Chapter 7 - The Endocrine System

Ie each hormone in the pathway feeds back to suppress

Info icon This preview shows pages 4–5. Sign up to view the full content.

View Full Document Right Arrow Icon
i.e. each hormone in the pathway feeds back to suppress hormone secretion by the “upstream” endocrine centers (E.5.c) This is referred to as long-loop negative feedback (E.5.d) Long vs. Short-Loop Negative Feedback Cortisol Secretion: Long-Loop Feedback Growth Hormone: Complex Endocrine Pathway IV)Hormone Interactions A) Sometimes the combined effect of two or more hormones is greater than the sum of the effects of the hormones individually – this is the concept of synergism or potentiation. B) Characteristics of Hormone Interactions: B.1) Permissiveness B.2) Some hormones cannot fully exert their effects without the presence of a second hormone – this is the concept of permissiveness. (B.2.a) e.g. thyroid hormone has a permissive effect on sexual maturation B.3) Hormone Interactions: Antagonism B.4) Two hormones can cause opposite effects and diminish the effectiveness of each other – this is the concept of antagonism. B.5) Two hormones are considered functional agonists if they have opposing physiological actions. (B.5.a) e.g. the action of glucagon to increase blood glucose is antagonistic to the action of insulin to decrease blood glucose B.6) Antagonistic hormones don’t necessarily compete for membrane receptors, rather they may act by a different metabolic pathway or by down- regulating the receptor population for an another hormone. V) Endocrine Pathologies
Image of page 4

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A) Three basic patterns of endocrine pathology A.1) Hormone excess A.2) Hormone deficiency A.3) Abnormal responsiveness of target tissues B) Hypersecretion exaggerates a hormones’s effect C) Hyposecretion diminishes or eliminates a hormone’s effects D) Receptor or second messenger problems cause abnormal tissue responsiveness E) Diagnosis of pathologies depends on the complexity of the reflex VI)Hormone Evolution A) Evolutionary conservation Endocrine System Summary I) Hormones II) The Classification of Hormones III) Control of Hormone Release IV)Hormone Interactions V) Endocrine Pathologies VI)Hormone Evolution
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern