Myocardial Contraction

==================================================

syllabus | home page | BME Home Page | search the web | e-mail Doug

==================================================

==================================================

Sample Problems:

1. Due to physical damage, the myocardium was deprived of Ca++ ions. What would the
effect be on a) contractibility of the myocardium, b) heart rate, c) cardiac output. 
2. A "defective" heart lacks the necessary 0.11s delay in signal transduction from AV node to
the nerve bundles, the signal being "short circuited" to the Purkinje fibers. What is the 
immediate and most devastating effect?

==================================================

Answers:

1. a) contractibility not significantly affected
   b) heart rate increased due reduced depolarization time
   c) CO increased, as HR increases
2. Since the signal is shorted to the ventricles directly from the atria, they both contract
simultaneously, causing reduced output due to partial evacuation of blood from the chambers.
Insufficient circulation results.

==================================================

For more information on this topic, please refer to Berne & Levy , pg. 63

Also, check out the following links that may be helpful:

==================================================

syllabus | home | BME | search the web | e-mail Doug

Or, Jump to Lesson Number:


respiratory

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Exam #1

auditory

17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | Exam #2

cardiovascular

28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | Exam #3

No!
Please don't make me go to any of those pages!
I want to go somewhere completely different!

This page was written by Emil Istoc, a student in this course.

BME 403 Pages maintained by the T.A., Douglas Miles.