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OVARIAN and uterine cycles By Dr Shivram Bhat. questions. Primordial follicle ( Short Answer) Primary follicle ( SA) Secondary follicles ( SA) Tertiary follicle ( SA) Graafian follicle - diagram ( SA) Corpus luteum ( SA) Corpus albicans ( SA) Folliculogenesis ( Short essay)
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questions • Primordial follicle ( Short Answer) • Primary follicle ( SA) • Secondary follicles ( SA) • Tertiary follicle ( SA) • Graafian follicle - diagram ( SA) • Corpus luteum ( SA) • Corpus albicans ( SA) • Folliculogenesis ( Short essay) • Graafian follicle (SE)
Female sexual cycles • Birth – Puberty • Menarche – Menopause • Post menopause
Ovarian cycle Uterine cycle contents
Learning objectives • To learn about cyclical events occurring in ovary leading to folliculogenesis • To learn about cyclical events seen in uterine endometrium. • To know about other changes occurring due to female hormones • To know about some of the applied aspects
Physiological changes in • Ovaries • Endometrium • Cervix • Vagina • Breasts • Body and Mind
Ovarian follicles • Each follicle consists of an immature egg called an oocyte • Cells around the oocyte are called: • Follicle cells (one cell layer thick) • Stimulated to mature by FSH from the pituitary gland • Granulosa cells (when more than one layer is present) • Thecal cells: Cells in the ovarian stroma • Thecal & granulosa cells work together to produce estrogen • A protective layer of glycoprotein forms around the egg called the zona pellucida
Follicle Development • Primordial follicle: one layer of squamous-like follicle cells surrounds the oocyte • Primary follicle: two or more layers of cuboidal granulosa cells enclose the oocyte • Secondary follicle: has a fluid-filled space between granulosa cells that coalesces to form a central antrum • Graafian follicle: secondary follicle at its most mature stage that bulges from the surface of the ovary • Corpus luteum : ruptured follicle after ovulation
Primary Follicle 1° Oocyte(arrested in prophase I) Nucleus Primordial follicle Zona pellucida Thecal cells Granulosa cells
Secondary Follicle Fluid-filled antrum
Graafian Follicle Fluid filled antrum Oocyte 2° Granulosa cells Stalk Corona radiata Zona pellucida
Corpus luteum • After ovulation, the remains of the follicle are transformed into a structure called the corpus luteum. • If a pregnancy occurs, it produces progesterone to maintain the wall of the uterus during the early period of development.
Corpus albicans • If fertilization does not occur, the corpus luteum will begin to break down about 2 weeks after ovulation. • Degeneration occurs when fibroblasts enter the corpus luteum and a clump of scar tissue forms called the corpus albicans.
Ovarian Cycle • Monthly changes that occur in the ovary during a woman’s reproductive life. • Each month FSH stimulates primordial follicles to grow and mature (follicular phase) • Ovulation- release of the egg (LH) • Luteal phase the corpus luteum produces progesterone that maintains uterine walls If fertilization does not occur, the corpus luteum degenerates, within 2 weeks into a mass of scar tissue called the corpus albicans
Uterine Histology • Endometrium • Simple columnar epithelium • Stroma of connective tissue and endometrial glands • Stratum functionalis: Shed during menstruation • Stratum basalis: Replaces stratum functionalis each month • Myometrium • 3 layers of smooth muscle • Perimetrium • Visceral peritoneum
Endometrium Simple columnar epithelium Endometrial glands
Endometrium • Proliferative phase: glands and blood vessels scattered throughout the functional zone with little or no branching. • New glands form and endometrium thickens. • Secretory phase: glands are enlarged and have branches. Preparing the endometrium for implantation • If no implantation then endometrium breaks down and menstruation begins.
Other changes • Cervix • Vagina • Breasts • Body and MIND
Endocervical canal Fornix
Applied embryology • Determination of ovulation • Mittelschmerz • Anovulatory cycles • Amenorrhoea • Menorrhagia • Oligomenorrhoea • Metrorrhagia • Dysmenorrhoea