Introduction to Human Anatomy & Physiology Acids, Bases & Chemicals Pima Medical Institute Cell types & structures Introduction to Human Anatomy & Physiology Acids, Bases & Chemicals Cell Types & Structure Pima Medical Institute Online Education David Shier, Jackie Butler, Ricki Lewis, Hole’s Essentials of Human Anatomy & Physiology, 10th Ed. CopyrightThe McGraw-Hill Companies, Inc. Created by Dr. Melissa Eisenhauer, Trevecca Nazarene University

Composite Cell Cells vary in size, shape, content, and function A composite cell includes many known cell structures Specialized cells differ in the numbers and types of organelles Nerve Cell Epithelial Cell Tissue Cell http://facstaff.gpc.edu Cell membrane Nucleus Controls cellular activities Organelles Divide the labor of the cell Describing a typical cell is impossible because cells vary in size, shape, content, and function.   A composite cell includes many known cell structures. Under a light microscope, a properly applied stain reveals three basic cell parts: the cell membrane that encloses the cell, the nucleus that houses the genetic material and controls cellular activities, and the cytoplasm that fills out the cell. Within the cytoplasm are specialized structures called organelles, which are suspended in a liquid called cytosol. These organelles perform specific functions, which divides the labor of the cell. Specialized cells differ in the numbers and types of organelles, reflecting their functions. Cytoplasm Generally includes organelles and cytosol

Cell Membrane ACTIVE Cell membrane (plasma membrane) Regulates movement of substances in and out of the cell Is thin, flexible, and elastic Maintains cell integrity Selectively permeable Complex surface features Nucleus The cell membrane (also called the plasma membrane) is more than a simple boundary surrounding the cellular contents. It is an actively functioning part of the living material. The cell membrane regulates movement of substances in and out of the cell and is the site of much biological activity. The cell membrane is extremely thin, flexible, and somewhat elastic. In addition to maintaining cell integrity , the cell membrane is selectively permeable, which means that only certain substances can enter or leave the cell. The cell membrane has complex surface features with many outpouchings and infoldings that increase surface area.

Signal Transduction www.scq.ubc.ca A series of molecules detect signals from outside the cell and transmit them inward Other molecules orchestrate the cell’s response Signal transduction is a molecular communication process through which the cell can interact with other cells. A series of molecules that are part of the cell membrane form pathways that detect signals from outside the cell and transmit them inward, where yet other molecules orchestrate the cell’s response. The cell membrane also helps cells adhere to certain other cells, which is important in forming tissues. Signal transduction enables cell interaction The cell membrane helps cells adhere to other cells

OILY Double layer (bilayer) of phospholipid molecules C O O Amino acids Sugars Proteins Nucleic Acids Various ions Double layer (bilayer) of phospholipid molecules The cell membrane is composed mainly of lipids and proteins, with few carbohydrates. Its basic framework is a double layer, or bilayer, of phospholipid molecules. The membrane’s interior is oily because it consists largely of the fatty acid portions of the phospholipid molecules. Molecules such as oxygen and carbon dioxide, which are soluble in lipids, can easily pass through this bilayer. However, the bilayer is impermeable to water-soluble molecules, such as amino acids, sugars, proteins, nucleic acids, and various ions. OILY O C O

Cholesterol & Membrane Proteins A cell membrane includes many kinds of proteins that are classified according to their positions Cholesterol Makes membrane less permeable to water-soluble substances Cholesterol molecules embedded in the cell membrane’s interior help make the membrane less permeable to water-soluble substances, while stabilizing the membrane with their rigid structure. A cell membrane includes a few types of lipid molecules, but many kinds of proteins which provide special functions. Membrane proteins are classified according to their positions. Membrane-spanning (transmembrane) proteins extend through the lipid bilayer and may protrude from one or both faces. Peripheral membrane proteins associate mostly with only one side of the bilayer. Peripheral protein Associate with one side of the bilayer Transmembrane protein Extends through the lipid bilayer www.cbu.edu

Cell Membrane Proteins www.scq.ubc.ca Some form receptors that start signal transduction Receptor Membrane proteins have a variety of functions Membrane proteins have a variety of functions, some form receptors on the cell surface that bind incoming hormones or growth factors, starting signal transduction. Other proteins transport ions or molecules across the cell membrane. Membrane proteins form selective channels that allow only particular ions to enter or leave. In nerve cells, for example, such selective channels control movement of sodium and potassium ions. Cell membrane Ion Some transport ions or molecules across the cell membrane www.hansenkg.de

Cell Membrane Proteins Another type of cell membrane protein is a cellular adhesion molecule (CAM) which guides a cell’s interactions with other cells www.nature.com Glycoprotein Attached to a carbohydrate Identify the cell Proteins that extend inward from the inner face of the cell membrane anchor it to the protein rods and tubules that support the cell from within. Proteins that extend from the outer surface of the cell membrane mark the cell as part of a particular tissue or organ in a particular person. This identification as self is important for the functioning of the immune system. Many of these proteins are attached to carbohydrates, forming glycoproteins. Another type of protein on a cell’s surface is a cellular adhesion molecule (CAM), which guides a cell’s interactions with other cells. For example, a series of CAMs helps a white blood cell move to the site of an injury, such as a splinter in the skin. Filaments anchored to the protein CAMs help a white blood cell move to the site of an injury

Cilia & Flagella CILIA FLAGELLA Cilia Flagella Cilia and flagella are motile (moht-l) extensions from the surfaces of cells. Cilia are short, motile extensions. There are many of these and they have a wave-like motion. This action serves to move fluids, such as mucus, over the surface of certain tissues, including those that form the inner linings of the respiratory tubes. Flagella are long, motile extensions. These have a whip-like motion that generally is used for movement, like the tail of a sperm cell. The tail of a sperm cell is a flagellum that enables this motile cell to “swim” and is the only example of a flagellum in humans. Are short, motile extensions Have a wave-like motion Serve to move fluids over the surface of certain tissues Are long, motile extensions Have a whip-like motion used for movement Like the tail of a sperm cell Including inner linings of the respiratory tubes

Do you want to see the parts of a typical animal cell? End of presentation INTERACTIVE TUTORIALS & VIDEOS A Typical Animal Cell http://www.wisc-online.com/objects/index_tj.asp?objID=AP11403 Do you want to see the parts of a typical animal cell? Yes!