1. Anatomy of Cells

2. “Typical” Cell

3. “Typical” Cell vs. Reality “Typical” cells do not actually exist in the body Cell are specialized structure to carry out specialized functions (see Table 3-1, pg. 73) –Nerve cells: have long extension  transmit nerve impulses throughout the body –Muscle cells: contain fibers that slide together  contracts/movement of body parts –RBCs: contain hemoglobin  carry oxygen from lungs to various parts of the body

4. Main Components of Cell Structure 1.Plasma Membrane 2.Cytoplasm –Cytosol (intracellular fluid) –Organelles 3.Nucleus 4.Cytoskeleton –Cell’s internal supporting framework

5. Plasma Membrane 1.Phospholipid bilayer Hydrophilic heads Hydrophobic tails Majority of membrane is hydrophobic – water and water-soluble molecules cannot pass Cholesterol – steroid lipid; provides stabilization for the plasma membrane

7. Plasma Membrane 2.Embedded proteins Penetrate into the hydrophobic regions of the plasma membrane Transport mechanism Transport proteins are often specific for certain molecules “Gates” can open or close

9. Plasma Membrane 3.Peripheral Proteins Glycoproteins (carbohydrates and proteins) Identification markers Recognize self vs. non-self (immune system) Receptors Proteins that react in the presence of hormones or other regulatory chemicals Trigger metabolic changes within the cells Signal transduction

11. Cytoplasm Cytosol –Watery solution –Intercellular fluid (ICF) Organelles –“tiny organs” –Thicken the cytosol to a gel-like consistency

12. Endoplasmic Reticulum Rough ER –Presence of ribosomes –Protein synthesis –Intracellular transport Smooth ER –Lipid and carbohydrate synthesis –Replenishes cell membrane material http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/images/endoplasmicreticulumfigure1.jpg

13. Ribosomes Attached to Rough ER or scattered throughout cytoplasm Composed of a large and a small subunit –Each subunit contains RNA (rRNA) bonded to protein Function – Protein synthesis –Cell’s “protein factory”

14. Golgi Apparatus Consists of tiny sacs or cisternea “processing & packaging plant” –Export proteins make in the Rough ER out of the cell – Secretion –Fig 3-5, page 81

15. Lysosomes Vesicles that have pinched off from the Golgi apparatus Contain enzymes capable of breaking down cell components “digestive bags” or “cellular garbage disposals” –Ex: rid cells of bacteria; Scavenger WBCs

16. Peroxisomes Similar to lysosomes Small sac containing enzymes Important in kidney and liver cells –Detoxification functions in the body

17. Mitochondria Structure: –Two membranes (sac within a sac) –Inner membrane contains folds ( cristae ) Function: –Enzymes embedded in cristae – essential in making adenosine tri-phosphate (ATP) –Cell “power plant” –# of mitochondria based on amt of work done by cell Ex: liver cells > sperm cells –Self-replicating – based on energy needs Aerobic exercise increases # of mitochondria in skeletal muscle cells

18. Mitochondria

19. Nucleus Large, spherical organelle Enclosed by a two nuclear membranes = nuclear envelope Nuclear pores – selectively allow molecules to enter/leave nucleus Contains DNA (genetic information) –Chromatin – uncondensed genetic material –Chromosomes – condensed genetic material Nucleolus – synthesizes rRNA

20. Nucleus

21. Cytoskeleton Cell Fibers 1.Microfilaments “Cellular muscles” Thin, twisted strains of protein Can contract (ex: muscle cells) 2.Intermediate Filaments slightly thicker Main component of the supporting framework in many cell types 3.Microtubules Thickest of the cell fibers; tiny, hollow tubes Cell “engine” – help with movement within the cell and the cell itself

24. Cytoskeleton Centrosome –Located near the nucleus –“microtubule-organization center” –Important role in cell division – move chromosomes around the cell Centrioles –Cylindrical structures within the centrosome –Replicate prior to cell division –Roles in cell division

26. Cell Extensions Microvilli –Epithelial cells found where absorption is necessary (ex: small intestine) –Increase surface area Cilia –Transport fluid across a cell surface –Ex: Line the respiratory tract – move mucous upward –Ex: Assist the ovum to move towards the uterus Flagella –Single, long structures; aids in locomotion –Ex: sperm cells

28. Anthony’s Textbook of Anatomy and Physiology 17 th Edition. Thibodeau, Gary A. PhD and Patton, Kevin T. PhD. Mosby, Inc.