1 Hypothalamus-Pituitary-Gonad Axis and Follicle Maturation

Total Page：16

File Type：pdf, Size：1020Kb

The Female Reproductive System - 1 Hypothalamus-Pituitary-Gonad Axis and Follicle Maturation Jennifer Carbrey Ph.D. Department of Cell Biology Common Axis once each cycle an increase in estrogen causes an increase in GnRH production (and progesterone) In males & females, GnRH secretion is pulsatile. Local secretion of testosterone is needed for development of ovum (female) and of sperm (male). Inhibin B decreases FSH secretion. Sex hormones regulate GnRH, LH and FSH. image by Uwe Gille (modified), http://commons.wikimedia.org/wiki/File:Hypothalamus-Hypophysis-Testicle-Hormone-Axis_%28engl.%29.svg, Creative Commons Attribution-Share Alike 3.0 Unported license The Roles of the Ovary Oocyte Number Germ cells (oocytes) are generated in embryogenesis (10-20 milllion per ovary at birth). 400-500 oocytes actually mature to ovulation. Oocyte Maturation oocyte granulosa cells theca cells LH FSH Theca cells Granulosa cells Estrogen increases the number of LH receptors -positive feedback produce convert As follicle matures, the follicle produces more and more estrogen testosterone testosterone In addition, the number of LH and FSH receptors increases, making the follicle to estrogen more sensitive to their effects Image modified from Cambridge Natural History, Volume X, Mammalia (1902), by Frank E. Beddard, Macmillan & Co., Limited, public domain Ovulation image by Uwe Gille (modified), http://commons.wikimedia.org/wiki/File:Hypothalamus-Hypophysis-Testicle-Hormone-Axis_%28engl.%29.svg, Creative Commons Attribution-Share Alike 3.0 Unported license Role of kisspeptin in LH surge LH mid cycle surge due to estrogen positive feedback to kisspeptin LH surge triggers ovulation. Phases of the Ovary 2., 3. follicle maturation 4. ovulation 5. corpus luteum formation 6. corpus luteum degeneration image by Shazz (modified), http://commons.wikimedia.org/wiki/File:Order_of_changes_in_ovary.svg , Creative Commons Attribution-Share Alike 3.0 Unported license Key Concepts Differentiation of germ cells as well as synthesis and secretion of sex hormones are the common functions of the ovaries and testes. FSH and LH govern germ cell maturation and sex steroid hormone production in both males and females. As the chosen follicle matures, it produces estrogen which increases its own sensitivity to LH (and FSH) and reduces the amount of FSH released by the pituitary. The reduction in FSH leads to the death of less mature follicles. In females, a second group of kisspeptin neurons is responsible for the ability of estrogen to cause the LH surge. .

Copy Link

Recommended publications

Expression Pattern of Delta-Like 1 Homolog in Developing Sympathetic Neurons and Chromaffin Cells
Published in "Gene Expression Patterns 30: 49–54, 2018" which should be cited to refer to this work. Expression pattern of delta-like 1 homolog in developing sympathetic neurons and chromaffin cells ∗ Tehani El Faitwria,b, Katrin Hubera,c, a Institute of Anatomy & Cell Biology, Albert-Ludwigs-University Freiburg, Albert-Str. 17, 79104, Freiburg, Germany b Department of Histology and Anatomy, Faculty of Medicine, Benghazi University, Benghazi, Libya c Department of Medicine, University of Fribourg, Route Albert-Gockel 1, 1700, Fribourg, Switzerland ABSTRACT Keywords: Delta-like 1 homolog (DLK1) is a member of the epidermal growth factor (EGF)-like family and an atypical notch Sympathetic neurons ligand that is widely expressed during early mammalian development with putative functions in the regulation Chromaffin cells of cell differentiation and proliferation. During later stages of development, DLK1 is downregulated and becomes DLK1 increasingly restricted to specific cell types, including several types of endocrine cells. DLK1 has been linked to Adrenal gland various tumors and associated with tumor stem cell features. Sympathoadrenal precursors are neural crest de- Organ of Zuckerkandl rived cells that give rise to either sympathetic neurons of the autonomic nervous system or the endocrine Development ffi Neural crest chroma n cells located in the adrenal medulla or extraadrenal positions. As these cells are the putative cellular Phox2B origin of neuroblastoma, one of the most common malignant tumors in early childhood, their molecular char- acterization is of high clinical importance. In this study we have examined the precise spatiotemporal expression of DLK1 in developing sympathoadrenal cells. We show that DLK1 mRNA is highly expressed in early sympa- thetic neuron progenitors and that its expression depends on the presence of Phox2B.
[Show full text]
The Morphology, Androgenic Function, Hyperplasia, and Tumors of the Human Ovarian Hilus Cells * William H
THE MORPHOLOGY, ANDROGENIC FUNCTION, HYPERPLASIA, AND TUMORS OF THE HUMAN OVARIAN HILUS CELLS * WILLIAM H. STERNBERG, M.D. (From the Department of Pathology, School of Medicine, Tulane University of Louisiana and the Charity Hospital of Louisiana, New Orleans, La.) The hilus of the human ovary contains nests of cells morphologically identical with testicular Leydig cells, and which, in all probability, pro- duce androgens. Multiple sections through the ovarian hilus and meso- varium will reveal these small nests microscopically in at least 8o per cent of adult ovaries; probably in all adult ovaries if sufficient sections are made. Although they had been noted previously by a number of authors (Aichel,l Bucura,2 and von Winiwarter 3"4) who failed to recog- nize their significance, Berger,5-9 in 1922 and in subsequent years, pre- sented the first sound morphologic studies of the ovarian hilus cells. Nevertheless, there is comparatively little reference to these cells in the American medical literature, and they are not mentioned in stand- ard textbooks of histology, gynecologic pathology, nor in monographs on ovarian tumors (with the exception of Selye's recent "Atlas of Ovarian Tumors"10). The hilus cells are found in clusters along the length of the ovarian hilus and in the adjacent mesovarium. They are, almost without excep- tion, found in contiguity with the nonmyelinated nerves of the hilus, often in intimate relationship to the abundant vascular and lymphatic spaces in this area. Cytologically, a point for point correspondence with the testicular Leydig cells can be established in terms of nuclear and cyto- plasmic detail, lipids, lipochrome pigment, and crystalloids of Reinke.
[Show full text]
Some Fundamentals of Gonadal Development and Function Richmond W
Henry Ford Hospital Medical Journal Volume 8 | Number 3 Article 8 9-1960 Some Fundamentals Of Gonadal Development And Function Richmond W. Smith Jr. Raymond C. Mellinger Follow this and additional works at: https://scholarlycommons.henryford.com/hfhmedjournal Part of the Life Sciences Commons, Medical Specialties Commons, and the Public Health Commons Recommended Citation Smith, Richmond W. Jr. and Mellinger, Raymond C. (1960) "Some Fundamentals Of Gonadal Development And Function," Henry Ford Hospital Medical Bulletin : Vol. 8 : No. 3 , 324-344. Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol8/iss3/8 This Article is brought to you for free and open access by Henry Ford Health System Scholarly Commons. It has been accepted for inclusion in Henry Ford Hospital Medical Journal by an authorized editor of Henry Ford Health System Scholarly Commons. For more information, please contact [email protected]. SOME FUNDAMENTALS OF GONADAL DEVELOPMENT AND FUNCTION* RICHMOND W. SMITH, JR., M.D.** AND RAYMOND C. MELLINGER, M.D.** The traditional division of animal life into male and female forms is based on obvious biological differences, but these distinctions become less striking when we realize that life, in a sheer physico-chemical sense, is a spectrum of sexuality that maleness and femaleness are relative terms. Our conceptual devotion to a two compartment universe is apparent in many areas of life, sociologic, moral, legal, spiritual or biologic. Although reproductive obligations remain clear, albeit increasingly restricted, man's greater social sophistication is molding an order in which underlying biological distinctions of the two sexes are sometimes obscured by the potent solvents of culture, leisure and intellect.
[Show full text]
Downloaded from Bioscientifica.Com at 09/30/2021 12:01:31AM Via Free Access 706 D BARON and Others · Foxl2 and Rainbow Trout Gonad Differentiation
705 An evolutionary and functional analysis of FoxL2 in rainbow trout gonad differentiation Daniel Baron1, Julie Cocquet2, Xuhua Xia3, Marc Fellous2, Yann Guiguen1 and Reiner A Veitia2 1INRA-SCRIBE, Campus de Beaulieu, 35042 Rennes Cedex, France 2INSERM E0021 & V361, Génomique fonctionnelle du Développement, Hôpital Cochin, 123 Bd de Port Royal, Paris, France 3Department of Biology and the Center for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, Canada (Requests for offprints should be addressed to R A Veitia; Email: [email protected]) Abstract FOXL2 is a forkhead transcription factor involved in ovarian development and function. Here, we have studied the evolution and pattern of expression of the FOXL2 gene and its paralogs in fish. We found well conserved FoxL2 sequences (FoxL2a) and divergent genes, whose forkhead domains belonged to the class L2 and were shown to be paralogs of the FoxL2a sequences (named FoxL2b). In the rainbow trout, FoxL2a and FoxL2b were specifically expressed in the ovary, but displayed different temporal patterns of expression. FoxL2a expression correlated with the level of aromatase, the key enzyme in estrogen production, and an estrogen treatment used to feminize genetically male individuals elicited the up-regulation of both paralogs. Conversely, androgens or an aromatase inhibitor down-regulated FoxL2a and FoxL2b in females. We speculate that there is a direct link between estrogens and FoxL2 expression in fish, at least during the period where the identity of the gonad is sensitive to hormonal treatments. Journal of Molecular Endocrinology (2004) 33, 705–715 Introduction been detected (Cocquet et al. 2002, Pannetier et al.
[Show full text]
Role of Thyroid Hormones in the Development of Gonadal Sex, External Morphology and Intestinal System of Zebrafish (Danio Rerio)
ROLE OF THYROID HORMONES IN THE DEVELOPMENT OF GONADAL SEX, EXTERNAL MORPHOLOGY AND INTESTINAL SYSTEM OF ZEBRAFISH (DANIO RERIO) by PRAKASH SHARMA, B.S., M.S. A Dissertation In BIOLOGY Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Approved Dr. Reynaldo Patiño Chair of Committee Dr. Gregory D. Mayer Dr. James Carr Dr. Lauren Gollahon Dr. Nathan Collie Dr. Richard Strauss Dominick Joseph Casadonte Dean of the Graduate School December, 2012 Copyright 2012, Prakash Sharma Texas Tech University, Prakash Sharma, December 2012 ACKNOWLEDGMENTS First, I am privileged to thank Dr. Reynaldo Patiño, my major advisor and mentor for his guidance and encouragement which have been of immense support. He has been there to help and extend his guidance, anywhere, anytime, even at wee hours despite his busy schedule. Through him, I have not only picked up skills and a sense of responsibility, but also a whole new level of dedication. It is definitely a lifetime opportunity to have worked with an efficient and resourceful scientist like him. I am honored to thank my Committee Members for their enthusiasm to scrutinize my research. Thanks to Drs. Gregory D. Mayer, James Carr, Lauren Gollahon, Nathan Collie, and Richard Strauss. Their suggestions, ideas and information on the analysis of my study were of great significance. I could not have asked for a better cooperating team. Also, a million thanks to Dr. Gregory D. Mayer for supporting and guiding me immensely throughout my research program and for allowing me the opportunity to work in his lab.
[Show full text]
A Macroscopical Study of the Inferior Phrenic Artery of Female Rats, With
Okajimas Folia Anat. Jpn.. 69(1): 1-10, May, 1992 A Macroscopical Study of the Inferior Phrenic Artery of Female Rats, with Reference to the Embryological Background of Occurrence of the Genital Artery from this Artery By Shigeki MIZUKAMI, Shigenori TANAKA and Madoka MORIYA School of Nursing, Fukui Prefectural College, Oohatamachi 97-21-3, Fukui 910 Department of Anatomy, School of Medicine, Kanazawa University, Takaramachi 13-1, Kanazawa 920 -Received for Publication, December 24, 1991- Key Words: Inferior phrenic artery, Diaphragm, Genital branch. Pleuroperitoneal fold, Female rat Summary: The principal aim of this study was to elucidate the general features of the inferior phrenic artery (IPA) of female rats which retain the original embryonic configuration of this artery. The artery of the right side was found to be detached from the renal artery, while that of the left side arose from the aorta. Between these fellow arteries, however, no essential morphological differences were discernible. At some point not far from their origin, they were found to break up into the ascending, suprarenal, suprareno genital and descending arteries. The ascending artery of the right side coursed along with the phrenic nerve, and vascularized a greatest portion of the total area of the partes sternalis et costalis of the diaphragm. Furthermore, the artery was found to be intimately associated with the inferior caval vein. Thus, it could be assumed that this artery of adult rats has been embryologically related to the musculus diaphragmaticus, transverse septum, ventral pleuroperitoneal fold, and the caval venous mesentery. The suprarenal artery took its course along the superior margin of this gland to reach the lateroinferior part of the pars costalis of the diaphragm.
[Show full text]
Hypothalamus Pituitary Gonadal Axis
LECTURE I: Hypothalamus Pituitary Gonadal Axis EDITING FILE IMPORTANT MALE SLIDES EXTRA FEMALE SLIDES LECTURER’S NOTES 1 HYPOTHALAMUS PITUITARY GONADAL AXIS Lecture One OBJECTIVES ● Define hypothalamic-pituitary –gonadal axis (HPG) ● Name the hormones and target tissues of the HPG axis. ● Describe the feedback mechanisms in the hypothalamic-pituitary-gonadal axis and their importance in the control of reproductive function. ● Outline the endocrine regulation of testicular function: the role of GnRH, FSH, LH, testosterone, and inhibin. ● Outline the endocrine regulation of ovarian function: the role of GnRH, FSH, LH, estrogen, Progesterone, and inhibin. ● Characterize hypothalamic pituitary relationship ● Name the hypophysiotropic hormones and outline the effects that each has on anterior pituitary function It is recommended that students be at least familiar with the histology of both male and female reproductive systems before starting this lecture, a brief overview can be found in page 5. Introduction What are hormones? Chemical substances secreted in a small amount from an endocrine gland directly to the bloodstream in response to stimulus to cause physiological responses at the target tissues. Figure 1-1 How hypothalamus controls anterior pituitary? By the secretion of hypothalamic-releasing and hypothalamic inhibitory hormones into the primary capillary plexus of the hypothalamo-hypophyseal portal system, which travel through portal veins to act on specific receptors on different pituitary cells to secrete their respective hormones. What are the hormones secreted by anterior pituitary? Figure 1-2 Numerous hormones are secreted by the anterior pituitary, main ones are: GH, LH, FSH, TSH, ACTH, Prolactin. How hypothalamus controls posterior pituitary? Through nervous signals that travel through hypothalamic-pituitary tract to trigger the release of hormones stored in axon terminals within the posterior pituitary.
[Show full text]
The Male Reproductive System - 1 Hypothalamus-Pituitary-Gonad Axis
The Male Reproductive System - 1 Hypothalamus-Pituitary-Gonad Axis Jennifer Carbrey Ph.D. Department of Cell Biology Sexual Differentiation Primordial germ cells in male & female generated in embryogenesis. Chromosomal sex determinants are XX and XY. Expression of the SRY gene on chromosome Y results in testes (male). Presence of testes vs ovaries determines gonadal sex. Gonads are the source of hormone which determines external and internal genitalia (phenotypic sex). The SRY gene is necessary for maleness but not sufficient. The testosterone receptor gene on the X chromosome is also required. Common Axis In males & females, GnRH secretion is pulsatile. Local secretion of testosterone is needed for development of ovum (female) and of sperm (male). Inhibin B decreases FSH secretion. Sex hormones regulate GnRH, LH and FSH. image by Uwe Gille (modified), http://commons.wikimedia.org/wiki/File:Hypothalamus-Hypophysis-Testicle-Hormone-Axis_%28engl.%29.svg, Creative Commons Attribution-Share Alike 3.0 Unported license Maturation of the H-P-Gonad Axis At puberty, adult pattern of GnRH secretion is attained. Male = 24 hr cycle. Female = 28 day cycle. Maturation requires kisspeptin and GRP54 activity in hypothalamic neurons secreting GnRH. Key Concepts Differentiation of germ cells as well as synthesis and secretion of sex hormones are common functions of the ovaries and testes. Reproduction in both males and females is controlled by pulsatile secretion of GnRH from the hypothalamus which controls FSH and LH secretion from the pituitary. FSH and LH govern germ cell maturation and sex steroid hormone production in both males and females. Sex steroid hormones regulate FSH and LH by negative feedback (through kisspeptin neurons), are required for fertility and secondary sexual physical characteristics.
[Show full text]
The Endocrine System from Our Neurotransmitter Chapter: Endocrine Neurotransmitters Convey a Message from the Glands Secrete Sending Neuron to the Receiving Neuron(S)
11/10/2014 The Endocrine System From Our Neurotransmitter Chapter: Endocrine Neurotransmitters convey a message from the glands secrete sending neuron to the receiving neuron(s). “hormones” Hormones, on the other hand, “broadcast” a message directly into throughout the body via the bloodstream, so are able bloodstream. to influence cells in many distant organs/tissues. But we’ll hold off on hormones for the moment, In Chap 11 the because before there could be hormones, there had Hypothalamus, to be genes to develop the glands. Pituitary, Gonads, and Adrenal glands will play a role in sexuality What defines male or female ? Sexual Differentiation in Mammals (Chap 11) How do we become the sexual individuals we are? Differentiation Role of Sex Chromosomes • Genetic sex (XX or XY) is determined by the sperm (X-bearing or Y-bearing) that fertilizes the egg. • Early gonads have potential to be either ovaries or testes for ~6 weeks. • Sex-determining region of the Y chromosome (SRY) is a gene producing a *protein causing the middle of baby gonads to become testes. • If testes develop, they begin to produce androgens like testosterone. • If SRY gene is not present, the outside of the early gonads turns into ovaries. *sometimes called testis-determining factor 1 11/10/2014 Experimental Evidence • Removal of SRY gene from Y XY mouse develops as a female • Add SRY gene to X XX mouse develops as a male • Injection of SRY’s protein in genetic female develops testes • Inject genetic male with drug that blocks the SRY’s protein develops ovaries Figure 13.6 Endocrine Glands – Release hormones directly into bloodstream Although the pituitary is sometimes called the “master gland” in Organizational Effects fact the hypothalamus is the “master” of the pituitary.
[Show full text]
Sex Determination
Sex Determination • Most animal species are dioecious – 2 sexes with different gonads • Females: produce eggs in ovaries • Males: produce sperm in testes • Exception • Hermaphrodites: have both types of gonads • Many animals also differ in secondary traits What Determines Sex? • Individual differentiates into male or female • Causes – Genetic factors (sex chromosomes) – occur at fertilization – Environmental factors – occur after fertilization How Do Vertebrate Gonads Develop? • Gonad differentiation – first morphological difference between males and females • Gonads develop from intermediate mesoderm • Paired structures What is a Bipotential Gonad? • Indifferent gonad develops – 4-6 wks in human = “bipotential stage” – genital ridge forms next to developing kidney (mesonephric ridge) Structure of the Indifferent Gonad • Sex cords form – Columns of epithelial cells penetrate mesenchyme – Primordial germ cells migrate from posterior endoderm – Become surrounded by sex cords What is the Fate of the Sex Cords? • Initially in central area (medulla, medullary) – Will develop in male – Proliferate • In outer area (cortex, cortical) – Develop in female • Normally binary choice Differentiation of the Gonad • Into testes or ovaries – primary sex determination – does not involve hormones network of internal sex cords (at new cortical sex cords puberty: --> seminiferous tubules, cluster around each germ cell Sertoli cells Male Differentiation • Male sex cords or testis cords proliferate and cortex becomes thick layer of extracellular matrix • Male
[Show full text]
The Endocrine System
PowerPoint® Lecture Slides The Endocrine System: An Overview prepared by Leslie Hendon University of Alabama, Birmingham • A system of ductless glands • Secrete messenger molecules called hormones C H A P T E R 17 • Interacts closely with the nervous system Part 1 • Endocrinology The Endocrine • Study of hormones and endocrine glands System Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Endocrine Organs Location of the Major Endocrine Glands Pineal gland • Scattered throughout the body Hypothalamus Pituitary gland • Pure endocrine organs are the … Thyroid gland • Pituitary, pineal, thyroid, parathyroid, and adrenal Parathyroid glands glands (on dorsal aspect of thyroid gland) • Organs containing endocrine cells include: Thymus • Pancreas, thymus, gonads, and the hypothalamus Adrenal glands • Plus other organs secrete hormones (eg., kidney, stomach, intestine) Pancreas • Hypothalamus is a neuroendocrine organ • Produces hormones and has nervous functions Ovary (female) Endocrine cells are of epithelial origin • Testis (male) Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc. Figure 17.1 Hormones Control of Hormones Secretion • Classes of hormones • Amino acid–based hormones • Secretion triggered by three major types of • Steroids—derived from cholesterol stimuli: • Basic hormone action • Humoral—simplest of endocrine control mechanisms • Circulate throughout the body in blood vessels • Secretion in direct response to changing • Influences only specific tissues— those with ion or nutrient levels in the blood target cells that have receptor molecules for that hormone • Example: Parathyroid monitors calcium • A hormone can have different effects on • Responds to decline by secreting different target cells (depends on the hormone to reverse decline receptor) Copyright © 2011 Pearson Education, Inc. Copyright © 2011 Pearson Education, Inc.
[Show full text]
The Endocrine System
Homework Due Tuesday 2/19 Replace a Missing Assignment Due in Lab PreLab #6 Homework 11 in study guide Omit #11 The Endocrine System Part 1 Overview Acts with the nervous system (NS) Influences metabolic activities using hormones Responses occur more slowly but last longer than NS Endocrine glands Pituitary, thyroid, thymus, pancreas, parathyroid, adrenal and pineal glands Pineal gland Hypothalamus Pituitary gland Thyroid gland Parathyroid glands (on dorsal aspect of thyroid gland) Thymus Adrenal glands Pancreas Ovary (female) Testis (male) Figure 16.1 Making Connections 16.1 Homeostatic Interrelationships Between the Endocrine System and Other Body Systems Copyright © 2010 Pearson Education, Inc. Overview Nervous System Endocrine System Nerve impulses Hormones Neurotransmitters Slower responses Faster responses Longer effects Brief effects Broader influence Acts on specific target Hormones Chemical substances secreted by cells Long-distance chemical signals Travel in the blood or lymph Most are amino-acid based or steroid molecules Hormones Two main classes 1. Amino acid-based hormones Amines, thyroxine, peptides and proteins 2. Steroids Synthesized from cholesterol Gonadal and adrenocortical hormones Figure 16.4 Three types of endocrine gland stimuli. (a) Humoral Stimulus (b) Neural Stimulus (c) Hormonal Stimulus 1 Capillary blood contains 1 Preganglionic sympathetic 1 The hypothalamus secretes low concentration of Ca2+, fibers stimulate adrenal hormones that... which stimulates... medulla cells... Hypothalamus
[Show full text]