Cells and Tissues PDF

3 PART A Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS...

3 PART A Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cells and Tissues ▪ Carry out all chemical activities needed to sustain life ▪ Cells are the building blocks of all living things ▪ Tissues are groups of cells that are similar in structure and function Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Cell ▪ Cells are not all the same ▪ All cells share general structures ▪ Cells are organized into three main regions ▪ Nucleus ▪ Cytoplasm ▪ Plasma membrane Figure 3.1a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Nucleus ▪ Control center of the cell ▪ Contains genetic material (DNA) ▪ Three regions ▪ Nuclear membrane ▪ Nucleolus ▪ Chromatin Figure 3.1b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nuclear Membrane ▪ Barrier of nucleus ▪ Consists of a double phospholipid membrane ▪ Contain nuclear pores that allow for exchange of material with the rest of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nucleoli ▪ Nucleus contains one or more nucleoli ▪ Sites of ribosome production ▪ Ribosomes then migrate to the cytoplasm through nuclear pores Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chromatin ▪ Composed of DNA and protein ▪ Scattered throughout the nucleus ▪ Chromatin condenses to form chromosomes when the cell divides Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Plasma Membrane ▪ Barrier for cell contents ▪ Double phospholipid layer ▪ Hydrophilic heads ▪ Hydrophobic tails ▪ Also contains protein, cholesterol, and glycoproteins PRESS TO PLAY MEMBRANE STRUCTURE ANIMATION Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Plasma Membrane Figure 3.2 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Plasma Membrane Specializations ▪ Microvilli ▪ Finger-like projections that increase surface area for absorption Figure 3.3 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Plasma Membrane Specializations ▪ Membrane junctions ▪ Tight junctions ▪ Desmosomes ▪ Gap junctions Figure 3.3 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasm ▪ Material outside the nucleus and inside the plasma membrane ▪ Cytosol ▪ Fluid that suspends other elements ▪ Organelles ▪ Metabolic machinery of the cell ▪ Inclusions ▪ Non-functioning units Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles Figure 3.4 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Ribosomes ▪ Made of protein and RNA ▪ Sites of protein synthesis ▪ Found at two locations ▪ Free in the cytoplasm ▪ Attached to rough endoplasmic reticulum Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Endoplasmic reticulum (ER) ▪ Fluid-filled tubules for carrying substances ▪ Two types of ER ▪ Rough Endoplasmic Reticulum ▪ Studded with ribosomes ▪ Site where building materials of cellular membrane are formed ▪ Smooth Endoplasmic Reticulum ▪ Functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Golgi apparatus ▪ Modifies and packages proteins ▪ Produces different types of packages ▪ Secretory vesicles ▪ Cell membrane components ▪ Lysosomes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Golgi Apparatus Figure 3.6 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Lysosomes ▪ Contain enzymes that digest nonusable materials within the cell ▪ Peroxisomes ▪ Membranous sacs of oxidase enzymes ▪ Detoxify harmful substances ▪ Break down free radicals (highly reactive chemicals) ▪ Replicate by pinching in half Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Mitochondria ▪ “Powerhouses” of the cell ▪ Change shape continuously ▪ Carry out reactions where oxygen is used to break down food ▪ Provides ATP for cellular energy Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Cytoskeleton ▪ Network of protein structures that extend throughout the cytoplasm ▪ Provides the cell with an internal framework Figure 3.7a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Cytoskeleton ▪ Three different types ▪ Microfilaments ▪ Intermediate filaments ▪ Microtubules Figure 3.7b–d Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles ▪ Centrioles ▪ Rod-shaped bodies made of microtubules ▪ Known for their role in generating microtubules ▪ Direct formation of mitotic spindle during cell division Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Projections ▪ Not found in all cells ▪ Used for movement ▪ Cilia moves materials across the cell surface ▪ Flagellum propels the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Projections Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Diversity Figure 3.8a–b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Diversity Figure 3.8c Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Diversity Figure 3.8d–e Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Diversity Figure 3.8f–g Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  3 PART A Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Physiology: Membrane Transport ▪ 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Selective Permeability ▪ The plasma membrane allows some materials to pass while excluding others ▪ This permeability includes movement into and out of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 PRESS TO PLAY DIFFUSION ANIMATION Figure 3.9 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Types of diffusion ▪ Simple diffusion ▪ Unassisted process ▪ Solutes are lipid-soluble materials or small enough to pass through membrane pores Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Types of diffusion ▪ Osmosis – simple diffusion of water ▪ Highly polar water easily crosses the plasma membrane ▪ Facilitated diffusion ▪ Substances require a protein carrier for passive transport Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Diffusion through the Plasma Membrane Figure 3.10 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes Figure 3.11 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Major Ions Inside and Outside the Cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Exocytosis Figure 3.12a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Endocytosis Figure 3.13a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Solutions ▪ Isotonic ▪ have the same solute and water concentrations as cells do ▪ cause no visible changes in cells ▪ Hypertonic ▪ contains more solutes, or dissolved substances, than there are inside the cells ▪ cells will begin to shrink Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings ▪ Hypotonic ▪ solution contains fewer solutes and more water than the cell does ▪ cells plump up rapidly as water rushes into them Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Life Cycle ▪ Cells have two major periods ▪ Interphase ▪ Cell grows ▪ Cell carries on metabolic processes ▪ Cell division ▪ Cell replicates itself ▪ Function is to produce more cells for growth and repair processes Copyright © 2006 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 3.14 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis ▪ 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 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis ▪ Metaphase ▪ Spindle from centromeres are attached to chromosomes that are aligned in the center of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15(cont) Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis ▪ Gene – DNA segment that carries a blueprint for building one protein ▪ Proteins have many functions ▪ Building materials for cells ▪ Act as enzymes (biological catalysts) ▪ RNA is essential for protein synthesis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Role of RNA ▪ Transfer RNA (tRNA) ▪ Transfers appropriate amino acids to the ribosome for building the protein ▪ Ribosomal RNA (rRNA) ▪ Helps form the ribosomes where proteins are built ▪ Messenger RNA ▪ Carries the instructions for building a protein from the nucleus to the ribosome Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Transcription and Translation ▪ Transcription ▪ Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA ▪ Translation ▪ Base sequence of nucleic acid is translated to an amino acid sequence ▪ Amino acids are the building blocks of proteins Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  3 PART A Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Copyright © 2006 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 ▪ Connective tissue ▪ Nervous tissue ▪ Muscle Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Tissues ▪ Found in different areas ▪ Body coverings ▪ Body linings ▪ Glandular tissue ▪ Functions ▪ Protection ▪ Absorption ▪ Filtration ▪ Secretion Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Epithelium Characteristics ▪ Cells fit closely together ▪ Tissue layer always has one free surface ▪ The lower surface is bound by a basement membrane ▪ Avascular (have no blood supply) ▪ Regenerate easily if well nourished Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Epithelium ▪ Number of cell layers ▪ Simple – one layer ▪ Stratified – more than one layer Figure 3.17a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Epithelium ▪ Shape of cells ▪ Squamous – flattened ▪ Cuboidal – cube-shaped ▪ Columnar – column-like Figure 3.17b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Epithelium ▪ Simple squamous ▪ Single layer of flat cells ▪ Usually forms membranes ▪ Lines body cavities ▪ Lines lungs and capillaries Figure 3.18a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Squamous Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 3.18b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Cuboidal Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Epithelium ▪ Simple columnar ▪ Single layer of tall cells ▪ Often includes goblet cells, which produce mucus ▪ Lines digestive tract Figure 3.18c Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Columnar Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Simple Epithelium ▪ Pseudostratified ▪ 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 absorption or secretion Figure 3.18d Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratified Epithelium ▪ Stratified squamous ▪ Cells at the free edge are flattened ▪ Found as a protective covering where friction is common ▪ Locations ▪ Skin ▪ Mouth ▪ Esophagus Figure 3.18e Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratified Squamous Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stratified Epithelium ▪ Transitional epithelium ▪ Shape of cells depends upon the amount of stretching ▪ Lines organs of the urinary system Figure 3.18f Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Transitional Epithelium Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Glandular Epithelium ▪ Gland – one or more cells that secretes a particular product ▪ Two major gland types ▪ Endocrine gland ▪ Ductless ▪ Secretions are hormones ▪ Exocrine gland ▪ Empty through ducts to the epithelial surface ▪ Include sweat and oil glands Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Exocrine Glands and Secretion Type Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Characteristics ▪ Variations in blood supply ▪ Some tissue types are well vascularized ▪ Some have poor blood supply or are avascular ▪ Extracellular matrix ▪ Non-living material that surrounds living cells Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 3.19a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Hyaline cartilage ▪ Most common cartilage ▪ Composed of: ▪ Abundant collagen fibers ▪ Rubbery matrix ▪ Entire fetal skeleton is hyaline cartilage Figure 3.19b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Hyaline Cartilage Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Elastic cartilage ▪ Provides elasticity ▪ Example: supports the external ear Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Elastic Cartilage Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Fibrocartilage ▪ Highly compressible ▪ Example: forms cushion-like discs between vertebrae Figure 3.19c Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Fibrocartilage Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Dense connective tissue ▪ Main matrix element is collagen fibers ▪ Cells are fibroblasts ▪ Examples ▪ Tendon – attach muscle to bone ▪ Ligaments – attach bone to bone Figure 3.19d Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Dense Connective Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Dense Connective Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Areolar connective tissue ▪ Most widely distributed connective tissue ▪ Soft, pliable tissue ▪ Contains all fiber types ▪ Can soak up excess fluid Figure 3.19e Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Loose Connective Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 fuel storage Figure 3.19f Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Loose Connective Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 3.19g Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Loose Connective Tissue Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Types ▪ Blood ▪ Blood cells surrounded by fluid matrix ▪ Fibers are visible during clotting ▪ Functions as the transport vehicle for materials Figure 3.19h Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Blood Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue ▪ Function is to produce movement ▪ Three types ▪ Skeletal muscle ▪ Cardiac muscle ▪ Smooth muscle Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue Types ▪ Skeletal muscle ▪ Can be controlled voluntarily ▪ Cells attach to connective tissue ▪ Cells are striated ▪ Cells have more than one nucleus Figure 3.20a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 3.20b Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue Types ▪ Smooth muscle ▪ Involuntary muscle ▪ Surrounds hollow organs ▪ Attached to other smooth muscle cells ▪ No visible striations ▪ One nucleus per cell Figure 3.20c Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue ▪ Neurons and nerve support cells ▪ Function is to send impulses to other areas of the body ▪ Irritability ▪ Conductivity Figure 3.21 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Tissue Repair ▪ 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Events in Tissue Repair ▪ Capillaries become very permeable ▪ Introduce clotting proteins ▪ Wall off injured area ▪ Formation of granulation tissue ▪ Regeneration of surface epithelium Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 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 decrease in mass and viabililty in most tissues Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings