Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 1 Cells Chapter 3 B. Souto

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 2 A Typical Cell A Typical Cell  The cell is the structural and functional unit of all living matter.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 3 A Typical Cell - cont’d  Cell Membrane (Plasma Membrane)  The cell membrane is composed of a two-layer phospholipid and protein.  The cell membrane is selectively permeable.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 4 A Typical Cell - cont’d  Structures Inside the Cell Structures Inside the Cell Structures Inside the Cell  The nucleus is the control center of the cell; it stores the genetic information.  The cytoplasm is a gel-like substance inside the cell membrane but outside of the nucleus.  Many different organelles are in the cytoplasm.  The mitochondria are the power plants of the cell.  Ribosomes are concerned with protein synthesis.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 5 A Typical Cell - cont’d  Structures Inside the Cell—cont’d  The Golgi apparatus packages and puts the finishing touches on the newly synthesized protein.  Lysosomes act as intracellular housekeepers.  The cytoskeleton provides shape and support to the cell.  Centrioles play a role in cell reproduction.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 6 A Typical Cell - cont’d  Structures on the Cell Membrane  Cilia are short, hair like projections.  Flagella are long, hairline projections; the sperm has a flagellum that allows it to swim.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc. Cell Membrane- Just Passing Thru Just Passing ThruJust Passing Thru Slide 7

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 8 Movement Across the Cell Membrane  Passive Transport Mechanisms  Passive transport mechanisms require no input of energy (ATP).  Diffusion is the movement of a substance from an area of greater concentration to an area of lesser concentration. It is the most common form of transport ( see pg. 40).  Facilitated diffusion is the same as diffusion but uses a helper molecule in the membrane to increase the rate of diffusion ( see pg. 41). Although there’s a helper cell it’s still considered __________ transport?

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 9 Movement Across the Cell Membrane - cont’d  Passive Transport Mechanisms—cont’d  Osmosis is a special case of diffusion using a semipermeable membrane. Osmosis involves the diffusion of water from an area with more water to an area of less water. The trapped solute is said to “pull water” because of osmosis ( see fig 3-9). Let’s look at the information in your textbook.  So what is osmotic pressure?  Define edema.  So why may a blood clot continue to grow even when the bleeding stops?

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc. Movement Across the Cell Membrane - cont’d  When two compartments containing different concentrations of solute ( dissolved substances) interact, the term used to describe the water concentration is tonicity. The concentrations of a solution are expressed as tonicity. Solutions are isotonic, hypotonic, or hypertonic  Isotonic solutions are commonly administered IV. Identify the solution commonly selected and explain why this solution is selected (see fig 3-10).  Filtration is the movement of water and dissolved substances from an area of high pressure to an area of low pressure in responses a pressure, or force. Identify places in the body where filtration occurs What instrument was used in the book to illustrate filtration?

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 11  Active Transport Mechanisms include active transport pumps, endocytosis and exocytosis  Active transport requires an input of energy (ATP).  Active transport pumps move substances from an area of low concentration to an area of high concentration ( see fig3-12A).  Endocytosis moves substances into a cell; pinocytosis is cellular “drinking,” and phagocytosis is cellular “eating.”  Exocytosis moves substances out of a cell ( see Fig 3-12C). Movement Across the Cell Membrane - cont’d

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 12 Cell Division  Mitosis: produces two identical cells ( see Fig 3- 13)  Splits a cell into two identical cells  Necessary for growth and repair throughout life  Meiosis: occurs only in sex cells ( reduces chromosome number by half & see Reproductive chapter)

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 13 Cell Cycle Cell Cycle  Interphase (G 1, S, and G 2 phases)  Mitosis (M phase)  The splitting of one mother cell into two identical daughter cells.  Four phases of mitosis: prophase, metaphase, anaphase, and telophase.  Clinical Correlation  Constant proliferation of CA cells  Cell Cycle–Phase Specific Drugs Some drugs are aimed at a specific phase of the cell cycle. Some drugs are aimed at a specific phase of the cell cycle. Some are cell cycle–phase nonspecific. Some are cell cycle–phase nonspecific.

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 14 Cell Differentiation   What does cell differentiation mean?   Specialization   Example: RBCs, nerve cells, muscle cells all look & function differently   Stem Cells   Undifferentiated of Specialized   What’s the significance of stem cells?

Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.Slide 15 Order, Disorder, and Death   Cell growth is normally orderly   Neoplastic cell growth, especially CA cell growth, is disorderly and disorganized with constant proliferation   Classification of neoplasms   Benign   Cancerous ( metastasis) Consequences of metastasis?   CA acronym= CAUTION   Disorders of Cellular growth:   Atrophy, dysplasia, hyperplasia, metaplasia, necrosis, neoplasm   Necrosis: cell death ( lack of O2, poisoned, damaged by bacterial toxins or damaging effects of radiation)   Dx aids...Pap smear and Bx