During most of the day little gh is secreted although

Info icon This preview shows pages 2–3. Sign up to view the full content.

View Full Document Right Arrow Icon
During most of the day, little GH is secreted, although bursts may be elicited by certain stimuli, like stress, hypoglycemia, and exercise. On the other hand, during the first hours of sleep, larger prolonged bursts of secretion occur. 5. Describe the hypothalamic and pituitary regulation of growth hormone secretion, including negative feedback mechanisms. (Sect11E.1, Fig11.28) PAGE 343 Diagrams. After increased levels of GHRH are secreted from the hypothalamus, the anterior pituitary gland somatotrophs secretes (release) growth hormone, which increases plasma GH levels. This, in turn, stimulates the liver and other cells to increase secretion of IGF-1. NEGATIVE FEEDBACK MECHANISM… Various stimuli can increase GH and IGF-1 levels by increasing GHRH secretion and decreasing SS secretion. Feedback control is accomplished by inhibition of GHRH & GH, and stimulation of SS.
Image of page 2

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

View Full Document Right Arrow Icon
Biol 2173 Learning Objectives Spring 2013 6. List the other growth-promoting hormones. What actions do the sex steroids have on the epiphyseal plates? (Sect11E.1) Other growth promoting hormones include: insulin, thyroid hormones (T3 & T4), testosterone, estrogen, and cortisol. SUMMARIZED ON TABLE P. 344. Unlike growth hormone, sex hormones not only stimulate bone growth but also STOP it by inducing epiphyseal closure (this explains the pattern seen in adolescence, rapid lengthening of bones then complete cessation of growth for life).
Image of page 3
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