HUMAN ANATOMY Fifth Edition Chapter 1 Lecture Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings Chapter 2 Lecture Chapter 2 The Cell Frederic Martini Michael Timmons Robert Tallitsch

Introduction Cell theory: –Cells are the smallest structural units that perform all vital functions.

Figure 2.1a,b,c Different Technique, Different Perspective The Study of Cells The study of cells is cytology: –Light microscopy –Transmission electron microscopy –Scanning electron microscopy

Figure 2.3 Anatomy of a Typical Cell Cellular Anatomy Cells have four types of component: 1)Membranes 2)Organelles 3)Cytoplasm 4)inclusions

Figure 2.4 A Flow Chart for the Study of Cell Structure Cellular Anatomy

Cell Structure PLAY Cell Structure This movie reviews cell structure.

Figure 2.5 The Cell Membrane The Cell Membrane

Major functions of the cell membrane can be described: –Regulation of exchange with the environment –Receptors and ID

Figure 2.6 Diffusion across the Cell Membrane Membrane Permeability: Passive Processes Diffusion Osmosis Facilitated Diffusion

Membrane Permeability: Active Processes Active transport uses enzymes and carrier proteins: –Ions pumps are carrier proteins for charged particles. –Ions moved regularly by active transport include Na +, Ca 2+, Mg 2+, K + –Ion pumps are specific. –An ion pump that moves two ions simultaneously in opposite directions is called an exchange pump.

Figure 2.7a Pinocytosis Membrane Permeability: Active Processes

Figure 2.7b Phagocytosis Membrane Permeability: Active Processes

Figure 2.8 Receptor-Mediated Endocytosis Membrane Permeability: Active Processes

Cytoplasm The cytoplasm is the general term for the material inside the cell. –It is a fluid very high in protein. –The cytosol is the intracellular fluid: It is high in potassium ions. It contains an overall negative charge. –Transmembrane potential It contains high concentrations of proteins. –Organelles are structures within the cyto- plasm that have a particular function and very distinct structure.

Nonmembranous Organelles The cytoskeleton: –Microfilaments –Microtubules Microvilli

Figure 2.9 The Cytoskeleton Nonmembranous Organelles

Figure 2.10 Centrioles and Cilia Nonmembranous Organelles Centrioles Cilia Flagella

Figure 2.11 Ribosomes Nonmembranous Organelles Ribosomes: –60% RNA and 40% protein –Free ribosomes: Float in the cytoplasm –Fixed ribosomes: Are attached to the endoplasmic reticulum

Figure 2.12 Mitochondria Membranous Organelles Mitochondria are double membraned organelles. –Cristae are the folds of the inner membrane –Inner fluid is the matrix.

Membranous Organelles The nucleus is the control center of the cell. –Nucleoplasm –Nuclear envelope –Perinuclear space –Nuclear pores –Nuclear matrix

Figure 2.13a The Nucleus Membranous Organelles

Figure 2.14 Chromosome Structure Membranous Organelles: Nucleus Chromosomes: –DNA wrapped around proteins called histones. –Nucleosomes –Chromatin

Membranous Organelles The ER has four major functions: –Synthesis of all classes of macromolecules –Storage of the manufactured molecules –Transport of substances from on area of the cell to another –Enzymes in the lumen of the ER provide detoxification

Figure 2.15 The Endoplasmic Reticulum Membranous Organelles

Figure 2.16b The Golgi Apparatus Membranous Organelles The three main functions of the Golgi apparatus: –Synthesis and packaging of secretions. –Packaging of enzymes for use in the cytosol. –Renewal and modification of the cell membrane.

Figure 2.18 Lysosomal Functions Membranous Organelles Lysosome function in three manners: 1.Fuse with phagosomes to digest solid materials. 2.Fuse with and recycle damaged organelles. 3.Sometimes rupture a process resulting in autolysis.

Figure 2.19 Cell Attachments Intercellular Attachment

Figure 2.20 The Cell Life Cycle The Cell Life Cycle

Figure 2.21 DNA Replication DNA Replication

Figure 2.22a Interphase

Figure 2.22b,c Prophase

Figure 2.22d,e Metaphase and Anaphase

Figure 2.22f,g Telophase and Cytokinesis