Dr Tara Swart Popular Books
Dr Tara Swart Biography & Facts
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy (i.e., progestational), although they are also present at other phases of the estrous and menstrual cycles. The progestogens are one of three types of sex hormones, the others being estrogens like estradiol and androgens/anabolic steroids like testosterone. In addition, they are one of the five major classes of steroid hormones, the others being the androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as the neurosteroids. All endogenous progestogens are characterized by their basic 21-carbon skeleton, called a pregnane skeleton (C21). In similar manner, the estrogens possess an estrane skeleton (C18), and androgens, an androstane skeleton (C19). The terms progesterone, progestogen, and progestin are mistakenly used interchangeably both in the scientific literature and in clinical settings. Progestins are synthetic progestogens and are used in medicine. Major examples of progestins include the 17α-hydroxyprogesterone derivative medroxyprogesterone acetate and the 19-nortestosterone derivative norethisterone. The progestins are structural analogues of progesterone and have progestogenic activity similarly, but differ from progesterone in their pharmacological properties in various ways. In addition to their roles as natural hormones, progestogens are used as medications, for instance in menopausal hormone therapy and transgender hormone therapy for transgender women; for information on progestogens as medications, see the progesterone (medication) and progestogen (medication) articles. Types and examples The most important progestogen in the body is progesterone (P4). Other endogenous progestogens, with varying degrees of progestogenic activity, include 16α-hydroxyprogesterone (16α-OHP), 17α-hydroxyprogesterone (17α-OHP) (very weak), 20α-dihydroprogesterone (20α-DHP), 20β-dihydroprogesterone (20β-DHP), 5α-dihydroprogesterone (5α-DHP), 5β-dihydroprogesterone (5β-DHP) (very weak), 3β-dihydroprogesterone (3β-DHP), 11-deoxycorticosterone (DOC), and 5α-dihydrodeoxycorticosterone (5α-DHDOC). They are all metabolites of progesterone, lying downstream of progesterone in terms of biosynthesis. Biological function The major tissues affected by progestogens include the uterus, vagina, cervix, breasts, testes, and brain. The main biological role of progestogens in the body is in the female reproductive system, and the male reproductive system, with involvement in regulation of the menstrual cycle, maintenance of pregnancy, and preparation of the mammary glands for lactation and breastfeeding following parturition in women; in men progesterone affects spermiogenesis, sperm capacitation, and testosterone synthesis. Progestogens also have effects in other parts of the body. Unlike estrogens, progestogens have little or no role in feminization. Biochemistry Biosynthesis Progesterone is produced from cholesterol with pregnenolone as a metabolic intermediate. In the first step in the steroidogenic pathway, cholesterol is converted into pregnenolone, which serves as the precursor to the progestogens progesterone and 17α-hydroxyprogesterone. These progestogens, along with another steroid, 17α-hydroxypregnenolone, are the precursors of all other endogenous steroids, including the androgens, estrogens, glucocorticoids, mineralocorticoids, and neurosteroids. Thus, many tissues producing steroids, including the adrenal glands, testes, and ovaries, produce progestogens. In some tissues, the enzymes required for the final product are not all located in a single cell. For example, in ovarian follicles, cholesterol is converted to androstenedione, an androgen, in the theca cells, which is then further converted into estrogen in the granulosa cells. Fetal adrenal glands also produce pregnenolone in some species, which is converted into progesterone and estrogens by the placenta (see below). In the human, the fetal adrenals produce dehydroepiandrosterone (DHEA) via the pregnenolone pathway. Ovarian production Progesterone is the major progestogen produced by the corpus luteum of the ovary in all mammalian species. Luteal cells possess the necessary enzymes to convert cholesterol to pregnenolone, which is subsequently converted into progesterone. Progesterone is highest in the diestrus phase of the estrous cycle. Placental production The role of the placenta in progestogen production varies by species. In the sheep, horse, and human, the placenta takes over the majority of progestogen production, whereas in other species the corpus luteum remains the primary source of progestogens. In the sheep and human, progesterone is the major placental progestogen. The equine placenta produces a variety of progestogens, primarily 5α-dihydroprogesterone and 5α,20α-tetrahydroprogesterone, beginning on day 60. A complete luteo-placental shift occurs by day 120–150. Chemistry The endogenous progestogens are naturally occurring pregnane steroids with ketone and/or hydroxyl groups at the C3 and C20 positions. Medical use Progestogens, including both progesterone and progestins, are used medically in hormonal birth control, hormone therapy, to treat gynecological disorders, to suppress sex hormone levels for various purposes, and for other indications. References Further reading Utian WH, Shoupe D, Bachmann G, Pinkerton JV, Pickar JH (June 2001). "Relief of vasomotor symptoms and vaginal atrophy with lower doses of conjugated equine estrogens and medroxyprogesterone acetate". Fertil. Steril. 75 (6): 1065–79. doi:10.1016/S0015-0282(01)01791-5. PMID 11384629.{{cite journal}}: CS1 maint: multiple names: authors list (link) (the Women's Health, Osteoporosis, Progestin, Estrogen study) Hulley S, Grady D, Bush T, et al. (August 1998). "Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group". JAMA. 280 (7): 605–13. doi:10.1001/jama.280.7.605. PMID 9718051. External links Progestins at the U.S. National Library of Medicine Medical Subject Headings (MeSH) The Nomenclature of Steroids The Million Women Study . Discover the Dr Tara Swart popular books. Find the top 100 most popular Dr Tara Swart books.
Best Seller Dr Tara Swart Books of 2024
-
Dracula
Bram StokerAn Apple Books Classic edition. Few characters have seized readers’ imaginations quite like Count Dracula of Transylvania, the hero of Bram Stoker’s classic. The 1897 novel put vam...
-
The Count of Monte Cristo
Alexandre DumasAn Apple Books Classic edition. Alexandre Dumas’ classic paints a portrait of Edmond Dantès, a dark and calculating man who is willing to wait years to exact his perfect plan for r...
-
A Green Kind of Witch
Sierra CrossCinderella crossed with Mean Girls.   That's what Hazel's daily existence feels like. Born to a family of elegant yet shallow Beige Witches, seventeen y...
-
The Adventures of Sherlock Holmes
Arthur Conan DoyleAn Apple Books Classic You get not one, not two, but 25 gripping mysteries in Arthur Conan Doyle’s first of five collections of Sherlock Holmes short stories. Follow the brilliant ...
-
You Are Kind
Michael GordonA little kindness goes a long way. How can you help encourage your kids to be kind from a young age? Teach kindness to preschoolers Acts of kindness can be fun, easy, and make a ...
-
Nothing to Hide
Scarlett FinnPrize of a lifetime: travel the world with a celebrity billionaire. Come to LA with us, Roxie… It will be so much fun! We have tickets for a latenight talk show! What could possibl...
-
The Odyssey
HomerAn Apple Books Classic edition. Homer’s eighthcentury epic poem is a companion to The Iliad . It tells the story of Odysseus, who journeys by ship for 10 years after the Trojan War...
-
The Seduction Series Boxset
Roxy Sloane“Sensual, thrilling and wild!”   Discover the bestselling series in one collection: THE SEDUCTION, THE BARGAIN, and THE INVITATION. Perfect for fans of Ana Huang, Sierra S...
-
Never Enough
Lexy TimmsBe good enough never is... Anthony Accardi is a man on a mission: make his father's watch company a success while bringing in millions of dollars. To do that, he needs an assi...
-
His Own Heaven
Jennie KewWinner of the 2021 Passionate Plume Award for BDSM Romance Finalist in the 2021 Stiletto Contest for Contemporary Romance He taught her to trust, she taught him to love. Lucy Bar...
-
Get Lucky
Lila MonroeFall for the hot and hilarious romcom spin on 'The Hangover', perfect for fans of Tessa Bailey, Ali Hazelwood, and Emily Henry! What happens when you wake up in a hotel s...
-
The Icing on the Cake
Linda SeedShe’s a baker without a kitchen. He’s got a double oven to spare. It’s a recipe for success, until his mother starts stirring up trouble … Cassie Jordan has a sweet dream to open a...
-
Whiskey Girl
Melissa BelleThey'll do anything for each other…except commit. Logan Wild isn’t just the hottest broncriding cowboy in Texas. He’s also my best friendwith benefits. And that’s all we’ll ev...
-
Masters of Restraint
Ines JohnsonMy new boss is good at giving orders. But his latest demand is NSFW. Especially when his two business partners want in on our deal. My new boss My boss’s boss Their investor &#...
-
Assisting the Bosshole
Kristin MacQueenNo hot water? Check Missed the train? Check Broke my heel? Check Dropped my coffee? Check My first day of my new job can’t possibly go worse, right? Wrong. When I meet Parker Scott...
-
Become A Better Version of Yourself
Ben LeightonThis ebook contains golden nuggets on how to motivate, inspire and improve your current situation. It encompasses the holistic view of self improvement from mental& emotion...
-
Meditations
Emperor of Rome Marcus AureliusMeditations is a series of personal writings by Marcus Aurelius, Roman Emperor 161–180 CE, setting forth his ideas on Stoic philosophy.
-
The Art of War
Sun TzuAn Apple Books Classic edition. It’s believed that Sun Tzu wrote this Chinese military primer during the 5th century BChundreds of years before the Bible. The book’s 13 chapters ex...
-
Holy Bible
The Church of Jesus Christ of Latter-day SaintsThe 2013 edition of the Holy Bible contains all of the study aids contained in the 1979 edition and includes revisions to the study aids, several new photos, updated maps, and adju...
-
A Christmas Carol
Charles DickensAn Apple Books Classic edition. It’s Christmas Eve in Victorian England. While some families don’t know where their next meal will come from, Ebenezer Scrooge sits in his large hom...
-
Teased by Fire
Molly O'HareFrom USA Today bestselling author Molly O’Hare comes an enemiestolovers, older brother’s best friend, romantic comedy with a curvy, antisocial, supernaturalobsessed, allyearround h...
-
Christmas in Sweetbriar Cove
Melody GraceCelebrate the holidays in Sweetbriar Cove with this festive romance collection, containing two sizzling smalltown holiday stories perfect for fans of Tessa Bailey, Sophie Kinsella...
-
Finding Cinderella
Colleen Hoover#1 New York Times bestselling author of It Starts with Us and It Ends With Us writes a free novella about the search for happily ever after. A chance encounter in the dark leads ei...
-
Wuthering Heights
Emily BrontëAn Apple Books Classic edition. If you’ve only ever seen Wuthering Heights on screen, you may have an image of Catherine and Heathcliff as the ultimate starcrossed lovers. But that...
-
Hard Love
Peyton BanksHe was football royalty. Legendary quarterback. A champion.  Reiner Strickland had led his team to three national championships and playing a knight in shining armor was a...
-
Always Yours
Claire RayeSome things are just meant to be... Ellen Somerville and Will McIntyre met by accident and under unusual circumstances. Getting sprayed by a skunk in a parking lot wouldn’t normall...
-
Salvation
Meghan O'FlynnIf you like mouthy detectives, serial killers, and suspenseful mysteries that don't quit, this chilling and actionpacked hardboiled detective series has you covered! Try this ...
-
Escape, A New Life
David J AntocciTo save herself, she had to lose everything. Trapped in a tropical paradise with no memory of how she got there, Abby is thrust into a fight for her life. Hunted by a madman, and c...
-
The Target
Lexy TimmsWhen you seek revenge be sure to dig two graves… Revenge was the only thing I had going for me. It kept me awake at night and drove me into desperate situations in dive bars across...
-
The Honeymoon Homicide
J. R. Mathis & Susan MathisEnjoy this SmallTown Murder Mystery Featuring A Unique Sleuthing Couple I'm Father Tom Greer, a Catholic Priest in a smalltown parish who never expected this . . . When I came...
-
Bewitching a Highlander
Roma CordonDefying all for the love of a bewitching lass. Breena MacRae, a healer from Skye with a touch of witchery in her blood, embarks on a dangerous search for her missing father. She ar...
-
Teach Me
Cassandra DeanFrom awardwinning author Cassandra Dean comes a tale where lessons of pleasure between a curious, sunshine widow and a dissolute, grumpy earl leads to passion and allconsuming love...
-
Eternal
W.J. MayShe will fight for what is hers. When the king is murdered, Katerina, his only daughter, must flee for her life. She finds herself on a strange and dangerous path. Alone for the fi...
-
Becoming Lady Dalton
Carrie LomaxA dance of desire and deceit... In the glittering world of London's ton, Mrs. Viola Cartwright revels in her newfound freedom as a lady of leisureuntil a series of jewel theft...
-
Saltwater Cove
Amelia AddlerSecond chances...and the secrets that sabotage them. At 48 years old, Margie Clifton never expected to be starting her life all over again. But when her brother gifts her a propert...
-
Just Me
Lexy TimmsWe all need somewhere where we feel safe… After leaving her abusive husband, Katherine Marshall is out on her own for the first time. She's hopped from city to city to avoid t...
-
Coffee Girl
Sophie SinclairMackenzie "Kiki" Forbes finds herself in a pickle. Either become her snarky sister's nanny, or move halfway across the country to work as assistanttothestylist of a ...
-
Noxious
Lexy TimmsStop setting yourself on fire to keep someone else warm. Brady and Levi have been together since high school, since before he became famous and started thinking only about himself....
-
The Holy Bible - King James Version
King JamesHoly Bible King James Version Few Sample Paragraphs from The Holy Bible eBook, Genesis (OT) 1 Gen. 1 IN the beginning God created the heaven and the earth. 2 And the earth was with...
-
Silver Santa
Lacey SilksTrapped together on Christmas, their unintended onenight stand becomes a lifechanging encounter amidst the snow. Laura Young's professional role as a security guard at the Sil...
-
Hot Off the Press
Lexy Timms"This is what really happened… reported by a free press, for a free people…" Wes Shaw leads a secret double life. As the secret owner of a billion dollar newspap...
-
Man In The Water
Jon HillAn attempted murder. A missing spouse. And an international conspiracy that could change the world. Jack Green has always been skeptical of socalled facts. Though he's forced ...
-
Little Women
Louisa May AlcottAn Apple Books Classic edition. Meet the Marches! Louisa May Alcott’s classic introduces us to four unforgettable sisters: beautiful Meg, tomboyish Jo, delicate Beth, and Amy, the ...
-
Think and Grow Rich
Greg Habstritt & Napoleon HillThink and Grow Rich is one of the most popular success book of alltime, having sold more than 60 million copies since it was first published more than 70...
-
The Wonderful Wizard of Oz
L. Frank BaumAn Apple Books Classic edition. You’ve seen the iconic 1939 movie, but do you know about the talking field mice, the Winkies, and the Witch of the North that appear in the original...
-
Dream Psychology
Sigmund FreudAn Apple Books Classic edition. Written by the founding father of psychoanalysis, Sigmund Freud’s 1899 book is the definitive text on learning to interpret dreams. Freud’s groundbr...
-
Pretty Little Lies
Ivy ThornFour years ago, Nicolo Marchetti took my innocence. But he left me with something else Nicolo almost took everything from me. My virginity, my reputation, and very nearly my future...
-
How to Choose a Guy in 10 Days
Lila MonroeThe only thing more hilarious than the movies is… real life?! Fall in love with the sizzling grumpysunshine romantic comedy perfect for fans of Sophie Kinsella and Ali Hazlewood! ...
-
Awaken Me
Jenna JacobHe was more than a ghost haunting my dreams…he was real. By day, I’m Julianna Garrett …a prim, proper accountant. By night, I’m tormented by dreams of an alpha, ambereyed Adonis wh...
-
Inception of Gold
Lexy TimmsThings are not as bad as they seem. They are worse. Being the personal assistant to a narcissistic actress who just happens to own the key to my family's undoing isn't ex...