Cells & Extracellular Matrix PDF

CELLS & EXTRACELLULAR MATRIX dr. Gladys Adipranoto, SpOT School of Medicine , University of Ciputra Surabaya  Cells in Human Body Cells are the basic structural, functional, and biological units of all living organisms Cells come...

CELLS & EXTRACELLULAR MATRIX dr. Gladys Adipranoto, SpOT School of Medicine , University of Ciputra Surabaya  Cells in Human Body Cells are the basic structural, functional, and biological units of all living organisms Cells come in various shapes as its function nucleus cytoplasm  Cell Interphase Nucleous contains: nucleolus chromatins nuclear sap Cytoplasm contains: orgnaelles inclusion  Nucleolus in Interphase Open Phase (active): Definition: During this phase, the nucleolus is fully active and transcriptionally engaged. Characteristics:. ○ Visible Structure: The nucleolus appears larger and more distinct under a microscope because it is actively synthesizing and processing rRNA. Closed Phase (inactive): Definition: The nucleolus enters a more condensed, inactive state where ribosomal RNA production is reduced or halted. Structural Changes: The nucleolus may appear smaller or less distinct.  Mitotic Phase (dividing or regeneration)  Prophase centrosomes move to opposite poles, the nuclear envelope disappears by fragmentation, the chromosomes condense and become visible. each chromosome consists of two chromatids joined at their centromere regions by kinetochore protein complexes.  Metaphase At the short metaphase, the chromosomes have become aligned at the equatorial plate as a result of their attachments to the dynamic microtubules of the mitotic spindle organized by the centrosomes. T he spindle consists of kinetochore microtubules, polar microtubules which interdigitate near the equatorial plate, and shorter astral microtubules anchoring the spindle to the cell membrane.  Anaphase During anaphase, the kinetochores separate and the chromatids (now called chromosomes themselves) are pulled on their microtubules toward each centrosome.  Nuclear membran terbentuk kembali. Benang kromosom menjadi butir chromatin lagi. Telophase Dan inti terbentuk satu atau lebih anak inti. Membran sel membentuk lekukan diantara kedua inti baru dan akhirnya terjadi 2 sel baru. In telophase, the cell pinches itself in two by contraction of the F-actin bundle in the cell cortex, after which the chromosomes decondense, transcription resumes, nucleoli reappear, and the nuclear lamina and nuclear envelope reassemble. (All ×500; H&E)  Meiosis Meiosis is a type of cell division that reduces the chromosome number by half, producing four genetically diverse haploid cells (gametes: sperm or eggs).  Cell Death Mechanism Apoptosis (Programmed Cell Death): ○ Controlled, energy-dependent process. ○ Features: Cell shrinkage, chromatin condensation, formation of apoptotic bodies. ○ Significance: Removes damaged or unnecessary cells without causing inflammation. Necrosis (Uncontrolled Cell Death): ○ Caused by external injury (e.g., trauma, toxins, infection). ○ Features: Cell swelling, membrane rupture, inflammation due to spillage of cell contents. ○ Significance: Often leads to tissue damage and inflammation. A. Pyknosis is the shrinkage of the cell nucleus. Neutrophils with concentrated and basophilic nuclei showing pyknosis. Toxic granulations are suggestive of infection. B. Karyolysis is the melting of nucleus chromatin with enzymes (nucleases) released from the lysosomes of the dead cell. The nuclear membrane is preserved. C, D. Karyorrhexis is the rupture of the nuclear membrane, division of chromatin into small basophilic granules and spreading into the cytoplasm. Neutrophils that have undergone karyorrhexis are seen. Moreover, a dysplastic neutrophil with increased basophilic staining in one part of the cytoplasm and vacuolization in the other part.  Cytoplasm Definition: The jelly-like substance inside the cell membrane, excluding the nucleus. Components: ○ Cytosol: Fluid portion containing ions, nutrients, and proteins. ○ Organelles: Specialized structures (e.g., mitochondria, ribosomes, ER) that perform specific cellular functions. ○ Cytoskeleton: Network of protein filaments providing cell shape, support, and movement (e.g., microtubules, actin filaments). Site of Metabolism: Enzymatic reactions, protein synthesis, and energy production occur here. Organelle Support: Suspends organelles, allowing their interaction and mobility. Intracellular Transport: Facilitates movement of materials within the cell. ORGANELLES: Nucleus Function: Contains genetic material (DNA) and controls cell activities. Key Features: Nuclear envelope, nucleolus (ribosome production). Mitochondria Function: Powerhouse of the cell; produces ATP through cellular respiration. Key Features: Double membrane, own DNA. Endoplasmic Reticulum (ER) Rough ER: Studded with ribosomes; synthesizes proteins. Smooth ER: Synthesizes lipids and detoxifies chemicals. Golgi Apparatus Function: Modifies, sorts, and packages proteins and lipids for transport. Key Features: Flattened stacks of membranes. Lysosomes Function: Digests and recycles cellular waste and pathogens. Key Features: Contains hydrolytic enzymes. Ribosomes Function: Protein synthesis. Key Features: Found in cytoplasm or attached to Rough ER. Cytoskeleton Function: Provides structure and facilitates cell movement. Key Features: Made of microtubules, actin filaments, and intermediate filaments. Organelles that can be seen under light microscope Nissl bodies ribosome  Inclusion Inclusion Bodies: Non-living structures within the cytoplasm of a cell, often involved in storage or waste removal. Composition: Composed of stored nutrients, waste products, or other cellular materials like pigments or glycogen. Food storage carbohydrates: PAS staining fat: osmic acid, sudan black, sudan IV, schariah red Endogen Pigments: Melanin, hemoglobin, hemosiderin, lipofusin Exogen Pigments: Dust phagocytosed by macrophage, lipochrome beta carotene from the carrot Crystals in Leidig Cells  Melanin Melanosit dan dermal cromatophore  Inclusion: lipid droplet spongiocyte cells in adrenal glands  Vacuola mucigen  Cell Membrane Cell Membrane/plasma membrane: A thin, flexible barrier that surrounds the cell, separating its internal environment from the external one. In absorptive cells, there are protrusions on the cell membrane surface called microvilli. These are evaginations of the cell membrane containing microfilaments in the center. When closely arranged, they form a brush border (visible under a light microscope). They can perform: Endocytosis: » Pinocytosis (liquid). » Phagocytosis (solid). Exocytosis BAHAN ANTAR SEL EXTRACELULLAR MATRIX 1. Definition Extracellular Matrix (ECM): A network of non-cellular components surrounding cells within tissues, providing structural and biochemical support. 2. Components of ECM Fibers: ○ Collagen: Provides tensile strength. ○ Elastin: Offers elasticity to tissues. ○ Reticular Ground Substance: ○ Proteoglycans & Glycosaminoglycans (GAGs): Hydrate the matrix and resist compression. ○ Glycoproteins: Mediate cell attachment (e.g., fibronectin, laminin). 3. Functions of ECM Structural Support : Provides a scaffold for tissue organization. Cell Communication : Influences cell behavior through biochemical signals. Tissue Repair : Involved in wound healing and regeneration. Barrier Function : Regulates molecule movement between cells and tissues. e Collagen Fibers ECM Collagen Synthesis  POLIMERISASI TROPOKOLGEN MEMBENTUK FIBRIL 12.000 x 124.000 x Elastin Fibers  Elastin Cartilage Artery Ligamentun Nuchae Reticular Fibers Reticular Fibers Amorph ECM / Ground Substances  Jar ikat embrional Dermis B.A.S.A: spt jelli Cairan jaringan Jaringan: Tulang Placenta  TALI PUSAT B.A.S.A konsistensi seperti jelli B.A.S.A. Dgn konsistensi PADAT LUNAK TL Rawan hialin TL Rawan elastis  JARINGAN: TULANG B.A.S.A. DGN KONSISTENSI DASAR PADAT KERAS