Gurpreet Singh HW# 4
Q1: Define “follicle” from the text, then in your own words describe the follicle’s structure and function.
- Each ovary contains 400,000 primary follicles, which are clusters of cells surrounding a single cell. The purpose of the follicles is to help an egg cell mature and to make it ready to be released into the reproductive tract, where it can be ready to be fertilized. When the follicle is completely matured, its egg is released through ovulation. The follicle breaks open, and the egg is swept from the surface of the ovary into the opening of one of the two fallopian tubes.
Q2: What is the reaction of the hypothalamus to low levels of estrogen from the ovaries at the beginning of the “Follicular Phase”?
- The reaction of the hypothalamus to low levels of estrogen from the ovaries at the beginning of the “Follicular Phase”, by producing a releasing hormones that acts on the pituitary gland. The releasing hormones stimulate the anterior pituitary to secrete follicle stimulating hormone and luetenizing hormone.
Q3: What is the effect on the ovaries of the hormones now released by the hypothalamus?
- Those two hormones travel through the circulatory system to the ovaries where they cause a follicle to develop to maturity. Generally, just a single follicle develops, but sometimes two or even three mature during the same cycle. As the follicle develops, the cells surrounding the egg enlarge and begin to produce increased amounts of estrogen.
Q4: What is the effect on the uterus of estrogen?
- As more estrogen is produced, the levels of that hormone rise very high, causing the lining of the uterus to thicken in preparation for receiving a fertilized egg. The development of an egg in this stage of the cycle takes about 10 days.
Q5: What is the effect of the “sudden rush” of the FSH and LH from the pituitary on the ovary, midway through the menstrual cycle?