Also called GnRH, it is secreted by the hypothalamus and helps coordinate menstrual and ovarian cycles.
Follicle-stimulating hormone
Also called FSH, it is secreted by the anterior pituitary and helps coordinate the menstrual and ovarian cycles.
Luteinizing hormone
Also called LH, it is secreted by the anterior pituitary and coordinates the menstrual and ovarian cycles.
LH and FSH produced by the anteriour pituitary in response to ________.
GnRH
_________ stimulates follicle cells, and follicle cells make ___________.
FSH, estrogen
Slow rise in estrogen keeps ________ and ________ low.
LS and FSH
Sharp rise in estrogen causes _________ and _________ levels to peak.
LH, FSH
LH stimulates the corpus luteum to secrete __________ and ___________.
Estrogens and progesterone.
High levels of estrogens and progesterone inhibit _________ and _________ secretion.
FSH and LH.
Near the end of the luteal phase of the ovarian cycle, what occurs to the corpus luteum?
It disintegrates.
At the end of the luteal phase of the ovarian cycle, what occurs to estrogen and progesterone?
Their levels decline abruptly.
Proliferative phase of mestrual cycle
Regeneration, thickening of endometrium. Lasts 1-2 weeks.
Secretory phase of menstrual cycle
Continued endometrial thickening and vascularization, the endometrium develops glands and secretes fluids rich in glycogen.
The luteal phase of the ovarian cycle is coordinated with what?
The secretory phase of the menstrual cycle.
The estrogens and progesterone of the luteal phase stimulate what?
The development and maintenance of the endometrium.
The disintegration of the corpus luteum causes what?
Estrogen and progesterone levels to decline.
Estrogens are responsible for female secondary sex characteristics such as:
Deposition of fat in the breasts and hips, increased water retention, calcium metabolism, breast development, and female sexual behavior.
How old are women when they start menopause and why does it occur?
Age 46-54, and it occurs because ovaries are not as responsive to gonadotropins.
Androgens are secreted int the male by ____________ and are responsible for ___________.
Leydig cells, primary and secondary sex characteristics, sexual behavior, and general aggressiveness.
A human pregnancy averages ______ days from conception.
266
How long after fertilization does the zygote begin cleavage?
24 hours
How long after fertilization does the zygote reach the uterus as the embryo in a ball of cells?
3-4 days
How long after fertilization does the blastocyst form? How long does it take for the blastocyst to implant in the endometrium?
1 week, 5 days.
Where does the embryo obtain its nutrients in the first 2-4 weeks of its life?
From the endometrium.
The placenta provides for the diffusion of materials between the __________ and ___________.
Maternal and embryonic circulations.
During what trimester does oogenesis occur?
The 1st trimester.
When does the heart start beating in an embryo?
4 weeks after fertilization.
When are the basic forms of body structures of adults present in a human embryo?
8 weeks after fertilization.
When will drinking and drugs be most likely to affect an embryo?
In the first 8 weeks of its life.
What does the embryo secrete?
Human chorionic gonadotropin (HCG).
What does HCG do?
It maintains the corpus luteum and endometrium.
When pregnant, a woman's corpus luteum makes more progesterone. What does this do?
Increases the mucus of the cervix, encourages placental growth, enlarges the uterus, causes menstrual and ovarian cycles to stop, and causes rapid enlargement of the breasts.
When does the corpus luteum deteriorate? What makes progesterone after it deteriorates?
During the 2nd trimester, the placenta.
What sets off oxytocin, what does oxytocin do, and what type of feedback loop does it have?
Estrogen from the ovaries, causes the uterus to contract for birth, positive feedback loop.
What is the first stage of labor?
The opening up and thinning of the cervix.
What is the second stage of labor?
Expulsion of the baby as a result of strong uterine contractions.
