[DEVBIO] LECTURE 10 (A&B) Hormonal Control of Reproduction.docx - Google Docs

Hormonal control of reproduction

The regulation of vertebrate reproduction through environmental cues and hormonal signals.

Cyclic activity

Reproduction in lower vertebrates that is related to changing seasons and occurs when environmental conditions are optimal.

Environmental cues

Factors such as day length, seasonal temperature, amount of rainfall, and lunar cycle that regulate reproductive cycles.

Ovulation

occurs on on the 7th 8th or 9th day and is the The release of an egg from the ovary during the reproductive cycle.

Gestation period

The 5 month long duration of pregnancy in mammals.

Palolo worms

Pelagic worms whose reproductive cycle is regulated by lunar cycle. October-November: last quarter of lunar cycle

Neurosecretory cells of the hypothalamus

Cells in the hypothalamus that secrete gonadotropin-releasing hormone (GnRH) to regulate reproductive hormones.

Gonadotropic hormones

Hormones released by the pituitary gland, including follicle stimulating hormone (FSH) and luteinizing hormone (LH), that act on the gonads to release their hormones.

Estrous cycle

The reproductive cycle characterized by behavioral changes and a limited window of sexual activity.

Estrus

The period of sexual activity and mating during the estrous cycle.

proestrus

estrus

metestrus

diestrus

5 stages of estrus cycle

mono di poly

types of estrus cycle

Metestrus, proestrus, estrus, diestrus

stages of estrus

[ ] - period of repair

[ ]- period of preparation when follicles grow

[ ] - period of heat; when mating occurs; corresponds to or within the time range of ovulation

[ ] - changes go back to original; becomes small and anemic

Menstrual cycle

The reproductive cycle characteristic of anthropoid primates, including humans, involving changes in the uterus and ovaries.

Gonadal steroids

Hormones produced by the ovaries (estrogen) and testes (testosterone) that play a role in reproductive control.

Negative feedback regulation

A mechanism in which high levels of a hormone inhibit the release of other hormones to maintain homeostasis.

Inhibin

A secretory factor released by Sertoli cells in the testes that regulates the release of FSH.

Primary sex characteristics

The development of reproductive organs and accessory organs.

Secondary sex characteristics

Physical and behavioral characteristics that distinguish males and females.

Granulosa cells

Cells in the ovary that respond to FSH and secrete estrogen.

Estrogen

Hormone secreted by granulosa cells, responsible for building up the said hormone secretion and regulating the menstrual cycle.

Negative feedback regulation

Mechanism where high levels of estrogen send signals to the hypothalamus and pituitary gland to regulate hormone levels.

Follicle stimulating hormone FSH

what hormone, stimulates the growth of granulosa cells and supports the development of follicles.

Luteinizing hormone LH

what hormone, stimulates ovulation and the development of the corpus luteum.

androgens

what hormone can cross the membrana granulosa in the development of follicle

this is also then converted to estrogen via the enzyme, aromatase

Ovarian Cycle

The histological changes occurring in the ovary, consisting of the follicular phase and luteal phase.

Follicular Phase

The phase of the ovarian cycle from day 1 to the middle of the cycle, characterized by the growth of follicles.

231

order of events in regulation of hormone among females

[ ] When estrogen level goes above the set point, these can send negative feedback regulation to the hypothalamus and anterior pituitary gland to regulate the blood, GNRH, FSH, and LH

[ ] FSH is also subject to negative feedback regulation by inhibin

[ ] The granulosa cells, in response to FSH, secrete additional estrogen and start to produce their own estrogen including the estrogen converted from theca cells. There is a building up of estrogen secretion

Luteal Phase

The phase of the ovarian cycle after ovulation, from the 15th to 28th day.

Ovulation

The release of a mature follicle from the ovary.

FSH

[ ] stimulates and supports the growth of granulosa cells surrounding the oocytes.

estrogen

Towards the middle of the cycle, the level of [ ] will increase because as the population of granulosa cell increases, there will be more granulosa cells that will secrete it

Corpus luteum

A collapsed yellow body that forms after ovulation and secretes progesterone and estrogen.

its formation is supported by levels of LH and FSH during luteal phase

Progesterone

Hormone that maintains the uterine lining and is secreted by the corpus luteum during the luteal phase.

Uterine Cycle

The histological changes occurring in the endometrium of the uterus, consisting of the menstrual phase and proliferative phase.

Menstrual Phase

The phase of the uterine cycle where the endometrial lining is shed and menstrual flow occurs.

Proliferative Phase

The phase of the uterine cycle where the endometrial lining thickens and prepares for embryonic development.

Secretory Phase

The phase of the uterine cycle where the endometrial lining is at its thickest and is conducive for implantation and support for the developing embryo.

Menstrual flow

The shedding of the endometrial lining and the start of a new menstrual cycle.

Gonadotropin-releasing hormone (GnRH)

Hormone released by the hypothalamus to stimulate the release of FSH and LH.

Pituitary Hormone Cycle

The release of FSH and LH by the pituitary gland, which regulates the ovarian cycle.

Sex Hormone Cycle

The release of estrogen and progesterone, which regulate the uterine cycle.

Hormone secretion variations

The length of the menstrual cycle and phases can vary, influenced by factors such as age.

FSH effects

Stimulates follicle growth, estrogen secretion, and enhances the effect of LH in stimulating ovulation.

LH effects

Stimulates final follicle development, ovulation, corpus luteum development, and progesterone production.

Estrogen effects

Stimulates repair of the uterine lining, inhibits FSH, and stimulates LH release.

Progesterone effects

Maintains the uterine lining, inhibits FSH and LH release, and its decline results in menstruation and the start of a new cycle.

Progesterone

A hormone that is responsible for maintaining the endometrial lining and supporting pregnancy.

hCG (human chorionic gonadotropin)

A hormone that helps maintain progesterone production until the end of the first trimester of pregnancy when the placenta takes over hormone production.

hPL (human placental lactogen)

A hormone that influences growth, lactation, and lipid and carbohydrate metabolism.