Related Experiment Video
Updated: May 27, 2026
09:05
Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle
Published on: August 30, 2021
Summary
This study questions the reliability of menstrual statistics used to propose a new calendar rhythm method for birth control. While James
Area of Science:
- Reproductive biology
- Medical statistics
Background:
- W. H. James defended E. J. Farris's menstrual statistics in prior publications.
- Farris's data were used to develop a new calendar rhythm formula for contraception.
Purpose of the Study:
- To critically evaluate the validity of E. J. Farris's menstrual statistics.
- To assess the reliability of W. H. James's proposed calendar rhythm formula.
Main Methods:
- Analysis of statistical data related to menstrual cycles.
- Critique of estimation methods for menstrual cycle parameters.
Main Results:
- Farris's data exhibit potential for significant bias.
- James's estimations of menstrual cycle parameters are questioned due to data limitations.
Conclusions:
- The study casts doubt on the foundational data used for the proposed birth control method.
- James's statistical methodologies may still hold value for future menstrual variation research.
More Related Videos
06:22Ex Vivo Method for Assessing the Mouse Reproductive Tract Spontaneous Motility and a MATLAB-based Uterus Motion Tracking Algorithm for Data Analysis
Published on: September 1, 2019
09:01Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification
Published on: September 15, 2012
Related Concept Videos
01:19The Menstrual Cycle
The menstrual cycle is a recurrent sequence of changes in the uterine endometrium, specifically its functional layer, the stratum functionalis. This cycle prepares the uterus for potential pregnancy. This cycle typically spans 21–35 days, averaging 28 days, and aligns with the ovarian cycle, regulated by fluctuating levels of ovarian hormones, primarily estrogen and progesterone.
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a uterine...
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a uterine...
01:22Hormonal Regulation of the Menstrual Cycle
The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
01:18Menses Phase
The uterine cycle begins with the menstrual phase, which is considered day one of the cycle and typically lasts about five days. This phase is characterized by the degeneration and shedding of the stratum functionalis, the functional layer of the endometrium.
When fertilization does not occur, the corpus luteum deteriorates, causing a significant drop in the levels of estrogen and progesterone in the body. This hormonal decrease triggers the release of prostaglandins, which cause the uterine...
When fertilization does not occur, the corpus luteum deteriorates, causing a significant drop in the levels of estrogen and progesterone in the body. This hormonal decrease triggers the release of prostaglandins, which cause the uterine...
01:19Secretory Phase
The secretory phase of the menstrual cycle, spanning from day 14 to 28 in a typical 28-day cycle, is a period of significant physiological changes in the female reproductive system. This phase commences immediately after ovulation and is characterized by the preparation of the endometrium for potential embryo implantation.
Following ovulation, the corpus luteum, a temporary endocrine structure, produces progesterone and estrogens. These hormones stimulate the growth and coiling of endometrial...
Following ovulation, the corpus luteum, a temporary endocrine structure, produces progesterone and estrogens. These hormones stimulate the growth and coiling of endometrial...
01:27Ovarian Cycle
The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle length...
01:30Hormonal Control of the Ovarian Cycle
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...