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Snakes in a Storm!

A Herpetologist’s Struggle with Hemostasis


Author(s)

P. Logan Mounce
Biological Sciences
Texas Tech University
Breanna N. Harris
Biological Sciences
Texas Tech University
breanna.n.harris@ttu.edu

Abstract

In this interrupted case study, students follow “Joseph Summers” as he attempts to do a late-night relocation of a snake exhibit as a response to an imminent hurricane. After a series of unfortunate events, Joseph is bitten by an unknown venomous snake. Based on his symptoms and other clues from the case, students must discover the likely culprit so that the correct antivenom can be administered to Joseph. Drawing upon their understanding of hemostasis, students will explore the mechanism of action of various venoms and learn about disseminated intravascular coagulation as it relates to exposure to snake venom. They will also be introduced to the true story of Karl P. Schmidt, who succumbed to a boomslang snake bite when he was working at the Field Museum of Natural History in 1957. The teaching notes include an optional homework assignment to prepare students with the necessary background knowledge. This case study is appropriate for use in a majors or non-majors anatomy and physiology, animal physiology, nursing, or intermediate-level biology course.


Objectives

  • Explain the mechanism of the blood coagulation cascade, starting at the point of factor X activation (if homework is used, students should also be able to diagram the cascade).
  • Describe and know the function of specific components of the blood such as clotting factors, fibrinogen, fibrin, prothrombin, and thrombin.
  • Become familiar with a unique physiological condition called disseminated intravascular coagulation (also known as consumption coagulopathy) and understand how it may disrupt hemostasis.
  • Practice data synthesis and interpretation skills by using patient data to generate hypotheses about which snake (venom) is responsible for the physiological changes noted in the case.

Keywords

Snakes; venom; hemostasis; boomslang; clotting; coagulation; blood; hemorrhage; cascade; Schmidt; herpetology; coagulopathy; fibrinogen; fibrin; prothrombin; thrombin;

Topical Areas

N/A

Educational Level

Undergraduate lower division, Undergraduate upper division

Format

PDF

Type / Methods

Directed, Discussion

Language

English

Subject Headings

Biology (General)  |   Physiology  |   Toxicology  |   Wildlife Management  |   Zoology  |  


Date Posted

1/20/20

Teaching Notes

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Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Answer Key

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Videos

The following video(s) are recommended for use in association with this case study.

  • Diary of a Snakebite Death
    In 1957 at The Field Museum of Natural History in Chicago, Dr. Karl P. Schmidt, famed snake expert and herpetologist, made a detailed scientific account of the effect of venom from a snake bite in the human body—his body. Running time: 7:35 min. Produced by Science Friday, 2015.
  • Disseminated Intravascular Coagulation
    This brief video on DIC explains the condition in which the body has both widespread clotting, leading to organ ischemia, with simultaneous depletion of clotting factors, leading to bleeding. Running time: 6:04 min. Produced by Osmosis, 2017.

Comments


Jennifer Filippi
JFilippi@fcusd.org
Science/Human Anatomy & Physiology
Folsom High School
Folsom, CA
02/12/2020
I just completed this case study last week over the course of three days. I adjusted it slightly for high school students but had great success with it. I taught hemostasis and followed my lecture with the Pre-Case Assignment. The next day students got into groups and had to complete their own research on five of the snakes (those listed in the table) then make a decision about which snake they thought was the "biter." They then completed Part Two which I followed with the two video clips. The last day was completion of Part Three. I did not have them complete the remainder of the case study. They did very well interpreting the coagulation cascade (I provided them with supplemental visual aids of it). I will use this case study again going forward--it was very effective and my students were extremely interested in the snake venom component.

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