Related Experiment Video
Updated: Aug 14, 2026

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle
Published on: August 30, 2021
Menstrual cycle and Yin-Yang in healthy nursing college students
Hye-Sook Jang1, Mee-Young Im, Byung-Cheul Shin
1Department of Nursing and Health, George Mason University, Fairfax, Virginia, USA.
Abstract:
The aim of this study was to investigate the relationship between several menstrual characteristics and Yin-Yang, using the traditional Korean Sasang typology in 565 female college students. Using the questionnaire for the Sasang Constitution Classification, which consists of 121 forced-choice items, subjects were classified into three groups: So-Yang (small Yang, n=194), Tae-Eum (large Yin, n=164) and So-Eum (small Yin, n=207). Tae-Eum-type subjects showed significantly higher body mass index (BMI) values than other types. There was also a significant difference in menstrual duration between the Tae-Eum and So-Eum groups. However, there were no differences in the cycle or pattern of menstruation, or in the amount of menstrual blood among the groups. There were also no significant differences in the menstrual variables between Yin and Yang subjects. In conclusion, our results regarding the relationship between menstrual cycle and Yin-Yang types are inconsistent with traditional theory. However, this study shows that menstrual duration and BMI differ significantly among Sasang types.
Related Concept Videos
Hormonal Regulation of the Menstrual Cycle
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.
The Menstrual Cycle
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a uterine...
Hormonal Control of the Ovarian Cycle
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...
Menses Phase
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...
Ovarian Cycle
Secretory Phase
Following ovulation, the corpus luteum, a temporary endocrine structure, produces progesterone and estrogens. These hormones stimulate the growth and coiling of endometrial...