Class Notes (806,766)
Canada (492,430)
HSCI 216 (49)


3 Pages
Unlock Document

Simon Fraser University
Health Sciences
HSCI 216
Pablo Nepomnaschy

Lecture 8: Friday June 1 st  Proximate explanation for variations in female fecundity o We don’t have to reproduce today o An adaptation does not have to be plesant, it has to get the job done o Stress is not always bad (ie: running away from someone who wants to beat you up)  If you keep getting stressed  you will stop your immune system from working probably  It will kill you slowly  Allocation of energy! o Understand this graph!!  Energetics o Energy flux: energy turnover  analogy of bank account, deposit a dollar everyday and take out a dollar everyday, or deposit 100$ everyday and take out $100 everyday.  The flow is different  “continuous change”  Energetic challenges can affect the chances of conceiving a pregnancy o Ovarian suppression: your ovaries are not making enough hormones for menstrual cycle to occur o If energy expenditure affect reproductive function then it would have happened before?  Therefore… seasons are a good predictor of energy availability and expenditure  If this is tied to seasons, peak energy expenditure tied with (?)  Having a baby in the spring so during summer you can eat and relax o Experiment in poland:  Women work hard during the summer for harvesting, and have winters off  Therefore energy expenditure was 1/3 higher during summer  During summer progesterone levels were low than in winter indicating ovarian suppression  Progesterone is produced from the luteal follicle  hormone that promotes of growth and thickening of the endometrium (inner lining of uterus where baby will grow, and important for vacuolization)  If the levels are low then the endometrium wont grow well o Not enough blood supply etc.  Therefore energy expenditure is a modulator of reproductive function**  Successful reproduction o Energy: burning a chip burns slowly, which is how your body will burn it o What happens when the requirements aren’t met  Stress-triggered reproductive suppression o How does a women’s body regulate fertility o “Inauspicious”  times not good for the body  physiologic alarm  anxiety generated o stress is the  physiological alarm  it affects ovarian function  “stress should lead to reproductive suppression” o social scientist would call women who had miscarriages and ask them if they were stressed o cortisol is the independent variable as it is a measure of stress  the dependent variable is ovarian function o real life stress: energetic, psychosocial and heath stressors are lead to change in cortisol therefore are all real life stress  they all interact together  ex: mudslide  psychosocial stress, collecting wood  energetic stress, getting sick because immune system went down from stress  health stress  therefore all interact!! Leading to same result of increased cortisol  you cant really know what type of stress effects someone with experiment unless locked in lab o (prediction) during menstrual cycle: cortisol will be associated with deleterious (causing harm/damage) changes in the profiles of the reproductive hormones during the menstrual cycle  cortisol will go up and progesterone will go down* o (prediction #2)  increased cortis
More Less

Related notes for HSCI 216

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.