Seeley's Essentials of Anatomy & Physiology Tenth Edition

Seeley’s ESSENTIALS OF Anatomy &...

Seeley’s ESSENTIALS OF Anatomy & Physiology Tenth Edition Cinnamon Vanputte Jennifer Regan Andrew Russo See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. © 2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  2 Chapter 4 Tissues Lecture Outline © 2019 McGraw-Hill Education  3 Tissue A tissue is a group of cells with similar structure and function, plus the extracellular substance surrounding them. Histology is the study of tissues. © 2019 McGraw-Hill Education  4 Types of Tissues There are four tissue types in the human body: 1. Epithelial – a covering or lining tissue 2. Connective – a diverse primary tissue type that makes up part of every organ in the body 3. Muscle – a tissue that contracts or shortens, making movement possible 4. Nervous – responsible for coordinating and controlling many body activities © 2019 McGraw-Hill Education  5 Epithelial Tissues Epithelium, or epithelial tissue, covers and protects surfaces, both outside and inside the body. Included under the classification of epithelial tissue are the exocrine and endocrine glands. © 2019 McGraw-Hill Education  6 Epithelial Tissue Characteristics 1. Mostly composed of cells 2. Covers body surfaces 3. Distinct cell surfaces 4. Cell and matrix connections 5. Nonvascular 6. Capable of regeneration © 2019 McGraw-Hill Education  7 Characteristics of Epithelium Figure 4.1 © 2019 McGraw-Hill Education (top) ©Victor Eroschenko; (bottom) ©Ed Reschke/Photolibrary/Getty Images  8 Functions of Epithelial Tissues 1. Protects underlying structures 2. Acts as a barrier 3. Permits passage of substances 4. Secretes substances 5. Absorption of substances © 2019 McGraw-Hill Education  9 Classification of Epithelia 1 Epithelial tissues are classified primarily according to the number of cell layers and the shape of the superficial cells. The cell layers can be simple, stratified, or pseudostratified. The cell shapes can be squamous, cuboidal, columnar, or a special transitional shape, that varies with the degree of stretch. © 2019 McGraw-Hill Education  10 Classification of Epithelia 2 Simple epithelium consists of a single layer of cells, with each cell extending from the basement membrane to the free surface. Stratified epithelium consists of more than one layer of cells, but only the basal layer attaches the deepest layer to the basement membrane. © 2019 McGraw-Hill Education  11 Classification of Epithelia 3 Pseudostratified columnar epithelium is a special type of simple epithelium, that appears to be falsely stratified. It consists of one layer of cells, with all the cells attached to the basement membrane. Due to variations in the shape of the cells, the epithelia appears stratified. © 2019 McGraw-Hill Education  12 Classification of Epithelia 4 There are three types of epithelium based on idealized shapes of the epithelial cells: 1. Squamous cells are flat or scalelike. 2. Cuboidal cells are cube-shaped—about as wide as they are tall. 3. Columnar cells tend to be taller than they are wide. © 2019 McGraw-Hill Education  13 Simple Squamous Epithelium 1 Simple squamous epithelium is a single layer of thin, flat cells. Some substances easily pass through this thin layer of cells, but other substances do not. The lungs, simple squamous epithelium, allows for gas exchange. The kidneys, simple squamous epithelium, helps filter wastes from the blood while keeping blood cells inside the blood vessels. © 2019 McGraw-Hill Education  14 Simple Squamous Epithelium 2 Table 4.2a © 2019 McGraw-Hill Education ©McGraw-Hill Education/Al Telser  15 Simple Cuboidal Epithelium 1 Simple cuboidal epithelium is a single layer of cube-like cells that carry out active transport, facilitated diffusion, or secretion. They have a greater secretory capacity than simple squamous epithelial cells. © 2019 McGraw-Hill Education  16 Simple Cuboidal Epithelium 2 Table 4.2b © 2019 McGraw-Hill Education ©Victor Eroschenko  17 Simple Columnar Epithelium 1 Simple columnar epithelium is a single layer of tall, thin cells. The large size of these cells enables them to perform complex functions, such as secretion. The simple columnar epithelium of the small intestine produces and secretes mucus and digestive enzymes. © 2019 McGraw-Hill Education  18 Simple Columnar Epithelium 2 Table 4.2c © 2019 McGraw-Hill Education ©Victor Eroschenko  19 Pseudostratified Columnar Epithelium 1 Pseudostratified columnar epithelium secretes mucus, which covers its free surface. Cilia in the airways move the mucus and accumulated debris toward the throat, where it is swallowed. © 2019 McGraw-Hill Education  20 Pseudostratified Columnar Epithelium 2 Table 4.2d © 2019 McGraw-Hill Education ©Victor Eroschenko  21 Stratified Squamous Epithelium 1 Stratified squamous epithelium forms a thick epithelium because it consists of several layers of cells. Though the deepest cells are cuboidal or columnar and are capable of dividing and producing new cells, the naming is based on the shape of the surface cells. There are two types of stratified squamous epithelia: keratinized stratified squamous and nonkeratinized stratified squamous epithelia. © 2019 McGraw-Hill Education  Keratinized Stratified Squamous 22 Epithelium The outer layer of the skin is comprised of a keratinized squamous epithelium. The keratin reduces the loss of water from the body. © 2019 McGraw-Hill Education  Nonkeratinized Stratified Squamous 23 Epithelium Stratified squamous epithelium of the mouth is a moist nonkeratinized stratified squamous epithelium. This nonkeratinized stratified squamous epithelium provides protection against abrasion and acts as a mechanical barrier. Water, however, can move across it more readily than across the skin (keratinized stratified squamous). © 2019 McGraw-Hill Education  24 Stratified Squamous Epithelium 2 Table 4.3a © 2019 McGraw-Hill Education ©McGraw-Hill Education/Al Telser  25 Stratified Cuboidal Epithelium Stratified cuboidal epithelium consists of more than one layer of cuboidal epithelial cells. This epithelial type is relatively rare and is found in sweat gland ducts, ovarian follicular cells, and the salivary glands. It functions in absorption, secretion, and protection. © 2019 McGraw-Hill Education  26 Stratified Columnar Epithelium Stratified columnar epithelium consists of more than one layer of epithelial cells; the surface cells are columnar but the deeper cells are irregular or cuboidal in shape. Like stratified cuboidal epithelium, stratified columnar epithelium is relatively rare, found in the mammary gland ducts, the larynx, and a portion of the male urethra. This epithelium carries out secretion, protection, and some absorption. © 2019 McGraw-Hill Education  27 Transitional Epithelium 1 Transitional epithelium is a special type of stratified epithelium that can be greatly stretched. The shape of the cells change as the epithelium is stretched. Transitional epithelium lines cavities that can expand greatly, such as the urinary bladder. It also protects underlying structures, like the urinary bladder, from the caustic effects of urine. © 2019 McGraw-Hill Education  28 Transitional Epithelium 2 Table 4.3b © 2019 McGraw-Hill Education ©Victor Eroschenko  29 Free Cell Surfaces Most epithelia have a free surface that is not in contact with other cells and faces away from underlying tissues. The characteristics of the free surface reflect its functions. The free surface can be smooth or lined with microvilli or cilia. Cilia move materials over the top of the cell. Microvilli increase surface area. © 2019 McGraw-Hill Education  30 Cell Connections 1 Cells have several structures that hold one cell to one another or to the basement membrane. These structures do three things: mechanically bind the cells together, help form a permeability barrier, and provide a mechanism for intercellular communication. Desmosomes are mechanical links that bind cells together. Hemidesmosomes are half desmosomes that anchor cells to the basement membrane. © 2019 McGraw-Hill Education  31 Cell Connections 2 Tight junctions prevent the passage of materials between epithelial cells because they completely surround each cell, similar to the way a belt surrounds the waist. Materials that pass through the epithelial layer must pass through the cells, so those cells regulate what materials can cross. Tight junctions are found in the lining of the intestines. © 2019 McGraw-Hill Education  32 Cell Connections 3 Gap junctions are small channels that allow small molecules and ions to pass from one epithelial cell to an adjacent one. Most epithelial cells are connected to one another by gap junctions, and researchers believe that molecules or ions moving through the gap junctions act as communication signals to coordinate the activities of the cells. © 2019 McGraw-Hill Education  33 Cell Connections 4 Figure 4.2 © 2019 McGraw-Hill Education  34 Glands 1 Glands are secretory organs that secrete substances onto a surface, into a cavity, or into the bloodstream. Glands are composed primarily of epithelium, with a supporting network of connective tissue. Glands with ducts are called exocrine glands. Both the gland and its ducts is lined with epithelium. Endocrine glands are ductless glands; they secrete their products (termed hormones) into the bloodstream. © 2019 McGraw-Hill Education  35 Glands 2 Most exocrine glands are multicellular, comprised of many cells. Some exocrine glands are composed of a single cell, like goblet cells, that secrete mucus. Multicellular exocrine glands can be classified according to the structure of their ducts and secretory regions. Simple glands have a single, non-branched duct, some have branched ducts. © 2019 McGraw-Hill Education  36 Glands 3 Compound exocrine glands have multiple, branched ducts. Glands with secretory regions shaped as tubules (small tubes) are called tubular, whereas those shaped in saclike structures are called acinar or alveolar. Tubular glands can be straight or coiled. Glands with a combination of the two are called tubuloacinar or tubuloalveolar. © 2019 McGraw-Hill Education  37 Exocrine Gland Structures Figure 4.3 © 2019 McGraw-Hill Education  38 Glands 4 Exocrine glands can also be classified according to how products leave the cell. Merocrine secretion involves the release of secretory products by exocytosis. Apocrine secretion involves the release of secretory products as pinched-off fragments of the gland cells. Holocrine secretion involves the shedding of entire cells. © 2019 McGraw-Hill Education  39 Exocrine Glands and Secretion Types Figure 4.4 © 2019 McGraw-Hill Education  40 Connective Tissue Connective tissue is a diverse primary tissue type that makes up part of every organ in the body. Connective tissue differs from the other three tissue types in that it consists of cells separated from each other by abundant extracellular matrix. Connective tissue is diverse in both structure and function. Connective tissue is comprised of cells, protein fibers, and an extracellular matrix. © 2019 McGraw-Hill Education  41 Functions of Connective Tissue 1. Enclose and separate other tissues 2. Connecting tissues to one another 3. Supporting and moving parts of the body 4. Storing compounds 5. Cushioning and insulating 6. Transporting 7. Protecting © 2019 McGraw-Hill Education  42 Connective Tissue Cells 1 The specialized cells of the various connective tissues produce the extracellular matrix. The name of the cell identifies the cell functions. Osteoblasts form bone, osteocytes maintain it, and osteoclasts break it down. Fibroblasts are cells that form fibrous connective tissue, and fibrocytes maintain it. Chondroblasts form cartilage and chondrocytes maintain it. © 2019 McGraw-Hill Education  43 Connective Tissue Cells 2 Found in connective tissue are cells associated with the immune system, such as white blood cells. Macrophages are large cells that are capable of moving about and ingesting foreign substances, including microorganisms in the connective tissue. Mast cells are nonmotile cells that release chemicals, such as histamine, that promote inflammation. © 2019 McGraw-Hill Education  44 Extracellular Matrix The extracellular matrix of connective tissue has three major components: protein fibers, ground substance, and fluid. Ground substance consists of non-fibrous protein and other molecules. The structure of the matrix is responsible for the functional characteristics of connective tissues—for example, they enable bones and cartilage to bear weight. © 2019 McGraw-Hill Education  45 Matrix Protein Fibers Three types of protein fibers—collagen, reticular, and elastic—help form most connective tissues. Collagen fibers, which resemble microscopic ropes, are very flexible but resist stretching. Reticular fibers are very fine, short collagen fibers that branch to form a supporting network. Elastic fibers have the ability to return to their original shape after being stretched or compressed, giving tissue an elastic quality. © 2019 McGraw-Hill Education  46 Matrix Ground Substance The ground substance consists of non-fibrous molecules and is shapeless.. It consists of proteoglycans, which are large molecules that consist of a protein core attached to many long polysaccharides. Proteoglycans trap large quantities of water between the polysaccharides, which allows them to return to their original shape when compressed or deformed. © 2019 McGraw-Hill Education  47 Types of Connective Tissues 1 The two main types of connective tissue are embryonic and adult connective tissue. By eight weeks of development, most of the embryonic connective tissue has become specialized to form the types of connective tissue seen in adults. © 2019 McGraw-Hill Education  48 Types of Connective Tissues 2 Loose connective tissue consists of relatively few protein fibers that form a lacy network, with numerous spaces filled with ground substance and fluid. Three subdivisions of loose connective tissue are areolar, adipose, and reticular. Areolar connective tissue primarily consists of collagen fibers and a few elastic fibers. The most common cells in loose connective tissue are the fibroblasts. © 2019 McGraw-Hill Education  49 Types of Connective Tissues 3 Adipose tissue consists of adipocytes, or fat cells, which contain large amounts of lipid for energy storage. Adipose tissue pads and protects parts of the body and acts as a thermal insulator. Reticular tissue forms the framework of lymphatic tissue, such as in the spleen and lymph nodes, as well as in bone marrow and the liver. © 2019 McGraw-Hill Education  50 Areolar Connective Tissue Table 4.5a © 2019 McGraw-Hill Education ©Ed Reschke  51 Adipose Tissue Table 4.5b © 2019 McGraw-Hill Education ©Ed Reschke  52 Types of Connective Tissues 4 Dense connective tissue has a relatively large number of protein fibers that form thick bundles and fill nearly all of the extracellular space. There are two major subcategories of dense connective tissue: collagenous and elastic. Dense collagenous connective tissue has an extracellular matrix consisting mostly of collagen fibers. © 2019 McGraw-Hill Education  53 Types of Connective Tissues 5 Dense collagenous connective tissue has an extracellular matrix consisting mostly of collagen fibers. Dense collagenous connective tissue having the collagen fibers oriented in the same direction is termed dense regular. Examples of dense regular are tendons and ligaments. © 2019 McGraw-Hill Education  54 Types of Connective Tissues 6 Dense collagenous connective tissue having the collagen fibers oriented in the multiple directions is termed dense irregular. Examples of dense irregular are in the dermis of the skin and in organ capsules. © 2019 McGraw-Hill Education  Dense Regular Collagenous 55 Connective Tissue Table 4.6a © 2019 McGraw-Hill Education ©Victor Eroschenko, ©Ed  56 Types of Connective Tissues 7 Dense elastic connective tissue has abundant elastic fibers among its collagen fibers. The elastic fibers allow the tissue to stretch and recoil. Examples include the dense elastic connective tissue in the vocal cords. A genetic condition called Marfan syndrome results from, in part the inability to properly maintain and form elastic fibers. © 2019 McGraw-Hill Education  Dense Regular Elastic Connective 57 Tissue Table 4.6b © 2019 McGraw-Hill Education ©Victor Eroschenko  58 Cartilage 1 Cartilage is composed of chondrocytes, located in spaces called lacunae within an extensive matrix. Collagen in the matrix gives cartilage flexibility and strength. Cartilage is resilient because the proteoglycans of the matrix trap water. Cartilage provides support, but if bent or slightly compressed, it resumes its original shape. © 2019 McGraw-Hill Education  59 Cartilage 2 There are three types of cartilage: hyaline, fibrocartilage, and elastic cartilage. Hyaline cartilage is the most abundant type of cartilage and has many functions, such as covering the ends of bones, where they form joints. Fibrocartilage has more collagen than does hyaline cartilage and is able to withstand compression and resist tearing or pulling. Fibrocartilage is found in the intervertebral disks. © 2019 McGraw-Hill Education  60 Hyaline Cartilage Table 4.7a © 2019 McGraw-Hill Education ©Victor Eroschenko  61 Cartilage 3 Fibrocartilage has more collagen than does hyaline cartilage and is able to withstand compression and resist tearing or pulling. Fibrocartilage is found in the disks between the vertebrae (bones of the back) and in some joints, such as the knee and temporomandibular (jaw) joints. © 2019 McGraw-Hill Education  62 Cartilage 4 Elastic cartilage contains elastic fibers in addition to collagen and proteoglycans. The elastic fibers appear as coiled fibers among bundles of collagen fibers. Elastic cartilage is able to recoil to its original shape when bent. The external ear, epiglottis, and auditory tube contain elastic cartilage. © 2019 McGraw-Hill Education  63 Fibrocartilage and Elastic Cartilages Table 4.7b,c © 2019 McGraw-Hill Education ©Victor Eroschenko  64 Bone 1 Bone is a hard connective tissue that consists of living cells and a mineralized matrix. Osteocytes are located within lacunae. The strength and rigidity of the mineralized matrix enables bones to support and protect other tissues and organs. Two types of bone tissue exist: spongy bone and compact bone. © 2019 McGraw-Hill Education  65 Bone 2 Spongy bone has spaces between trabeculae or plates, of bone and therefore resembles a sponge. Compact bone is more solid, with almost no space between many thin layers of mineralized matrix. © 2019 McGraw-Hill Education  66 Bone 3 Table 4.8 © 2019 McGraw-Hill Education ©Trent Stephens  67 Blood 1 Blood is a liquid connective tissue It contains a liquid matrix, termed the plasma, along with formed elements. The formed elements are erythrocytes, leukocytes, and platelets. It functions in transport of food, oxygen, waste, hormones, and other substances. © 2019 McGraw-Hill Education  68 Blood 2 Table 4.9 © 2019 McGraw-Hill Education ©Ed Reschke/Photolibrary/Getty Images  69 Muscle 1 The main function of muscle tissue is to contract, or shorten, making movement possible. Muscle contraction results from contractile proteins located within the muscle cells. The three types of muscle tissue are skeletal, cardiac, and smooth. © 2019 McGraw-Hill Education  70 Muscle 2 Skeletal muscle attaches to the skeleton and enables the body to move. Skeletal muscle cells are striated, or banded, because of the arrangement of contractile proteins within the cells. © 2019 McGraw-Hill Education  71 Skeletal Muscle Table 4.10a © 2019 McGraw-Hill Education ©Ed Reschke  72 Muscle 3 Cardiac muscle is the muscle of the heart; it is responsible for pumping blood. Cardiac muscle cells are cylindrical but much shorter than skeletal muscle cells. Cardiac muscle cells are striated and usually have one nucleus per cell. They are often branched and connected to one another by intercalated disks. © 2019 McGraw-Hill Education  73 Cardiac Muscle Table 4.10b © 2019 McGraw-Hill Education ©Ed Reschke  74 Muscle 4 Smooth muscle forms the walls of hollow organs; it is also found in the skin and the eyes. Smooth muscle is responsible for a number of functions, such as moving food through the digestive tract and emptying the urinary bladder. Smooth muscle cells are tapered at each end, have a single nucleus, and are not striated. © 2019 McGraw-Hill Education  75 Smooth Muscle Table 4.10c © 2019 McGraw-Hill Education ©McGraw-Hill Education/Dennis Strete  76 Nervous Tissue 1 Nervous tissue forms the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities. Nervous tissue consists of neurons and support cells, termed glial cells. The neuron is responsible for conducting action potentials. It is composed of three parts: a cell body, dendrites, and an axon. © 2019 McGraw-Hill Education  77 Nervous Tissue 2 Table 4.11 © 2019 McGraw-Hill Education ©Trent Stephens  78 Tissue Membranes 1 A tissue membrane is a thin sheet or layer of tissue that covers a structure or lines a cavity. Most membranes consist of epithelium and the connective tissue on which the epithelium rests. There are four tissue membranes in the body: cutaneous, mucous, serous, and synovial. The skin, termed the cutaneous membrane, is an external body surface membrane. © 2019 McGraw-Hill Education  79 Tissue Membranes 2 The mucous membranes line cavities that open to the outside of the body, such as the digestive, respiratory, and reproductive tracts. Mucous membranes consist of epithelial cells, their basement membrane, and a thick layer of loose connective tissue. Many, but not all, mucous membranes secrete mucus. The functions of mucous membranes include protection, absorption, and secretion. © 2019 McGraw-Hill Education  80 Tissue Membranes 3 Serous membranes line cavities that do not open to the exterior of the body, such as the pericardial, pleural, and peritoneal cavities. Serous membranes consist of three components: a layer of simple squamous epithelium, its basement membrane, and a delicate layer of loose connective tissue. Serous membranes do not contain glands, but they secrete a small amount of fluid called serous fluid, which lubricates the surface of the membranes. © 2019 McGraw-Hill Education  81 Tissue Membranes 4 Synovial membranes line the cavities of freely movable joints. They are made up of only connective tissue and consist of modified connective tissue cells. Synovial membranes produce synovial fluid, which makes the joint very slippery, thereby reducing friction and allowing smooth movement within the joint. © 2019 McGraw-Hill Education  82 Internal Membranes Figure 4.5 © 2019 McGraw-Hill Education  83 Tissue Inflammation 1 Inflammation is usually a beneficial process occurring when tissues are damaged. When viruses infect epithelial cells of the upper respiratory tract, inflammation and the symptoms of the common cold are produced. The inflammatory process occurs in stages. © 2019 McGraw-Hill Education  84 Tissue Inflammation 2 Inflammation mobilizes the body’s defenses and isolates and destroys microorganisms, foreign materials, and damaged cells so that tissue repair can proceed. Inflammation produces five major symptoms: redness, heat, swelling, pain, and disturbance of function. © 2019 McGraw-Hill Education  85 Inflammation Figure 4.6 © 2019 McGraw-Hill Education  86 Tissue Repair 1 Tissue repair involves substitution of dead cells for viable cells. Tissue repair can occur by regeneration or by fibrosis. In regeneration, the new cells are the same type as those that were destroyed, and normal function is usually restored. In fibrosis, or replacement, a new type of tissue develops that eventually causes scar production and the loss of some tissue function. © 2019 McGraw-Hill Education  87 Tissue Repair 2 Regeneration can completely repair some tissues, such as the skin and the mucous membrane of the intestine. In these cases, regeneration is accomplished primarily by stem cells. Stem cells are self-renewing, undifferentiated cells that continue to divide throughout life. Tissue repair occurs in sequential steps. © 2019 McGraw-Hill Education  88 Tissue Repair 3 Figure 4.7 © 2019 McGraw-Hill Education