Basic Tissue - Chapter 8 PDF

1 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. CELL: Smallest living unit of organization: Epithelial cell, neuron, myofiber, chondrocyte, fibroblast, erythrocyte, ma...

1 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. CELL: Smallest living unit of organization: Epithelial cell, neuron, myofiber, chondrocyte, fibroblast, erythrocyte, macrophage, sperm TISSUE: Collection of similarly specialized cells: Epithelium, nervous tissue, muscle, cartilage, bone, blood ORGAN: Independent body part formed from tissue: Skin, brain, heart, liver SYSTEM: Organs functioning together: Central nervous system, respiratory system, immune system, cardiovascular system 2 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  3 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  4 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Epithelium is avascular ▪ Cellular nutrition is obtained by diffusion from the adjoining connective tissue ▪ It serves to protect ▪ The basement membrane is located between most epithelium and deeper connective tissue ▪ Produced by both the epithelium and the adjoining connective tissue. 5 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 7-5 6 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  7 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Epithelium can be classified into two main categories based on its arrangement into layers of cells: simple or stratified. ▪ The further classification of tissue involves different types of epithelial cells according to cellular shape ▪ simple squamous ▪ simple cuboidal ▪ simple columnar 8 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Simple epithelium consists of a single layer of epithelial cells. 9 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Simple squamous epithelium consists of flattened platelike epithelial cells, or squames, lining blood and lymphatic vessels, heart, and serous cavities as well as interfaces in the lungs and kidneys. Applegate EJ. The Anatomy and Physiology Learning System, ed 3. Elsevier, 2006 10 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Simple cuboidal epithelium consists of cube-shaped cells that line the ducts of various glands, such as certain ducts of the salivary glands. Simple columnar epithelium consists of rectangular or tall cells, such as in the lining of other salivary gland ducts, as well as the inner enamel epithelium, whose cells become enamel-forming ameloblasts. **Remember IEE from Chapter 6? Applegate EJ. The Anatomy and Physiology Learning System , ed 3. Elsevier, 2006 11 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Simple collumnar cells 12 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. PSEUDOSTRATIFIED COLUMNAR EPITHELIUM: NASAL CAVITY Figure 8-2 13 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  14 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  https://o.quizlet.com/2c7wxmpvd99UWxlJYD2oyQ_b.png Figure 8-7 Most epithelium in the body is stratified squamous epithelium, which includes the superficial layer of the skin and oral mucosa. Applegate EJ. The Anatomy and Physiology Learning System, ed 3. Elsevier, 2006 16 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Interdigitation of the outer epithelium with the deeper connective tissue, having a basement membrane between them, appears on two-dimensional microscopic section as the rete ridges (or rete pegs). Figure 8-7 17 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 8-1B 18 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The epidermis overlies a basement membrane and the adjoining deeper layers of connective tissue (dermis and hypodermis, respectively. ▪ The skin has varying degrees of keratinization depending on the region of the body. 19 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ As discussed earlier, the basement membrane is a thin, acellular structure always located between any form of epithelium and its underlying connective tissue, as noted in both the skin and oral mucosa. Figure 8-4 20 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 8-4 The basement membrane consists of two layers: basal lamina and reticular lamina. ▪ The superficial layer of the basement membrane is the basal lamina, which is produced by the epithelium. Figure 8-4 22 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The basal lamina consists of two sub- layers microscopically: lamina lucida is a clear layer that is closer to the epithelium, and lamina densa is a dense layer that is closer to the connective tissue. Figure 8-4 23 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The deeper layer of the basement membrane is usually the reticular lamina. ▪ It consists of collagen fibers and reticular fibers produced and secreted by the underlying connective tissue. Figure 8-4 24 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. SOMITES Figure 3-12 Connective tissue is derived from the somites during prenatal development. Differentiated mesoderm gives rise to the somites that will give rise to muscle tissue. Somites are located on the sides of the developing central nervous system. 25 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 8-5B A fibroblast is a type of cell that contributes to the formation of connective tissue 26 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Innermost layer of tissue. ▪ Lies beneath the epidermis and dermis Figure 8-7 27 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Adipose connective tissue is a fatty tissue that is found beneath the skin, around organs and various joints, and in regions of the oral cavity. National Center for Biotechnology, Accessed 2010 at http://www.ncbi.nlm.nih.gov/ 28 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Cartilage 29 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. CARTILAGE ▪ Cartilage is a firm, nonmineralized connective tissue that serves as a skeletal tissue in the body. Figure 8-8 30 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 19-3 31 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Chondroblasts, lie internal to the perichondrium and produce cartilage matrix. ▪ Chondrocytes, are mature chondroblasts that maintain the cartilage matrix. Figure 8-8 32 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Hyaline cartilage is the most common type found in the body and contains only collagen fibers as part of its matrix. Figure 8-8 33 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Cartilage can develop or grow in size in two ways: ▪ interstitial growth and appositional growth. ▪ Interstitial growth is growth from deep within the tissue by the mitosis of each chondrocyte, producing larger numbers of daughter cells within a single lacuna, each of which secretes more matrix, thus expanding the tissue. 34 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Because it has no vascularity of its own, cartilage takes longer to repair than does vascularized bone. ▪ Cartilage also has no nerve supply within its tissue. ▪ Thus cartilage, even when subjected to trauma or surgery, does not produce overly painful symptoms. 35 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Bone 36 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. BONE ▪ Bone is a rigid connective tissue that constitutes most of the mature skeleton. ▪ Thus bone protects and structurally supports soft tissue and also serves as an attachment mechanism. ▪ Bone aids in movement, manufactures blood cells by way of its red bone marrow, and is a storehouse for calcium and other minerals. Figure 8-9 37 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ When bone is examined grossly, the outer part of bone is covered by periosteum. ▪ Deep to the periosteum is a dense layer of compact bone. ▪ Deep to the compact bone is a spongy bone, or cancellous bone. Figure 8-9 38 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ On the innermost part of bone in the medullary cavity is the bone marrow. ▪ This gelatinous substance is where the stem cells of the blood are located and lymphocytes are created and B-cells mature. Figure 8-9 39 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Bone consists of cells and a partially mineralized matrix that is 50% inorganic (or mineralized) material. ▪ It is this inorganic substance in a crystalline formation of mainly calcium hydroxyapatite with the chemical formula of Ca10 (PO4)6(OH)2 that gives bone its hardness. ▪ This inorganic material has matrix packed between its bone cells. ▪ The matrix is composed of organic collagen fibers and intercellular substance. 40 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Bone matrix is initially formed as osteoid, which later undergoes mineralization. ▪ The osteoid is produced by osteoblasts, cuboidal cells that arise from fibroblasts. ▪ Osteoblasts are also involved in the later mineralization of osteoid to form bone. ▪ Always present in the periosteum is a layer of osteoblasts at the external surface of the compact bone to Figure 8-10 allow for the remodeling of bone and to allow repair of injured bone. 41 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Within fully mineralized bone are osteocytes, which are entrapped mature osteoblasts. Figure 8-10 42 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The cytoplasmic processes of the osteocyte radiate outward in all directions in the bone and are located in tubular canals of matrix, or canaliculi. ▪ These canals provide for interaction between the osteocytes. Figure 8-10 43 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Bone matrix in compact bone is formed into closely apposed sheets, or lamellae ▪ Contain osteocytes ▪ This highly organized arrangement of concentric lamellae form concentric layers of matrix into cylinders or osteons. ▪ The Haversian canal (or osteonic or central canal) is a central vascular canal within the each osteon, surrounded by the lamellae. Figure 8-11A 44 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  The osteon is the unit of structure in compact bone and consists of 5 to 20 lamellae. This arrangement in the osteon is similar to the growth rings in a cross section of a tree trunk. However, unlike tree rings that form at a rate of one per year, an entire Haversian system is produced all at the same time, no matter the number of concentric lamellae that may be involved. 45 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Nanci A. Ten Cate ’s Oral Histology, ed 7. Mosby, St. Louis, 2008 46 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Located on the outer part of the Haversian system in compact bone are Volkmann canals, or similar nutrient canals that contain the same vascular and nerve components as the Haversian canals, also Figure 8-11A lined by endosteum. 47 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Lamellae of the matrix of cancellous bone are not arranged into concentric layers around a central blood vessel as with the compact bone, but rather their concentric rings are formed into cone-shaped spicules. ▪ Osteocytes in lacunae with their cytoplasmic processes are located between the lamellae of the trabeculae. 48 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Development of Bone 49 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Bone development, or ossification, has two methods of development: intramembranous and endochondral ossification. ▪ The bone produced by these developmental methods is microscopically the same; only the process of formation is different. 50 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Intramembranous ossification is formation of osteoid between two dense connective tissue sheets, which then eventually replaces Figure 8-12 the outer connective tissue. 51 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The maxilla and the majority of the mandible are formed by intramembranous ossification. 52 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 8-13 53 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Appositional growth, with layered formation of bone along its periphery, is accomplished by the osteoblasts, which later become entrapped as Figure 8-10 osteocytes. 54 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The cell that causes resorption of bone is the osteoclast. ▪ It is a large multinucleated cell located on the surface of secondary bone in a large, shallow pit created by this resorption, Howship lacuna. Figure 8-15 55 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  NCI, Accessed 2010, at http://training.seer.cancer.gov/ RBC, Active Platelet, and Leukocyte 56 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ Skeletal muscles are also called striated muscles because the muscle cells appear striped microscopically. ▪ Each muscle is composed of numerous muscle bundles, or fascicles, which then are composed of numerous muscle cells or myofibers. 57 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 8-18 58 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ A nerve is a bundle of neural processes outside the central nervous system and in the peripheral nervous system. Figure 8-19 59 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The two functional types of nerves are afferent and efferent nerves. ▪ An afferent nerve, or sensory nerve, carries information or relays impulses from the periphery of the body to the brain (or spinal cord). ▪ An efferent nerve, or motor nerve, carries information away from the brain to the periphery of the body. 60 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. ▪ The nervous system has two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). ▪ These two parts are not separate but reliant on each other and thus constantly interacting. ▪ The CNS consists of the brain and spinal cord. ▪ The PNS consists of the spinal and cranial nerves and includes both the somatic and the autonomic nervous systems. 61 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.