Activity 5 Post Lab - Animal Tissues PDF

ACTIVITY 5 ANIMAL TISSUES: EPITHELIAL AND CONNECTIVE FARivera 1 Objectives 1. Describe the microscopic structure of the specific types of epithelial and connective tissue. 2. Describe the basic functions of the epithelial and connective tissues. 3...

ACTIVITY 5 ANIMAL TISSUES: EPITHELIAL AND CONNECTIVE FARivera 1 Objectives 1. Describe the microscopic structure of the specific types of epithelial and connective tissue. 2. Describe the basic functions of the epithelial and connective tissues. 3. Identify the major locations where each epithelial and connective tissue is found. FARivera 2 EPITHELIAL TISSUE Found in different areas Cells fit closely together Body coverings Tissue layer always has one free surface Body linings The lower surface is bound by a Glandular tissue basement membrane Functions Avascular (have no blood supply) Protection Regenerate easily if well Absorption nourished Filtration Secretion FARivera 3 EPITHELIAL TISSUE FARivera Number of cell layers Simple – one layer Stratified – more than one layer Shape of cells 4  Squamous – flattened Cuboidal – cube-shaped Columnar – column-like 4 EPITHELIAL TISSUE FARivera 5 EPITHELIAL TISSUE FARivera 6 EPITHELIAL TISSUE 1. X-S Human Artery 2. X-S Renal (Kidney) Tubules 3. X-S Duodenum 4. X-S Trachea 5. X-S Esophagus 6. X-S Human palm skin 7. X-S Urinary bladder FARivera 7  Type of Epithelium: Simple Squamous Epithelium Function: Diffusion Artery Medium, X.S. FARivera LPO, 100x 8  Type of Epithelium: Simple Cuboidal Epithelium Functions: Filtration, Human Kidney, X.S. (Renal Tubules) FARivera diffusion HPO, 400X HPO 9  Type of Epithelium: Simple Columnar Epithelium Functions: absorption, Human Duodenum X.S. FARivera secretion LPO, 100X 10  Type of Epithelium: Simple Columnar Epithelium Functions: absorption, Human Duodenum X.S. FARivera secretion HPO, 400X HPO-2 11  Type of Epithelium: Pseudostratified, ciliated Functions: Secretion, cilia moves mucus Human Trachea, X.S. FARivera HPO, 400X HPO 12  Type of Epithelium: Stratified squamous epithelium, non-keratinized Function: protection against Esophagus, X.S. HPO, 400x FARivera abrasion HPO 13  Type of Epithelium: Stratified squamous, keratinized Function: Protection Human Palm Skin, X.S. FARivera LPO, 100x LPO 14  Type of Epithelium: Stratified squamous, keratinized Function: Protection Human Palm Skin, X.S. FARivera HPO, 400x HPO 15 Urinary Bladder, X.S. Urinary Bladder, X.S. FARivera SO, 40x LPO, 100x 16  Type of Epithelium: Transitional epithelium Function: Distention Urinary Bladder, X.S. FARivera HPO, 400x Transitional epithelium: without distention (relaxed), the cells appear cuboidal-shaped when distended (tensed), the cells appear squamous-shaped Other organs with transitional epithelium Male Urethra: 1.Pre-prostatic urethra - transitional epithelium (urothelium) 2. Prostatic urethra -glandular and stromal tissue of the periurethral zone of the prostate 3. Membranous urethra - changes into pseudostratified columnar epithelium 4. Spongy urethra - Pseudostratified columnar epithelium except for the terminal portion which is stratified squamous epithelium Female urethra: Looks like stratified cuboidal when not stretched and stratified squamous when stretched 17 CONNECTIVE TISSUE Found everywhere in the body Variations in blood supply Includes the most abundant Some tissue types are well and widely distributed tissues vascularized Functions Some have poor blood supply or are avascular Binds body tissues together Extracellular matrix Supports the body Non-living material that Provides protection surrounds living cells FARivera 18 CONNECTIVE TISSUE FARivera 19 COMPONENTS OF THE CONNECTIVE TISSUE Two main elements Ground substance – mostly water along with adhesion proteins and polysaccharide molecules Fibers Produced by the cells Three types Collagen fibers Elastic fibers Reticular fibers FARivera Fixed Cells: Production & maintenance of extracellular matrix. Free (wandering)Cells: Tissue reaction to injury or invasion of microorganisms Ground substance is primarily composed of water and large organic molecules, such as glycosaminoglycans (GAGs), proteoglycans, and glycoproteins. GAGs are polysaccharides that trap water, giving the ground substance a gel-like texture. 20 COMPONENTS OF THE CONNECTIVE TISSUE FARivera Fixed Cells: Production & maintenance of extracellular matrix. Free (wandering)Cells: Tissue reaction to injury or invasion of microorganisms Ground substance is primarily composed of water and large organic molecules, such as glycosaminoglycans (GAGs), proteoglycans, and glycoproteins. GAGs are polysaccharides that trap water, giving the ground substance a gel-like texture. 21 COMPONENTS OF THE CONNECTIVE TISSUE FARivera Fixed Cells: Production & maintenance of extracellular matrix. Free (wandering)Cells: Tissue reaction to injury or invasion of microorganisms Ground substance is primarily composed of water and large organic molecules, such as glycosaminoglycans (GAGs), proteoglycans, and glycoproteins. GAGs are polysaccharides that trap water, giving the ground substance a gel-like texture. 22 CONNECTIVE TISSUE A. Loose Connective Tissue a.1. Areolar connective tissue a.2. Adipose connective tissue a.3 Reticular connective tissue FARivera 23  Fibroblast nucleus Fibers: Collagen (thicker) Elastic (thinner) Functions: strength, elasticity, support Areolar Connective Tissue HPO, 400X FARivera Fibroblast – cell that synthesizes ECM and collagen, forms the structural framework of tissues and plays an important role in tissue repair - in and around nearly every body structure (thus, called “packing material” of the body) - most widely distributed type of CT - soft and pliable tissues - contains all fiber types - particularly found in: subcutaneous layer deep to skin papillary (superficial) region of dermis of skin lamina propria of mucous membranes around blood vessels, nerves, and body organs 24  Adipocytes Functions: Reduce heat loss (skin), energy reserve, supports and Adipose Connective Tissue FARivera protects organs HPO, 400x Adipocytes contain large lipid deposits (fat droplet) Location: subcutaneous layer deep to skin, around heart and kidneys, yellow bone marrow, padding around joints and behind eyeball in eye socket 25  Reticular fibers Functions: binding (smooth muscle tissue cells), forms stroma of organs, filtration Mammal Reticular Tissue FARivera HPO, 400x Reticular connective tissue Delicate network of interwoven fibers Forms stroma (internal supporting network) of lymphoid organs 26  Lymph nodes Spleen Bone marrow 26 CONNECTIVE TISSUE B. Dense Connective Tissue b.1. Dense regular (tendon) b.2. Dense irregular (human dermis) FARivera 27  Collagen fibers Fibroblast Functions: attachment, withstand tension Human Tendon FARivera HPO, 400x Dense regular The collagen fibers are oriented in the same direction Main matrix element is collagen fibers Cells are fibroblasts Examples: Tendon – attach muscle to bone Ligaments – attach bone to bone 28  Collagen fibers Functions: provides tensile strength Human Dermis FARivera HPO, 400x Dense irregular The collagen fibers are oriented in many directions This type of connective tissue is found mostly in the reticular layer (or deep layer) of the dermis. 29 CONNECTIVE TISSUE C. Supporting Connective Tissue c.1. Elastic cartilage c.2. Hyaline cartilage c.3. Fibrocartilage c.4. x-s of the human bone FARivera 30  Chondrocyte Functions: allows stretching, support Elastic Cartilage FARivera LPO, 100x Strong and can recoil to original shape after being stretched. Elastic cartilage Provides elasticity Example: supports the external ear 31  Chondrocyte in a lacuna Elastic fibers in matrix Elastic Cartilage FARivera HPO, 400x Chondrocytes – cells of mature cartilage Lacunae – spaces Matrix- gelatinous ground substance 32  Chondrocyte in a lacuna Ground substance Functions: movement, Hyaline Cartilage flexibility, support FARivera HPO, 400x Hyaline cartilage Most common cartilage Composed of: Abundant collagen fibers Rubbery matrix Contains a resilient gel as 33  ground substance Example: Entire fetal skeleton is hyaline cartilage sternal ends of the ribs, in the larynx, trachea, and bronchi, and on the articulating surfaces of bones 33  Collagen fibers in ground substance Chondrocyte in a lacuna Functions: support and joining structures Fibrocartilage HPO, 400x FARivera together Fibrocartilage Highly compressible Has thick bundles of collagen fibers. Strength and rigidity make it the strongest type of cartilage. 34  Example: forms cushion- like discs between vertebrae 34  Haversian canal Haversian System (Osteon) Osteocyte in a lacuna Lamellae Functions: support, protection, Human Bone Decalcified, X.S. HPO, 400x FARivera storage Bone (osseous tissue) Composed of: Bone cells in lacunae (cavities) Hard matrix of calcium salts 35  Large numbers of collagen fibers Used to protect and support the body Haversian canal/Osteonic canal/Central canal – contains blood vessels and nerves Osteocyte – mature bone cells Lacuna – houses the osteocytes Lamellae – concentric rings of extracellular matrix that consist of mineral salts (mostly Ca and phosphates), which gives bone its hardness and compressive strength Haversian system/Osteon: composed of the Haversian canal, osteocyte in a lacuna, and the lamellae 35 CONNECTIVE TISSUE D. Vascular (Fluid) Connective Tissue d.1 Human blood smear FARivera 36  Red blood cells (RBCs) White blood cell (WBC) Platelets Human Blood Smear FARivera HPO, 400x Blood Blood cells surrounded by fluid matrix Red blood cells (Erythrocytes) RBCs are biconcave cells without nucleus in humans; also known as erythrocytes. RBCs contain the iron-rich protein called hemoglobin; give blood its red color. RBCs are the most copious blood cells produced in bone marrows. Their main function is to transport oxygen from and to various tissues and organs. White blood cells (Leucocytes) 37 Leucocytes are colorless blood cells. They are colorless because it is devoid of hemoglobin. They are further classified as granulocytes and agranulocytes. WBCs mainly contribute to immunity and defense mechanism. Platelets (Thrombocytes) Thrombocytes are specialized blood cells produced from bone marrow. Platelets come into play when there is bleeding or hemorrhage. They help in clotting and coagulation of blood. Platelets help in coagulation during a cut or wound. 37 ENRICHMENT QUESTIONS FARivera 38 ENRICHMENT QUESTIONS 1. Differentiate epithelial from connective tissue proper in terms of the following: definition, embryonic origin, basal membrane, number of cell layers, vascularization, general function. Tabulate your answer. Answers may vary. FARivera 39 FARivera 40 FARivera 41 2. Briefly describe one recent advancement in tissue engineering and regenerative medicine. Answers may vary. a. Hydrogel Engineering - use of hydrogels (polymeric materials) that mimic the native tissue environment, providing a supportive matrix for cell growth and integration b. 3D Bioprinting - allow the precise placement of cells and biomaterials to create complex tissue structures FARivera 42 2. Briefly describe one recent advancement in tissue engineering and regenerative medicine. c. Stem Cell application - enables the regeneration of tissues through the use of mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs) - innovations in cell-based therapies involve encapsulating these cells within biomaterials or utilizing MSC-derived exosomes to enhance tissue repair processes FARivera 43