Principles of Human Physiology (6th Edition)
Principles of Human Physiology (6th Edition)
6th Edition
ISBN: 9780134169804
Author: Cindy L. Stanfield
Publisher: PEARSON
bartleby

Videos

Question
Book Icon
Chapter 1, Problem 1E
Summary Introduction

Introduction:

Positive feedback is a physiological phenomenon in which a change in the system’s internal condition generates a response in the same direction as the cause of the change. In other words, positive feedback intensifies a physiological condition.

Expert Solution & Answer
Check Mark

Answer to Problem 1E

Solution:

The correct answer is option (e).

Explanation of Solution

Explanation/justification for the correct answer:

During childbirth, the uterus undergoes contractions in order to push the fetus out of the cervix. This is aided by the action of the hormone oxytocin. It is known that uterine contractions during parturition induce the production of oxytocin. Oxytocin functions to intensify these contractions and help the fetus to move out of the cervix with ease. Hence, oxytocin sets up a positive feedback loop by increasing the uterine contraction. So, the correct answer is option (e).

Explanation for the incorrect answer:

Option (a) states that in conditions of increased acidity suppresses the cells lining the stomach walls to produce more acid. This is an example of negative feedback as the response to the change is in reverse direction to the cause. So, this is an incorrect option.

Option (b) states that a rise in blood pressure Triggers the elimination of water in the urine, which reduces blood pressure. This is an example of negative feedback as the response to the change is in reverse direction to the cause. So, this is an incorrect answer.

Option (c) states that an risein the concentration of H+in blood causes an risein excretion in urine. This is a case of negative feedback as elimination in urine reduces the concentration of H+in blood. Hence this option is incorrect.

Option (d) states that an risein carbon dioxide concentration in the blood Triggers breathing, which increases the rate at which carbon dioxide is eliminated from the body. Elimination reduces the carbon dioxide concentration in blood hence it is negative feedback. So this option is incorrect.

Conclusion

Among the given options option (e) Contraction of the uterus push the fetus against the cervix that triggers the release of oxytocin in the bloodstream; oxytocin the Triggers stronger contraction of the uterus. is an example of positive feedback.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Text book image
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Text book image
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Text book image
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Text book image
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Text book image
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Text book image
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education
Excretory System; Author: Amoeba Sisters;https://www.youtube.com/watch?v=q5qaGHfdmYM;License: Standard youtube license