Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Connective Tissue II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper a. Loose/Areolar i. Elastic fibers ii. Reticular fibers b. Dense i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils SEM of mesenchymal stem cell. Steve Gschmeissner. V. Summary Lab 5 – Connective Tissue IUSM – 2016 Connective Tissue (CT) I. Introduction II. Learning Objectives 1. Forms the stroma of most organs, serving to connect III. Keywords and support the other primary tissue types. IV. Slides A. Types of Connective Tissue 2. Derived from embryonic mesenchyme. 1. Mesenchyme 3. Unlike the other tissue types which are composed 2. Connective Tissue Proper primarily of cells, CT consists of only a few dispersed, a. Loose/Areolar inconspicuous cells within a prominent extracellular i. Elastic fibers matrix (ECM). ii. Reticular fibers are the principal resident cells of b. Dense • Fibroblasts connective tissue, responsible for its synthesis and i. Irregular maintenance. ii. Regular 3. Specialized CT • ECM is tissue-specific and composed of protein a. Adipose fibers (collagen, reticular, and elastic) and ground b. Cartilage (Lab 6) substance (amorphous gel-like substance). c. Bone (Lab 6/7) 4. Function and classification of CT is primarily based d. Blood (Lab 8) upon the composition and organization of the B. Resident and Wandering Cells extracellular matrix and its functions. 1. Lymphocytes 2. Plasma cells 5. Within connective tissue, several types of cells, 3. Macrophages primarily leukocytes (white blood cells), can be found; some are long-lived in the tissue ( ) while 4. Mast cells resident cells others are transient and short-lived (wandering cells). 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction II. Learning Objectives III. Keywords Learning Objectives IV. Slides A. Types of Connective Tissue 1. Be able to identify the major types of connective tissue and 1. Mesenchyme understand how the structure of each reflects its function. 2. Connective Tissue Proper a. Loose/Areolar 2. Understand how to distinguish the various cells found in connective i. Elastic fibers tissue (fibroblasts, adipocytes, mast cells, plasma cells, macrophages, ii. Reticular fibers and undifferentiated mesenchymal cells) and to describe their b. Dense functions and key features. i. Irregular ii. Regular 3. Know the composition, morphology, and variations in distribution of 3. Specialized CT the ground substance and the three types of extracellular fibers and a. Adipose their functions. b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction II. Learning Objectives III. Keywords Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme Brown adipose tissue Loose/areolar CT 2. Connective Tissue Proper Collagen fibers Macrophages a. Loose/Areolar Connective tissue proper Mast cells i. Elastic fibers Dense irregular CT Mesenchyme ii. Reticular fibers Dense regular CT Plasma cells Elastin (elastic) fibers Reticulin (reticular) fibers b. Dense Fibroblasts White adipose tissue i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 91: Hamster Embryo, H&E II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper look here for a. Loose/Areolar mesenchyme i. Elastic fibers ii. Reticular fibers look here for b. Dense mesenchyme i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 91: Hamster Embryo, H&E II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper a. Loose/Areolar i. Elastic fibers mesenchyme ii. Reticular fibers b. Dense i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells mesenchyme, or primitive connective tissue, derives from embryonic mesoderm and gives rise to the various 5. Eosinophils connective tissues of the body; it contains spindle-shaped cells in an immature, loose extracellular matrix V. Summary (ECM) containing reticular fibers, collagen, and ground substance; in general, its appearance is best described as “very loose” connective tissue Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 40a (464): Lower Fetal Jaw, H&E II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue look here for 1. Mesenchyme mesenchyme 2. Connective Tissue Proper a. Loose/Areolar i. Elastic fibers ii. Reticular fibers b. Dense i. Irregular ii. Regular look here for 3. Specialized CT mesenchyme a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) tongue d. Blood (Lab 8) (with developing skeletal muscle) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 40a (464): Lower Fetal Jaw, H&E II. Learning Objectives III. Keywords Slide Overview IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper a. Loose/Areolar mesenchyme i. Elastic fibers ii. Reticular fibers b. Dense i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) skeletal c. Bone (Lab 6/7) muscle d. Blood (Lab 8) B. Resident and Wandering Cells developing 1. Lymphocytes bone 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 40a (464): Lower Fetal Jaw, H&E II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper a. Loose/Areolar spindle-shaped mesenchymal cell i. Elastic fibers ii. Reticular fibers b. Dense extracellular i. Irregular matrix fibers ii. Regular (reticular and collagen) 3. Specialized CT a. Adipose ground b. Cartilage (Lab 6) substance c. Bone (Lab 6/7) the “stuff” between d. Blood (Lab 8) the fibers and cells B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages 4. Mast cells 5. Eosinophils V. Summary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 36: Thin Skin, H&E II. Learning Objectives III. Keywords IV. Slides epithelium (epidermis) A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper (areolar l oose oose a. Loose/Areolar abundant i. Elastic fibers vasculature is CT ii. Reticular fibers usually seen in ) b. Dense loose CT, i. Irregular especially to dense ii. Regular support the 3. Specialized CT overlying irregular CT irregular a. Adipose epithelium b. Cartilage (Lab 6) which is avascular c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells loose (or areolar) CT has loosely arranged, thin protein fibers (primarily type I collagen) and abundant ground 3. Macrophages substance, with a relatively large number of cells embedded within it, as compared to the underlying dense CT; 4. Mast cells loose CT is usually found beneath epithelia and surrounding glands and vessels; notice the gradual transition 5. Eosinophils between the loose CT and the underlying dense irregular CT, making a distinct border between the two types of V. Summary tissue arbitrary Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 36: Thin Skin, H&E II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme 2. Connective Tissue Proper a. Loose/Areolar i. Elastic fibers what is this fibroblast ii. Reticular fibers pigmented b. Dense inclusion i. Irregular within these eosinophilic ii. Regular epithelial cells collagen 3. Specialized CT of the skin? protein fibers a. Adipose unstained spaces b. Cartilage (Lab 6) are composed of c. Bone (Lab 6/7) ground d. Blood (Lab 8) substance B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages the principal cells of connective tissue proper are fibroblasts which synthesize and maintain the ECM components (both the fibers and ground substance); they generally appear elongated with an ovoid, condensed 4. Mast cells nucleus with one or two nucleoli (if visible); their thin cytoplasmic processes not readily seen; however, they 5. Eosinophils may become “activated” and appear more ovoid with a more extensive basophilic cytoplasm (lots of rER) during V. Summary periods of growth or wound repair (note: the term fibrocyte is sometimes used to refer to “inactive” fibroblasts) Lab 5 – Connective Tissue IUSM – 2016 I. Introduction Slide 4a (464): Areolar Connective Tissue II. Learning Objectives III. Keywords IV. Slides A. Types of Connective Tissue 1. Mesenchyme collagen fiber 2. Connective Tissue Proper (thick) a. Loose/Areolar i. Elastic fibers fibroblast ii. Reticular fibers elastic fiber b. Dense (thin) i. Irregular ii. Regular 3. Specialized CT a. Adipose b. Cartilage (Lab 6) c. Bone (Lab 6/7) d. Blood (Lab 8) B. Resident and Wandering Cells 1. Lymphocytes 2. Plasma cells 3. Macrophages while collagen fibers provide strength to a tissue, elastic (or elastin) fibers are found interwoven in varying 4. Mast cells amounts in the ECM of most connective tissues providing stretch and recoil (e.g., in skin and lung); the fibers 5. Eosinophils are produced by fibroblasts or smooth muscle cells and are eosinophilic but are usually only seen with V.