Student’s Practical Activities

Student’s
Practical Activities

Task No 1. Students must know and illustrate such a
histologic specimens.

Specimen
1. Human spermatozoa
(smear).

Stained
with nigrosin and eosin.

Find spermatozoa at a low magnification. They
have fibers-like structures and lie irregularly. Then investigate male sex
cells at high magnification. Pay a special attention on flagellate form of
these cells. Their heads are oval shaped and small, tails are much longer.

Illustrate and indicate: 1. Head. 2. Nucleus. 3.
Acrosome. 4. Neck. 5. Tail.

Specimen
2. Oocyte
of Graafian follicle. (Cat ovarium).

Stained
with hematoxylin and eosin.

Ovarian surface is covered with flat epithelium,
which rests on tunica albuginea (dense connective tissue). Ovary of cat usually
has a lot of follicles at the same time. At low magnification find mature
follicle in the cortex of ovary. It is large and has space inside. Two well prominet
layers are seen in its wall:
the inner one consists of numerous small follicular cells and the outer one –
theca externa has two sublayers – innermost with blood vessels and the outer –
without, consists mainly of fibrous connective tissue. Find some follicle with
ovum, which rests on the cumulus oophorus (is connected with wall of follicle).

Student’s Practical Activities Clip_image002

Student’s Practical Activities Clip_image003

At high magnification explore the structure of
oocyte and surrounding tunics. Pay attention - nucleus is situated
eccentrically. There are some yolk inclusions in cytoplasm. The female sex cell
is surrounded with transparent tunic of a rose colour, which refract the light very much -
zona pellucida. Follicular cells (small cells with violet nuclei) and their
processes form the radiant crown (corona radiata) of oocyte.

Illustrate and indicate: 1.
Oocyte. 2. Zona pellucida. 3. Crown radiant. 4. Follicular epithelial cells.

Specimen
3. Ascaridae fertilized oocyte.

Stained
with Iron hematoxylin.

In cross section
of horse acaridae uterus at a low magnification numerous oocytes are seen, most
of them are fertilized. At high magnification you can see one or two residual
cells in perivitelline space (the space, which originate due to cortical
reaction after spermatozoon penetration in oocyte). This
space lie
between tunic of fertilization and proper oolemma. Find the cell with two
nuclei. One of them is larger - female pronucleus and the smaller ones - male
pronucleus.

So, synkarion is
unicellular organism, surrounded by tunic of fertilization and containing two
pronuclei with haplod chromosomal each one.

Student’s Practical Activities Clip_image004

Polar body is ovalshaped basophilic structure,
which lies in the perivitelline space between oolemma and tunic of
fertilization.

Illustrate and indicate: 1. Synkaryon. 2. Male
pronucleus. 3. Female pronucleus.

3. Polar
body.

Task No 2. Students
must know and illustrate such a scheme.

Embryoblast

Scheme 1. Human blastocyst.

Trophoblast

Blastocyst cavity

Student’s Practical Activities Clip_image005

Blastocyst
consists of two different kinds of blastomers: dark large (embryoblast) and
small light, which surround the embryoblast and is called trophoblast. There is
a cavity with fluid in central part of blastula - blastocel.

Illustrate and indicate: 1. Embryoblast. 2.
Trophoblast. 3. Blastocel.

Endometrial epithelium

Endometrial stroma

Scheme 2. Implantation.

Blastocyst cavity

Embryoblast

Cells of trophoblast

Trophoblast

Student’s Practical Activities Clip_image006

At the first stage of implantation (adhesion) blastocyst attaches
to the surface of endometrium, mainly between the uterine glands. The second
phase (invasion) of blastocyst into endometrium continues under the influence
of trophoblast ferments, which are destroying mucosa and blastocyst falls into
pit and is covering with connective tissue and then epithelium.

Illustrate and indicate: 1. Embryoblast. 2.
Trophoblast. 3. Trophoblast villi. 4. Uterine epithelium. 5. Uterine
connective tissue. 6. Uterine gland.

Task No 3. Students should be able to indicate
elements in the electron micrographs:

1. Flagella (tail of the spermatozoon).

2. System of
microtubules doublets.

References:

1.
Medical Embryology. Langman J. Baltimore. Wilkins
Co. 1969.
P. 3-34.

2. L.
Carlos Junqueira, Jose Carneiro, Robert O. Kelley. Basic
Histology. - 7^thed. Appleton and Lange. Norwalk, Connecticut, 1992.

3.
Inderbir Singh. Textbook of Human Histology with colour atlas. – 4^thed. Jaypee
Brothers Medical Publishers (P) LTD, 2002.

4.
Victor P. Eroschenko. Atlas of Histology with functional correlations. - 9^thed. Lippincott Williams and Wilkins, 2000.

5.
Wheater P.R., Burkitt H.G., Daniels V.G. Functional Histology: a text and
colour atlas. - 2^nd ed. Longman Group UK Limited, 1987.

6. Webster’s Medical Desk Dictionary. – Springfield. –
Merriam-Webster Inc. – 1995.

http://217.196.164.19/index.php?dir_name=kafedra&file_name=tl_34.php#n15

7. Disk:

http://217.196.164.19/index.php?dir_name=cd&file_name=index.php#3

8.
Волков К.С. - Ультраструктура клiтин i
тканиню Навчальний
посiбник-атлас. 1997 р., 95 с.

http://217.196.164.19/data/books/Volkov(atlas).pdf

9.
О.Д.Луцик і співавт. – Гiстологiя
людини. – Київ: Книга плюс, 2003 р. –592 с.

http://217.196.164.19/data/books/gistologia_lucyk.pdf

http://www.morphology.dp.ua/hist.php?lang=uk

http://en.wikipedia.org/wiki/Histology

http://www.meddean.luc.edu/LUMEN/MedEd/Histo/frames/histo_frames.html

http://www.kumc.edu/instruction/medicine/anatomy/histoweb/

http://www.udel.edu/biology/Wags/histopage/histopage.htm