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- 1. © 2012 Pearson Education, Inc. 3 Foundations: Tissues and Early Embryology PowerPoint® Lecture Presentations prepared by Steven Bassett Southeast Community College Lincoln, Nebraska
- 2. © 2012 Pearson Education, Inc. Introduction • This chapter concentrates on cells and tissues • There are over 75 trillion cells in the body • All cells can be placed into one of the four tissue categories • Epithelial tissue • Connective tissue • Muscular tissue • Neural tissue
- 3. © 2012 Pearson Education, Inc. Figure 3.1 An Orientation to the Tissues of the Body MOLECULES ATOMS CELLS EXTRACELLULAR MATERIAL AND FLUIDS TISSUES with special functions ORGANS with multiple functions Organic / Inorganic Combine to form Interact to form That secrete and regulate Combine to form Combine to form ORGAN SYSTEMS Chapters 4–27 Interact in EPITHELIA CONNECTIVE TISSUES MUSCLE TISSUE NEURAL TISSUE • Cover exposed surfaces • Line internal passageways and chambers • Produce glandular secretions See Figures 3.2 to 3.10 • Store energy See Figures 3.11 to 3.19, 3.21 • Contracts to produce active movement See Figure 3.22 • Conducts electrical impulses • Carries information See Figure 3.23 • Fill internal spaces • Provide structural support
- 4. © 2012 Pearson Education, Inc. Epithelial Tissue • Epithelial Tissue Characteristics • Cellularity • Cells are bound close together • No intercellular space • Polarity • Have an exposed apical surface • Have an attached basal surface
- 5. © 2012 Pearson Education, Inc. Epithelial Tissue • Epithelial Tissue Characteristics (continued) • Attachment • Basal layer is attached to the basal lamina • Avascularity • Do not consist of blood vessels
- 6. © 2012 Pearson Education, Inc. Epithelial Tissue • Epithelial Tissue Characteristics (continued) • Arranged in sheets • Composed of one or more layers of cells • Regeneration • Cells are continuously replaced via cell reproduction
- 7. © 2012 Pearson Education, Inc. Figure 3.2a Polarity of Epithelial Cells Cilia Microvilli Apical surface Golgi apparatus Nucleus Mitochondria Basal lamina Basolateral surfaces Many epithelial cells differ in internal organization along an axis between the apical surface and the basal lamina. The apical surface frequently bears microvilli; less often, it may have cilia or (very rarely) stereocilia. A single cell typically has only one type of process; cilia and microvilli are shown together to highlight their relative proportions. Tight junctions prevent movement of pathogens or diffusion of dissolved materials between the cells. Folds of plasmalemma near the base of the cell increase the surface area exposed to the basal lamina. Mitochondria are typically concentrated at the basolateral region, probably to provide energy for the cell’s transport activities.
- 8. © 2012 Pearson Education, Inc. Epithelial Tissue • Functions of Epithelial Tissue • Provides physical protection • Controls permeability • Provides sensation • Produces secretions
- 9. © 2012 Pearson Education, Inc. Epithelial Tissue • Specialization of Epithelial Cells • Microvilli • For absorption and secretion • Stereocilia • Long microvilli, commonly found in the inner ear • Ciliated epithelium • Moves substances over the apical surfaces of the cells
- 10. © 2012 Pearson Education, Inc. Figure 3.2a Polarity of Epithelial Cells Cilia Microvilli Apical surface Golgi apparatus Nucleus Mitochondria Basal lamina Basolateral surfaces Many epithelial cells differ in internal organization along an axis between the apical surface and the basal lamina. The apical surface frequently bears microvilli; less often, it may have cilia or (very rarely) stereocilia. A single cell typically has only one type of process; cilia and microvilli are shown together to highlight their relative proportions. Tight junctions prevent movement of pathogens or diffusion of dissolved materials between the cells. Folds of plasmalemma near the base of the cell increase the surface area exposed to the basal lamina. Mitochondria are typically concentrated at the basolateral region, probably to provide energy for the cell’s transport activities.
- 11. © 2012 Pearson Education, Inc. Figure 3.2b Polarity of Epithelial Cells Cilia Microvilli An SEM showing the surface of the epithelium that lines most of the respiratory tract. The small, bristly areas are microvilli found on the exposed surfaces of mucus-producing cells that are scattered among the ciliated epithelial cells.
- 12. © 2012 Pearson Education, Inc. Epithelial Tissue • Maintaining the Integrity of the Epithelium • Three factors involved in maintenance • Intercellular connections • Attachment to the basal lamina Lamina lucida: a clear layer of proteins that provides a barrier that restricts the movement of proteins and other large molecules. Lamina densa: provided by underlying connective tissue and gives strength to basal lamina. • Epithelial maintenance and renewal is self- perpetuated
- 13. © 2012 Pearson Education, Inc. Figure 3.3b Epithelia and Basal Laminae Basal lamina Clear layer Dense layer CAMs Proteoglycans (intercellular cement) Plasmalemma Connective tissue At their basal surfaces, epithelia are attached to a basal lamina that forms the boundary between the epithelial cells and the underlying connective tissue.
- 14. © 2012 Pearson Education, Inc. Epithelial Tissue • Classification of Epithelia • Simple • Epithelium has only one layer of cells • Stratified • Epithelium has two or more layers of cells
- 15. © 2012 Pearson Education, Inc. Epithelial Tissue • Epithelial Tissue Cells • Squamous cells • Thin, flat cells / “squished” nuclei • Cuboidal cells • Cube-shaped cells / centered, round nucleus • Columnar cells • Longer than they are wide / nucleus near the base • Transitional cells • Mixture of cells / nuclei appear to be scattered
- 16. © 2012 Pearson Education, Inc. Figure 3.4a Histology of Squamous Epithelia Simple Squamous Epithelium Connective tissue Locations: Mesothelia lining ventral body cavi- ties; endothelia lining heart and blood vessels; portions of kidney tubules (thin sections of nephron loops); inner lining of cornea; alveoli of lungs Functions: Reduces friction; controls vessel permeability; performs absorption and secretion A superficial view of the simple squamous epithelium (mesothelium) that lines the peritoneal cavity Lining of peritoneal cavity Cytoplasm Nucleus LM × 238
- 17. © 2012 Pearson Education, Inc. Figure 3.4b Histology of Squamous Epithelia Stratified Squamous Epithelium Locations: Surface of skin; lining of mouth, throat, esophagus, rectum, anus, and vagina Functions: Provides physical protection against abrasion, pathogens, and chemical attack Sectional views of the stratified squamous epithelium that covers the tongue Surface of tongue Stem cells Basal lamina Squamous superficial cells Connective tissue LM × 310
- 18. © 2012 Pearson Education, Inc. Figure 3.5a Histology of Cuboidal Epithelia Simple Cuboidal Epithelium LOCATIONS: Glands; ducts; portions of kidney tubules; thyroid gland FUNCTIONS: Limited protection, secretion, absorption A section through the simple cuboidal epithelium lining a kidney tubule. The diagrammatic view emphasizes structural details that permit the classification of an epithelium as cuboidal. Connective tissue Cuboidal cells Basal lamina Nucleus LM × 1400 Kidney tubule
- 19. © 2012 Pearson Education, Inc. Figure 3.5b Histology of Cuboidal Epithelia Stratified Cuboidal Epithelium LM × 1413 Lumen of duct Basal lamina Nucleus Connective tissue Stratified cuboidal cells Sweat gland duct A sectional view of the stratified cuboidal epithelium lining a sweat gland duct in the skin FUNCTIONS: Protection, secretion, absorption LOCATIONS: Lining of some ducts (rare)
- 20. © 2012 Pearson Education, Inc. Figure 3.6a Histology of Columnar Epithelia Simple Columnar Epithelium Intestinal lining A light micrograph showing the characteristics of simple columnar epithelium. In the diagrammatic sketch, note the relationships between the height and width of each cell; the relative size, shape, and location of nuclei; and the distance between adjacent nuclei. Contrast these observations with the corresponding characteristics of simple cuboidal epithelia. LM × 350 Loose connective tissue Basal lamina Nucleus Cytoplasm Microvilli LOCATIONS: Lining of stomach, intestine, gallbladder, uterine tubes, and collecting ducts of kidneys FUNCTIONS: Protection, secretion, absorption
- 21. © 2012 Pearson Education, Inc. Figure 3.6b Histology of Columnar Epithelia Stratified Columnar Epithelium Salivary gland duct FUNCTION: Protection LOCATIONS: Small areas of the pharynx, epiglottis, anus, mammary gland, salivary gland ducts, and urethra Lumen A stratified columnar epithelium is sometimes found along large ducts, such as this salivary gland duct. Note the overall height of the epithelium and the location and orientation of the nuclei. Loose connective tissue Deeper basal cells Superficial columnar cells Cytoplasm Nuclei Basal lamina Lumen LM × 175
- 22. © 2012 Pearson Education, Inc. Figure 3.7a Histology of Pseudostratified Ciliated Columnar and Transitional Epithelia Pseudostratified ciliated columnar epithelium Pseudostratified ciliated columnar epithelium. The pseudostratified, ciliated, columnar epithelium of the respiratory tract. Note the uneven layering of the nuclei. LOCATIONS: Lining of nasal cavity, trachea, and bronchi; portions of male reproductive tract FUNCTIONS: Protection, secretion Trachea Cilia Cytoplasm Nuclei Basal lamina Loose connective tissue LM × 350
- 23. © 2012 Pearson Education, Inc. Figure 3.7b Histology of Pseudostratified Ciliated Columnar and Transitional Epithelia Transitional epithelium Transitional epithelium. A sectional view of the transitional epithelium lining the urinary bladder. The cells from an empty bladder are in the relaxed state, while those lining a full urinary bladder show the effects of stretching on the arrangement of cells in the epithelium. LM × 450 LM × 450 Epithelium (relaxed) Basal lamina Connective tissue and smooth muscle layers Relaxed bladder LOCATIONS: Urinary bladder; renal pelvis; ureters FUNCTIONS: Permits expansion and recoil after stretching Basal lamina Epithelium (stretched) Stretched bladder Connective tissue and smooth muscle layers
- 24. © 2012 Pearson Education, Inc. Epithelial Tissue • Glandular Epithelia • Many epithelia are mixed with gland cells • Types of glands • Serous glands: secrete watery fluids rich in enzymes • Mucous glands: secrete glycoproteins (mucins) that absorb water to produce mucus • Mixed exocrine glands: contain both serous and mucous secretions
- 25. © 2012 Pearson Education, Inc. Epithelial Tissue • Glandular Epithelia (continued) • Endocrine glands • Secretions enter into the blood or lymph • Exocrine glands • Secretions travel through ducts to the epithelial surface
- 26. © 2012 Pearson Education, Inc. Figure 3.9 A Structural Classification of Simple and Compound Exocrine Glands (Part 1 of 2) Simple Glands SIMPLE TUBULAR SIMPLE COILED TUBULAR SIMPLE BRANCHED TUBULAR SIMPLE ALVEOLAR (ACINAR) SIMPLE BRANCHED ALVEOLAR Examples: Examples: Examples: Examples: Examples: Gland cells Duct • Intestinal glands • Merocrine sweat glands • Gastric glands • Mucous glands of esophagus, tongue, duodenum • Not found in adult; a stage in development of simple branched glands • Sebaceous (oil) glands Those that form blind pockets are alveolar or acinar. Glands whose glandular cells form tubes are tubular; the tubes may be straight or coiled.
- 27. © 2012 Pearson Education, Inc. Epithelial Tissue • Glandular Epithelia • Modes of Secretion • Merocrine secretion • Apocrine secretion • Holocrine secretion
- 28. © 2012 Pearson Education, Inc. Epithelial Tissue • Modes of Secretion • Merocrine Secretion • Secretions released through exocytosis • Examples: • Goblet cells of the trachea • Cells in the axilla region regarding sweat production
- 29. © 2012 Pearson Education, Inc. Figure 3.10a Mechanisms of Glandular Secretion Salivary gland Secretory vesicle Golgi apparatus Nucleus TEM × 2300 In merocrine secretion, secretory vesicles are discharged at the surface of the gland cell through exocytosis.
- 30. © 2012 Pearson Education, Inc. Epithelial Tissue • Modes of Secretion • Apocrine Secretion • Secretions released via the loss of cytoplasm • Example: • Cells of the mammary glands for milk secretion
- 31. © 2012 Pearson Education, Inc. Figure 3.10b Mechanisms of Glandular Secretion Mammary gland Breaks down Secretion Regrowth Apocrine secretion involves the loss of cytoplasm. Inclusions, secretory vesicles, and other cytoplasmic components are shed at the apical surface of the cell. The gland cell then undergoes a period of growth and repair before releasing additional secretions. Golgi apparatus
- 32. © 2012 Pearson Education, Inc. Epithelial Tissue • Modes of Secretion • Holocrine Secretion • Secretions released upon bursting of the glandular cells • Example: • Cells of the sebaceous glands
- 33. © 2012 Pearson Education, Inc. Figure 3.10c Mechanisms of Glandular Secretion Hair Sebaceous gland Hair follicle Cells burst, releasing cytoplasmic contents Cells produce secretion, increasing in size Cell division replaces lost cells Stem cell Holocrine secretion occurs as superficial gland cells break apart. Continued secretion involves the replacement of these cells through the mitotic division of underlying stem cells.
- 34. © 2012 Pearson Education, Inc. Connective Tissues • All connective tissues have three main components: • Specialized cells • Matrix • The matrix is the collective term for the extracellular component of any connective tissue that is made of protein fibers and the ground substance Collagen fibers are very long, cylindrical fibers made up of three subunits coiled around one another. Collagen is the most common and strongest fiber. Reticular fibers are a single unit of collagen proteins. Elastic fibers contain the protein elastin.
- 35. © 2012 Pearson Education, Inc. Connective Tissues • Functions of Connective Tissue • Establishing the structural framework of the body • Transporting fluid and dissolved materials • Protecting organs • Supporting, surrounding, and connecting other tissues • Storing energy • Defending the body from microorganisms
- 36. © 2012 Pearson Education, Inc. Connective Tissues • Classification of Connective Tissue • Connective tissue proper • Has a matrix of fibers (loose fibers and dense fibers) • Fluid connective tissue • Has a matrix of liquid (blood and lymph) • Supporting connective tissue • Has a matrix consisting of a gel or a solid (cartilage and bone)
- 37. © 2012 Pearson Education, Inc. Figure 3.11 A Classification of Connective Tissues Connective Tissues Connective Tissue Proper Supporting Connective TissueBlood and Lymph Loose Dense Blood Lymph Cartilage Bone Solid, crystalline matrix Solid, rubbery matrix • hyaline cartilage • elastic cartilage • fibrous cartilage Contained in lymphoid system Contained in cardiovascular system Fibers densely packed Fibers create loose, open framework • areolar tissue • adipose tissue • reticular tissue • dense regular • dense irregular • elastic can be divided into three types
- 38. © 2012 Pearson Education, Inc. Connective Tissue Proper • Connective Tissue Proper • Loose fibers • Areolar tissue • Adipose tissue • Reticular tissue • Dense fibers • Dense regular • Dense irregular • Elastic
- 39. © 2012 Pearson Education, Inc. Connective Tissue Proper • Areolar Tissue (details) • Location • Deep dermis • Between muscles • Function • Connects skin to muscle • Matrix • Fibers
- 40. © 2012 Pearson Education, Inc. Figure 3.14a Histology of Loose Connective Tissues Areolar Tissue Areolar tissue. Note the open framework; all the cells of connective tissue proper are found in areolar tissue. LOCATIONS: Within and deep to the dermis of skin, and covered by the epithelial lining of the digestive, respiratory, and urinary tracts; between muscles; around blood vessels, nerves, and around joints FUNCTIONS: Cushions organs; provides support but permits independent movement; phagocytic cells provide defense against pathogens Areolar tissue from pleura Collagen fibers Mast cell Elastic fibers Adipocyte Fibrocytes Macrophage LM × 380
- 41. © 2012 Pearson Education, Inc. Connective Tissue Proper • Adipose Tissue (details) • Location • Hypodermis • Buttocks, surrounds organs • Function • Cushion • Insulation • Matrix • Fibers
- 42. © 2012 Pearson Education, Inc. Figure 3.14b Histology of Loose Connective Tissues Adipose Tissue Adipose tissue. Adipose tissue is a loose connective tissue dominated by adipocytes. In standard histological views, the cells look empty because their lipid inclusions dissolve during slide preparation. LM × 300 Adipocytes (white adipose cells) LOCATIONS: Deep to the skin, especially at sides, buttocks, breasts; padding around eyes and kidneys FUNCTIONS: Provides padding and cushions shocks; insulates (reduces heat loss); stores energy
- 43. © 2012 Pearson Education, Inc. Connective Tissue Proper • Reticular Tissue (details) • Location • Liver, spleen, kidney, lymph nodes, tonsils, appendix, bone marrow • Function • Supporting framework • Matrix • Fibers
- 44. © 2012 Pearson Education, Inc. Figure 3.14c Histology of Loose Connective Tissues Reticular Tissue Reticular tissue. Reticular tissue consists of an open framework of reticular fibers. These fibers are usually very difficult to see because of the large numbers of cells organized around them. LOCATIONS: Liver, kidney, spleen, lymph nodes, and bone marrow FUNCTIONS: Provides supporting framework Reticular tissue from liver Reticular fibers LM × 375
- 45. © 2012 Pearson Education, Inc. Connective Tissue Proper • Dense Regular Connective Tissue (details) • Location • Tendons, aponeuroses, ligaments • Elastic tissue • Function • Tendons: connect muscle to bone • Aponeuroses: connect muscle to muscle or covers entire muscle • Ligaments: connect bone to bone • Elastic: stabilizes the vertebrae • Deep fasciae: which surrounds the muscles. • Matrix • Fibers
- 46. © 2012 Pearson Education, Inc. Figure 3.15a Histology of Dense Connective Tissues Dense Regular Connective Tissue Tendon. The dense regular connective tissue in a tendon consists of densely packed, parallel bundles of collagen fibers. The fibrocyte nuclei can be seen flattened between the bundles. Most ligaments resemble tendons in their histological organization. LM × 440 Collagen fibers Fibrocyte nuclei LOCATIONS: Between skeletal muscles and skeleton (tendons and aponeuroses); between bones or stabilizing positions of internal organs (ligaments); covering skeletal muscles; deep fasciae FUNCTIONS: Provides firm attachment; conducts pull of muscles; reduces friction between muscles; stabilizes relative positions of bones
- 47. © 2012 Pearson Education, Inc. Figure 3.15b Histology of Dense Connective Tissues Elastic Tissue Elastic Ligament. Elastic ligaments extend between the vertebrae of the spinal column. The bundles of elastic fibers are fatter than the collagen fiber bundles of a tendon or typical ligament. LM × 887 Fibrocyte nuclei Elastic fibers LOCATIONS: Between vertebrae of the spinal column (ligamentum flavum and ligamentum nuchae); ligaments supporting penis; ligaments supporting transitional epithelia; in blood vessel walls FUNCTIONS: Stabilizes positions of vertebrae and penis; cushions shocks; permits expansion and contraction of organs
- 48. © 2012 Pearson Education, Inc. Connective Tissue Proper • Dense Irregular Connective Tissue (details) • Location • Nerve and muscle sheaths • Function • Provides strength • Matrix • Fibers
- 49. © 2012 Pearson Education, Inc. Figure 3.15c Histology of Dense Connective Tissues Dense Irregular Connective Tissue Deep Dermis. The deep portion of the dermis of the skin consists of a thick layer of interwoven collagen fibers oriented in various directions. LM × 111 Collagen fiber bundles FUNCTIONS: Provides strength to resist force applied from many directions; helps prevent overexpansion of organs such as the urinary bladder LOCATIONS: Capsules of visceral organs; periostea and perichondria; nerve and muscle sheaths; dermis
- 50. © 2012 Pearson Education, Inc. Fluid Connective Tissue • Blood (details) • Location: circulatory system • Erythrocytes • Transport oxygen and carbon dioxide • Leukocytes • Fight infections • Platelets • Blood clotting • Matrix • Liquid (plasma)
- 51. © 2012 Pearson Education, Inc. Figure 3.16 Formed Elements of the Blood Red blood cells White blood cells Platelets Red blood cells are responsible for the transport of oxygen (and, to a lesser degree, of carbon dioxide) in the blood. Red blood cells account for roughly half the volume of whole blood, and give blood its color. White blood cells, or leukocytes (LOO-ko-sıts; leuko-, white), help defend the body from infection and disease. Monocytes are related to the free macrophages in other tissues. Lymphocytes are relatively rare in the blood, but they are the dominant cell type in lymph. Eosinophils and neutrophils are phagocytes. Basophils promote inflammation much like mast cells in other connective tissues. Eosinophil Neutrophil Basophil The third type of formed element consists of membrane-enclosed packets of cytoplasm called platelets. These cell fragments function in the clotting response that seals leaks in diamaged or broken blood vessels.
- 52. © 2012 Pearson Education, Inc. Fluid Connective Tissue • Lymph (details) • Location • Lymphoid system • Lymphocytes • Develop into T cells and B cells (for example) • Function • Involved with the immune system
- 53. © 2012 Pearson Education, Inc. Supporting Connective Tissue • Supporting Connective Tissue • Cartilage and Bone • Provide a strong framework that supports rest of body
- 54. © 2012 Pearson Education, Inc. Supporting Connective Tissue • Cartilage • Types of Cartilage: • Hyaline cartilage: the most common type of cartilage. • Elastic cartilage • Fibrous cartilage
- 55. © 2012 Pearson Education, Inc. Figure 3.18a Histology of the Three Types of Cartilage Hyaline Cartilage Hyaline cartilage. Note the translucent matrix and the absence of prominent fibers. LOCATIONS: Between tips of ribs and bones of sternum; covering bone surfaces at synovial joints; supporting larynx (voice box), trachea, and bronchi; forming part of nasal septum FUNCTIONS: Provides stiff but somewhat flexible support; reduces friction between bony surfaces Chondrocytes in lacunae Matrix LM × 500
- 56. © 2012 Pearson Education, Inc. Figure 3.18b Histology of the Three Types of Cartilage Elastic Cartilage Elastic cartilage. The closely packed elastic fibers are visible between the chondrocytes. LM × 358 Chondrocyte in lacuna Elastic fibers in matrix LOCATIONS: Auricle of external ear; epiglottis; auditory canal; cuneiform cartilages of larynx FUNCTIONS: Provides support, but tolerates distortion without damage and returns to original shape
- 57. © 2012 Pearson Education, Inc. Figure 3.18c Histology of the Three Types of Cartilage Fibrous Cartilage Fibrous cartilage. The collagen fibers are extremely dense, and the chondrocytes are relatively far apart. LM × 400 Chondrocytes Fibrous matrix LOCATIONS: Pads within knee joint; between pubic bones of pelvis; intervertebral discs FUNCTIONS: Resists compression; prevents bone-to-bone contact; limits relative movement
- 58. © 2012 Pearson Education, Inc. Supporting Connective Tissue • Bone • Location • Skeletal system • Function • Support and strength • Matrix • Solid (lamellae)
- 59. © 2012 Pearson Education, Inc. Figure 3.19 Anatomy and Histological Organization of Bone Osteon Osteon LM × 375 Canaliculi Osteocytes in lacunae Matrix Central canal Blood vessels Fibrous layer Cellular layer Periosteum Periosteum Compact bone Compact bone Spongy bone Small vein (contained in central canal) Capillary Concentric lamellae
- 60. © 2012 Pearson Education, Inc. Membranes • Membranes • Epithelia and connective tissue combine to form membranes • Each membrane consists of: • Sheet of epithelial cells • An underlying connective tissue
- 61. © 2012 Pearson Education, Inc. Membranes • Mucous membrane: • Covers the cavities that open to exterior. • Lines digestive, respiratory, urinary and reproductive system. • Serous membrane: • Lines thoracic and abdominopelvic cavity. • Made of two leyers: • Parietal layer: lines inside surface of thoracic andabdominopelvic cavity. • Visceral layer: lines the outer surface of organs in the thoracic and abdominopelvic cavity. • Synovial membrane: • Lines the joints. • Cutaneous membrane: • Makes skin.
- 62. © 2012 Pearson Education, Inc. Figure 3.20a Membranes Mucous secretion Epithelium Lamina propria (areolar tissue) Mucous membranes are coated with the secretions of mucous glands. Mucous membranes line most of the digestive and respiratory tracts and portions of the urinary and reproductive tracts.
- 63. © 2012 Pearson Education, Inc. Figure 3.20b Membranes Transudate Mesothelium Areolar tissue Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities).
- 64. © 2012 Pearson Education, Inc. Figure 3.20c Membranes Epithelium Areolar tissue Dense irregular connective tissue The cutaneous membrane, the skin, covers the outer surface of the body.
- 65. © 2012 Pearson Education, Inc. Figure 3.20d Membranes Articular (hyaline) tissue Synovial fluid Capsule Capillary Adipocytes Areolar tissue Epithelium Bone Synovial membrane Synovial membranes line joint cavities and produce the fluid within the joint.
- 66. © 2012 Pearson Education, Inc. The Connective Tissue Framework of the Body • Connective tissue creates the internal framework of the body • Layers of connective tissue connect organs with the rest of the body • Layers of connective tissue are called fascia • Superficial fascia • Deep fascia • Subserous fascia
- 67. © 2012 Pearson Education, Inc. Figure 3.21 The Fasciae Connective Tissue Framework of Body Superficial Fascia Deep Fascia Subserous Fascia • Between skin and underlying organs • Areolar tissue and adipose tissue • Also known as subcutaneous layer or hypodermis • Forms a strong, fibrous internal framework • Dense connective tissue • Bound to capsules, tendons, ligaments, etc. • Between serous membranes and deep fascia • Areolar tissue Body cavity Rib Serous membrane Cutaneous membrane Skin Body wall
- 68. © 2012 Pearson Education, Inc. Muscle Tissue • Three types of muscle tissue • Skeletal muscle • Has striations • Smooth muscle • Ends of the cells are pointy • Cardiac muscle • Has intercalated discs
- 69. © 2012 Pearson Education, Inc. Muscle Tissue • Skeletal muscle • Muscles that move the skeleton • Voluntary control • Smooth muscle • Muscles that line the digestive tract, respiratory tract, and blood vessels • Involuntary control • Cardiac muscle • Found in the myometrium of the heart • Muscles cells that contract rhythmically
- 70. © 2012 Pearson Education, Inc. Figure 3.22a Histology of Muscle Tissue Skeletal Muscle Tissue Cells are long, cylindrical, striated, and multinucleate. LOCATIONS: Combined with connective tissues and neural tissue in skeletal muscles FUNCTIONS: Moves or stabilizes the position of the skeleton; guards entrances and exits to the digestive, respiratory, and urinary tracts; generates heat; protects internal organs Skeletal Muscle Fibers. Note the large fiber size, prominent banding pattern, multiple nuclei, and unbranched arrangement. Nuclei Muscle fiber Striations LM × 180
- 71. © 2012 Pearson Education, Inc. Figure 3.22c Histology of Muscle Tissue Smooth Muscle Tissue Cells are short, spindle-shaped, and nonstriated, with a single, central nucleus LOCATIONS: Found in the walls of blood vessels and in digestive, respiratory, urinary, and reproductive organs FUNCTIONS: Moves food, urine, and reproductive tract secretions; controls diameter of respiratory passageways; regulates diameter of blood vessels Smooth Muscle Cells. Smooth muscle cells are small and spindle shaped, with a central nucleus. They do not branch, and there are no striations. LM × 235 Nucleus Smooth muscle cell
- 72. © 2012 Pearson Education, Inc. Figure 3.22b Histology of Muscle Tissue Cardiac Muscle Tissue Nuclei Striations Cardiac muscle cells Intercalated discs Cells are short, branched, and striated, usually with a single nucleus; cells are interconnected by intercalated discs. LOCATION: Heart FUNCTIONS: Circulates blood; maintains blood (hydrostatic) pressure LM × 450 Cardiac Muscle Cells. Cardiac muscle cells differ from skeletal muscle fibers in three major ways: size (cardiac muscle cells are smaller), organization (cardiac muscle cells branch), and number of nuclei (a typical cardiac muscle cell has one centrally placed nucleus). Both contain actin and myosin filaments in an organized array that produces the striations seen in both types of muscle cell.
- 73. © 2012 Pearson Education, Inc. Neural Tissue • Neural Tissue • Specialized to conduct electrical signals through the body • Two types of neural cells • Neurons are the cells that actually transmit the impulse (electrical signals) • Neuroglia are the supporting cells of the neural tissue; these cells protect the neurons
- 74. © 2012 Pearson Education, Inc. Figure 3.23a Histology of Neural Tissue Brain Spinal cord Cell body Axon Nucleus of neuron Nucleolus Dendrites Diagrammatic view of a representative neuron
- 75. © 2012 Pearson Education, Inc. Figure 3.23b Histology of Neural Tissue Nuclei of neuroglia Cell body Nucleus of neuron Nucleolus Axon Dendrites Neuron cell body LM × 600 Histological view of a representative neuron
- 76. © 2012 Pearson Education, Inc. Tissues, Nutrition, and Aging • Repair and maintenance become less efficient as one ages • Hormonal changes and lifestyle changes also affect the functioning of tissues • Epithelia become thinner and connective tissues become fragile • Cardiac muscle cells and neural tissue cannot regenerate; therefore, relatively minor damage adds up over time, sometimes causing severe health issues