Functions of Estrogen and Progesterone Flashcards

This set of flashcards covers the chemistry, biosynthesis, metabolism, and physiological functions of estrogen based on the medical lecture transcript.

C18 steroid

The chemical classification of estrogen based on the number of carbon atoms in its structure.

Forms of Estrogen

The three forms present in plasma: $\beta\text{-estradiol}$, Estrone, and Estriol.

Relative Potency of Estrogens

The quantity and potency of $\beta\text{-estradiol}$ are more significant than those of estrone and estriol.

Follicular Phase Estrogen Range

The plasma level of estrogen in females at a normal reproductive age during the follicular phase, ranging from $30 \, pg/mL$ to $200 \, pg/mL$.

Male Estrogen Range

The normal range of estrogen in adult males, which is $12 \, pg/mL$ to $34 \, pg/mL$.

Theca Interna Cells

The cells within ovarian follicles that secrete a large quantity of estrogen in non-pregnant females.

Corpus Luteum

The ovarian structure that secretes a small quantity of estrogen in non-pregnant females.

Placenta

The organ that secretes a large amount of estrogen in pregnant women.

Albumin

The primary plasma protein responsible for transporting a large quantity of estrogen in the blood.

Starting Material for Steroids

Cholesterol is the starting material for both male and female steroid hormones.

C19 androstenedione and testosterone

The androgenic steroid precursors that are transformed into $C18$ estrogenic steroids in the testes, ovaries, adrenal cortex, and placenta.

Aromatase

The enzyme identified in the synthesis pathway that converts androstenedione to estrone and testosterone to $\beta\text{-estradiol}$.

Liver

The primary site of estrogen degradation where it is conjugated with glucuronides and sulfates.

Estrogen Excretion Ratio

About $1/5\text{th}$ of conjugated products are excreted in the bile and $4/5\text{th}$ are excreted in the urine.

Main Function of Estrogen

To promote cellular proliferation and tissue growth in the sexual organs and other reproduction-related tissues.

Isocitrate Dehydrogenase (ICD)

The estradiol-sensitive enzyme responsible for an increase in $O_2$ consumption in the endometrium, placenta, and mammary glands.

Vaginal Glycolysis

The process by which vaginal glycogen is converted to lactic acid ($LA$), creating an acidic environment with a $pH$ of $4.0$ to $5.0$.

Hypocholesterolemic Effect

The cholesterol-lowering effect of estrogen characterized by a fall in $LDL$ levels and an increase in $HDL$ levels.

Uterine Oxytocin Sensitivity

Estrogen increases the sensitivity of uterine muscles to oxytocin, leading to increased contractility.

Effect on Fallopian Tubes

Estrogen increases the number and size of ciliated epithelial cells and the activity of the cilia to facilitate ovum movement.

Gynecoid Pelvis

The normal female type of pelvis characterized by broadening with an increased transverse diameter and an oval shape, optimal for childbirth.

Epiphyseal Fusion

The effect where estrogen causes the fusion of the epiphysis with the shaft in long bones by the end of puberty, which happens earlier in females than in males.

Osteoporosis

A condition in menopausal women where bones become weak and fragile due to a lack of $\beta\text{-estradiol}$ secretion.

Electrolyte Balance Regulation

Estrogen causes sodium ($Na^+$) and water retention from the renal tubules, a significant effect during pregnancy that increases extracellular fluid ($ECF$) volume.

Follicle-Stimulating Hormone (FSH)

The anterior pituitary hormone that regulates estrogen secretion after being stimulated by $GnRH$ from the hypothalamus.

Inhibin

A hormone secreted by granulosa cells that decreases estrogen secretion by inhibiting the secretion of $FSH$ and $GnRH$.