Ovaries: Anatomy

Overview

Definition

The ovaries are the female gonads Gonads The gamete-producing glands, ovary or testis. Hormones: Overview and Types, located within the pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy as paired structures. The ovaries contain haploid Haploid The chromosomal constitution of cells, in which each type of chromosome is represented once. Symbol: n. Basic Terms of Genetics gametes known as oocytes.

Functions

• Produce and release female germ cells Germ Cells The reproductive cells in multicellular organisms at various stages during gametogenesis. Gametogenesis (oocytes)
• Secrete sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria hormones Hormones Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. Hormones play critical roles in coordinating cellular activities throughout the body in response to the constant changes in both the internal and external environments. Hormones: Overview and Types:
  • Estrogen 
  • Progesterone Progesterone The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation; pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Gonadal Hormones  
  • Testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens (small amounts)

Embryology

Ovarian development

Weeks 5–10: 

• Gonads Gonads The gamete-producing glands, ovary or testis. Hormones: Overview and Types arise around week 5 from the gonadal ridge Gonadal ridge Development of the Urogenital System:
  • Epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology arises from the coelomic epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology ( mesoderm Mesoderm The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube. Gastrulation and Neurulation)
  • Stroma arises from the sub-coelomic mesoderm Mesoderm The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube. Gastrulation and Neurulation
  • Invaginations of the epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology in the cortex region form the primary sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria cords (pregranulosa cells) → rete ovarii
• Primordial germ cells Primordial germ cells Gametogenesis:
  • Differentiate into oocytes in females
  • Originate in the epiblast Epiblast Embryoblast and Trophoblast Development
  • Migrate to the yolk sac Yolk Sac The first of four extra-embryonic membranes to form during embryogenesis. In reptiles and birds, it arises from endoderm and mesoderm to incorporate the egg yolk into the digestive tract for nourishing the embryo. In placental mammals, its nutritional function is vestigial; however, it is the source of intestinal mucosa; blood cells; and germ cells. It is sometimes called the vitelline sac, which should not be confused with the vitelline membrane of the egg. Embryoblast and Trophoblast Development → through the allantois Allantois An extra-embryonic membranous sac derived from the yolk sac of reptiles; birds; and mammals. It lies between two other extra-embryonic membranes, the amnion and the chorion. The allantois serves to store urinary wastes and mediate exchange of gas and nutrients for the developing embryo. Development of the Abdominal Organs ( umbilical cord Umbilical cord The flexible rope-like structure that connects a developing fetus to the placenta in mammals. The cord contains blood vessels which carry oxygen and nutrients from the mother to the fetus and waste products away from the fetus. Placenta, Umbilical Cord, and Amniotic Cavity) → along the dorsal mesentery Mesentery A layer of the peritoneum which attaches the abdominal viscera to the abdominal wall and conveys their blood vessels and nerves. Peritoneum: Anatomy of the hindgut Hindgut Development of the Abdominal Organs → gonadal ridges
  • Germ cells Germ Cells The reproductive cells in multicellular organisms at various stages during gametogenesis. Gametogenesis invade into the gonadal ridges by approximately 6 weeks
• Up until 6 weeks of gestation, sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria development is identical and nonbinary
• Development of the ovary from the bipotent gonad requires absence of the SRY gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics (normally found on the Y chromosome Y chromosome The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained. Basic Terms of Genetics), preventing differentiation into testes Testes Gonadal Hormones
  • If the SRY gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics is present, testes Testes Gonadal Hormones will begin developing around week 6.
  • If the SRY gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics is absent, testes Testes Gonadal Hormones will not develop.
  • Around week 10, if testes Testes Gonadal Hormones have not yet developed, ovarian development begins.

Weeks 10–20:

• Oocyte formation occurs by:
  • Rapid multiplication of the primordial germ cells Primordial germ cells Gametogenesis → oogonia
  • Oogonia differentiate into primary oocytes and arrest at this stage until puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty
• Follicle formation occurs by:
  • Pregranulosa cells encircling the germ cells Germ Cells The reproductive cells in multicellular organisms at various stages during gametogenesis. Gametogenesis to form primordial follicles
  • Theca cells Theca cells The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells. Puberty encircling the primordial follicles 
• Estrogen production by the follicular cells stimulates the indifferent external genitalia to differentiate into female structures

Ovarian descent

• Ovaries develop in the abdomen and descend into the pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy
• Guided by the gubernaculum Gubernaculum An embryonic structure that helps guide proper descent of gonads into their final positions. It attaches the caudal end of the fetal gonads to the developing scrotum in male and the labium majorum in female. It gives rise to the caudal ligaments of the gonad: the scrotal ligament in male and the uterine round and proper ovarian ligaments in female. It includes morphofunctional equivalent structures in non-mammals. Congenital Malformations of the Female Reproductive System ( a band A band Skeletal Muscle Contraction of fibrous Fibrous Fibrocystic Change tissue from the posterior wall)
• Gubernaculum Gubernaculum An embryonic structure that helps guide proper descent of gonads into their final positions. It attaches the caudal end of the fetal gonads to the developing scrotum in male and the labium majorum in female. It gives rise to the caudal ligaments of the gonad: the scrotal ligament in male and the uterine round and proper ovarian ligaments in female. It includes morphofunctional equivalent structures in non-mammals. Congenital Malformations of the Female Reproductive System becomes the ovarian ligament postnatally

Gross Anatomy

Size

• 2 almond-shaped organs (left and right) 
• Approximately 4 x 2 x 1 cm during the reproductive years
• Weight: 5–10 g
• Size varies somewhat throughout the cycle and stage of reproductive age
• Smaller after menopause Menopause Menopause is a physiologic process in women characterized by the permanent cessation of menstruation that occurs after the loss of ovarian activity. Menopause can only be diagnosed retrospectively, after 12 months without menstrual bleeding. Menopause

Location

• Suspended by ligaments in the pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy
• Found in the lateral pelvic cavity, within the ovarian fossa (depressions in the dorsal pelvic wall)
• Intraperitoneal Intraperitoneal Peritoneum: Anatomy structures
• Positioned on the posterior aspect of the broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy
• Somewhat mobile structures:
  • Often found posterior to the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy in the rectovaginal pouch (i.e., Douglas pouch) 
  • May be found lateral or even (rarely) anterior to the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy (e.g., retroflexed uterus Retroflexed Uterus Female Genitourinary Examination)
  • May be scarred against the pelvic sidewall

Ligaments

Ovaries are suspended within the peritoneal cavity Peritoneal Cavity The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the stomach. The two sacs are connected by the foramen of winslow, or epiploic foramen. Peritoneum: Anatomy between the pelvic sidewall and uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy via the several important ligaments.

• Suspensory ligament of the ovary:
  • Also known as infundibulopelvic (IP) ligament
  • Connects the ovary laterally to the pelvic wall
  • Contains the ovarian vessels:
    • Ovarian artery (direct branch off the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy)
    • Ovarian vein 
• Utero-ovarian (UO) ligament:
  • Also known as the ovarian ligament
  • Connects the ovary medially to the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy 
  • A thickened portion of the broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy within the mesovarium Mesovarium Uterus, Cervix, and Fallopian Tubes: Anatomy
• Broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy:
  • A thin sheet of peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum: Anatomy that drapes over the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy and fallopian tubes Fallopian tubes The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The fallopian tubes receive an ovum after ovulation and help move it and/or a fertilized embryo toward the uterus via ciliated cells lining the tubes and peristaltic movements of its smooth muscle. Uterus, Cervix, and Fallopian Tubes: Anatomy like a sheet hanging over a clothesline
  • Divided into 3 parts: mesosalpinx Mesosalpinx Uterus, Cervix, and Fallopian Tubes: Anatomy, mesovarium Mesovarium Uterus, Cervix, and Fallopian Tubes: Anatomy, and mesometrium Mesometrium Uterus, Cervix, and Fallopian Tubes: Anatomy
  • Mesosalpinx Mesosalpinx Uterus, Cervix, and Fallopian Tubes: Anatomy:
    • Area adjacent to the fallopian tubes Fallopian tubes The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The fallopian tubes receive an ovum after ovulation and help move it and/or a fertilized embryo toward the uterus via ciliated cells lining the tubes and peristaltic movements of its smooth muscle. Uterus, Cervix, and Fallopian Tubes: Anatomy
    • Contains the tubal branches of the ovarian and ascending uterine arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
  • Mesovarium Mesovarium Uterus, Cervix, and Fallopian Tubes: Anatomy:
    • Area adjacent to the ovaries
    • Contains the UO vessels
  • Mesometrium Mesometrium Uterus, Cervix, and Fallopian Tubes: Anatomy: 
    • Area below the UO ligament
    • Superiorly, contains the round ligament Round ligament A fibromuscular band that attaches to the uterus and then passes along the broad ligament, out through the inguinal ring, and into the labium majus. Uterus, Cervix, and Fallopian Tubes: Anatomy (a thickening of the broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy off the anterior surface of the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy, connecting the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy to the anterior abdominal wall Abdominal wall The outer margins of the abdomen, extending from the osteocartilaginous thoracic cage to the pelvis. Though its major part is muscular, the abdominal wall consists of at least seven layers: the skin, subcutaneous fat, deep fascia; abdominal muscles, transversalis fascia, extraperitoneal fat, and the parietal peritoneum. Surgical Anatomy of the Abdomen before passing through the inguinal canal Inguinal canal The tunnel in the lower anterior abdominal wall through which the spermatic cord, in the male; round ligament, in the female; nerves; and vessels pass. Its internal end is at the deep inguinal ring and its external end is at the superficial inguinal ring. Inguinal Canal: Anatomy and Hernias, terminating in the labia majora Labia majora Vagina, Vulva, and Pelvic Floor: Anatomy)
    • Inferiorly, contains uterine vessels, ureters Ureters One of a pair of thick-walled tubes that transports urine from the kidney pelvis to the urinary bladder. Urinary Tract: Anatomy, and uterosacral ligaments Uterosacral ligaments Vagina, Vulva, and Pelvic Floor: Anatomy

Microscopic Anatomy

Microscopic structure of the ovaries

• Ovaries are covered by a simple cuboidal epithelium Simple cuboidal epithelium Surface Epithelium: Histology called the germinal epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology.
• Tunica albuginea Tunica albuginea Penis: Anatomy:
  • A capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides surrounding the ovary located under the epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology 
  • Composed of a dense, irregular collagenous connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology.
• Ovarian cortex:
  • Outer region
  • Contains the developing follicles, which include:
    • Developing oocytes
    • Granulosa cells (surrounding the developing oocytes) → secrete estrogen
    • Theca cells Theca cells The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells. Puberty (outside the granulosa cell Granulosa cell Supporting cells for the developing female gamete in the ovary. They are derived from the coelomic epithelial cells of the gonadal ridge. Granulosa cells form a single layer around the oocyte in the primordial ovarian follicle and advance to form a multilayered cumulus oophorus surrounding the ovum in the graafian follicle. The major functions of granulosa cells include the production of steroids and LH receptors. Puberty cells) → produce testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens that is converted to estrogen by the granulosa cells
• Ovarian medulla:
  • Inner region
  • Composed of:
    • Blood vessels and nerves
    • Connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology → provides structure
    • Interstitial cells → become theca cells Theca cells The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells. Puberty
    • Myocontractile cells
• Ovarian hilum Hilum Lungs: Anatomy: region where the major neurovasculature enters the ovary

Formation of ovum

Oogenesis Oogenesis The process of germ cell development in the female from the primordial germ cells through oogonia to the mature haploid ova (ovum). Gametogenesis is the process of ovum production from primordial germ cells Primordial germ cells Gametogenesis. 

• Mitosis Mitosis A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. Cell Cycle:
  • Occurs during the embryonic and fetal periods
  • Maximum numbers of oogonia (6 million–7 million) occur around 20 weeks of gestation 
  • Oogonium Oogonium Euploid female germ cells of an early stage of oogenesis, derived from primordial germ cells during ovarian differentiation. Oogonia undergo meiosis and give rise to haploid oocytes. Gametogenesis → differentiates into primary oocytes or undergo atresia Atresia Hypoplastic Left Heart Syndrome (HLHS) (the vast majority)
  • Ploidy: diploid Diploid The chromosomal constitution of cells, in which each type of chromosome is represented twice. Symbol: 2n or 2x. Basic Terms of Genetics
  • 46 chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure
• Meiosis I Meiosis I Following DNA replication, meiosis I creates 2 daughter cells containing half the genetic information of the mother cell (1n) but the same number of chromosomes (2c) by segregating sister chromatids into the same daughter cell Meiosis:
  • Primary oocytes arrest in prophase I Prophase I The prophase of the first division of meiosis (in which homologous chromosome segregation occurs). It is divided into five stages: leptonema, zygonema, pachynema, diplonema, and diakinesis. Meiosis in utero and remain there until puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty.
  • At puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty, approximately 400,000 primary oocytes are present.
  • Primary oocyte → divides into a secondary oocyte and 1st polar body
  • Ploidy: diploid Diploid The chromosomal constitution of cells, in which each type of chromosome is represented twice. Symbol: 2n or 2x. Basic Terms of Genetics → haploid Haploid The chromosomal constitution of cells, in which each type of chromosome is represented once. Symbol: n. Basic Terms of Genetics
  • 46 → 23 chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure
• Meiosis II Meiosis II Meiosis II is a cellular division event wherein the number of chromosomes in the daughter cells is halved from that of the mother cell. Meiosis II: similar to meiosis I but not preceded by interphase (DNA replication) Meiosis: 
  • At puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty, hormonal stimulation (follicle-stimulating hormone ( FSH FSH A major gonadotropin secreted by the adenohypophysis. Follicle-stimulating hormone stimulates gametogenesis and the supporting cells such as the ovarian granulosa cells, the testicular sertoli cells, and leydig cells. Fsh consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity. Menstrual Cycle)) triggers meiosis Meiosis The creation of eukaryotic gametes involves a DNA replication phase followed by 2 cellular division stages: meiosis I and meiosis II. Meiosis I separates homologous chromosomes into separate cells (1n, 2c), while meiosis II separates sister chromatids into gametes (1n, 1c). Meiosis to resume
  • Arrests in metaphase Metaphase The phase of cell nucleus division following prometaphase, in which the chromosomes line up across the equatorial plane of the spindle apparatus prior to separation. Cell Cycle II until fertilized by a sperm
  • Upon fertilization Fertilization To undergo fertilization, the sperm enters the uterus, travels towards the ampulla of the fallopian tube, and encounters the oocyte. The zona pellucida (the outer layer of the oocyte) deteriorates along with the zygote, which travels towards the uterus and eventually forms a blastocyst, allowing for implantation to occur. Fertilization and First Week, the secondary oocyte divides → mature ovum and 2nd polar body
  • Ploidy: haploid Haploid The chromosomal constitution of cells, in which each type of chromosome is represented once. Symbol: n. Basic Terms of Genetics
  • 23 chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure

Follicle development

Folliculogenesis is a complex process in which an ovarian follicle, containing an oocyte, matures through several stages.

• Primordial follicle:
  • Develops in ovaries during the fetal period Fetal period Prenatal and Postnatal Physiology of the Neonate 
  • Oogonia become surrounded by somatic epithelial cells from the gonadal ridge Gonadal ridge Development of the Urogenital System.
• Primary follicle:
  • Contains a primary oocyte
  • A glycoprotein layer is created ( zona pellucida Zona pellucida A tough transparent membrane surrounding the ovum. It is penetrated by the sperm during fertilization. Fertilization and First Week).
  • Follicular cells proliferate and differentiate to become the granulosa cell Granulosa cell Supporting cells for the developing female gamete in the ovary. They are derived from the coelomic epithelial cells of the gonadal ridge. Granulosa cells form a single layer around the oocyte in the primordial ovarian follicle and advance to form a multilayered cumulus oophorus surrounding the ovum in the graafian follicle. The major functions of granulosa cells include the production of steroids and LH receptors. Puberty layer (single-cell layer).
• Secondary follicle (also known as preantral follicles):
  • This stage is responsive to gonadotropins (i.e., FSH FSH A major gonadotropin secreted by the adenohypophysis. Follicle-stimulating hormone stimulates gametogenesis and the supporting cells such as the ovarian granulosa cells, the testicular sertoli cells, and leydig cells. Fsh consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity. Menstrual Cycle).
  • Granulosa cell Granulosa cell Supporting cells for the developing female gamete in the ovary. They are derived from the coelomic epithelial cells of the gonadal ridge. Granulosa cells form a single layer around the oocyte in the primordial ovarian follicle and advance to form a multilayered cumulus oophorus surrounding the ovum in the graafian follicle. The major functions of granulosa cells include the production of steroids and LH receptors. Puberty layer grows.
  • Cells transform from squamous → cuboidal
  • Hormone production increases.
  • Recruitment Recruitment Skeletal Muscle Contraction of theca cells Theca cells The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells. Puberty → surround basement membrane Basement membrane A darkly stained mat-like extracellular matrix (ecm) that separates cell layers, such as epithelium from endothelium or a layer of connective tissue. The ecm layer that supports an overlying epithelium or endothelium is called basal lamina. Basement membrane (bm) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. Bm, composed mainly of type IV collagen; glycoprotein laminin; and proteoglycan, provides barriers as well as channels between interacting cell layers. Thin Basement Membrane Nephropathy (TBMN)
• Tertiary follicle (also known as antral follicles):
  • Granulosa cells produce:
    • Fluid → create an antrum
    • Estrogen and growth factors → critical for maturation of a healthy oocyte
  • Granulosa cells around the oocyte become the cumulus oophorus
  • Thecal cells differentiate into:
    • Theca interna: contains small vessels and glandular cells; produces testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens that is converted to estrogen in the granulosa cells
    • Theca externa: stabilizes follicles; derived from connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology
• Mature follicle (also known as a graafian follicle):
  • Only 1 follicle each cycle will reach this stage.
  • Primary oocyte → secondary oocyte just before ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle
  • Antrum enlarges (makes up most of the follicle)
  • Innermost layer of the cumulus oophorus → corona radiata
• Corpus luteum:
  • Formed from the follicle after oocyte release at ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle
  • Center contains a blood clot formed after ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle
  • Granulosa and theca cells Theca cells The flattened stroma cells forming a sheath or theca outside the basal lamina lining the mature ovarian follicle. Thecal interstitial or stromal cells are steroidogenic, and produce primarily androgens which serve as precursors of estrogens in the granulosa cells. Puberty produce estrogen and progesterone Progesterone The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation; pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Gonadal Hormones
  • Atrophies if pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care does not occur

Neurovasculature

• Arterial supply: primarily by the ovarian artery
  • Direct branch off the abdominal aorta Abdominal Aorta The aorta from the diaphragm to the bifurcation into the right and left common iliac arteries. Posterior Abdominal Wall: Anatomy (exits at L2) just below the renal arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
  • Contained within the suspensory ligament of the ovary (IP ligament)
  • Splits into:
    • Ovarian branch
    • Tubal branch
  • Both branches anastomose with the ascending branch of the uterine artery Uterine Artery A branch arising from the internal iliac artery in females, that supplies blood to the uterus. Uterus, Cervix, and Fallopian Tubes: Anatomy (which also splits into ovarian and tubal branches).
  • The anastomotic region of the ovarian branches is often referred to as the utero-ovarian artery.
• Venous supply: drained by the ovarian veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology  
  • Venous plexus located within the mesosalpinx Mesosalpinx Uterus, Cervix, and Fallopian Tubes: Anatomy and mesovarium Mesovarium Uterus, Cervix, and Fallopian Tubes: Anatomy → converge into a single ovarian vein on each side
  • The ovarian veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology are contained within the IP ligaments.
  • Right ovarian vein → inferior vena cava Inferior vena cava The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy ( IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy)
  • Left ovarian vein → left renal vein Renal vein Short thick veins which return blood from the kidneys to the vena cava. Glomerular Filtration → IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy
• Lymphatic drainage: drainage via vessels along ovarian veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology to paraaortic nodes
• Innervation: 
  • Derived from autonomic plexuses:
    • Upper part of ovarian plexus is formed by the renal and aortic plexuses.
    • Lower part is from the superior and inferior hypogastric plexuses.
  • Afferent Afferent Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology visceral pain Visceral pain Pain originating from internal organs (viscera) associated with autonomic phenomena (pallor; sweating; nausea; and vomiting). It often becomes a referred pain. Pain: Types and Pathways fibers: run with sympathetic fibers from T11–L1

Clinical Relevance

Related anatomical structures

• Pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy: consists of the bony pelvic girdle, pelvic cavity, pelvic floor Pelvic floor Soft tissue formed mainly by the pelvic diaphragm, which is composed of the two levator ani and two coccygeus muscles. The pelvic diaphragm lies just below the pelvic aperture (outlet) and separates the pelvic cavity from the perineum. It extends between the pubic bone anteriorly and the coccyx posteriorly. Vagina, Vulva, and Pelvic Floor: Anatomy (muscles and connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology), and all the viscera, vessels, and muscles that it contains. The pelvic cavity houses various GI and urogenital structures. 
• Uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy: pear-shaped, hollow organ composed of smooth muscle that functions to nourish the developing fetus until the end of the pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care. At the end of pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care, the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy is also responsible for expulsion of the newborn Newborn An infant during the first 28 days after birth. Physical Examination of the Newborn.
• Fallopian tubes Fallopian tubes The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The fallopian tubes receive an ovum after ovulation and help move it and/or a fertilized embryo toward the uterus via ciliated cells lining the tubes and peristaltic movements of its smooth muscle. Uterus, Cervix, and Fallopian Tubes: Anatomy: thin tubes that act as a conduit between the ovary and the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy. The fallopian tubes Fallopian tubes The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The fallopian tubes receive an ovum after ovulation and help move it and/or a fertilized embryo toward the uterus via ciliated cells lining the tubes and peristaltic movements of its smooth muscle. Uterus, Cervix, and Fallopian Tubes: Anatomy collect the ovulated oocytes; if sperm are present, fertilization Fertilization To undergo fertilization, the sperm enters the uterus, travels towards the ampulla of the fallopian tube, and encounters the oocyte. The zona pellucida (the outer layer of the oocyte) deteriorates along with the zygote, which travels towards the uterus and eventually forms a blastocyst, allowing for implantation to occur. Fertilization and First Week typically occurs in the fallopian tubes Fallopian tubes The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The fallopian tubes receive an ovum after ovulation and help move it and/or a fertilized embryo toward the uterus via ciliated cells lining the tubes and peristaltic movements of its smooth muscle. Uterus, Cervix, and Fallopian Tubes: Anatomy and the early embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week is transported to the uterine cavity, where it implants.

Physiology

• Menstrual cycle Menstrual cycle The menstrual cycle is the cyclic pattern of hormonal and tissular activity that prepares a suitable uterine environment for the fertilization and implantation of an ovum. The menstrual cycle involves both an endometrial and ovarian cycle that are dependent on one another for proper functioning. There are 2 phases of the ovarian cycle and 3 phases of the endometrial cycle. Menstrual Cycle: cyclic pattern of hormonal and tissular activity that prepares the uterine environment for the fertilization Fertilization To undergo fertilization, the sperm enters the uterus, travels towards the ampulla of the fallopian tube, and encounters the oocyte. The zona pellucida (the outer layer of the oocyte) deteriorates along with the zygote, which travels towards the uterus and eventually forms a blastocyst, allowing for implantation to occur. Fertilization and First Week and implantation Implantation Endometrial implantation of embryo, mammalian at the blastocyst stage. Fertilization and First Week of the embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week. The menstrual cycle Menstrual cycle The menstrual cycle is the cyclic pattern of hormonal and tissular activity that prepares a suitable uterine environment for the fertilization and implantation of an ovum. The menstrual cycle involves both an endometrial and ovarian cycle that are dependent on one another for proper functioning. There are 2 phases of the ovarian cycle and 3 phases of the endometrial cycle. Menstrual Cycle includes endometrial and ovarian cycles.
• Menopause Menopause Menopause is a physiologic process in women characterized by the permanent cessation of menstruation that occurs after the loss of ovarian activity. Menopause can only be diagnosed retrospectively, after 12 months without menstrual bleeding. Menopause: process of aging with a gradual decrease in ovarian function over several years, until ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle no longer occurs. The menopause Menopause Menopause is a physiologic process in women characterized by the permanent cessation of menstruation that occurs after the loss of ovarian activity. Menopause can only be diagnosed retrospectively, after 12 months without menstrual bleeding. Menopause transition is characterized by fluctuating hormone levels, after which time, estrogen and progesterone Progesterone The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation; pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Gonadal Hormones levels permanently decline.

Ovarian disorders

• Ovarian cancer Ovarian cancer Ovarian cancer is a malignant tumor arising from the ovarian tissue and is classified according to the type of tissue from which it originates. The 3 major types of ovarian cancer are epithelial ovarian carcinomas (EOCs), ovarian germ cell tumors (OGCTs), and sex cord-stromal tumors (SCSTs). Ovarian Cancer: leading cause of cancer-related deaths in gynecologic malignancies. Ovarian tumors can be epithelial, germ cell, sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria cord–stromal, or metastatic.
• Ovarian cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change: fluid-filled lesions within the ovary.
  • Follicular cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change (also known as physiologic cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change): As an oocyte develops in the 1st ½ of the menstrual cycle Menstrual cycle The menstrual cycle is the cyclic pattern of hormonal and tissular activity that prepares a suitable uterine environment for the fertilization and implantation of an ovum. The menstrual cycle involves both an endometrial and ovarian cycle that are dependent on one another for proper functioning. There are 2 phases of the ovarian cycle and 3 phases of the endometrial cycle. Menstrual Cycle, the follicle grows into a small cyst, approximately 2–3 cm in size, prior to ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle. Occasionally, an oocyte may not ovulate and the follicle can become larger (typically < 10 cm) and may persist. On ultrasonography, these oocytes are visible as simple cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change with smooth walls. The cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change typically resolve spontaneously, though large persistent cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change may be treated surgically.
  • Corpus luteal cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change: After ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle, the follicle transforms into a corpus luteal cyst Corpus luteal cyst Following ovulation, follicles become corpus luteal cysts. Secrete progesterone Ovarian Cysts, secreting both estrogen and progesterone Progesterone The major progestational steroid that is secreted primarily by the corpus luteum and the placenta. Progesterone acts on the uterus, the mammary glands and the brain. It is required in embryo implantation; pregnancy maintenance, and the development of mammary tissue for milk production. Progesterone, converted from pregnenolone, also serves as an intermediate in the biosynthesis of gonadal steroid hormones and adrenal corticosteroids. Gonadal Hormones. On ultrasonography, these cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change may have slightly thicker walls and contain some internal debris. Corpus luteal cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change may also become enlarged (< 10 cm) but still usually resolve spontaneously. A corpus luteum is critical to sustaining an early pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care and should not be confused with an ectopic pregnancy Ectopic pregnancy Ectopic pregnancy refers to the implantation of a fertilized egg (embryo) outside the uterine cavity. The main cause is disruption of the normal anatomy of the fallopian tube. Ectopic Pregnancy.
  • Hemorrhagic cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change: Occasionally, follicular or corpus luteal cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change will bleed, which is known as a hemorrhagic cyst Hemorrhagic Cyst Gynecological Imaging. Hemorrhagic cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change typically present with sudden-onset pelvic pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in an ovulating female. On ultrasonography, these cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change appear as simple cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change with internal echos (representing blood and clot) and resolve spontaneously over 1–2 menstrual cycles, though if bleeding is significant at presentation, emergency surgery may be warranted to stop the bleeding.
  • Neoplastic cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change: like ovarian cancer Ovarian cancer Ovarian cancer is a malignant tumor arising from the ovarian tissue and is classified according to the type of tissue from which it originates. The 3 major types of ovarian cancer are epithelial ovarian carcinomas (EOCs), ovarian germ cell tumors (OGCTs), and sex cord-stromal tumors (SCSTs). Ovarian Cancer, these cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change are classified according to their cell of origin: epithelial cells, germ cells Germ Cells The reproductive cells in multicellular organisms at various stages during gametogenesis. Gametogenesis, and sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria cord–stromal cells. Each classification has multiple histologic subtypes. These tumors are benign Benign Fibroadenoma (noninvasive) but have an increased likelihood of torsion, menstrual irregularities, and other bulk-related symptoms.
• Polycystic ovarian syndrome Polycystic ovarian syndrome Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder of reproductive-age women, affecting nearly 5%-10% of women in the age group. It is characterized by hyperandrogenism, chronic anovulation leading to oligomenorrhea (or amenorrhea), and metabolic dysfunction. Polycystic Ovarian Syndrome: heterogeneous multisystem endocrinopathy Endocrinopathy IPEX Syndrome that is characterized by hyperandrogenism Hyperandrogenism A condition caused by the excessive secretion of androgens from the adrenal cortex; the ovaries; or the testes. The clinical significance in males is negligible. In women, the common manifestations are hirsutism and virilism as seen in patients with polycystic ovary syndrome and adrenocortical hyperfunction. Potassium-sparing Diuretics, ovarian dysfunction leading to oligomenorrhea Oligomenorrhea Polycystic Ovarian Syndrome, and multiple cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change in the ovaries. Fertility challenges are also common.
• Primary ovarian insufficiency Primary ovarian insufficiency Cessation of ovarian function after menarche but before the age of 40, without or with ovarian follicle depletion. It is characterized by the presence of oligomenorrhea or amenorrhea, elevated gonadotropins, and low estradiol levels. It is a state of female hypergonadotropic hypogonadism. Etiologies include genetic defects, autoimmune processes, chemotherapy, radiation, and infections. The most commonly known genetic cause is the expansion of a cgg repeat to 55 to 199 copies in the 5′ untranslated region in the X-linked fmr1 gene. Primary Ovarian Insufficiency: condition resulting from the depletion or dysfunction of the ovarian follicles, leading to cessation of ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle and menses Menses The periodic shedding of the endometrium and associated menstrual bleeding in the menstrual cycle of humans and primates. Menstruation is due to the decline in circulating progesterone, and occurs at the late luteal phase when luteolysis of the corpus luteum takes place. Menstrual Cycle at < 40 years of age. Symptoms include oligomenorrhea Oligomenorrhea Polycystic Ovarian Syndrome or amenorrhea Amenorrhea Absence of menstruation. Congenital Malformations of the Female Reproductive System, vaginal dryness (often leading to dyspareunia Dyspareunia Recurrent genital pain occurring during, before, or after sexual intercourse in either the male or the female. Primary Ovarian Insufficiency), and infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility. Key laboratory findings include an elevated FSH FSH A major gonadotropin secreted by the adenohypophysis. Follicle-stimulating hormone stimulates gametogenesis and the supporting cells such as the ovarian granulosa cells, the testicular sertoli cells, and leydig cells. Fsh consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity. Menstrual Cycle level and low estrogen levels. 
• Ovarian torsion Ovarian torsion Ovarian torsion is a clinical emergency in which the ovaries (with or without the fallopian tubes) twist along their axis, leading to partial or complete obstruction of their blood supply. Ovarian torsion is also called adnexal or tubo-ovarian torsion, especially if a fallopian tube is also involved. Ovarian Torsion: clinical emergency in which the ovaries twist around the suspensory ligament of the ovary and ovarian ligament, cutting off the blood supply to the ovary, resulting in ovarian edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema and severe, sudden onset pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. Ovarian torsion Ovarian torsion Ovarian torsion is a clinical emergency in which the ovaries (with or without the fallopian tubes) twist along their axis, leading to partial or complete obstruction of their blood supply. Ovarian torsion is also called adnexal or tubo-ovarian torsion, especially if a fallopian tube is also involved. Ovarian Torsion occurs in women of reproductive age, typically in an enlarged ovary (> 5 cm). Management is surgical in order to prevent necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage of the ovary. 
• Amenorrhea Amenorrhea Absence of menstruation. Congenital Malformations of the Female Reproductive System: absence of menses Menses The periodic shedding of the endometrium and associated menstrual bleeding in the menstrual cycle of humans and primates. Menstruation is due to the decline in circulating progesterone, and occurs at the late luteal phase when luteolysis of the corpus luteum takes place. Menstrual Cycle in a woman of reproductive age. If ovulation Ovulation The discharge of an ovum from a rupturing follicle in the ovary. Menstrual Cycle does not occur, menses Menses The periodic shedding of the endometrium and associated menstrual bleeding in the menstrual cycle of humans and primates. Menstruation is due to the decline in circulating progesterone, and occurs at the late luteal phase when luteolysis of the corpus luteum takes place. Menstrual Cycle will not occur. Amenorrhea Amenorrhea Absence of menstruation. Congenital Malformations of the Female Reproductive System may be a symptom of ovarian disease.