METHODICAL INSTRUCTION FOR STUDENTS OF THE I COURSE
MEDICAL FACULTY
LESSON № 2 (PRACTICAL – 6 HOURS)
Theme. Cytology. Cytoplasm structure. Cell nucleus. Cell reproduction. Aging and death of the cell.
Place: histology department.
Aim: To learn the structure and functions of main cytoplasm components. To know microscopic and submicroscopic structure of the cell nucleus. To be able to identify their components in the specimens and electron micrographs. To know the cell cycle periods and different types of cells reproduction. To be able to identify different stages of mitoses in specimens.
Professional motivation: A cell is the morphofunctional unit of the living substance. It consists of plasmalemma, cytoplasm and nucleus. Organelles and inclusions disposed in hyaloplasm are the main components of the cytoplasm. Knowledge of the cell nucleus and chromosomes structure is especially necessary for understanding the heredity information reproduction essence, chromosomal diseases diagnosis and for the elaboration of prophylaxis measures as for hereditary defects in infant birth.
Contradiction between fast cell growth and its metabolism decrease is solved by cell division into two daughter cells. Thus the main results of cell reproduction are organism growth, development, physiologic and reparative regeneration, transmission of genetic information. Impairment of the cells prolifarative processes and divergention under the influence of unfavourable environment factors (radiation, carcinogenes, pesticides and etc.) may lead to some severe consequences (neoplasma growth, chromosomal diseases and etc.). Knowledge of normall cell division and pathologic processes development mechanisms is especially important for the prevention of human hereditary and acquisitive diseases.
Basic level:
1. General structure of the cell (school biology).
2. Interphase nucleus structural compounds (biology department).
3. Chromosomes, karyotype disorders, chromosomal diseases (biology department).
4. Light microscopy skill (biology department).
5. Cell cycle. Chromosomal set (biology department).
6. Light microscopy skill (biology department).
І. Practical work – 900-1200 (4 hours)
Illustrations.
1. Charts:
1. The ultrastructure of the cell.
2. Organelles of special-meaning – neurofibrilla.
3. Organoids of special-meaning – myofibrilla.
4. Different kinds of cell inclusions.
5. Mitochondria.
6. Golgi complex.
7. Rough-surfaced endoplasmic reticulum.
8. Smooth-surfaced endoplasmic reticulum.
9. Lysosomes.
10. Cell nucleus structure (scheme).
11. General structure of the cell.
12. Human karyotype.
13. Chromosome structure.
14. Cell with elongated nucleus (smooth muscular cell).
15. Cell with round-shaped nucleus (oocyte).
16. Cell center.
17. Animal cell division.
18. Division of the plant cell.
Student’s Practical Activities
Task No 1. Students must know and illustrate such a histologic specimens.
Specimen 1. Lipid inclusions in hepatocytes.
Stained with
At a low magnification find group of cells with lipid inclusions. Under the high magnification watch them carefully, notice different size of black drops of lipid. Pay attention to red colour of the round-shaped nucleus.
Illustrate and indicate: 1. Nucleus 2. Cytoplasm 3. Lipid inclusions.
Specimen 2. Glycogen inclusions in hepatocytes.
Stained with Schiff reaction.
At low magnification find the specimen part where the inclusions are uniformly placed in hepatocyte. Under the high magnification you can see small red colour glycogen granulae surrounding the blue nucleus.
Illustrate and indicate 1. Nucleus 2. Cytoplasm 3. Glycogen granulae.
Specimen 3. Cell with a spherical nucleus (dorsal root ganglion cell).
Stained with haematoxylin and eosin.
At low magnification one must find the round-shaped cells with spherical nuclei under the ganglion envelope. Under a high magnification one must watch the structure of nucleus. They look like vesicles that are separated from the cytoplasm by nuclear envelope and contain chromatin granules and nucleolus inside and unstained portion of karyoplasm.
Illustrate and indicate: 1. Nuclear envelope. 2. Chromatin. 3. Nucleolus. 4. Nucleo-plasm. 5. Cell cytoplasm. 6. Plasmolemma.
Specimen 4. Cell with an elongated nucleus (smooth muscle cell)
Stained with haematoxylin and eosin.
Find the elongated section of smooth myocytes under low magnification. Watch this portion under high magnification, notice the spindle shape of the myocytes, that atteched to each other. An elongated-shaped violet nucleus is observed in the middle of the pink-stained cell cytoplasm.
Illustrate and indicate: 1. Plasmolemma. 2. Cytoplasm. 3. Nucleus.
Specimen 5. Mitosis of the plant cell (onion root section).
Stained with iron haematoxylin.
At a low magnification one must find in the specimen a portion with dividing cells. Under a high magnification one must watch 4 stages of mitosis: prophase – chromosomal tangle (ball), metaphase – equatorial disposition (maternal star) of the chromosomes, anaphase – two daughter stars in the poles and telophase – daughter cells formation. Notice: there are no centrioles in the cells (a specific feature of the plant cells mitosis).
Illustrate and indicate:
Specimen 6. Mitosis of the animal cell (liver).
Stained with iron haematoxylin.
At a low magnification one must find the marginal zone, that contains small polygonal cells capable of division. Watch mitosis stages under a high magnification.
Illustrate and indicate: Mitosis. 1. Prophase. 2. Metaphase. 3. Anaphase. 4. Telophase.
Task No 2. Students must know and illustrate such a scheme.
Scheme of the interphase cell nucleus.
Illustrate and indicate: 1. Nuclear envelope: a) outer membrane, b) inner membrane, c) perinuclear space, d) nuclear pores. 2. Nucleoplasm. 3. Chromatin: a) heterochromatin, b) euchromatin. 4. Nucleolus.
Task No 3. Students should be able to indicate elements in the electron micrographs:
1. Mitochondria.
2. Golgi complex.
3. Rough-surfaced endoplasmic reticulum.
4. Smooth-surfaced endoplasmic reticulum.
5. Lysosomes.
6. Myofibril.
7. Cilia.
8. Round-shaped nucleus.
9. Fragment of the nucleus.
10. Ovoid and elongated nucleus.
11. Structure of the nucleolus.
12. Cell center – centrosome.
13. Cells with degenerative changed nuclei (karyopicnosis, karyorexis, karyolisis).
ІІ. Discussion of practical work– 1230-1400 (2 hours)
Samples of tests and real-life situations
1. What is main mitochondrion function?
a) energy production
b) protein synthesis
c) lipid synthesis
d) intracellular digestion
e) intracellular transport
2. Under radiation some cell compounds were destroyed. How will they be utilized?
3. Microsurgically the cell was divided into two portions: with a nucleus and without it. What will happen with both parts? What is the reason?
4. Indicate in order the phases of mitosis.
a) prophase, metaphase, anaphase, telophase
b) metaphase, anaphase, prophase, telophase
c) anaphase, metaphase, Telophase, prophase
d) telophase, prophase, metaphase, anaphase
e) metaphase, Telophase, prophase, anaphase
Answers for tests and real-life situations
1. a) energy production.
2. Destroyed compounents of the cell will be utilized by lysosomes.
3. Part of the cell with nucleus will renew its structure and function; nucleusless part will die without hereditary information.
5. At the anaphase stage each daughter star contains diploid chromosomal set of s-chromosomes.
Theoretical questions discussion
1. Cytoplasm structural components.
2. What does hyaloplasm consist of?
3. Organelles: attribute and classification:
a) in accordance with its meaning;
b) accordingly to its size;
c) by the structure.
4. Microscopic- and ultrastructure and functions of common meaning organelles (mitochondria, Golgi complex, endoplasmic reticulum, lysosomes, peroxysomes, ribosomes, cell center, filaments and microtubules).
5. Special organelles: species, location and functions.
6. Inclusions: attribute, differences from organelles, classification.
7. Morphofunctional characteristic of inclusions.
8. General morphology of the interphase cell nucleus and their biological significance.
9. Nuclear envelope ultrastructure and functions.
10. Chromatin chemical compounds. Euchromatin, heterochromatin.
11. Chromosomes types and significance. Thin structure and chemical composition of chromosomes.
12. Human karyotype (chromosomal set).
13. Sex chromatin, its investigation significance in medicine.
14. Nucleolus and karyoplasma structure and compositions.
15. Cell cycle definition. Interphase stages characteristic features.
16. Main types of cell division.
17. Mitosis stages and reasons that force the cell to divide.
18. Nucleus and cytoplasm changes in different stages of mitosis.
19. Endomitosis morphologic features and examples.
20. Meiosis peculiarities.
21. Aging and death of the cell. Paranecrosis and degeneration.
ІІІ. Individual student’s work – 1415-1500 (1 hour)
References:
a) main
1. Practical classes materials from theme “Cytology. Cytoplasm structure. Cell nucleus. Cell reproduction. Aging and death of the cell” (Intranet).
2. Lecture presentations from theme “Introduction in histology. Cytology and embryology subject and tasks” (Intranet).
3. Stevens A. Human Histology / A. Stevens, J. Lowe. – [second edition]. –Mosby, 2000. – P. 14–32.
4. Wheter’s Functional Histology : A Text and Colour Atlas / [Young B., Lowe J., Stevens A., Heath J.]. – Elsevier Limited, 2006. – P. 6–44.
5. Inderbir Singh Text book of Human Histology with colour atlas / Inderbir Singh. – [fourth edition]. – Jaypee Brothers Medical Publishers (P) LTD, 2002. – P. 14–36.
6. Ross M. Histology : A Text and Atlas / M. Ross W.Pawlina. – [sixth edition]. – Lippincott Williams and Wilkins, 2011. – P. 22–25, 35–97.
b) additional
1. Eroschenko V.P. Atlas of Histology with functional correlations / Eroschenko V.P. [tenth edition]. – Lippincott Williams and Wilkins, 2008. – P. 10–13, 19–25.
2. Junqueira L. Basic Histology / L. Junqueira, J. Carneiro, R. Kelley. – [seventh edition]. –
3. Disk:
http://intranet.tdmu.edu.ua/data/teacher/video/hist/
4. Volkov K. S. Ultrastructure of cells and tissues / K.
http://intranet.tdmu.edu.ua/data/books/Volkov(atlas).pdf
http://en.wikipedia.org/wiki/Histology
http://www.meddean.luc.edu/LUMEN/MedEd/Histo/frames/histo_frames.html
http://www.udel.edu/biology/Wags/histopage/histopage.htm
Methodical instruction has been worked out by assist. S. B. Kramar
Methodical instruction was discussed
and adopted at the Department sitting
27th of August 2012. Minute No 1.
Readopted at a chair sitting
8 th of January 2013. Minute No 6.
