Anatomy & Physiology Lecture Outline PDF

Chapter 04 Lecture Outline Anatomy & Physiology AN INTEGRATIVE APPROACH Fourth Edition Michael P. McKinley Valerie Dean O’Loughlin Theresa Stouter Bidle Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent o...

Chapter 04 Lecture Outline Anatomy & Physiology AN INTEGRATIVE APPROACH Fourth Edition Michael P. McKinley Valerie Dean O’Loughlin Theresa Stouter Bidle Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  4.1c Common Features and General Functions 1 Plasma membrane Forms outer, limiting barrier separating internal contents from external environment Modified extensions of plasma membrane Cilia, flagellum, microvilli Nucleus Largest structure in cell; enclosed by a nuclear envelope Contains genetic material (DNA); also contains a nucleolus Nucleoplasm—inner fluid Cytoplasm Cellular contents between plasma membrane and nucleus Includes: cytosol, organelles, and inclusions 2  4.1c Common Features and General Functions 2 Cytoplasmic components Cytosol (intracellular fluid ) Viscous fluid of cytoplasm High water content Contains dissolved macromolecules and ions Organelles (“little organs”) Complex, organized structures within cells Unique shapes and functions Two categories Membrane-bound organelles Non-membrane-bound organelles 3  4.1c Common Features and General Functions 3 Organelles (“little organs”) (continued ) Membrane-bound organelles Enclosed by a membrane Separates contents from cytosol Includes endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria Non-membrane-bound organelles Not enclosed within a membrane Composed of protein Includes ribosomes, cytoskeleton, centrosome, proteasomes 4  4.1c Common Features and General Functions 5 Cells perform general functions: Maintain integrity and shape of a cell Dependent on plasma membrane and internal contents Obtain nutrients and form chemical building blocks Harvest energy for survival Dispose of wastes Avoid accumulation that could disrupt cellular activities Some are also capable of cell division Make more cells of same type Help maintain tissue by providing cells for new growth and replacing dead cells 5  4.2a Lipid Components 1 Plasma membrane Fluid mixture composed of equal parts lipid and protein by weight Regulates movement of most substances in and out of cell Contains several different types of lipids: Phospholipids Cholesterol Glycolipids 6  4.2a Lipid Components 2 Phospholipids “Balloon with two tails” Polar and hydrophilic “head”; two nonpolar and hydrophobic “tails” Form two parallel sheets of molecules lying tail to tail Hydrophobic tails form internal environment of membrane Hydrophilic polar heads directed outward Phospholipid bilayer is the basic structure of the framework Ensures cytosol remains inside the cell Ensures interstitial fluid/EXTRACELLULAR remains outside 7  Structure and Functions of the Plasma Membrane (b) ©Don W. Fawcett/Science Source Figure 4.5 Access the text alternative for slide images. 8  4.2b Membrane Proteins 1 Membrane proteins Half of plasma membrane by weight Float and move in fluid bilayer Performs most of membrane’s functions Two structural types Integral Peripheral 9  4.2b Membrane Proteins 3 Proteins are also categorized functionally: Transport proteins Regulate movement of substances across membrane For example, channels, carrier proteins, pumps, symporters, and antiporters Cell surface receptors Bind molecules called ligands For example, neurotransmitters released from a nerve cell that binds to a muscle cell to initiate contraction Identity markers: Self vs. Not Self Communicate to other cells that they belong to the body These markers are used to distinguish healthy cells from cells to be destroyed 10  4.2b Membrane Proteins 4 Functional categories of proteins (continued ) Enzymes May be attached to either internal or external surface of a cell Catalyze chemical reactions Anchoring sites Secure cytoskeleton to plasma membrane Cell-adhesion proteins Perform cell-to-cell attachments 11  Plasma Membrane Proteins Figure 4.6 Access the text alternative for slide images. 12  4.3 Membrane Transport 1 Plasma membrane Serves as physical barrier between cell and fluid that surround it (interstitial fluid) Regulates movement into and out of a cell Establishes and maintains electrochemical gradient Functions in cell communication Membrane transport Process of obtaining and eliminating substance across the plasma membrane Two categories Passive processes Active processes 13  Membrane Transport Key Concept Water follows solute Substances move from areas of high concentration to areas of low concentration until an equilibrium is reached 14  Membrane Transport Figure 4.7 Access the text alternative for slide images. 15  4.3 Membrane Transport 2 Substances moved across a membrane Passive processes of membrane transport Do not require energy Depend on substances moving down concentration gradient Move from area of more substance to area of less Two types: diffusion, osmosis Active processes of membrane transport Require energy Substance must be moved up its concentration gradient (active transport) Membrane-bound vesicle must be released (vesicular transport) 16  4.3a Passive Processes: Diffusion 1 Diffusion Net movement of ions or molecules from area of greater concentration to area of lesser concentration Down the concentration gradient Also influenced by “steepness” of concentration gradient Measure of the difference in concentration between two areas Steeper gradient causes faster rate of diffusion If unopposed, diffusion continues until substance reaches equilibrium Molecules evenly distributed throughout a given area 17  Diffusion Figure 4.8 18  Simple Diffusion of Solutes Figure 4.9 Access the text alternative for slide images. 19  4.3a Passive Processes: Diffusion 4 Facilitated diffusion Transport process for small charged or polar solutes requires assistance from plasma membrane proteins Two types: Channel-mediated diffusion Carrier-mediated diffusion 20  Channel-Mediated Diffusion Figure 4.10a Access the text alternative for slide images. 21  4.3a Passive Processes: Diffusion 6 Carrier-mediated diffusion Small polar molecules assisted across membrane by carrier protein Binding of substance causing change in carrier protein shape Releases substances on other side of membrane 22  Carrier-Mediated Diffusion Figure 4.10b Access the text alternative for slide images. 23  4.3b Passive Processes: Osmosis 1 Osmosis Movement of water, not solutes Passive movement of water through semipermeable membrane Osmosis is promoted by differences in water concentration on either side of a membrane 24  Osmosis in Cells Figure 4.11 Access the text alternative for slide images. 25  4.3b Passive Processes: Osmosis 5 Osmosis and tonicity cells gain or lose water with osmosis and that changes the cell volume Tonicity—ability of a solution to change the volume or pressure of a cell by osmosis Terms that describe relative concentration of solutions: Isotonic Hypotonic Hypertonic 26  4.3b Passive Processes: Osmosis 6 Isotonic solution Both cytosol and solution have same relative concentration of solutes For example, normal saline with a concentration of 0.9% NaCl Commonly used in IV solutions No net movement of water 27  4.3b Passive Processes: Osmosis 7 Hypotonic solution Solution has a lower concentration of solutes, higher concentration of water than in cytosol For example, erythrocytes in pure water Water moves down concentration gradient from outside cell to inside Increases volume and pressure of cell Lysis—rupturing of red blood cells occurs if difference is large enough Hemolysis—rupturing erythrocytes 28  4.3b Passive Processes: Osmosis 8 Hypertonic solution Solution with a higher concentration of solutes than cytosol For example, erythrocytes in 3% NaCl water solution Water moves down concentration gradient Moves from inside cell to outside Decreases volume and pressure of cell Crenation—cell shrinks 29  Erythrocytes Immersed In Three Different Solution Concentrations ©Dennis Kunkel Microscopy, Inc./Medical Images Figure 4.13 Access the text alternative for slide images. 30  4.3c Active Processes 1 Active processes are organized into active transport and vesicular transport Active transport Movement of a solute against its concentration gradient (that is, from lower to higher concentration) Maintains gradient between cell and interstitial fluid Requires energy 31  4.3c Active Processes 3 Ion pumps Cellular protein pumps that move ions across membrane Maintain internal concentrations of ions For example, Ca2+ pumps in plasma membrane of erythrocytes Prevent cell rigidity from accumulated calcium Erythrocytes remain flexible enough to move Figure 4.14 Access the text alternative for slide images. 32  4.3c Active Processes 4 Sodium-potassium (Na/K) pump Type of exchange pump Moves one type of ion into cell against gradient, while moving another type of ion out of cell against gradient Plasma membrane preserves steep gradient differences Continuously exports Na+ out of the cell and moves K into the cell Must be working for cell to survive! 33  Na+/K+ Pump Figure 4.15 Access the text alternative for slide images. 34  4.3c Active Processes 7 Vesicular transport Also called bulk transport Involves energy input to transport large substances across the plasma membrane by a vesicle Membrane-bounded sac filled with materials Organized into processes of Exocytosis- out of the cell Endocytosis- into the cell 35  Exocytosis Figure 4.17 Access the text alternative for slide images. 36  4.3c Active Processes 10 Three types of endocytosis: phagocytosis, pinocytosis, receptor- mediated endocytosis Phagocytosis Cellular eating Occurs when a cell engulfs a large particle external to cell They surround particle, enclosing it in a membrane sac Sac is internalized, contents digested after fusing with lysosome Only a few cell types perform this For example, when a white blood cell engulfs and digests a microbe 37  Phagocytosis 1 Figure 4.18a Access the text alternative for slide images. 38  4.3c Active Processes 11 Pinocytosis Cellular drinking Internalization of droplets of interstitial fluid containing dissolved solutes Multiple, small vesicles formed Performed by most cells 39  Pinocytosis 2 Figure 4.18b Access the text alternative for slide images. 40  4.4a Introduction Electrical charge difference at plasma membrane Membrane potential—potential energy of charge difference Resting membrane potential (RMP)—potential when a cell is at rest Two conditions for RMP: 1. Unequal distribution of ions/molecules across plasma membrane More K+ in cytoplasm than in interstitial fluid More Na+in interstitial fluid than in cytoplasm Due to Na+/K+ pumps 2. Unequal relative amounts of positive and negative charges More positive on outside than inside of cell 41  Resting Membrane Potential (RMP) Figure 4.20 Access the text alternative for slide images. 42  4.4b Establishing and Maintaining RMP 3 Maintaining an RMP Na/K pumps significant Maintains K+ and Na+ gradients following their diffusion Na+ pumped out K+ pumped in Opposite directions Against concentration gradient 43  4.5 Cell Communication Plasma membrane serves an important role in cell communication Structures such as glycolipids and glycoproteins facilitate both direct interaction between cells as well as recognition and response to external molecular signals 44  4.5b Ligand-Receptor Signaling Most cell communication occurs through ligands Molecules that bind with macromolecules Neurotransmitters from nerve cells and hormones from endocrine cells Important for controlling growth, reproduction, and other cellular processes 45  Channel-Linked Receptors Permit ion passage into or out of cells Occurs in response to neurotransmitter binding Help initiate electrical changes to RMP in muscle and nerve cells Figure 4.21a Access the text alternative for slide images. 46  4.6 Cellular Structures Membrane-bound organelles Non-membrane-bound organelles Vesicles for transport Structures extending from cell surface 47  4.6a Membrane-Bound Organelles 1 Membrane-bound organelles Surrounded by membrane Allows activities in isolated environment Endoplasmic Reticulum (ER) Extensive interconnected membrane network Point of attachment for ribosomes With ribosomes—rough ER RIBOSOMES MAKE PROTEINS Without ribosomes—smooth Smooth ER: Synthesis, transport, and storage of lipids 48  The Endoplasmic Reticulum (ER) (photo) ©Dennis Kunkel Microscopy, Inc./Medical Images Figure 4.22 Access the text alternative for slide images. 49  4.6a Membrane-Bound Organelles 3 Golgi apparatus Post office of the cell Composed of cisternae, elongated saclike membranous structures Functions: modification, packaging, and sorting of proteins Formation of secretory vesicles Some vesicles become part of plasma membrane Others release contents outside cell 50  The Golgi Apparatus and Endomembrane System (a) ©Biophoto Associates/Science Source Figure 4.23 Access the text alternative for slide images. 51  Lysosomes Small, membranous sacs Contain digestive enzymes formed by Golgi Participate in digestion of unneeded substances Digest contents of endocytosed vesicles Garbage disposal of the cell ©Science Source; (photo) ©McGraw-Hill Education Access the text alternative for slide images. 52  Peroxisomes The detoxifier Membrane-enclosed sacs, smaller than lysosomes Pinched off vesicles from rough ER Proteins are incorporated to serve as their enzymes Metabolic functions include Role in chemical digestion Lipid synthesis ©Don W. Fawcett/Science Source; (photo) ©McGraw-Hill Education/Electronic Publishing Services, Inc., NY Access the text alternative for slide images. 53  Mitochondria Oblong shaped organelles with double membrane Aerobic cellular respiration Complete digestion of fuel molecules to synthesize ATP “Powerhouses” of cell Cellular Respiration to ©Don W. Fawcett/Science Source Figure 4.26 make ATP Access the text alternative for slide images. 54  Proteasomes ©Edward P. Morris Figure 4.29 Access the text alternative for slide images. 55  4.6b Non-Membrane-Bound Organelles 4 Cytoskeleton Plays roles in Intracellular support Organization of organelles Cell division Movement of materials Extends throughout cell interior; anchor proteins in membrane Includes Microfilaments Intermediate filaments Microtubules 56  The Cytoskeleton Figure 4.30 Access the text alternative for slide images. 57 Molecular Motor Structure and Direction From Pollard T, Earnshaw W: Cell biology, revised reprint, international edition, ed 1, Philadelphia, 2004, Saunders.  4.6c Structures of the Cell’s External Surface Cilia Hair-like projections that move substances along cell surface Flagella Longer and wider than cilia; propels entire cell Microvilli Extensions of plasma membrane that increase surface area 59  Microvilli ©Don W. Fawcett/Science Source Figure 4.31 60  4.6d Membrane Junctions Tight junctions Strands or rows of proteins linking cells Prevent substances from passing between cells Requires materials to move through, rather than between cells Maintain polarity of epithelia Desmosomes Composed of proteins that bind neighboring cells Hemidesmosomes anchor basal layer of cells of epidermis to underlying components Gap junctions Form tiny, fluid-filled tunnels Provide direct passageway for substances to travel between cells (For example ions between cells in cardiac muscle) 61  Membrane Junctions Figure 4.32 Access the text alternative for slide images. 62  Structure of the Nucleus (a) ©Don W. Fawcett/Science Source Figure 4.34a Access the text alternative for slide images. 63  4.7b DNA, Chromatin, and Chromosomes 1 DNA Housed in nucleus Composed of repeated monomers (nucleotides) DNA has deoxyribonucleotides Each deoxyribonucleotide composed of Five-carbon sugar deoxyribose A phosphate One of four nitrogenous bases Adenine Cytosine Guanine Thymine 64  4.7b DNA, Chromatin, and Chromosomes 3 DNA (continued ) Each double helix is wound around nuclear proteins called histones Together form nucleosomes When not dividing, DNA are in form of finely filamented mass called chromatin When dividing, DNA chromatin becomes tightly coiled mass called chromosomes 65  DNA and Chromatin Structure Figure 4.34b Access the text alternative for slide images. 66  4.7b DNA, Chromatin, and Chromosomes 4 DNA and genes Genes = stretches of nucleotides that provide instructions for synthesis of specific proteins Figure 4.34c Access the text alternative for slide images. 67  4.8 Function of the Nucleus and Ribosomes Cellular activities dependent upon protein synthesis Directed by DNA Transcription Ribonucleic acid Copy of a gene formed from DNA in nucleus Translation Uses RNA for synthesis of protein by ribosomes in cytosol Access the text alternative for slide images. 68  Process of Transcription Figure 4.36 Access the text alternative for slide images. 69  4.8b Translation: Synthesizing Protein 1 Translation Synthesis of a new protein Occurs at ribosomes within cytoplasm mRNA threaded through ribosome Code in nucleotide sequence of mRNA translated Converted into amino acids to produce protein 70  4.8b Translation: Synthesizing Protein 5 Three events of translation: Initiation Elongation Termination 71  4.8c DNA as the Control Center of a Cell DNA directs synthesis of proteins that carry out body functions Indirectly responsible for other metabolic changes Synthesis of steroids Enzymatic pathway of glucose oxidation Controls enzymes responsible for decomposition and synthesis of chemical structures 72