Chapter1 intromarieb

180 views
118 views

Published on

Published in: Technology, Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
180
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Chapter1 intromarieb

  1. 1. Goals:•Anatomy of a typical cell•Cell Membrane•Discussion of internalstructure of a cell withemphasis on the variousorganelles Developed by John Gallagher, MS, DVM
  2. 2. Some Terminology:1. Cells are the smallest living structure2. Cell = functional unit of the body3. Cytology = The Study of Cells4. Ultrastructural Cytology = Cytology at the Electron Microscopic level5. Histology = the study of tissues (next meeting)
  3. 3. Anatomy of a typical cell1. Cell membrane2. Cytoplasm = cytosol + organelles3. Organelles•Smallest: •Granule cell in cerebellum: 4 μ Fig. 2.1 •RBC: 5-7 μ = 0.005-0.007 mm•Largest: •Anterior horn cell in spinal cord: 135 μ •Ovum: 120 μ = 0.12 mm•Longest: •Pseudounipolar cell (CNS to toe)
  4. 4. Anatomy of a typical cell, cont’d_ Shapes: – Squamous (scale) - flat, capillaries, lungs – Cuboidal - lines ducts – Columnar - length > width, digestive tract – Stratified - many layers – Many others will be covered in histology (next two lectures)
  5. 5. Cell Membrane = phospholipid bilayer _ Physical isolation of the cell contents from the environment (interstitium) _ Regulation of exchange of materials with the environment _ Sensitivity to changes in the environment _ Structural support of the cell – Organelles, too!
  6. 6. Cell MembraneSynonyms:•plasma membrane•plasmalemma•axolemma•others
  7. 7. Membrane Permeability _ Diffusion – Concentration Gradient of Solutes _ Osmosis – Water (solvent) through semipermeable membrane _ Filtration – Hydrostatic Pressure » Capillaries! _ Active Transport – Requires energy (ATP)
  8. 8. Endocytosis = into the cell _ Pinocytosis – Extracellular Fluid _ Phagocytosis – Solid Objects, e.g., bacteria _ Receptor-mediated Endocytosis – Special membrane proteins required
  9. 9. Exocytosis = out of the cell _ Secretory vesicles (e.g. hormones) – Fluid and waste removal
  10. 10. Cytosol vs. cytoplasm Cytosol = The thick fluid inside any cell Often synonymous with cytoplasm (protoplasm)  Cytoplasm = cytosol + organelles Suspends organelles
  11. 11. Organelles_ Structures INSIDE a cell that have specific functions wrt cellular structure, maintenance, or metabolism – Membranous » Nucleus » Golgi apparatus » Endoplasmic reticulum » Mitochondria » Vesicles and lysosomes – Nonmembranous » Ribosomes » Microtubules (cytoskeleton) » Actin/Myosin in muscle cells
  12. 12. Nucleus (= center)_ Visible with LM_ Membrane bound – Many pores_ DNA – 23 Pairs of Chromosomes » Except gametes_ Nucleolus – Most active DNA
  13. 13. Nucleus
  14. 14. Golgi Apparatus•Packaging and shipping ofproteins (secretory granulesand transport vesicles)•Membrane renewal•Synthesis of Lysosomes
  15. 15. ExocytosisFig 2.17
  16. 16. Golgi Apparatus
  17. 17. Endoplasmic Reticulum Synthesis, Storage, transport Smooth ER  Lipid synthesis Rough ER  Ribosomes make it rough ER  Protein synthesis
  18. 18. Mitochondrion / -a•Energy Conversion for cellularactivities •Formation of ATP•Double membrane •Glycolysis and TCA cycle•More prevalent in active cells, e.g.,rods and cones•Their own genome •Self-replicating
  19. 19. Lysosomes
  20. 20. Ribosomes - RNA 60% RNA + 40% protein Protein Factories Fixed vs. free ribosomes
  21. 21. Cytoskeleton4 major components:1. Microfilaments (mostly actin)2. Intermediate filaments3. Microtubules (composed of tubulin subunits)Function: support & movement of cellular structures & materials
  22. 22. Cilium – Cilia (pl.) In 9+2 array Compare to microvilli and flagella
  23. 23. Actin/Myosin _ The contractile proteins in muscle cells _ Striations Skeletal muscle
  24. 24. Intercellular AttachmentsChapter 4, pp 74-76 Act as: 1. Seals betw cells 2. Intercellular communication 3. Added strength to resist separation1. Gap Junctions2. Tight Junctions3. Desmosomes4. Basement Membrane Fig 4-7
  25. 25. 1) Gap Junctions Channel proteins (connexons) interlock and form pores Abundant in cardiac and smooth muscle Allows efficient intercellular communication
  26. 26. 2) Tight JunctionsInterlocking membrane proteinsFound near surface of cells lining the digestive tract. Explain!Adhesive Belt Junctions deep to tight junctions reinforce the seal
  27. 27. 3) DesmosomesProteoglycan layer reinforced by transmembrane proteins (cell adhesion molecules or CAMs)Belt, button and hemidesmosomesFound in superficial layers of skin
  28. 28. 4) Basement Membrane_ Reticular fibers + Basal Lamina_ Between epithelium and deeper connective tissue_ Acts as a filter, and helps epithelial regeneration
  29. 29. Fig 2.19 a
  30. 30. Mitosis (vs. meiosis) _ Cell Division – Interphase – Between mitosis – Prophase – Chromosomes become bunched – Metaphase – Chromosomes gather at equator – Anaphase – Chromosomes move to poles – Telophase – The two new nuclei form – Cytokinesis – Actual cell separation – Two new diploid cells
  31. 31. Mitosis
  32. 32. Some cellsFat cells (adipocytes) Cartilage cells (chondrocytes)
  33. 33. More cellsNeutrophil Plasma cell
  34. 34. Still more cellsColumnar cells Sperm cells (spermatozoa)
  35. 35. River Cullenagh, Ennistymon, Co Clare, Ireland

×