ch04lectureppta-210924134734-1.pdf
- 1. 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. © 2019 McGraw-Hill Education 2 Chapter 4 Tissues Lecture Outline
- 3. © 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.
- 4. © 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
- 5. © 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.
- 6. © 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
- 7. © 2019 McGraw-Hill Education 7 Characteristics of Epithelium Figure 4.1 (top) ©Victor Eroschenko; (bottom) ©Ed Reschke/Photolibrary/Getty Images
- 8. © 2019 McGraw-Hill Education 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
- 9. © 2019 McGraw-Hill Education 9 Classification of Epithelia1 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.
- 10. © 2019 McGraw-Hill Education 10 Classification of Epithelia2 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.
- 11. © 2019 McGraw-Hill Education 11 Classification of Epithelia3 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.
- 12. © 2019 McGraw-Hill Education 12 Classification of Epithelia4 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.
- 13. © 2019 McGraw-Hill Education 13 Simple Squamous Epithelium1 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.
- 14. © 2019 McGraw-Hill Education 14 Simple Squamous Epithelium2 Table 4.2a ©McGraw-Hill Education/Al Telser
- 15. © 2019 McGraw-Hill Education 15 Simple Cuboidal Epithelium1 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.
- 16. © 2019 McGraw-Hill Education 16 Simple Cuboidal Epithelium2 Table 4.2b ©Victor Eroschenko
- 17. © 2019 McGraw-Hill Education 17 Simple Columnar Epithelium1 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.
- 18. © 2019 McGraw-Hill Education 18 Simple Columnar Epithelium2 Table 4.2c ©Victor Eroschenko
- 19. © 2019 McGraw-Hill Education 19 Pseudostratified Columnar Epithelium1 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.
- 20. © 2019 McGraw-Hill Education 20 Pseudostratified Columnar Epithelium2 Table 4.2d ©Victor Eroschenko
- 21. © 2019 McGraw-Hill Education 21 Stratified Squamous Epithelium1 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.
- 22. © 2019 McGraw-Hill Education 22 Keratinized Stratified Squamous Epithelium The outer layer of the skin is comprised of a keratinized squamous epithelium. The keratin reduces the loss of water from the body.
- 23. © 2019 McGraw-Hill Education 23 Nonkeratinized Stratified Squamous 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).
- 24. © 2019 McGraw-Hill Education 24 Stratified Squamous Epithelium2 Table 4.3a ©McGraw-Hill Education/Al Telser
- 25. © 2019 McGraw-Hill Education 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.
- 26. © 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.
- 27. © 2019 McGraw-Hill Education 27 Transitional Epithelium1 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.
- 28. © 2019 McGraw-Hill Education 28 Transitional Epithelium2 Table 4.3b ©Victor Eroschenko
- 29. © 2019 McGraw-Hill Education 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.
- 30. © 2019 McGraw-Hill Education 30 Cell Connections1 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.
- 31. © 2019 McGraw-Hill Education 31 Cell Connections2 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.
- 32. © 2019 McGraw-Hill Education 32 Cell Connections3 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.
- 33. © 2019 McGraw-Hill Education 33 Cell Connections4 Figure 4.2
- 34. © 2019 McGraw-Hill Education 34 Glands1 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.
- 35. © 2019 McGraw-Hill Education 35 Glands2 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.
- 36. © 2019 McGraw-Hill Education 36 Glands3 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.
- 37. © 2019 McGraw-Hill Education 37 Exocrine Gland Structures Figure 4.3
- 38. © 2019 McGraw-Hill Education 38 Glands4 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.
- 39. © 2019 McGraw-Hill Education 39 Exocrine Glands and Secretion Types Figure 4.4
- 40. © 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.
- 41. © 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
- 42. © 2019 McGraw-Hill Education 42 Connective Tissue Cells1 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.
- 43. © 2019 McGraw-Hill Education 43 Connective Tissue Cells2 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.
- 44. © 2019 McGraw-Hill Education 44 Extracellular Matrix The extracellular matrix of connective tissue has three major components: protein fibers, ground substance, and fluid. 1. 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.
- 45. © 2019 McGraw-Hill Education 45 1. Matrix Protein Fibers Three types of protein fibers—collagen, reticular, and elastic—help form most connective tissues. a. Collagen fibers, which resemble microscopic ropes, are very flexible but resist stretching. b. Reticular fibers are very fine, short collagen fibers that branch to form a supporting network. c. Elastic fibers have the ability to return to their original shape after being stretched or compressed, giving tissue an elastic quality.
- 46. © 2019 McGraw-Hill Education 46 2. 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.
- 47. © 2019 McGraw-Hill Education 47 Types of Connective Tissues1 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.
- 48. © 2019 McGraw-Hill Education 48 Types of Connective Tissues2 1. 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. a. Areolar connective tissue primarily consists of collagen fibers and a few elastic fibers. The most common cells in loose connective tissue are the fibroblasts.
- 49. © 2019 McGraw-Hill Education 49 Types of Connective Tissues3 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.
- 50. © 2019 McGraw-Hill Education 50 Areolar Connective Tissue Table 4.5a ©Ed Reschke
- 51. © 2019 McGraw-Hill Education 51 Adipose Tissue Table 4.5b ©Ed Reschke
- 52. © 2019 McGraw-Hill Education 52 See page 80. Reticular tissue
- 53. © 2019 McGraw-Hill Education 53 Types of Connective Tissues4 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.
- 54. © 2019 McGraw-Hill Education 54 Types of Connective Tissues5 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.
- 55. © 2019 McGraw-Hill Education 55 Types of Connective Tissues6 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.
- 56. © 2019 McGraw-Hill Education 56 Dense Regular Collagenous Connective Tissue Table 4.6a ©Victor Eroschenko, ©Ed Reschke/Photolibrary/Getty Images
- 57. © 2019 McGraw-Hill Education 57 Types of Connective Tissues7 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. (blood vessels) A genetic condition called Marfan syndrome results from, in part the inability to properly maintain and form elastic fibers.
- 58. © 2019 McGraw-Hill Education 58 Dense Regular Elastic Connective Tissue Table 4.6b ©Victor Eroschenko
- 59. © 2019 McGraw-Hill Education 59 Supporting connective tissue
- 60. © 2019 McGraw-Hill Education 60 Cartilage1 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.
- 61. © 2019 McGraw-Hill Education 61 Cartilage2 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.
- 62. © 2019 McGraw-Hill Education 62 Hyaline Cartilage Table 4.7a ©Victor Eroschenko
- 63. © 2019 McGraw-Hill Education 63 Cartilage3 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.
- 64. © 2019 McGraw-Hill Education 64 Cartilage4 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.
- 65. © 2019 McGraw-Hill Education 65 Fibrocartilage and Elastic Cartilages Table 4.7b,c ©Victor Eroschenko
- 66. © 2019 McGraw-Hill Education 66 Bone1 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.
- 67. © 2019 McGraw-Hill Education 67 Bone2 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.
- 68. © 2019 McGraw-Hill Education 68 Bone3 Table 4.8 ©Trent Stephens
- 69. © 2019 McGraw-Hill Education 69 fluid
- 70. © 2019 McGraw-Hill Education 70 Blood1 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.
- 71. © 2019 McGraw-Hill Education 71 Blood2 Table 4.9 ©Ed Reschke/Photolibrary/Getty Images
- 72. © 2019 McGraw-Hill Education 72 Muscle1 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.
- 73. © 2019 McGraw-Hill Education 73 Muscle2 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.
- 74. © 2019 McGraw-Hill Education 74 Skeletal Muscle Table 4.10a ©Ed Reschke
- 75. © 2019 McGraw-Hill Education 75 Muscle3 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.
- 76. © 2019 McGraw-Hill Education 76 Cardiac Muscle Table 4.10b ©Ed Reschke
- 77. © 2019 McGraw-Hill Education 77 Muscle4 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.
- 78. © 2019 McGraw-Hill Education 78 Smooth Muscle Table 4.10c ©McGraw-Hill Education/Dennis Strete
- 79. © 2019 McGraw-Hill Education 79 Nervous Tissue1 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.
- 80. © 2019 McGraw-Hill Education 80 Nervous Tissue2 Table 4.11 ©Trent Stephens
- 81. © 2019 McGraw-Hill Education 81 Tissue Membranes1 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.
- 82. © 2019 McGraw-Hill Education 82 Tissue Membranes2 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.
- 83. © 2019 McGraw-Hill Education 83 Tissue Membranes3 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.
- 84. © 2019 McGraw-Hill Education 84 Tissue Membranes4 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.
- 85. © 2019 McGraw-Hill Education 85 Internal Membranes Figure 4.5
- 86. © 2019 McGraw-Hill Education 86 Tissue Inflammation1 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.
- 87. © 2019 McGraw-Hill Education 87 Tissue Inflammation2 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.
- 88. © 2019 McGraw-Hill Education 88 Inflammation Figure 4.6
- 89. © 2019 McGraw-Hill Education 89 Tissue Repair1 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.
- 90. © 2019 McGraw-Hill Education 90 Tissue Repair2 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.
- 91. © 2019 McGraw-Hill Education 91 Tissue Repair3 Figure 4.7