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Solution s and Transpo rt Part 2/2  Solutions and Transport Solution – homogeneous mixture of two or more components Solvent – dissolving medium Solutes – components in smaller quantities within a solution Intracellular fluid – nucleoplasm and cytos...

Solution s and Transpo rt Part 2/2  Solutions and Transport Solution – homogeneous mixture of two or more components Solvent – dissolving medium Solutes – components in smaller quantities within a solution Intracellular fluid – nucleoplasm and cytosol Interstitial fluid – fluid on the exterior of the cell Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.2 Cellular Physiology: Membrane Transport Membranes are selectively permeable – Membrane Transport – movement of substance into and out of the cell Transport is by two basic methods Passive transport No energy is required Active transport The cell must provide metabolic energy Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.3  Selective Permeability The plasma membrane allows some materials to pass while excluding others This permeability includes movement into and out of the cell Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.4  Passive Transport Processes Diffusion Particles tend to distribute themselves evenly within a solution Movement is from high concentration to low concentration, or down a concentration gradient Figure 3.8 Movement is due to kinetic energy in the molecules and affected by size and temperature Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.5  Passive Transport Processes Types of diffusion Simple diffusion – Passive diffusion Unassisted process Solutes transported are lipid-soluble materials or small enough to pass through membrane pores Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.6  Passive Transport Processes Types of diffusion Osmosis – simple diffusion of water Highly polar water easily crosses the plasma membrane Occurs all the time  Facilitated diffusion Substances require a protein carrier for passive transport Still moving down concentration gradient and so no energy is needed Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.7  Diffusion through the Plasma Membrane Figure 3.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.8  Passive Transport Processes Filtration Water and solutes are forced through a membrane by fluid, or hydrostatic pressure A pressure gradient must exist Solute-containing fluid is pushed from a high pressure area to a lower pressure area Not very selective on what is filtered out – size Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.9  Active Transport Processes Transport substances that are unable to pass by diffusion They may be too large They may not be able to dissolve in the fat core of the membrane They may have to move against a concentration gradient Two common forms of active transport Solute pumping Bulk transport Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.10  Active Transport Processes Solute pumping Amino acids, some sugars and ions are transported by solute pumps ATP energizes protein carriers, and in most cases, moves substances against concentration gradients Can transport different molecules in different directions such as the sodium- potassium pump Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.11  Active Transport Processes Figure 3.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.12  Active Transport Processes Bulk transport Exocytosis Moves materials out of the cell Material is carried in a membranous vesicle Vesicle migrates to plasma membrane Vesicle combines with plasma membrane Material is emptied to the outside Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.13  Active Transport Processes Figure 3.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.14  Active Transport Processes Bulk transport Endocytosis Extracellular substances are engulfed by being enclosed in a membranous vescicle Types of endocytosis Phagocytosis – cell eating Pinocytosis – cell drinking Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.15  Active Transport Processes Figure 3.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.16  Cell Life Cycle Series of changes a cell goes through from the time it is formed until it divides Cells have two major periods Interphase – metabolic phase Longest phase where the cell grows Cell carries on metabolic processes Cell division Cell replicates itself Function is to produce more cells for growth and repair processes Slide 3.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  DNA Replication Genetic material duplicated and readies a cell for division into two cells Occurs toward the end of interphase DNA uncoils and each side serves as a template Figure 3.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.18  Events of Cell Division Mitosis Division of the nucleus Results in the formation of two daughter nuclei Cytokinesis Division of the cytoplasm Begins when mitosis is near completion Results in the formation of two daughter cells Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.19  Stages of Mitosis IPMAT Interphase No cell division occurs The cell carries out normal metabolic activity and growth Prophase First part of cell division Centromeres migrate to the poles and direct the assembly of the mitotic spindle Chromosomes form Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.20  Stages of Mitosis Metaphase Short stage Spindle from centromeres are attached to chromosomes that are aligned in the center of the cell Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.21  Stages of Mitosis Anaphase Daughter chromosomes are pulled toward the poles The cell begins to elongate Telophase Daughter nuclei begin forming A cleavage furrow (for cell division) begins to form and finished dividing the cell into two by the end of cytokinesis Everything from prophase is reversed Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.22  Stages of Mitosis Figure 3.14; 1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.23  Stages of Mitosis Figure 3.14; 2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.24  Protein Synthesis Gene – is DNA segment that carries a blueprint for building one protein or polypeptide chain Proteins have many functions Building materials for cells Act as enzymes (biological catalysts) RNA is essential for protein synthesis Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.25  Role of RNA Transfer RNA (tRNA) Transfers appropriate amino acids to the ribosome for building the protein Ribosomal RNA (rRNA) Helps form the ribosomes along with proteins where proteins are built Messenger (mRNA) Carries the instructions for building a protein from the nucleus to the ribosome Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.26  Transcription and Translation Transcription Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA – switching T for U Translation Base sequence of mRNA is translated to an amino acid sequence based on codon/anticodon complements Amino acids are the building blocks of proteins Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.27  Protein Synthesis Figure 3.15 Slide 3.54 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Body Tissues Cells are specialized for particular functions Tissues Groups of cells with similar structure and function Four primary types Epithelium - covering Connective tissue - support Nervous tissue - control Muscle - movement Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.29  Epithelial Tissues Found in different areas Body coverings Body linings Glandular tissue Functions Protection Absorption Filtration Secretion Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.30  Epithelium Characteristics Cells fit closely together Tissue layer always has one free surface – unattached, the apical surface The lower surface is bound by a basement membrane – structureless material secreted by the cells Avascular (have no blood supply) – depend on diffusion Regenerate easily if well nourished Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.31  Classification of Epithelium Number of cell layers Simple – one layer Stratified – more than one layer Figure 3.16a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.32  Classification of Epithelium Shape of cells Squamous – flattened Cuboidal – cube-shaped Columnar – column-like Figure 3.16b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.33  Simple Epithelium Simple squamous Single layer of flat cells Usually forms membranes where filtration or exchange occurs Lines body cavities – serous membranes Lines lungs and capillaries Figure 3.17a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.34  Simple Epithelium Simple cuboidal Single layer of cube- like cells Common in glands and their ducts Forms walls of kidney tubules Covers the ovaries Figure 3.17b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.35  Simple Epithelium Simple columnar Single layer of tall cells that fit closely together Often includes goblet cells, which produce mucus Lines digestive tract Mucosae – mucous membranes line body cavities open to the body Figure 3.17c exterior Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.36  Simple Epithelium Pseudostratified columnar Single layer, but some cells are shorter than others Often looks like a double cell layer Sometimes ciliated, such as in the respiratory tract May function in Figure 3.17d absorption or secretion Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.37  Stratified Epithelium – 2+ layers Stratified squamous Cells at the free edge are flattened while cells close to the basement membrane are cuboidal or columnar Found as a protective covering where friction is common Locations Skin Mouth Figure 3.17e Esophagus Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.38  Stratified Epithelium Stratified cuboidal Two layers of cuboidal cells Stratified columnar Surface cells are columnar, cells underneath vary in size and shape Stratified cuboidal and columnar Rare in human body Found mainly in ducts of large glands Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.39  Stratified Epithelium Transitional epithelium Shape of cells depends upon the amount of stretching Cells of the basal layer are cuboidal or columnar while those at the free surface vary Lines organs of the urinary system Figure 3.17f Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.40  Glandular Epithelium Gland – one or more cells that secretes a particular product – a secretion, which contains protein molecules in an aqueous fluid Two major gland types Endocrine gland Ductless Secretions are hormones – diffuse into blood Exocrine gland Empty through ducts to the epithelial surface Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.41 Include sweat and oil glands  Connective Tissue Found everywhere in the body Includes the most abundant and widely distributed tissues Functions Binds body tissues together Supports the body Provides protection Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.42  Connective Tissue Characteristics Variations in blood supply Some tissue types are well vascularized Some have poor blood supply or are avascular such as tendons, ligaments, and cartilage Extracellular matrix Non-living material that surrounds living cells Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.43  Extracellular Matrix Two main elements Ground substance – mostly water along with adhesion proteins and polysaccharide molecules Fibers Produced by the cells Three types Collagen fibers Elastic fibers Reticular fibers Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.44  Connective Tissue Types Bone (osseous tissue) Composed of: Bone cells in lacunae (cavities) Hard matrix of calcium salts Large numbers of collagen fibers Used to protect and support the body Figure 3.18a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.45  Connective Tissue Types Hyaline cartilage Most common cartilage Abundant collagen fibers Rubbery matrix Entire fetal skeleton is hyaline cartilage Figure 3.18b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.46  Connective Tissue Types Fibrocartilage Highly compressible Example: forms cushion-like discs between vertebrae Figure 3.18c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.47  Connective Tissue Types Elastic cartilage Provides elasticity Example: supports the external ear Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.48  Connective Tissue Types Dense connective tissue Main matrix element is collagen fibers Crowded between the collagen fibers are rows of cells called fibroblasts Examples Tendon – attach muscle to bone Ligaments – attach bone to bone Figure 3.18d Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.49  Loose Connective Tissue Types Areolar connective tissue Most widely distributed connective tissue Soft, pliable tissue Functions as universal packing tissue and connective tissue glue Contains all fiber types Figure 3.18e Can soak up excess Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.50 fluid  Connective Tissue Types Adipose tissue Matrix is an areolar tissue in which fat globules predominate Many cells contain large lipid deposits Functions Insulates the body Protects some organs Serves as a site of Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.51 fuel storage F i  Connective Tissue Types Reticular connective tissue Delicate network of interwoven fibers Forms stroma (internal supporting network) of lymphoid organs Lymph nodes Spleen Bone marrow Figure 3.18g Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.52  Connective Tissue Types Blood Blood cells surrounded by fluid matrix Fibers are visible during clotting Functions as the transport vehicle for materials Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 3.18h Slide 3.79  Muscle Tissue Function is to produce movement by contracting or shortening Three types Skeletal muscle Cardiac muscle Smooth muscle Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.54  Muscle Tissue Types Skeletal muscle Can be controlled voluntarily Cells attach to connective tissue Cells are striated Cells have more than one nucleus Figure 3.19b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.55  Muscle Tissue Types Cardiac muscle Found only in the heart Function is to pump blood (involuntary) Cells attached to other cardiac muscle cells at intercalated disks Cells are striated One nucleus per cell Figure 3.19c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.56  Muscle Tissue Types Smooth muscle – visceral muscle Involuntary muscle Surrounds hollow organs Attached to other smooth muscle cells No visible striations Spindle shaped Figure 3.19a One nucleus per cell Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.83  Nervous Tissue Neurons and nerve supporting cells (those that insulate, support, and protect neurons) Function is to receive and send impulses to other areas of the body Irritability Conductivity Figure 3.20 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.84  Tissue Repair (wound Healing) Regeneration Replacement of destroyed tissue by the same kind of cells Fibrosis Repair by dense fibrous connective tissue (scar tissue) Determination of method Type of tissue damaged Severity of the injury Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.85  Events in Tissue Repair Capillaries become very permeable Introduce clotting proteins to make clot Wall off injured area to prevent blood loss infection and Formation of granulation tissue Contains capillaries and phagocytes Regeneration of surface epithelium just below the scab Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.86  Regeneration of Tissues Tissues that regenerate easily Epithelial tissue Fibrous connective tissue and bone Tissues that regenerate poorly Skeletal muscle Tissues that are replaced largely with scar tissue Cardiac muscle Nervous tissue within the brain and spinal cord Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.87  Developmental Aspects of Tissue Epithelial tissue arises from all three primary germ layers Muscle and connective tissue arise from the mesoderm Nervous tissue arises from the ectoderm With old age there is a mass and in decrease viabililty in most tissues Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.88  END OF LESSON 2 Part 2/2