Cytology I - Dentistry 2024-2025 PDF

Faculty of Oral and Dental Medicine ‫كلية طب الفم واألسنان‬ CYTOLOGY –I Dr/ Amel Marzouk Professor of Histology 2024-2025  ‫‪Faculty of Oral and Dental Medicine‬‬ ‫كلية طب الفم واألسنان‬...

Faculty of Oral and Dental Medicine ‫كلية طب الفم واألسنان‬ CYTOLOGY –I Dr/ Amel Marzouk Professor of Histology 2024-2025  ‫‪Faculty of Oral and Dental Medicine‬‬ ‫كلية طب الفم واألسنان‬ ‫رؤية الكلية ‪:‬‬ ‫العمل علي تمديم مستوي متميز في تعليم طب الفم واألسنان والبحث العلمي‬ ‫وخدمة المجتمع لتحميك الريادة والتميز علي المستويين المحلي وااللليمي ‪.‬‬ ‫رسالة الكلية ‪:‬‬ ‫حشد االمكانيات والطالات وتوظيفها لتمديم برنامج تعليمي يتوافك مع معايير‬ ‫الجودة لتخرج أطباء أسنان متميزين الي سوق العمل ذوي كفاءة مهنية وليم‬ ‫أخاللية لادرين علي المنافسة في مجاالت عمل طب الفم واالسنان كما تلتزم‬ ‫باالرتماء بمنظومة البحث العلمي الهادف وتعظيم المشاركة المجتمعية ‪.‬‬  CYTOLOGY –I (Plasma Membrane & Membranous cell organelles) Learning Objectives: Compare between eukaryotic & prokaryotic cells.  Identify the components of the cell.  Recognize the structure and functions of plasma membrane.  Identify the components of the cytoplasm.  Enumerate the membranous cell organelles. Mention the structure & functions of membranous cell organelles.  What is Histology? Histology is the study of the microscopic structure of cells, tissues and organs of the body. * The cell is the structural & functional unit of human body. *Tissues have two interacting components: cells and extracellular matrix (ECM). *The study of histology depends on the use of microscope: light microscope (LM) & electron microscope (EM).  Eukaryotic & Prokaryotic Cells Eukaryotic cells Prokaryotic cells 1. Larger 1. Smaller. 2. Have NO cell wall. 2. Have cell wall. 3. Have a nucleus. 3. Have NO nuclei. 4. Have membranous organelles. 4. Lack (=Don’t have) membranous organelles. 5. Example: Animal & human cells. 5. Example: Bacteria.  Let’s Think (A) (B) a) Write the type of the cell labeled (A) & (B). b) Compare between the two types of cells.  The Cell Structure Each cell contains: 1. Plasma membrane 2. Cytoplasm 3. Nucleus  Plasma Membrane (PM) -PM defines the outer limit of the cell. -PM is extremely thin (ranges from 7.5-10 nm in thickness). -Structure of PM: The PM is composed of lipids, proteins and carbohydrates.  Structure of Plasma Membrane Membrane lipids composed of: a) Phospholipid molecules arranged into a double layer called the phospholipid bilayer. b) Cholesterol molecules.  Structure of Plasma Membrane Membrane proteins composed of: a) Integral proteins: are embedded within the phospholipid bilayer. When these proteins completely span the bilayer, they are called transmembrane proteins. b) Peripheral proteins: are loosely associated with the membrane surface.  Structure of Plasma Membrane Membrane carbohydrates composed of sugar chains linked to lipids (glycolipids) and to proteins (glycoproteins). The sugar chains are always oriented towards the outside of the plasma membrane forming the cell coat.  Functions of Plasma Membrane 1. Protection of the cell. 2. Membrane transport: PM regulates material movements into & out of the cell. 3. Communication between cells.  Let’s Think a) Write the name of the diagram. b) Write the name of labels 1, 2, 3, 4, 5 & 6.  Cytoplasm The cytoplasm contains: 1- Cell organelles (membranous & non-membranous organelles). 2 - Cell inclusions.  Membranous Cell Organelles 1- Rough & smooth endoplasmic reticulum 2- Golgi apparatus 3- Secretory vesicles 4- Lysosomes 5- Mitochondria  Endoplasmic Reticulum *Endoplasmic reticulum is a network of membrane- bound spaces. Types of Endoplasmic Reticulum: 1- Smooth endoplasmic reticulum (SER) 2- Rough endoplasmic reticulum (RER) Diagram of SER and RER  Smooth Endoplasmic Reticulum (SER) - With L.M: Cells rich in SER are highly acidophilic with H&E stain. - With E.M: SER Has NO ribosomes on its membranes. - Functions: 1- Lipid synthesis. L.M. of muscle cells rich in SER by H&E stain 2- Detoxification of drugs. 3- Helps muscular contraction.  Rough Endoplasmic Reticulum (RER) - With L.M: Cells rich in RER are highly basophilic with H&E stain. - With E.M: RER Has ribosomes on its membranes. - Function: Synthesis of proteins. L.M. of nerve cells rich in RER by H&E stain Let’s Think a) Write the name of (A) & (B). b) Compare between A & B?  Golgi Apparatus (Golgi complex) - With L.M: Golgi apparatus is stained with silver stain. - With E.M: Golgi apparatus is formed of cisternae and vesicles. - Function: 1. Modifications of proteins. 2. Packing of proteins to form lysosomes and secretory vesicles. L.M. of Golgi apparatus by Silver stain  Lysosomes - Are membrane-bound vesicles rich in hydrolytic enzymes. - Function: 1- Digestion of materials entering the cell. 2- Removal of damaged cell components, e.g. old mitochondria. - Types of Lysosomes: 1- Primary lysosomes: are newly formed lysosomes. 2- Secondary lysosomes: are lysosomes that started digestive activity. 3- Residual bodies: are the remaining lysosomes after complete digestion. Diagram of Types of Lysosomes  Mitochondria (Power House of the cell) - With L.M: Mitochondria are stained with iron hematoxylin stain. - With E.M: Mitochondria are surrounded by two membranes. The outer membrane is smooth and the inner membrane has LM of mitochondria by Iron Hematoxylin stain folds called cristae. -The space inside the inner membrane contains the matrix which has a high concentration of enzymes in addition to small circular DNA, ribosomes, and Ca++ particles. - Function: Production of energy for the cell. Diagram of EM of mitochondria Diagram of E.M. of Mitochondria  Lecture References Junqueira's Basic Histology: Text and Atlas 17th Edition.  Enumerate: 1. Structure of plasma membrane. 2. 3 Functions of plasma membrane. 3. Types of lipids in the plasma membrane. 4. Types of proteins in the plasma membrane. 5. Membranous cell organelles. 6. Functions of smooth endoplasmic reticulum. 7. Functions of lysosomes. 8. Types of lysosomes. 9. Functions of Golgi apparatus. 10. Contents of the matrix of mitochondria. 11. Differences between eukaryotic and prokaryotic cells.  Complete: 1. Proteins in plasma membrane include ……..……… and ……………….. 2. Sugar chains linked to lipids and to proteins form the ………….………. 3. Cells rich in SER are highly ………………with H&E stain. 4. Cells rich in RER are highly ….………… with H&E stain. 5. Golgi apparatus is stained with ………………. stain. 6. The functions of lysosomes are ………….… and ……………. 7. Mitochondria is stained with …………………. stain. 8. The function of mitochondria is ……………………  Choose the correct answer: 1-Which of the following organelles is rich in hydrolytic enzymes? a. Lysosomes. b. Smooth endoplasmic reticulum. c. Mitochondria. d. Golgi complex. 2- Which of the following is NOT a membranous organelle? a. Lysosomes. b. Golgi complex. c. Mitochondria. d. Ribosomes. 3- Which of the following organelles is the power house of the cell? a. Lysosomes. b. Golgi complex. c. Mitochondria. d. Ribosomes. 4- Which of the following is a character of prokaryotic cells? a. Cell wall. b. Larger than eukaryotic cells. c. Nucleus. d. Membrane-limited organelles. 5- The thickness of plasma membrane is? a. 7.5-10 µm. b. 7.5-10 nm. c. 15-20 µm. d. 15-20 mm. 6- Which of the following is a function of smooth endoplasmic reticulum? a. Detoxification of drugs. b. Production of energy. c. Removal of old mitochondria. d. Synthesis of proteins.  Let’s Think (A) (B) a) Write the type of the cell labelled (A) & (B). b) Compare between the two types of cells.  Let’s Think a) Write the name of the diagram. b) Write the name of labels 1, 2, 3, 4, 5 & 6. Let’s Think a) Write the name of (A) & (B). b) Compare between A & B?  Let’s Think 1. This diagram shows the types of …………………. 2. Enumerate these types: a-……….……. b-…………….……. c-…….……..…. Thank YOU