Guide to Examination of Histological Specimens
of the Female Reproductive Tract
ANS 3315L, ANS 3316L, ANS 33317L - Fall, 2003
P.J. Hansen, Dept. of Animal Sciences, University of Florida
Epithelium | Stroma/Conn Tissue | Blood Vessels | Smooth Muscle
The following types of issues are common components of organs. The organization and location of these tissues gives clues as to the function of the organ.
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The epithelium is a layer of cells that line surfaces such as the skin, the lungs, and glandular structures. The epithelium is involved in secretory processes, absorption, and host defense. The epithelium is bounded by an acellular structure called the basement membrane. Blood vessels are located outside the basement membrane. |
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Cells of the epithelium are often polarized with the apical portion (the part of the cell nearest the surface of the epithelium) involved in secretion and with the nucleus at the basal part of the cell near the basement membrane. |
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Epithelia are categorized
several different ways
 by shape of
cells - squamous, cuboidal, columnar (i.e., flat, square and tall)
by number of
layers - simple (one layer), stratified (multiple layers) or
pseudostrafiied (one layer but
looks like many)
by whether any
cells are ciliated
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Examples of epithelia can be seen at the website for the University of Delaware's course on mammalian histology and at the JayDoc site from the University of Kansas Medical Center. |
The stroma contains the connective tissue that typically makes up a major portion of an organ. It is through stroma that blood vessels, lymphatic vessels, and nerves course. The major cell type in the stroma is the fibroblast. Fibroblasts secrete the extracellular proteins that produce the extracellular matrix. In addition, some fibroblasts serve a regulatory function by secreting growth factors or regulatory molecules. Fibroblasts can differentiate into cells exerting specialized functions (for example, the thecal cells of the ovarian follicle). Leukocytes can also be abundant in the stroma. See the JayDoc site for examples of connective tissue or University of Delaware's website for examples of connective tissue and for drawings of connective tissue elements (click to enlarge).
BLOOD VESSELS
There are three main types of vessels present in tissues - arteries and arterioles, veins and venules, and capillaries. They can be distinguished by the degree of the smooth muscle layers and connective tissue around the vessel. Arteries and arterioles consist of an inner layer of endothelial cells and associated basement membrane (tunica intima), a layer of smooth muscle (tunica media) and an outer connective tissue sheath (tunica adventia). The thickness of the layers is determined by many factors, one of which is size (the larger the vessel, the larger the layers). Veins and venules, which experience much lower pressures than arteries, also have the same three layers of tissue as arteries and arterioles but the tunica media and tunica adventia are much less developed.The lumen of veins and venules is characteristically larger and less rounded than for arteries and arterioles. Capillaries, where exchange between blood and extracellular fluid takes place, consist of endothelial cells and a small basement membrane. Examples of blood vessels can be found at the JayDoc website.
The musculature of the reproductive tract is smooth muscle. Smooth muscle differs from striated muscle (the most common type in skeletal muscle) in several regards. The muscle is composed of individual cells rather than a synctium, control is via the autonomic nerves only (voluntary contraction is not possible). Examples of smooth muscle can be found at the JayDoc website.
STRUCTURES TO IDENTIFY IN SPECIFIC ORGANS
Ovary | CL | Oviduct | Endometrium | Cervix | Vagina
IN CLASS: The instructor will use Powerpoint to review specific histological characteristics of a specific organ. After reviewing the organ, students will go to a nearby microscope and examine a slide of the organ while trying to identify all of the structures listed and to answer the questions associated with that slide. The process will then be repeated for each organ in turn.
ON YOUR OWN: Examine the images on the links associated with each organ to review its histological characteristics.
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Specimens |
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Find the Following Structures |
Primordial Follicle
Primary Follicle
Secondary Follicle
Tertiary Follicle (also called antral or
Graafian follicle)
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Find the Following Parts of the Follicle |
Granulosa cells
mural granulosa
cumulus
oophorus
Thecal cells
Oocyte
Zona pellucida (is it there on all
follicles?)
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Questions |
How many oocytes are in each follicle?
___________________________
Does a zona pellucida surround every oocyte?
______________________
Are blood vessels located inside
the granulosa layer of follicles? ________________
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Specimens |
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Find the Following Structures |
Small vs
large luteal cells
Blood
vessels (the CL is one of the most vascularized tissues in the body)
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Questions |
Which cell type (large or small) do you think produces more
progesterone?_____________________________________
Which cell type do you think is from the theca and which from
the granulosa? ______________________________________
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Specimens |
Note that the oviduct can be separated into three portions - infindibulum, ampulla, and isthmus. Sections of ampulla and isthmus are available.
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Find the Following Structures |
Endosalpinx (meaning endo = inside and salpinx (Gr.) =
trumpet)
epithelium
stroma
Smooth
muscle layer (called myosalpinx; myo means muscle)
Serosa
(called perisalpinx; peri =around, surrounding)
Ciliated
cells in the epithelium (observe under high power)
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Questions |
How does
the epithelium of the ampulla differ from that of the isthmus?
___________________________________________________
How would
you describe the epithelium of the oviduct (stratified or simple, columnar,
etc)?
___________________________________________________
How does the myosalpinx of the ampulla differ from that of the
isthmus?
___________________________________________________
Are the
ciliated cells more abundant in ampulla or isthmus?
________________________
What do
you think is the function of the cilia? ____________________________________
Why part of
the oviduct is more secretory (Explain)?
___________________________________________________________________________
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Specimens |
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Find the Following Structures |
Endometrium (meaning endo = inside and metrium (Gr.) = womb)
luminal
epithelium
glandular
epithelium
stroma
Smooth
muscle layer (called myometrium) - may not be visible depending on thickness of
endometrium
Note: serosa
(called perimetrium) will not be visible because the uterine wall is too thick
to get entire crossection on one slide.
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Questions |
Where do you think implantation takes place?
____________________________________
What is the function of endometrial glands? ______________________________________
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Specimens |
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Find the Following Structures |
Endocervix (meaning endo = inside and cervix = neck)
epithelium
stroma
Note: each of the
reproductive tract organs (oviduct, uterus, cervix and vagina has a similar
organization into an inner secretory tissue (endosalpinx, endometrium,
endocervix), a intermediate layer of smooth muscle (myosalpinx, myometrium),
and an outer connective tissue sheath of serosa
(perisalpinx, perimetrium, etc.).
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Questions |
How would you classify the epithelium of the cervix?
____________________________________
Why is the epithelium of the cervix thicker than for the
endometrium?
______________________________________
What aspect of the histology of the cervix gives the organ its
rigid texture?
______________________________________
VAGINA
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Specimens |
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Find the Following Structures |
Epithelium
Stroma
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Questions |
Is the vagina keratinized like skin?
_________________________________________________
How would you classify the epithelium of the vagina?
___________________________________
Website maintained by Peter J. Hansen Modified 10-20-2003
Photos (from left to right) are from the PJ Hansen's collection (heifers in estrus), Paolete Soto and PJ Hansen (bovine embryo stained for TUNEL), Roslin Institute (Dolly and her first lamb, Bonnie and a Meishan x Large White sow and piglets), and John Parrish (stallion with lip curl).
Links to commercial sites do not constitute endorsement by the authors or the University of Florida
© Peter J. Hansen
