Tissue PDF - Anatomy and Physiology Lecture Notes

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE #5: TISSUE PROFESSOR: Prof. Daisy Sucaldito 1ST SEMESTER | A.Y 2022-2023...

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE #5: TISSUE PROFESSOR: Prof. Daisy Sucaldito 1ST SEMESTER | A.Y 2022-2023 ○ Basal Surface - base of the cell; attached OBJECTIVES to the basement surface. I. Identify and describe the major types of tissues Basement membrane - attach the in the human body as well as their various epithelial cells to the underlying functions. tissues. It supports and guides II. List the structural and functional characteristics the cell mitigation during tissue of the different membranes of the body. repair. III. Describe the process of inflammation and explain why inflammation protects the body. Cell and matrix connections IV. Describe the major events involved in tissue Nonvascular no blood vessels repair. Capable of regeneration V. Describe the age-related changes that occur in tissues. TISSUE Group of cells with similar structure and function, plus the extracellular substance surrounding them. HISTOLOGY Study of Tissues TYPES OF TISSUES There are Four (4) tissue types in the human body; FUNCTIONS EPITHELIAL covering/lining Protects underlying structures COVERING OR LINING tissue Acts as a barrier. Permits passage of substances. Secretes substances. CONNECTIVE for organs· Absorption of substances. Diverse primary tissue type that makes up part of every organ in the body CLASSIFICATION OF EPITHELIA MUSCLE contraction and shortching · Classified primarily according to the number of cell layers and the shape of the superficial cells. A tissue that contracts or shortens, making movement possible ○ Cell Layers Simple · layer one NERVOUS - coordination and control Stratified than - more layer one Responsible for coordinating and controlling Pseudostratified -specialized simple many body activities ○ Cell Shapes- varies from degree of stretch EPITHELIAL TISSUE Squamous Covers and protects surfaces, both inside and Cuboidal outside the body. Columnar; or Special Transitional Shape Also known as Epithelium, or epithelial tissue SIMPLE SQUAMOUS EPITHELIUM Included under the classification of epithelial A single layer of thin flat cells. tissue are the exocrine and endocrine glands. Some substances easily pass through this thin layer of cells, but other substances do not. CHARACTERISTICS Example 1: The lungs’ simple Mostly composed of body cells squamous epithelium,allows for Covers body surfaces gas exchange. Distinct cell surfaces Example 2 : The kidneys, simple ○ Free (Apical) Surface - cells are exposed squamous epithelium, helps filter and not attached to other cells. wastes from the blood while ○ Lateral surface - cells are attached to keeping blood cells inside the other epithelial cells. blood vessels. MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 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. SIMPLE CUBOIDAL EPITHELIUM 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. STRATIFIED SQUAMOUS EPITHELIUM Forms a thick epithelium because it consists of several layers of cells. Two types: keratinized stratified squamous and nonkeratinized stratified squamous epithelia. ○ Keratinized stratified squamous - reduces the loss of water from the body ○ Nonkeratinized stratified squamous - provides protection against abrasion; acts as a mechanical barrier SIMPLE COLUMNAR EPITHELIUM 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. STRATIFIED CUBOIDAL EPITHELIUM Secretes mucus, which covers its free surface. ○ Consist more than one layer of cuboidal ○ Functions in absorption, secretion, and protection STRATIFIED COLUMNAR EPITHELIUM More than one layer; surface cells are columnar, but deeper cells are irregular ○ Carries out secretion, protection, and absorption MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 2  Transitional Epithelium ○ Special type of stratified epithelium that can be greatly stretched ○ Lines cavities that expand greatly ○ It protects underlying structures, like the urinary bladder Glands-made up of epithelial calls and connective tissues GLANDS FREE CELL SURFACES Glands are secretory organs that secrete Most epithelia have a free surface that is not substances onto a surface, into a cavity, or into the contact with other cells bloodstream. Can be smooth or lined with microvilli or cilia composed primarily of epithelium, with a supporting Cilia - move materials over the network of connective tissue. top of the cell Both the gland and its ducts are lined with Microvilli - increase surface area epithelium. ENDOCRINE GLANDS ductless · CELL CONNECTION are ductless glands; they secrete their products Cells have several structures that hold one cell to (termed hormones) into the bloodstream. one another or to the basement membrane. EXOCRINE GLANDS -may duct These structures do three things: mechanically Glands with ducts bind the cells together, help form a permeability barrier, and provide a mechanism for intercellular Most exocrine glands are multicellular, composed communication. of many cells. DESMOSOMES cell to cell - Some exocrine glands are composed of a single mechanical links that bind cells together. cell, like goblet cells, that secrete mucus. HEMIDESMOSOMES cell to basement membranc - Multicellular exocrine glands can be classified half desmosomes that anchor cells to the basement according to the structure of their ducts and membrane. secretory regions. ○ can also be classified according to how TIGHT JUNCTIONS products leave the cell prevent the passage of materials between epithelial cells because they completely surround each cell, Compound exocrine glands have similar to the way a belt surrounds the waist. multiple,branched ducts. (e.g mammary glands) ○ found in the lining of the intestines. - branched Simple glands have a single, non-branched duct, Materials that pass through the epithelial layer must some have branched ducts. (e.g sweat glands) pass through the cells, so those cells regulate what - unbranched materials can cross. Tubular Glands - glands with secretory regions shaped as tubules (small tubes) GAP JUNCTIONS acts · of conversation for cells as a means ○ can be straight or coiled small channels that allow small molecules and ions to pass from one epithelial cell to an adjacent one. Acinar or Alveolar- shaped in saclike structures Most epithelial cells are connected to one another Glands with a combination of the two are called by gap junctions, and researchers believe that tubuloacinar or tubuloalveolar. (e.g pancreatic molecules or ions moving through the gap junctions gland) act as communication signals to coordinate the activities of the cells. MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 3  EXOCRINE GLAND STRUCTURE 5.Cushioning and insulating example:adipose tissue responsible as an insulator 6.Transporting example:the blood suctioning a liquid connective tissue (the blood transport nutrients,oxygen,carbohydrates,hormone) 7.Protecting example:the bones can protect the body,ribs protecting lungs CONNECTIVE TISSUE CELLS The specialized cells that various connective tissues produce the extracellular matrix. The name of the cells identifies the cell functions, ↓ lasts - formation Osteoblasts from bone,osteocytes maintain it,and EXOCRINE GLAND AND SECRETION TYPES Cytes-maintenanceosteoclasts break it down. clasts-breakdown Fibroblasts are cells that form fibrous connective tissue and fibrocytes maintain it. Chondroblasts form cartilage and chondrocytes maintain it. CONNECTIVE TISSUE CELLS Found in connective tissue are cells associated with the immune system,such as white cells, Macrophages are large cells that are capable of moving about and ingesting foreign substances,including microorganism in the connective tissue. Merocrine secretion involves the release of secretory products by exocytosis. (e.g sweat, Mast cells are nonmotile cells that release and salivary glands) ↳ palabas chemicals,such as histamine,that promote inflammation, Apocrine secretion involves the release of secretory products as pinched-off fragments of EXTRACELLULAR MATRIX the gland cells. (e.g mammary gland) The extracellular matrix connective tissue has three major components:protein,fibers,around Holocrine secretion involves the shedding of substances and fluid. entire cells. (e.g sebaceous gland) MATRIX PROTEIN FIBERS CONNECTIVE TISSUE Three types of protein fibers collagen,reticular,and elastic-help form most Connective tissue Is a diverse primary tissue type connective tissues. that makes up part of every organ in the body. Connective tissue Differs From the other three Collagen fibers ,which resemble microscopic tissue types in that consists of cells separated robes,are very flexible but resist stretching from each other by abundant extracellular matrix Reticular fibers are very fine,short collagen fibers Connective tissue diverse in both structure and that branch to form a supporting network. function. Elastic fibers have the ability to return to their FUNCTION OF CONNECTIVE TISSUE original shape after being stretched or 1.Enclose and separate other tissues. compressed,giving tissue an elastic quality example: ligaments enclose with the connective tissue. 2.Connecting tissues to one another. MATRIX GROUND SUBSTANCES example:ligaments connecting one bone to another bone. The ground substance consists of non fibrous protein,other molecules,and is shapeless 3.Supporting and moving parts of the body. example:bone in the body supports the entire weight of the The structure of the matrix is responsible for the body and organs functional characteristics of connective tissues example:they enable bones and cartilage to bear 4.Storing compounds weight.\] example:bones stores calcium,minerals,phosphate TYPES OF CONNECTIVE TISSUES MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 4  Loose connective tissue consists of a lacy DENSE COLLAGENOUS CONNECTIVE TISSUE network,with numerous spaces filled with has an extracellular matrix consisting mostly of ground substance and fluid. collagen fibers. ○ Dense collagenous connective tissue Three subdivisions of loose connective tissue are having the collagen fibers oriented in areolar,adipose,and reticular. the same direction is termed dense regular, Areolar connective tissue primarily consists of Examples of dense regularity are collagen fibers and a few elastic fibers. tendons and ligaments. ○ The most common cells in loose connective tissue are the fibroblasts. Dense collagenous connective tissue having the collagen fibers oriented in the multiple direction Adipose tissue consists of adipocytes,or fat cells, is termed dense irregular. which contain large amounts of lipid for energy ○ Examples of dense irregular are in the storage, dermis of the skin and in organ ○ Adipose tissues pads and protects parts of capsules. the body and act as thermal insulators. 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. AREOLAR CONNECTIVE TISSUE 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 in the vocal cords. A genetic condition called Marfan syndrome results from,in part the inability to properly maintain and from elastic fibers TYPES OF CONNECTIVE TISSUE DENSE CONNECTIVE TISSUE has a relatively large number of protein fibers that form thick bundles and fill nearly all the CARTILAGE extracellular space. Composed of chondrocytes, located in spaces called LACUNAE within an extensive matrix. There are two major subcategories of dense connective tissue: collagenous and elastic. Collagen in the matrix gives cartilage flexibility and strength. MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 5  Provides support, but if bent or slightly compressed, it resumes its original shape. BONE A hard connective tissue that consists of living THREE TYPES OF CARTILAGE cells and mineralized matrix. OSTEOCYTES are located within lacunae. 1. HYALINE CARTILAGE - is the most abundant type of cartilage and has many functions, such as The strength and rigidity of the mineralized matrix covering the ends of bones, where they form enables bones to support and protect other tissues joints. and organs. TWO TYPES OF BONE SPONGY - has spaces between trabeculae or plates of bone therefore resembles a sponge. COMPACT - more solid, with almost no space between many thin layers of mineralized matrix. 2. FIBROCARTILAGE - has more collagen than does hyaline cartilage and is able to withstand compression and resist tearing or pulling. - found in the disks between the vertebrae (bones of the back) and in some joints, such as the knee and TEMPOROMANDIBULAR (JAW) JOINTS. BLOOD 3. ELASTIC CARTILAGE - contains elastic fibers in Is a liquid connective tissue. addition to collagen and proteoglycans (important to retain water that can be present in our Contains a liquid matrix, termed the plasma, cartilage). along with formed elements. - Elastic fibers appear as coiled fibers among Forming elements such as ERYTHROCYTES (red bundles of collagen fibers. blood cells), LEUKOCYTES (white blood cells) and PLATELETS (capable of blood clotting). - Elastic cartilage is able to recoil to its original shape when bent. Functions in transport of food, oxygen, waste, hormones, and other substances. - EXTERNAL EAR, EPIGLOTTIS, and AUDITORY TUBE contain elastic cartilage. MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 6  MUSCLE SMOOTH MUSCLE Forms the walls of hollow organs:found in the FUNCTION skin and eyes. Contract to, or shorten, making movement possible. Function such as, moving food through the digestive tract and emptying the urinary Muscle contraction results from contractile proteins bladder. located within the muscle cell. Tapered at each end and have a Three types of muscle tissue single nucleus, and not striated. Skeletal, cardiac and smooth. SKELETAL MUSCLES mechanical links that bind cells together. Attaches to the skeleton and enables the body to move. Striated, or banded because of the arrangement of contractile proteins within the cells. NERVOUS SYSTEM Forms the brain spinal cord and nerves. Responsible for coordinating and controlling. Neurons and support cells termed glial cells. ○ Neuron is responsible for conducting action potentials. ○ Composed of three parts: Cell body, dendrites, axon. CARDIAC MUSCLE.Muscles of the heart and responsible for pumping blood. Cylindrical but much shorter than skeletal muscle cells. Striated and usually have one nucleus per cell. Branched and connected to one another by intercalated discs. MENESES, M., PAREDES, J., PAREDES, S., PINO, R., PLURAD, N, QUIÑONES, M., RAMOS, A., REPE, A. | 1NU02 7