Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Oogenesis

Oogenesis

In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...

Interphase

Interphase

The cell cycle occurs over approximately 24 hours (in a typical human cell) and in two distinct stages: interphase, which includes three phases of the cell cycle (G1, S, and G2), and mitosis (M). During interphase, which takes up about 95 percent of the duration of the eukaryotic cell cycle, cells grow and replicate their DNA in preparation for mitosis.
Phases of Interphase
Following each period of mitosis and cytokinesis, eukaryotic cells enter interphase, during which they grow and replicate...

Ovarian Cycle

Ovarian 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...

Oogenesis

Oogenesis

Oogenesis, the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...

Hormonal Control of the Ovarian Cycle

Hormonal 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...

The Menstrual Cycle

The 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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

The relationship between cyclic changes in thyroid function and behavior of cats with brain stem lesions.

Journal of psychiatric research·2009

Same author

Gender differences in abused children with and without disabilities.

Child abuse & neglect·1997

Same author

Patterns of human reproduction and geographic latitude.

International journal of biometeorology·1995

Same author

Photoperiod, temperature, and regional patterns of conceptions in the USA.

International journal of biometeorology·1993

Same author

An eleven-year cycle in human births.

International journal of biometeorology·1991

Same author

The solar wind and hallucinations--a possible relation due to magnetic disturbances.

Bioelectromagnetics·1991

Search research articles

Related Experiment Video

Updated: Jul 21, 2026

Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification

Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification

Published on: September 15, 2012

The 11-year cycle in human births

W Randall¹, W S Moos

¹Department of Psychology, University of Iowa, Iowa City 52242.

International Journal of Biometeorology

|May 1, 1993

Summary

Human conception rhythms show an 11-year cycle, correlating with solar activity and geophysical variables. This finding may aid in regulating human conception patterns.

Area of Science:

Environmental Science
Human Biology
Astronomy

Background:

Human birth rates exhibit cyclical patterns that warrant investigation.
Previous research suggests potential links between biological rhythms and environmental factors.

Purpose of the Study:

To analyze annual human birth numbers for an 11-year cycle.
To investigate correlations between human conception rhythms and solar/geophysical variables.

Main Methods:

Analysis of annual birth data from seven global regions (1930-1984).
Application of periodic regression and Fourier series fitting to identify temporal patterns.
Comparison of identified rhythms with sunspot cycles, solar flares, magnetic indices, and temperature.

More Related Videos

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle

Published on: August 30, 2021

Alignment of Synchronized Time-Series Data Using the Characterizing Loss of Cell Cycle Synchrony Model for Cross-Experiment Comparisons

Alignment of Synchronized Time-Series Data Using the Characterizing Loss of Cell Cycle Synchrony Model for Cross-Experiment Comparisons

Published on: June 9, 2023

Related Experiment Videos

Last Updated: Jul 21, 2026

Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification

Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification

Published on: September 15, 2012

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle

Published on: August 30, 2021

Alignment of Synchronized Time-Series Data Using the Characterizing Loss of Cell Cycle Synchrony Model for Cross-Experiment Comparisons

Alignment of Synchronized Time-Series Data Using the Characterizing Loss of Cell Cycle Synchrony Model for Cross-Experiment Comparisons

Published on: June 9, 2023

Main Results:

Significant 11-year rhythms were detected in human birth data across multiple regions.
Correlations were established between these rhythms and sunspot activity, solar flares, magnetic disturbances, and temperature.
The 11-year solar cycle showed a notable correlation with human conceptions.

Conclusions:

Human conception patterns are influenced by an 11-year cycle, strongly linked to solar and geophysical phenomena.
Understanding these correlations provides insights for potential regulation of human conception rhythms.
Further research into controlling these biological rhythms based on solar and geophysical cycles is suggested.