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Neurotransmitter and Maximal Contractile Response Essay

Decent Essays

Department of Physiology

PHY2021
Body Systems Physiology

Activity of Gastrointestinal
Smooth Muscle Worksheet

Due by:

Noon (12 pm) Friday April 12

Pre-prac Reading: Vander, 12th Edition:
Section 6D.4 (pp 175-180), Section 15.2 (pp 521-522), Section 15.4 (pp 528-529, 536-538 & 542-543).

INTRODUCTION
Give a brief description in your own words of the objectives and aims of this practical.

The aim of this practical was to discover the effects that numerous hormones and drugs have on the sample ileum’s nerves and relate this to the human autonomic nervous system.
The objectives include observing the change in contractions during different levels of stimulation and inhibition, such as that from different …show more content…

A decrease in stimulus frequency results in a greater number of contractions within the ileum. An increase in the stimulus frequency results in a decrease in the release of neurotransmitters, further inhibiting the contractions of the ileum.

B. MIMICKING THE ACTION OF THE AUTONOMIC NERVOUS SYSTEM USING DRUGS
 Attach copies of your experimental recordings showing the response of the ileum to the direct addition of noradrenaline and of acetylcholine to the tissue bath.

1) What was the final bath concentration of noradrenaline you used? Briefly describe the response of the ileum to the direct addition of noradrenaline.

2) What was the final bath concentration of acetylcholine you used? Briefly describe the response of the ileum to the direct addition of acetylcholine.

3) Since an inhibitory response to nerve stimulation was observed in all (or most) of the tissues studied in the practical, how is differential control (i.e., both inhibition and excitation) of gut contraction achieved in the body? Is it always inhibitory in vivo? What happens in the intact animal?

C. BLOCKING AUTONOMIC NERVOUS SYSTEM TRANSMITTER TARGETS
Effect of phentolamine on the responses to nerve stimulation and added transmitter substances
 Attach copies of your experimental recordings showing the response of the ileum to nerve stimulation and to the direct addition of

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