaded on 01/24/2010 for the course BIO 1311 taught by Professor Shinkle during the Fall '06 term at Trinity University.

Ask a homework question - tutors are online