Endocrine System and Menstrual Cycle Hormonal Control

Vocabulary flashcards covering the major glands and hormones of the human endocrine system, as well as the hormonal regulation, phases, and structures of the ovarian and menstrual cycles.

Hypothalamus

A brain region that makes hormones that control the pituitary gland, as well as hormones that are stored in the pituitary gland.

Pituitary gland

An endocrine gland that produces hormones that regulate many of the other endocrine glands.

Parathyroid glands

Four glands that release parathyroid hormone, which regulates the level of calcium in the blood.

Thymus

An organ that releases thymosin during childhood, which stimulates T cell development.

Adrenal glands

Glands that release epinephrine and nonepinephrine, which help the body deal with stress.

Pineal gland

An endocrine gland that releases melatonin, which is involved in rhythmic activities such as daily sleep-wake cycles.

Thyroid

An endocrine gland that produces thyroxine, which regulates metabolism.

Pancreas

A gland that produces insulin and glucagon, which regulate the level of glucose in the blood.

Insulin

A pancreatic hormone that regulates blood sugar by taking glucose out of the blood.

Glucagon

A pancreatic hormone that regulates blood sugar by adding glucose into the blood.

Ovaries

Female reproductive organs that produce estrogen (required for egg development and secondary sex characteristics) and progesterone (which prepares the uterus for a fertilized egg).

Testes

Male reproductive organs that produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics.

Follicular phase

The phase of the menstrual cycle that focuses on the maturity of follicular cells.

FSH (Follicle Stimulating Hormone)

A hormone released from the pituitary gland that stimulates the growth, maturity, and development of the primary follicle.

Graafian follicle

A fluid-filled follicle containing a developing egg cell that matures from a primary follicle under the influence of FSH; during this process, the egg cell undergoes meiosis to form a haploid egg cell.

Ovulation phase

The phase taking place on the $14^{\text{th}}$ day of the cycle where the maturing Graafian follicle moves to the surface of the ovary and LH causes it to rupture and release an egg cell.

LH (Luteinizing Hormone)

A hormone released from the pituitary gland that triggers ovulation (the release of an egg from the ovary) and stimulates the formation of the corpus luteum.

Corpus luteum

Glandular tissue formed from the remains of the ruptured Graafian follicle with the help of FSH and LH, which secretes progesterone and oestrogen.

Uterine phase

A series of changes occurring in the endometrium lining of the uterus throughout the cycle.

Endometrium lining

The inner uterine lining that is built and thickened by oestrogen and maintained as glandular secretory by progesterone to prepare for implantation of an egg cell.

Menstruation

The breakdown of the uterine lining that occurs when pregnancy does not happen, leading the corpus luteum to break down and causing both estrogen and progesterone levels to decrease.

Negative feedback

A control mechanism that reverses a change in order to restore conditions to normal.