HYPOTHALAMO-PITUITARY-OVARIAN AXIS Roots to Obstetrics & Gynaecology Prof. Hemantha Dodampahala (MBBS, MD, FRCSE, FRCOG. FISUOG) Dept of Obstetrics & Gynaecology.

Slides:



Advertisements
Similar presentations
MEN: feedback loop.
Advertisements

Physiology of menstruation
Female Reproductive Hormones
2 Sexual Differentiation
Puberty and associated changes
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. C H A P T E R Copyright © 2007 The McGraw-Hill Companies,
CHEMICAL REGULATION OF THE REPRODUCTIVE SYSTEM ANATOMY & PHYSIOLOGY
Female Reproductive function and cycles
Puberty Is the period which links the childhood and adulthood.
MCB 135E Discussion GSI: Jason Lowry Nov 29 – Dec 3.
COGNITIVE SCIENCE 17 Why Sex is Necessary Jaime A. Pineda, Ph.D.
Aging and the Female Reproductive System Spring 2007.
Lecture outline I. Puberty & Development of Secondary Sexual Characteristics A. Establishing the ovarian cycle B. Breast development C. Pubic and Axillary.
Growth and Development 1 PUBERTY Viv Rolfe. Discuss the age of onset of puberty in males and females Development of secondary sexual characteristics at.
Aging and the Female Reproductive System Jason Lowry April 25, 2005.
ENDOCRINE PROJECT By: Katie Glaeser Melanie Olmedo 8 th January 13, 2014.
Human Reproduction Spermatogenesis.
C) The Menstrual Cycle The female menstrual cycle takes an average of 28 days. (Variation is common). The cycle occurs in four phases if no fertilization.
The Male Reproductive System
Reproductive Hormones
8.5: Reproductive Hormones Male Reproductive System Female Reproductive System.
Emily Bartlett Katrina Bush
Sex, Menopause, and Aging
Ovaries and the Fertility Cycle
Reproductive Hormones
Biology Seminar  Testosterone.
Prepared by Dr. Amel Eassawi
Which came first - the chicken or the egg? Physiology of Reproduction Jennifer McDonald DO.
Accelerated Biology.  Some important vocabulary  Follicle – a cluster of cells that surrounds an immature egg and provides it with nutrients (where.
Objectives By the end of this lecture, you should be able to: 1. List the hormones of female reproduction and describe their physiological functions 2.
Reproductive System Cont. Female Anatomy & Physiology Chapter 28.
Reproductive Hormones Gonads Source of sex hormones: androgens estrogens progestins produced in different proportions by both males and females.
AN ONLINE TUTORIAL. CONTENTS HOW TO USE THIS TUTORIAL OBJECTIVES INTRODUCTION AND DEFINITION COMPONENTS OF THE AXIS THE HYPOTHALAMUS THE PITUITARY THE.
3 Puberty, Health, and Biological Foundations. Puberty The period of rapid physical maturation involving hormonal and bodily changes that take place primarily.
Reproductive System Section 1 Reproductive and Hormonal Functions of the Male Section 2. Reproductive and Hormonal Functions of the Female Section 3. Hormonal.
Physiology of the female reproductive system. 1. Different periods of Female  Neonatal period :  4 weeks  childhood: 4 weeks to age of 12  adolescence:
1 Eric P. Widmaier Boston University Hershel Raff Medical College of Wisconsin Kevin T. Strang University of Wisconsin - Madison *See PowerPoint Image.
Menopause: a natural event
9.4 Hormonal Regulation of the Reproductive System
THE NORMAL MENSTRUAL CYCLE Allison Eliscu, MD, FAAP Rev. July 2012.
Physiological Changes During Puberty & Menopause
Sponge: Set up Cornell Notes on pg. 75 Topic: 22.2 Male and Female Sex Hormones Essential Question: How do hormones play a key role in the menstrual cycle?
PUBERTY. Definition: Hormonal changes during period of infancy and early childhood [Age 9-15] Mechanism: Separation of newly born infant from maternal.
Biology 12 Unit 2: Reproduction and Development Female System.
Biology, Grade 12 SBI4U Female Reproductive System.
1. Primary sex characteristics (gonads and sperm) are produced while the fetus is still in utero (testes descend into scrotum at third month of development).
Reproductive System Ch 19. General Functions of reproductive system.  Produce and nurture sex cells  Gametes  Sperm  Eggs  Transport them to sites.
Reproductive Systems This is posted online Take notes if you need to – but DO NOT COPY WORD FOR WORD.
Aim: How can hormones influence the reproductive cycles in humans?
Aim: How can hormones influence the reproductive cycles in humans? Do Now: Using the diagrams below, which structures produce hormones? What hormones are.
Biology 12 THE FEMALE MENSTRUAL CYCLE.  The menstrual cycle is the term for the physiological changes that can occur in fertile women for the purposes.
Physiological Changes During Puberty & Menopause
The Female Reproductive System. Overview The female reproductive system produces only a limited number of gametes Most structures are located inside the.
Higher Human Biology Unit 2 Physiology & Health KEY AREA 2: Hormonal Control of Reproduction.
Male and female sex hormones
Reproductive System-L3
Unit B: Reproduction and Development
Reproduction and Development
Reproduction-Related Disorders
Chapter 28: The Reproductive System Bio 211 lecture notes
Physiological Changes During Puberty & Menopause
PUBERTY IT IS THE TIME IN LIFE WHEN A BOY OR GIRL
Reproduction and Puberty!
Puberty February 17, 2019 puberty.
The Female Menstrual Cycle
Development and Puberty
The Reproductive System
A Time of Change.
The Reproductive system
Presentation transcript:

HYPOTHALAMO-PITUITARY-OVARIAN AXIS Roots to Obstetrics & Gynaecology Prof. Hemantha Dodampahala (MBBS, MD, FRCSE, FRCOG. FISUOG) Dept of Obstetrics & Gynaecology Faculty of Medicine, Colombo

Physiology Hypothalamo- Pituitary - Ovarian Axis (HPOA) GnRHH FSH / LH P OestrogenO Negative feedback Maintains homeostasis

Spectrum of events in both sexes Birth Puberty Menarche /adrenarche Reproduction / coitarche Climacteric Menopause /Andropause

Genotype and Phenotype  Genetic sex determines the gonad based on Y chromosome (SRY)  Testosterone/DHT Anti-Müllerian Hormone  LH FSH via GnRH (HPO axis) fetal, early infancy, childhood, late pre-puberty and puberty

Puberty Altered endocrine system occurs years earlier to physical, mental and social change Fetal – GnRh neurone activity at 12 week Male – T secreted from 7 weeks and peaks weeks Female – maintenance of oöcyte population depends on normal X chromosome complement

Puberty, Menarche and Primary Amenorrhoea Breast Development Pubic hair growth Axillary hair growth Growth – Increase in body contours, proteins, fat = weight gain Menarche ** Good practice is to check the items in order in case of primary amenorrhoea Mean age of puberty Menarche before 16 years

HYPOTHALAMUS GnRH Pituitary FSH / LH Gonad ESTROGEN/TESTOSTERONE Negative feedback Positive feedback for LH ovulation

Functions of HPO axis in an adult female cyclicalMajor aspect of reproductive capacity is its cyclical activity dominant folliclesStrikingly reflected in the growth and development of dominant follicles. single ovulationNormally in human ovaries - a single dominant follicle that results in a single ovulation each menstrual cycle Relationships that underlie folliculogenesis, ovulation, and luteogenesis

Follicular growth is gonadotrophin dependent D1D14D28 Recruitment Dominant OvulationCorpus follicleluteum FSH LH Progesterone P E2

Anovular Subfertility and Male Hypogonadism

Recruitment at a constant rate in first three decades OR reaches a critical number of ~25,000 at 37.5 y Then rate of loss accelerates ~2-fold A decrease in fecundity accompanies this accelerated loss of OR Ovarian reserve Reflected in serum FSH concentration

Two Cell Theory

Follicle selection FSH  LH Inhibin Activin E 2  Progesterone  Follicular atresia

Climacteric Reproductive decline occurs after third decade Follicular atresia accelerates from 37.5 years Thus reproductive aging precedes the menopause by years Increased FSH & low Inhibin B

Hormonal changes with established menopause Decline in E2 Less marked decline in E1 (peripheral aromatization)  E1 higher in obese women  In the menopuse E2 < E1

Summary Basis of the H-P-O axis In terms of the life cycle of females Diagnostic relevance

Menopause from Individual Point of View

Thank You!