Tissues - MT13 LAB - Chapter 3

CHAPTER III TISSUE: THE LIVING FABRIC DANIEL CHARLES C. LLENOS, RMT Institute of Clinical Laboratory Sciences Silliman University MT 13 – ANATOMY AND PHYSIOLOGY Tissue: The Living Fabric Tissues are a group of cells that are similar in structure and fu...

CHAPTER III TISSUE: THE LIVING FABRIC DANIEL CHARLES C. LLENOS, RMT Institute of Clinical Laboratory Sciences Silliman University MT 13 – ANATOMY AND PHYSIOLOGY Tissue: The Living Fabric Tissues are a group of cells that are similar in structure and function Four primary tissue types include: Epithelial tissue Connective tissue Nervous tissue Muscle Tissue MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 2 I. EPITHELIAL TISSUE (EPITHELIUM) The lining, covering, and glandular tissue of the body Covers all free body surfaces, both inside and out, and has versatile cells Functions: ▪ Protection – 1st line of defense in immunity ▪ Absorption – lining of stomach and small intestine ▪ Filtration – kidneys filter ▪ Secretion – glandular epithelium forms various glands, secrete sweat, oil, enzymes, mucus MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 3 I. EPITHELIAL TISSUE (EPITHELIUM) HALLMARK OF EPITHELIUM 1.) Special Contacts. Epithelial cells fit closely together to form continuous sheets (except for glandular epithelium) 2.) Polarity. Membranes always have one free (unattached) surface. o This apical surface is exposed to the body’s exterior or to the cavity of an internal organ o Some are smooth, some have microvilli or cilia MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 4 I. EPITHELIAL TISSUE (EPITHELIUM) Hallmark of Epithelium 3.) Supported by connective tissue. The anchored (basal) surface of epithelium rests on a basement membrane. 4.) Avascular but innervated. Epithelial tissues have no blood supply of their own (avascular) 5.) Regeneration. If well nourished, they regenerate themselves easily MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 5 I. EPITHELIAL TISSUE (EPITHELIUM) Classification of Epithelia Each epithelium is given two names: 1.) By cell arrangement ▪ Simple epithelium (one layer of cells) ▪ Stratified epithelium (more than one cell layer) 2. ) By the shape of its cells ▪ Squamous cells (flattened like fish scales, squam = scale) ▪ Cuboidal cells (cube-shaped like dice) ▪ Columnar cells (shaped like columns) MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 6 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 7 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 8 CLASSIFICATION OF EPITHELIA A. SIMPLE EPITHELIA is the most concerned with absorption, secretion, and filtration. Usually very thin, not used for protection. 1.) Simple Squamous Epithelium – forms membranes where filtration or exchange of substances by rapid diffusion occurs. ▪ Found in air sacs of the lungs (alveoli) – Oxygen and Carbon Dioxide exchange. ▪ Forms the walls of capillaries – nutrients and gases pass between the blood and capillaries and IF. ▪ Forms the serous membranes (serosae), the membranes that line the ventral body cavity and cover the organs in the cavity. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 9 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 10 A. SIMPLE EPITHELIA 2.) Simple Cuboidal Epithelium – common in glands and their associated small tubes (ducts) ▪ Seen in the salivary glands and pancreas. ▪ Forms the walls of the kidney tubules ▪ Covers the surface of the ovaries MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 11 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 12 A. SIMPLE EPITHELIA 3.) Simple Columnar Epithelium – lines the entire length of the digestive tract from the stomach to the anus. Mainly functions in absorption and secretion. ▪ Goblet cells are seen in this type of epithelium (produce a lubricating mucus) ▪ Epithelial membranes that line body cavities open to the body exterior are called mucosae/ mucous membrane. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 13 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 14 A. SIMPLE EPITHELIA 4.) Pseudostratified Columnar Epithelium – all cells of this classification rest on a basement membrane. ▪ However, some of its cells are shorter than others, and nuclei appear at different heights above the basement membrane. ▪ Mainly functions in absorption and secretion Variation: Pseudostratified ciliated columnar epithelium, lines most of the respiratory tract o Goblet cells produce mucus that serves as a sticky trap, while cilia propel mucus upward away from the lungs. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 15 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 16 CLASSIFICATION OF EPITHELIA B. STRATIFIED EPITHELIA consists of two or more cell layers. Function primarily in protection. 1.) Stratified Squamous Epithelium – the most common stratified epithelium in the body. The cells at the free edge are squamous cells, while those at the basement membrane are cuboidal or columnar. ▪ Found in sites that receive a good deal of abuse or friction ▪ Examples: Surface of the skin, the mouth, and the esophagus MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 17 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 18 B. STRATIFIED EPITHELIA 2.) Stratified Cuboidal and Stratified Columnar Epithelia – protection and limited secretion/absorption. Both are rare in the human body. Found mainly in ducts of large glands. ▪ Stratified cuboidal epithelium – typically just two cell layers with (at least) the surface cells being cuboidal in shape. o Found in ducts of adult sweat glands and esophageal gland, and part of male urethra. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 19 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 20 B. STRATIFIED EPITHELIA 2.) Stratified Cuboidal and Stratified Columnar Epithelia – protection and limited secretion/absorption. Both are rare in the human body. Found mainly in ducts of large glands. ▪ Stratified columnar epithelium – the surface cells are typically columnar cells, but its basal cells vary in size and shape. o Lines part of urethra, large excretory ducts of glands, small areas in anal mucous membrane, and part of the conjunctiva of the eye MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 21 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 22 B. STRATIFIED EPITHELIA 3.) Transitional Epithelium – highly modified, stratified squamous epithelium; forms the lining of only a few organs – Urinary bladder, the ureters, and part of the urethra. All these organs are subject to considerable stretching. ▪ Organ is not stretched: o The membrane is many-layers o Superficial cells are rounded and domelike ▪ Organ is distended with urine o Epithelium thins like a rubber band o Surface cells flatten and become squamous like MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 23 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 24 CLASSIFICATION OF EPITHELIA C. GLANDULAR EPITHELIUM a gland consists of one or more cells that make and secrete a particular product. This product (a secretion) contains protein molecules in an aqueous (water-based) fluid. Secretion – can also indicate an active process in which glandular cells obtain needed materials from the blood and use them to make their products, which they then discharge by exocytosis. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 25 C. GLANDULAR EPITHELIUM TYPES OF GLANDS 1. Endocrine Gland – lose their ducts (ductless); their secretions (all hormones) diffuse DIRECTLY into the blood vessels that weave through the glands. ▪ Example: Thyroid gland, Adrenals, Pituitary Gland MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 26 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 27 C. GLANDULAR EPITHELIUM TYPES OF GLANDS 2.) Exocrine Gland – retain their ducts, and their secretions exit through the ducts to the epithelial surface. Functions both internally and externally. ▪ Example: Sweat and oil glands, liver, and pancreas MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 28 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 29 II. CONNECTIVE TISSUE ▪ Most abundant and widely distributed of the tissue types ▪ Connects body parts. Found everywhere in the body. ▪ Functions are primarily involved in protecting, supporting, and binding together other body tissues. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 30 II. CONNECTIVE TISSUE HALLMARKS OF CONNECTIVE TISSUE 1.) Common origin - all are from embryonic tissue, mesenchyme 2.) Variation in blood supply – MOST connective tissue are well vascularized Exceptions: Tendons and ligaments (poor blood supply), and cartilages (avascular) 3.) Extracellular Matrix – in addition to the many different types of cells, connective tissue is also made up of varying amounts of nonliving substances found outside of the cells – extracellular matrix MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 31 II. CONNECTIVE TISSUE Two Main Elements of the Extracellular Matrix Ground Substance – composed largely of water plus some cell adhesion proteins and charged polysaccharides. o Cell Adhesion proteins – allows connective tissue to attach themselves to the matrix fibers o Charged polysaccharide – trap water as they intertwine Fibers – various types and amounts of fibers contribute to the matrix o Collagen (white) fibers – high tensile strength o Elastic (yellow) fibers – ability to stretch and recoil o Reticular fibers – form the internal skeleton of soft organs (e.g. spleen) MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 32 TYPES OF CONNECTIVE TISSUE A. BONE (“OSSEOUS TISSUE”) ▪ Major Cell Type: Osteocytes (bone cells) sitting in cavities called lacunae (“pits”) o Lacunae are surrounded by layers of a very hard matrix that contains calcium salts in addition to large numbers of collagen fibers. ▪ Main function: Protection and support other body organs (e.g., skull protects the brain) MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 33 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 34 TYPES OF CONNECTIVE TISSUE B. CARTILAGE ▪ Less hard and more flexible than bone. Found in only a few places. ▪ Major cell type: Chondrocytes (cartilage cells). TYPES OF CARTILAGE 1.) Hyaline cartilage – most seen type, has abundant collagen fibers hidden by a rubber matrix with a glassy (hyalin = glass), blue-white appearance. Location: Forms trachea (windpipe), attaches to ribs to the breastbone, covers bone ends at joints, embryonic and fetal skeleton. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 35 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 36 B. TYPES OF CARTILAGE 2.) Fibrocartilage – highly compressible, forms the cushion-like disks between the vertebrae of the spinal column. Also found in menisci (cartilage pads) of knees & portions of tendons. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 37 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 38 B. TYPES OF CARTILAGE 3.) Elastic Cartilage – found in structures with elasticity, such as the external ear (auricle). Also found in Auditory (eustachian) tubes and lid on top of larynx (epiglottis). MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 39 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 40 TYPES OF CONNECTIVE TISSUE C. DENSE CONNECTIVE TISSUE 1.) Dense Regular Fibrous Tissue ▪ Collagen fibers are the main matrix element. ▪ Crowded between the collagen fibers are rows of fibroblast ▪ Form strong, rope-like structures such as tendons and ligaments (withstand tension in one direction). o Tendons attach skeletal muscles to bones. o Ligaments connect bones to bones at joints. o Aponeuroses attach muscle to muscle or muscle to bone. Sheetlike tendons. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 41 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 42 TYPES OF CONNECTIVE TISSUE C. DENSE CONNECTIVE TISSUE 2) Dense irregular Connective tissue ▪ Location: Fasciae (tissue beneath skin and around muscles and other organs), reticular (deeper) region of dermis of skin, periosteum of bone, perichondrium of cartilage, joint capsules, membrane capsules around various organs (kidneys, liver, testes, lymph nodes), pericardium of the heart, and heart valves. ▪ Arranged in sheets and withstands tension in many directions. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 43 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 44 TYPES OF CONNECTIVE TISSUE D. LOOSE CONNECTIVE TISSUE are softer and have more cells and fewer fibers than any other connective tissue type except blood. TYPES OF LOOSE CONNECTIVE TISSUE 1.) Areolar Connective Tissue 2.) Adipose Connective Tissue 3.) Reticular Connective Tissue MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 45 D. LOOSE CONNECTIVE TISSUE 1.) Areolar Connective Tissue ▪ Most widely distributed connective tissue variety in the body ▪ Soft, pliable, “cobwebby” tissue that cushions and protects the body organs it wraps. ▪ It functions as universal packing tissue and connective tissue “glue” because it helps to hold the internal organs together and in their proper positions. ▪ Note: A soft layer of areolar connective tissue (lamina propria) underlies all mucous membranes. ▪ The matrix contains all types of fibers, which form a loose network. o Matrix appears to be empty space (hence, “areola” = small open space). MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 46 D. LOOSE CONNECTIVE TISSUE 1.) Areolar Connective Tissue ▪ Function: Provides a reservoir of water and salts for the surrounding tissues, and essentially all body cells obtain their nutrients from and release their wastes into this “tissue fluid”. ▪ Many types of phagocytes wander through this tissue. ▪ Pathology: When a body region is inflamed, the local areolar tissue soaks up the excess fluid like a sponge, and the area swells and becomes puffy, a condition called edema. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 47 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 48 D. LOOSE CONNECTIVE TISSUE 2.) Adipose Connective Tissue (“Fat”) ▪ A type of areolar tissue in which adipose cells predominate. ▪ A droplet of oil occupies most of a fat cell’s volume and compresses the nucleus, displacing it to one side. ▪ Forms the subcutaneous tissue beneath the skin. o Insulates the body and protects it from bumps and extremes of both heat and cold. ▪ Fat “depots” also exist in the body (hips, breasts, belly) where fat is stored and available for fuel. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 49 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 50 D. LOOSE CONNECTIVE TISSUE 3.) Reticular Connective Tissue ▪ Consists of a delicate network of interwoven reticular fibers associated with reticular cells (resemble fibroblasts) ▪ Limited to certain sites; forms the stroma (“bed” or mattress), or the internal framework of an organ. ▪ Binds together smooth muscle tissue cells. o Support many free blood cells (largely WBC called lymphocytes), in lymphoid organs such as lymph nodes, the spleen, and bone marrow. o Filters and removes worn-out blood cells (spleen) and Microbes (lymph nodes) MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 51 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 52 TYPES OF CONNECTIVE TISSUE E. BLOOD (“VASCULAR TISSUE”) ▪ Considered to be a connective tissue because it consists of blood cells surrounded by a non-living, fluid matrix (Blood Plasma). o The fibers of blood are soluble proteins. ▪ An atypical connective tissue. ▪ Function: transport vehicle for the cardiovascular system, carrying nutrients, wastes, respiratory gases, white blood cells, and many other substances throughout the body. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 53 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 54 III. MUSCLE TISSUE ▪ Highly specialized to contract, or shorten, which generates the force required to produce movement. ▪ To contract, muscle must be irritable – able to respond to stimuli. TYPES OF MUSCLE TISSUE 1.) Skeletal Muscle Tissue 2.) Cardiac Muscle Tissue 3.) Smooth Muscle Tissue MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 55 TYPES OF MUSCLE TISSUE 1.) Skeletal Muscle Tissue ▪ These muscles can be controlled voluntarily (consciously) ▪ These skeletal muscles form the flesh of the body ▪ When they contract, they pull on bones or skin. As a result, there is gross body movement. ▪ Cell characteristic: long, cylindrical, multinucleate, have obvious striations (stripes) MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 56 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 57 TYPES OF MUSCLE TISSUE 2.) Cardiac Muscle ▪ Found ONLY in the heart wall. ▪ As it contracts, the heart pumps to propel blood through the vessels ▪ Cell characteristics: Striated, but only have a single nucleus, and is relatively shorter. They are branching cells that fit tightly together (“clasped fingers”) at junctions called intercalated discs. ▪ Involuntary control MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 58 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 59 TYPES OF MUSCLE TISSUE 3.) Smooth (Visceral) Muscle ▪ Cell Characteristics: No Striations are visible. Single nucleus and are tapered at both ends. ▪ Found in the walls of hollow organs such as stomach, uterus, and blood vessels. ▪ As they contact, the cavity of an organ alternately becomes smaller (constricts when smooth muscle contracts) or enlarges (dilates when smooth muscle relaxes) so that substances are mixed/and or propelled through the organ along a specific pathway. ▪ Contractions are longer and slower compared to the other two types. ▪ Peristalsis, a wavelike motion that keeps food moving through the small intestine. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 60 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 61 IV. NERVOUS TISSUE Cell composition: Neuron and Neuroglia. 1.) Neurons receive and send electrochemical impulses from one part of the body to another. ▪ Major Functions: Irritability and Conductivity ▪ Neurons have a unique structure: o Cytoplasm is drawn out into long processes (extensions) as long as 3 feet or more in the leg. o This long process allows a SINGLE NEURON to conduct an impulse to distant body locations. 2.) Neuroglia is a special group of supporting cells. o Insulate, support, and protect the delicate neurons in the structures of the nervous system. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 62 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 63 MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 64 REFERENCES ▪ Marieb E.N & Keller S.M. (2022). Essentials of Human Anatomy and Physiology, Thirteenth Edition. England, United Kingdom: Pearson Education Limited. ▪ Marieb E.N. & Keller S.M. (2018). Essentials of Human Anatomy and Physiology, Twelfth Edition. England, United Kingdom: Pearson Education Limited. ▪ Marieb E.N & Jackson P.B. (2018). Essentials of Human Anatomy and Physiology Laboratory Manual, Seventh Edition. Singapore: Pearson Education South Asia Pte Ltd. ▪ Tortora G.J. & Derrickson B. (2009). Principles of Anatomy and Physiology, Twelfth Edition. New Jersey, U.S: John Wiley & Sons, Inc. MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 65 END OF DISCUSSION For inquiries: [email protected] MT 13 ANATOMY AND PHYSIOLOGY I DCC-LLENOS 66