MMS Histology Virtual Laboratory - Fall 2020 Directives: 1. Examine the virtual microscope slides on the LUMEN website: a. http://www.meddean.luc.edu/lumen/MedEd/Histo/virtualhistology.htm b. Please note that each slide can be scanned and zoomed – see Image Navigation Help. c. You will need to examine each slide under both low (-) and high power (+) to identify all structures for which you are responsible. 2. Most slides on the LUMEN site include a “Show description” which provides a brief description and/or guide to the section. 3. It is recommended that you study additional virtual specimens using the links below: a. http://www.histologyguide.com/slidebox/slidebox.html ****(very good resource) b. http://126.96.36.199/Histology/Basic%20Tissues/view.apml 4. For each slide: a. Identify the organ and tissues present, cell types, connective tissue and character of the extracellular matrix. b. Correlate structure of cells/tissue with function. 5. Use your class notes and text book to work through the sections. The Atlas part of each chapter will be especially helpful. October 14, 2020 Lab 1: Epithelium, Connective Tissue Proper, Blood Objectives: 1. Examine the slides listed below. Classify all epithelium and identify types of connective tissue. Identify cell types and connective tissue fibers/extracellular matrix where appropriate. a. Epithelium - http://zoomify.lumc.edu/epithelium/epithelium_main.htm Trachea #98 What type of epithelium lines the trachea? • Pseudostratified ciliated columnar epithelium (cilia – motility) Identify the different cell types. • LCT, DRCT, fibroblasts, basement membrane (thick in trachea) • Scattered goblet cells (secret mucus) and plasma cells Zoom in (+) to identify microvilli and cilia. Salivary Gland #117 and #118 #117 #118 What type of epithelium lines the duct system? • Simple cuboidal – both What types of secretions are made by these glands? • Mix of mucous (sublingual – low water content) and serous (parotid – high water content), as well as serous demilunes (caps - submandibular) – both What type of glands are present? • Compound tubuloacinar – both Esophagus #120 What type of epithelium lines the esophagus? • Stratified squamous Do all epithelial cells exhibit the same morphology? • No! The most superficial cells still contain visible, albeit, pyknotic nuclei and may retain some viability prior to their sloughing • Look more cuboidal as you go down the epithelium What type of glands are present? • Simple branched tubular Jejunum #130 What type of epithelium lines the jejunum? • Simple columnar Identify microvilli and villi • Microvilli – absorption What type of glands are present? • Simple tubular a. Identify a goblet cell (first picture) Be sure to examine the epithelium at the base of the glands. Goblet cell Mesentery DMS030 The mesentery is composed of what type of epithelium? • Simple squamous (pic from lab wasn’t great so I found another) Ureter #157 What type of epithelium lines the ureter? • Transitional (dome/umbrella cells) How does this particular epithelium change with alterations in volume? • Specialized for distension – cells flatten and “unfold” Thyroid #195 What type of epithelium lines the thyroid follicles? • Simple cuboidal What type of gland is this? • Endocrine (ductless) – glands that synthesize and secrete products, called hormones (thyroid hormone here), directly into the blood rather than through a duct b. Skin and Oral Cavity - http://zoomify.lumc.edu/skin/skin_main.htm i. Lip Sagittal #112 What are the two types of lining epithelium? • Keratinized (outer) and non-keratinized (inner) stratified squamous epithelium What glands are present? • Simple coiled tubular c. Connective Tissue Proper - http://zoomify.lumc.edu/connective/connective_main.htm i. Mesenchyme DMS051 Zoom in. Identify the features of mesenchyme. • Embryonic CT, undifferentiated CT, very cellular, sparse collagen and reticular fibers, high nuclear to cytoplasmic ratio, contains developing collagen ii. Areolar CT #12 Zoom in. What types of cells and CT fibers are present? • Loose CT • (purple) elastic fibers and (pale pink) collagen fibers • Relatively cellular (many “wandering” cells) with thin, sparse fibers • Abundant ground substance– site of inflammatory/immune response, ideal for diffusion iii. Tendon #16 Zoom in. What types of cells and CT fibers are present? • Dense regular CT, fibroblasts present, collagen bundles in parallel iv. Ileum #131 Zoom in. What types of cells and CT fibers are present? • Simple columnar epithelium w/ microvilli (absorption) Dense irregular CT (fibroblasts, collagen bundles) White adipose tissue v. Colon #135 Dense regular CT (fibroblasts, collagen bundles) LCT under basement membrane What type of connective tissue is present? • Dense regular CT and LCT • LCT What CT cells can be found? • Fibroblasts, collagen, plasma cells, goblet cells, some eosinophils Also note: simple columnar epithelium and simple tubular glands d. Blood and Capillaries - http://zoomify.lumc.edu/blood/blood_main.htm i. Blood smear – Wright stain DMS101 (see description!) What properties warrant the classification of blood as a “connective tissue”? • • Platelet (thrombocyte) Has ECM and different cell types; it’s a fluid CT Cells: RBCs (erythrocytes – 45%), WBCs – leukocytes (agranulocytes and granulocytes – WBC w/ secretory granules in cytoplasm – i.e. neutrophil, basophil, or eosinophil), and platelets (thrombocytes) What composes the matrix? • Plasma: liquid extracellular material that gives fluid properties to blood. Volume of cells and plasma in blood is 45-55% Zoom and scan for leukocytes. Identify them. What histological features distinguish the different types of leukocytes? RBC (erythrocyte) Eosinophil Neutrophil Monocyte Lymphocyte (small) Lymphocyte (large - activated) Basophil ii. See slide 63X @ http://virtualslides.med.umich.edu/histology/Cardiovascular%20System/Hematology%20Lab%2 0Normal1%2063X.svs/view.apml?X=0&Y=0&zoom=4.77038310412574 October 27, 2020 Lab 2: Bone and Cartilage Objectives: 1. Examine the slides listed below. Identify and classify all tissues, cell types and structures. a. Bone and Cartilage - http://zoomify.lumc.edu/bone/bone_main.htm i. Elastic cartilage #19, External Ear DMS056 Find the cartilage. What features designate it as “elastic” cartilage? Elastic cartilage is like hyaline cartilage except that the matrix also contains a dense network of branching and anastomosing elastic fibers. It provide support and is present in the outer ear and epiglottis. When stained with H&E, the elastic fibers are unstained. Elastic cartilage is in extracellular matrix and does not calcify. The perichondrium is a layer of dense irregular connective tissue that surrounds the cartilage. It is divided into 2 layers: 1) Outer fibrous layer-fibroblasts that produce the type I collagen on the outer surface of the perichondrium 2) the inner chondrogenic layer-contains mesenchymal cells that differentiate into chondroblasts, initiate matrix production (elastin and type II collagen) and become immature chondrocytes. What cell type is present in the cartilage? Chondrocytes- cells within lacunae inside the cartilage that occurs singularly or in clusters called isogenous groups What type of epithelium is on the outside? What other CT is present? Fibroblasts produce the type I collagen on the outer surface of the perichondrium. The perichondrium is the layer of dense irregular CT ii. Pubic Symphysis DMS066, Fibro-cartilage #20 Identify the cartilage. Compare and contrast to elastic and hyaline cartilage. Made of hyaline cartilage and fibrocartilage. x Identify an isogenous group. What other locations in the human body can you find fibrocartilage? iii. Trachea – transverse section LU095, Larynx DMS065 What type of cartilage is present? Tracheal cartilage & hyaline cartilage which is “C”-shaped (have chondrocytes) Hyaline cartilage Review the epithelium and glands. Respiratory epithelium- the trachea is lined with. Pseudostratified columnar epithelium with cilia and goblet cells (secrete mucus). Have sero-mucous glands that add moisture to air and aid in trapping contaminants. The cilia propel mucus towards the esophagus where it is swallowed. Sero-mucous glands iv. Bone #22, Bone #23 Identify the periosteum, endosteum and bone marrow. Outer surface: the periosteum covers the outside surface of all bones and consists of dense irregular connective tissue with collagen type I and fibroblasts (outer fibrous layer (pink, only fibroblasts), inner cellular layer (purple nuclei, osteoblasts, fibroblasts) ), periosteal cells, Sharpey’s fibers Inner surface: endosteum (osteoblasts, osteoclasts), endosteal cells, bone marrow Osteoblasts are cuboidal-columnar and are flattened with inactive- they make bone! Osteoclasts are giant multinucleated cells What cell types are present? Osteoprogenitor cellsdifferentiate into osteoblasts and can also form chondroblasts, adipocytes, and fibroblasts Dense irregular connective tissue v. Ground Bone #24 Identify an osteon, Haversian canal and the lamellae (interstitial, outer and inner circumferential). What cell type lines the Haversian canals? osteoblasts Identify an osteocyte. vi. Developing long bone DMS072 Identify all component features. Identify the endosteum and periosteum. vii. Endochondral Ossification - Fetal Finger #26, Ossification DMS068 Identify all cartilaginous and bony regions and all zones of epiphyseal cartilage. Find newly formed bone. What type of cartilage is present? Find perichondrium. November 3, 2020 Lab 3: Muscle and Nerve Objectives: 1. Examine the slides listed below. Identify and classify all tissues, cell types and structures. a. Muscle - http://zoomify.lumc.edu/muscle/muscle_main.htm i. Skeletal Muscle #46, #48, DMS076, DMS078 Be able to distinguish skeletal muscle from dense regular CT and peripheral nerve. Zoom in to identify Z lines, etc. ii. Heart #50, #54, DMS082 Identify the features that characterize this as cardiac muscle. iii. Smooth Muscle – Ileum #131 Distinguish smooth muscle from dense irregular CT and peripheral nerve. b. Nerve - http://zoomify.lumc.edu/neuro/neuro_main.htm i. Peripheral Nerve #57, #58, #60, DMS094 and DMS095 Identify the CT layers associated with peripheral nerve. Also, identify axons and myelin sheaths. Compare and contrast to dense regular CT, skeletal muscle and smooth muscle. ii. Dorsal root #62 + Spinal cord #75 Examine the gray and white matter of the spinal cord and dorsal root ganglion. What cell types are present in the dorsal root ganglion? iii. Spinal cord #76, DMS092 Zoom in to find neuronal cell bodies and primary dendrites. Identify Nissl substance, the cell nucleus and the nucleolus. Identify other cell types that are present. iv. Sympathetic ganglion #64, DMS093 Compare and contrast to dorsal root ganglion. What neuronal cell types are present?