THE FEMALE REPRODUCTIVE SYSTEM - Texas A&Mpeer.tamu.edu/histology/25 Female Repro System Pres...

The Female Reproductive

System

Ovary

Objective

To learn the structure of the ovary, fallopian tube, uterus, cervix, and vagina

To learn how these organs contribute to the many functions of the female reproductive system

To learn how hormones regulate and/or orchestrate the female reproductive processes

Functions of the female

reproductive system

• Ova production

• Ova and sperm transportation

• Microenvironments for fertilization

• Implantation and fetal-placental growth

• Nourishment and support of offspring

• Postnatal repetition

Female Reproductive System

Female

Reproductive System

Ovary

General structure

• Germinal epithelium

• Tunica Albuginea

• Medulla

• Cortex

Functional

overview

Origin of

germ cells

Germinal epithelium

Cortex

Ovary

Primary Follicle

Follicle Maturation

Primordial follicles

• Oocyte

• Follicular (granulosa) cells

Follicle Maturation

Primary follicle

• Zona pellucida

• Stratum granulosum

• Thecal folliculi

• Call-Exner bodies

Follicle Maturation

• Secondary (antral) follicle:

Follicular fluid

Membrana

granulosa

Cumulus oophorus

Corona radiata

Theca interna

Theca externa

Follicles

Follicle maturation

Graafian follicle

Graafian follicle egg

Primordial Follicle

Primordial Follicles

Primary Follicle Zona Pellucida

Primary Follicle

Primary Follicles

Primary follicle

http://en.wikipedia.org/wiki/Call-Exner_bodies

Secondary (antral) Follicle

Secondary (antral) follicle

Graafian follicle

Graafian follicle

Ovulation

Ovulation

Rupture of follicle

– Mechanism unknown collagenase, protease, plasmins

– Not pressure related

Oocyte surrounded by zona pellucida & corona radiata

– Lost at ovulation in cow

– Lost after sperm penetration in most species

After ovulation, the corpus luteum develops from remains of the follicular wall after ovulation.

Corpus Luteum - yellow body

Corpus hemorrhagicum –

transitory structure

caused by hemorrhage

into ruptured follicle

Corpus Luteum - yellow body

Luteinization of

granulosa and theca

cells to luteal cells

Corpus Luteum - yellow body

Granulosa lutein cells - granulosa cells proliferate, hypertrophy, and transform

– (Yellow lipid pigment - lutein marks transitory membrana granulosa cells into granulosa lutein cells)

Corpus Luteum - yellow body

(Invasion of stromal cells and vasculature removes clot, deposition of reticular fibers, highly vascularized)

Theca lutein cells - lipid producing cells formed from theca folliculi interna

Fate relates to pregnancy

– If not pregnant: slow regression corpus albicans

– If pregnant: active for all or to various time during pregnancy

Ovary

Atresia

– Glassy membrane

Ovary

Corpus Luteum

– Granulosa lutein cells

– Theca lutein cells

Corpus Luteum

Corpus Luteum

Corpus luteum – Corpus albicans

Hormones orchestrate the process

Ovarian Hormones

Androgens

– LH stimulation causes theca interna cells to produce androgens (androstenedione and testosterone)

Estrogens

– FSH stimulation causes membrana granulosa cells to produce estrogens (estradiol - 17b)

• Granulosa cells aromatize androgens from theca interna cells to produce estrogens

• Estrogens - induce further proliferation of granulosal cells

Ovarian Hormones

Inhibition of FSH

– Folliculostatin - inhibitory substance has negative feedback on FSH

– Steroidsthemselves work through negative feedback

Progesterone - granulosa lutein cells of corpus luteum

– Uterine gland development

– Maintenance of pregnancy

Relaxin - produced by corpus luteum

– Causes relaxation of ligaments associated with pubic symphysis before partarition

Oogenesis - formation and

development of ova

Mitosis (oocytogenesis) – oogonia

– Prenatal development (ruminants, rodent, swine, human)

– Postnatal development (carnivores)

Oogenesis - formation and

development of ova

Meiosis – oocytes

Early development

Maturation arrest (dictyate step of meiotic prophase)

Later development synchronized with development and maturation of follicles

Division

• First meiotic division –

reduction division –

first polar body

• Second meiotic division – equational division –

second polar body

Meiosis

Zygote

Fertilized

1n

Meiosis (only in spermatogenesis and

oogenesis)

Exchange of genetic material in homologous chromosomes (leptotene, zygotene, pachytene, and diplotene steps of development)

Produces haploid condition of gametes

Meiosis (only in spermatogenesis and

oogenesis)

Produces haploid condition of gametes

Species difference in time of polar

body formation

Polar body extrusion many mammals horse and dog

First preovulation postovulation

Second zona penetration zona penetration

of sperm of sperm

First polar body

Birth

Follicular development - synchronized with

gamete development

Type Description Germ cell type

Primordial flattened follicular primary oocyte cells

Primary low cuboidal primary oocyte follicular cells

Secondary yolk formation primary oocyte zona pellucida theca interna theca folliculi externa

Follicular development - synchronized with

gamete development (cont’d)

Type Description Germ Cell type

Vesicular follicle - Call-Exner bodies primary oocyte (tertiary follicle) (precursors of liquor folliculi)

- Formation of follicular antrum

- Cumulus oophorus- mound of cells

- Corona radiata- adjacent to oocyte nutrients

- Stratum granulosum

Mature follicle - preovulatory primary/ (graafian follicle) largest, extend secondary from cortex to surface of ovary oocyte

Fallopian tube (oviduct or uterine tube)

Segments

• Infundibulum with fimbriae

• Ampulla

• Isthmus

• Intramural segment

Fallopian tube (oviduct or uterine tube)

Wall structure and Variation

Epithelium

• Ciliated cells

• Secretory cells

Oviduct

Oviduct

Oviduct

Normal

Lack of

estrogen

Oviduct

Oviduct

Oviduct

Acrosome reacted

Intact

Uterus

General structure:

Perimetrium

Myometrium

Endometrium

• Zona basalis

• Zona functionalis

- spiral arteries

Zona Functionalis

Spiral arteries

Proliferative Phase

Phases of the Menstrual Cycle

Overview

Menstrual phase: days 1-4

Proliferative phase

– Early: days 4-7

– Late: days 7-14

Secretory phase:

– Early: days 15-21

– Late: days 21-28

Menstruation

Decidual reaction

Hormones Orchestrate the Process

Menstruation

Phases of the Menstrual Cycle

Implantation and Fetal-Placental

Growth

Implantation and Fetal-Placental

Growth

Slide 272

Implantation and Fetal-Placental

Growth

Decidual

Reaction

Cervix

Vagina

Endocervix

– Cervical mucus

External os

Ectocervix

Vagina

Structural components

Epithelium

Endocervix Cervical Mucus

Endocervix ends in the

vagina which has no mucus glands

http://women.webmd.com/vaginal-discharge-whats-abnormal

Vagina

Nourishment and

protection of

offspring

Nourishment and

protection of

offspring

Other glands of epidermal origin –

mammary gland

Gland for which our class, mammalia, was named.

Mammals are characterized by hair on skin, special

ear bones, and in females, milk-producing mammary

glands for nourishment of young.

• Http://www.Youtube.Com/watch?V=_44uagjogyk&feature=fvwrel

Leiomyoma

Ovary

Ovary

Primary follicle

Primordial follicles

Corpus luteum

Female Reproductive System

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