Master Ovulatory Hormones I - Follicular Phase with Picmonic for Medicine

With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.

Ovulatory Hormones I - Follicular Phase

Oval-egg Harmonica with (1) Wand in Follicle
Picmonic
The 28-day menstrual cycle can be described by the ovulatory hormones in two phases: the follicular (proliferative) phase and the luteal (secretory) phase. The follicular phase describes balance between FSH, estrogen, LH and ovulation.
8 KEY FACTS
0-14 Days
Days 0-14 on February Calendar

Though roughly 14 days on average, the follicular phase can vary in length. The follicular phase ends at ovulation. After day 14 (or ovulation), the luteal cycle begins.

GnRH Stimulates FSH and LH
Gonad-gopher stimulating Fish and Luge

The follicular phase begins with hypothalamic secretion of GnRH, stimulating the secretion of FSH and LH.

Follicle Secretes Estrogen
Follicle releasing Easter-eggs

As FSH increases, it induces follicle recruitment and folliculogenesis and growth of granulosa cells. Soon, these cells begin to grow and express LH receptors which then secrete Estrogen.

Negative Feedback from Estrogen
Negative feedback from Easter-egg

Initially, when Estrogen is first secreted, its levels are low. During this time in the follicular phase, low (but still rising) levels of Estrogen work via negative feedback to inhibit hypothalamic GnRH, and subsequently FSH and LH release from the anterior pituitary.

Increased Estrogen Leads to Positive feedback
Up-arrow Easter-egg giving Positive Feedback

Though Estrogen is inhibiting production of FSH and LH, the growing size of the primary follicle (and internal theca/granulosa cells) leads to steadily increasing Estrogen levels. At high enough Estrogen levels, the negative feedback is turned off, and switched to positive feedback. This causes a sudden increase in FSH and LH production.

FSH and LH Surge
Fish and Luge Surging

Due to positive feedback from Estrogen, FSH and LH levels increase dramatically, leading to a "surge" of LH.

Increased Estrogen from Follicle
Up-arrow Easter-egg in Follicle

Estrogen continues to rise, due to stimulus from increasing follicle size, along with increased activity at LH receptors on the follices.

LH Spike Leads to Ovulation
Luge spike causing Ovulation

The event leading to ovulation is the LH spike. Under positive feedback from Estrogen, LH is secreted even more. This ensuing "spike" of LH is responsible for ovulation.

Unlock all 8 facts & definitions with Picmonic Free!

JOIN FREE

Take the Ovulatory Hormones I - Follicular Phase Quiz

Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.

START QUIZ NOW

It's worth every penny

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Ace Your Medical (MD/DO) Classes & Exams with Picmonic:

Over 900,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Medical (MD/DO) student study app.

Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medical (MD/DO) education. Whether you’re studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, we’re here to help.

Works better than traditional Medical (MD/DO) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.