• Jesse Heaton

    Jesse Heaton

    Graduate Student
    Heyworth, IL
    Doctor of Physical Therapy

    Jesse's Bio:
    I graduated in 2015 with a B.S. in Exercise Physiology and am now in the Doctorate of Physical Therapy program here at CSS. I played on the baseball team at CSS for four years. I was also a statistics tutor and currently work as personal care assistant in Duluth. I love the outdoors, hunting fishing, hiking, etc. While being at St. Scholastica I have noticed the “family” atmosphere and I am truly enjoying every second of it.

  • Malvern Madondo

    Harare, Zimbabwe
    Mathematics & Computer Science

    Yael Ikoba-Ndjip

    Brussels, Belgium
    Accounting Major; Finance minor

    Takudzwa Munjanja

    Gweru, Zimbabwe
    Health Information Management, CIS minor

    Bryan Chavez

    Richfield, MN
    Accounting and Finance

  • Katelyn Gehling

    East Bethel, MN
    Exercise Physiology for Pre-Physical Therapy

    Laila Zemar

    Casablanca, Morocco
    Biochemistry, Biology and Pre-med

    Neena Koslowski

    Apple Valley, MN

    Shauney Moen

    Graduate Student
    Oak Grove, MN
    Doctorate of Physical Therapy

  • Laura Salazar

    Bogotá, Colombia
    Marketing and Business Management

    Kathryn McCarrick

    Saint Paul, MN
    Elementary Education

    Shivani Singh

    Mumbai, India
    Management & Marketing

    Conrado Eiroa Solans

    Madrid, Spain
    Psychology Major, Biology minor

  • Halle Nystrom

    Graduate Student
    Fargo, ND
    M.S. Health Information Management

    Brooke Elvehjem

    Mora, MN

    Jason Chavez

    Minneapolis, MN
    Psychology, Organizational Behavior, and Social Work

    Jin Baek

    Aurora, CO
    Biology and Chemistry (Pre-Med)

  • Daniela Moreno Gomez

    San Salvador, El Salvador
    Computer Information Systems and Finance

Mammalian Dive Reflex – Ex Phys Lab

Mammalian Dive Reflex

This is a photo of me about to take the face dive into the icy cold water in Advanced Exercise Physiology lab.

This is a photo of me about to take the face dive into the icy cold water in Advanced Exercise Physiology lab.

A few weeks ago in Advanced Exercise Physiology lab, myself and a few other students chose to be the participants for the Mammalian Dive Reflex lab. What happens in mammals is when they go into extremely cold water their body reacts by slowing down the heart rate tremendously in order to decrease oxygen consumption.This optimization of the respiration rate allows for the mammal to stay under water for extended periods of time. This trait can be viewed in aquatic animals like seals and dolphins, but can be seen in weaker mamals like humans.

The mammalian dive reflex is triggered when the face hits cold water. The V cranial nerve sends a message ot the brain and is innervated by the X cranial nerve, which is part of the autonomic nervous system. The heart intitally speeds up (tachycardia) and then begins to rapidly slow (bradycardia) thanks to the autonomic nervous system response. This reflex causes bradycardia and peripheral vasoconstriciton. The blood in the body is removed from the limbs and organs and used between the brain and heart circuits allowing the body to conserve oxygen and stay underwater for long periods of time. There are real life incidences where young children have fallen into icy rivers for over 20 minutes and have been revived later with no lasting implications because of the bodies ability to conserve oxygen when the mammalian dive reflex sets in.

This reflex is occassionally used in the pediatric world when a child has a supraventricular tachycardia. The reflex causes bradycardia to set in, which will hopefully reset the heart to a more normal rhythm.

This was an awesome lab and a very neat experience. By the way…it is really hard to hold your breath for 30 seconds in freezing cold ice water!

We were hooked up to an ECG that we recorder…Check out the video above of my ECG reading during my mammalian dive reflex!!!

Sometimes when the heart is put under much stress it may do weird things that you wouldn’t often times see. During my video you can see at 16 seconds “inverted P waves” start showing up, ectopic atrial rhythm not originating from the sinus node.

If you pause at 29 seconds, you can see in between the last QRS complex (ventricular contraction) there is a P wave but no QRS! Super weird and very rare, but is nothing to be worried about.

At 47 seconds you can see my professor point out a Premature Ventricular Contraction (PVC). An occassional PVC is nothing to worry about either, but it is still neat to see these kinds of things show up on ypur own personal ECG reading.

The College of St. Scholastica’s Exercise Physiology department is top notch. With many resources and high-quality equiptment we are able to have labs where we take the material we learn in class and are able to have a hands on learning experience with our classmates as subjects. Not to mention the 12-1 student to teacher ratio in lab that makes for a very personalized learning experience!

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