female reproductive system - lab

MICROSCOPIC STRUCTURE OF OVARIES, UTERUS, AND FALLOPIAN

TUBE.

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Dr. Amal Abd El hafezAssociate professor of histopathology

Objectives• At the end of this practical session you will be able to

identify sections, label diagrams and discuss:• The ovarian structure. • Varying stages of follicular development leading to

ovulation or follicular atresia.• The histological characteristics of the oviducts

[Fallopian tubes= uterine tubes].• The body of a mature uterus and various layers of the

uterus.

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The female reproductive system consists of: two ovaries, two oviducts (uterine= Fallopian tubes), the uterus including body and cervix, the vagina, and the external genitalia.

Its functions: 1-Produce female gametes (oocytes=ova)

2-Site of fertilization, hold a fertilized oocyte during its complete development through embryonic and fetal stages until birth. 3- The ovaries produce female sex hormones [estrogen and progesterone] that control organs of the reproductive system and influence other organs of the body.

INTRODUCTION

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The Female Reproductive System 4

• Ovaries are covered by:1-Simple cuboidal germinal epithelium [misnomer, its

mesothelial derived], 2- tunica albuginea.

• the ovary is divided into:1- outer cortical region, 2- inner medullary region.3-Ovarian hilum

• Ovarian tissue is composed of:1- ovarian follicles [at different stages of development, in the

cortex], 2- ovarian stroma [spindle cells + collagen fibers].

The ovarian structure

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The ovary

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• consists of:1. Oocyte=ovum=egg: in the center.2. Follicle cells: surround the oocyt and include: Granulosa cells

and Theca cells [derived from ovarian stroma]• Theca & granulosa cells work together to produce hormones.

• 4 types of follicles are known:1. Primordial follicle2. Primary follicle3. Secondary follicle4. Tertiary=Graafian follicle

What are the ovarian follicles?

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Follicle Development= Folliculogenesis

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• The process in which a primordial follicle grows and

develops into Graafian follicle with the potential to

either ovulate its egg into the oviduct at mid-cycle or

to die by atresia.

Stages of Folliclar Development= Folliculogenesis

1. Primordial follicles: Present in ovary from birth till puberty [about half a million], oocyte surrounded by one layer of flat squamous cells.

2. Primary follicle: Start to develop after puberty, [each month 20-30 follicle] two or more layers of cuboidal granulosa cells called zona granulosa and a layer called zona pellucida surround the oocyte.

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3. Secondary follicle: oocyte surrounded by the zona pellucida, multiple layers of granulosa cells [cumulus oophorus]+ theca cells, has a fluid-filled spaces between granulosa cells.

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4. Graafian follicle : Bulges from the surface of the ovary. Shows the theca externa, theca interna, basal lamina, granulosa cells forms corona radiata, around the oocyte, and follicular antral fluid.

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At ovulation: Oocyte + Zona pellucida+ corona radiataare expelled to peritoneal cavity

5. Corpus luteum : ruptured follicle after ovulation, it produces progesterone for 2 weeks [Corpus luteum of menstruation]

• If a pregnancy occurred, it continues hormone production to maintain the wall of the uterus during the early period of fetal development [Corpus luteum of pregnancy]

6. If fertilization does not occur, the corpus luteum degenerates into a mass of scar tissue called the corpus albicans.

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Corpus albicans

Corpus luteum

7. Atretic follicle: WHAT? An ovarian follicle that has undergone

degeneration or involution. WHEN? Follicles at any stage of development [fetal

period, before puberty, reproductive period] may undergo atresia.

HOW? Follicle →Glassy membrane → corpus fibrosa→ disappear.

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Uterine Tubes (Fallopian Tubes=oviduct)• Formed of interstitial part, isthmus, ampulla,

infundibulum, fimbriae.• Function: Capture ovum from ovarian surface toward

the uterus, site of fertilization.

• Histology:(1) a mucosa: folds of a simple columnar epithelium

[ciliated and secretory] and a lamina propria composed of loose connective tissue.

(2) a thick muscularis composed of smooth muscle.(3) a serosa composed of visceral peritoneum.

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Fallopian Tube Histology16

Cilia and tubal fluid move ovum/zygote toward the uterus

• Hollow, thick-walled organ composed of: body, and cervix. The wall of the uterus is relatively thick and is composed of three layers

• Endometrium:

– Simple columnar epithelium [ciliated and secretory, some times pseudostratified ]

– Stroma of connective tissue and endometrial glands

• Stratum functionalis: Shed during menstruation.

• Stratum basalis: Replaces stratum functionalis each month.

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The Uterus

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• Myometrium

Interlacing bundles of smooth muscle, contain large blood vessels.

• Perimetrium

Serosa or adventitia.

Phases of the Endometrium [stages of the menstrual cycle]

Proliferative phase: from end of menstruation to 14 days of menstrual cycle under estrogen effect. Endometrial glands are straight. Cells are crowded with frequent mitoses. The stroma is dense.

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Secretory phase (or luteal): Second 14 days of menstrual cycle under progesterone effect. Glands are tortuous [serrated, Saw-toothed] and their lumena are filled with gslycoprotein secretions. Stroma is edematous.

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The menstrual phase: First 4-5 days of the cycle. Ischemia [due to↓ER,PR] leads to shedding of stratum functionalis.

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ovary

ovary

uterus

uterus

Fallopian tube

Fallopian tube

RECOMMENDED REFERENCES, WEBSITES

• Junqueira's Basic Histology: Text and Atlas, Thirteenth Edition 2013

• ISBN-13: 978-0071780339 ISBN-10: 0071780335 Edition: 13th

• The histology tutor:http://www2.yvcc.edu/

histologyzoomer/HistologyTutorials/histology_tutorials.htm

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