Mammillian Diving Reflex

While touching on the idea of fixed action patterns  in class today, we were searching for examples of such actions in humans. I thought that the mammalian diving reflex is quite an interesting example.

Upon submersion into cold water (the temperature of the water modulates the effect), the mammalian body slows respiration and decreases heart rate, then shuts off blood circulation to the extremities in order to conserve oxygen.  This instinct helps explain why certain mammals such as seals are able to dive for extended periods of time without resurfacing; for humans, the reflex is weakened but present. Interestingly enough, the face must be submerged in water to activate the reflex – dipping the limbs into water will not. It’s a pretty cool system, in my opinion, and it apparently also explains why hypothermic individuals can survive without oxygen for longer periods of time.

Anyway, that’s the idea I had for my first post. If anyone wants to know more, I included the websites I looked up (yay wikipedia). I’m looking forward to seeing other people’s posts!


Published in: on January 25, 2011 at 6:53 pm  Comments (2)  

The URI to TrackBack this entry is:

RSS feed for comments on this post.

2 CommentsLeave a comment

  1. That is interesting — will you try to work this into your observations in some way? (Imagining watching animals jump in the water . . . )

    • Well, currently my plan is to work on bees so I doubt they’re going to do much diving!

      However, I was considering the seals at the Aquarium which definitely utilize this reflex to dive. In addition, penguins go under similar physiological changes when diving.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: