Medical School Histology Basics Connective Tissue VIBS 289 Mast cell Macrophage Fibroblasts Fibroblasts Plasma cell Fat cells Larry Johnson Texas A&M University

Function of Connective Tissue The histological glue which binds the other tissues together to form organs Mechanical support - stroma below epithelium, skeleton Metabolite exchange - vascular beds Energy storage - adipose tissue Inflammation - site of action for blood borne immune cells skin Slide 109 Plasma cells 140

Distinguishing features and histological identification Loose connective tissue – sparse collagen and elastic fibers, plentiful cells including fibroblasts, leukocytes Dense connective tissue – concentrated collagen, few cells Cartilage – avascular homogeneous matrix of collagen and protein-polysaccharides with few cells Bone – calcified collagen matrix with few cells trapped in the caves of bone Cartilage Epithelium Bone Loose connective tissue Dense connective tissue

SKIN Dense irregular connective tissue (few cells and lots of fibers) Loose connective tissue (lots of cells and few fibers)

Slide 109: Skin, hand, monkey Irregular connective tissue, dense surface region and loose subdermal region Adipose cells, Location of a high density of collagen fibers Loose connective tissue Dense irregular connective tissue

Slide 109: Skin, hand, monkey Dense Irregular connective tissue Collagen fibers in bundles Fibroblasts Adipose cells Loose connective tissue Dermis Epidermis

Skin, hand, monkey Slide 109 Fibroblasts subdermal region Loose connective tissue Dense irregular connective tissue Nerve Bundles of collagen fibers Dense Irregular connective tissue Endothelium Epithelium of the epidermis Dense surface region of dermis

SPLEEN

Spleen (reticulum stain)- capsule and reticulum fibers 218 Spleen (reticulum stain)- capsule and reticulum fibers capsule reticulum fibers

Slide 118: Liver & spleen with colloidal carbon, rat Dense irregular connective tissue capsule Macrophages mesothelium

Kidney Capsule, urinary vascular poles slide #19713 Dense irregular connective tissue of capsule fibroblasts nephrons Bundles of collagen

Penis – transitional epithelium and surrounding slide 277 spongy cavernous of penal urethra Skin Dense irregular connective tissue creating the tunica albuginea Erectile vascular tissue

Small intestinal villi Epithelium Lamina propria Smooth muscle

Slide 32409: Rat intestine (toluidine blue) Loose connective tissue (e.g., lamina propria) Fibroblasts Blood vessels

Dense irregular connective tissue Dense regular connective tissue

Slide 202: Tendon Dense regular connective tissue High density of collagen fibers Fibroblasts

CELLS OF CT FIBROBLASTS MESENCHYMAL CELLS and RBC ADIPOSE CELLS MACROPHAGE PLASMA CELLS MAST CELLS and WBC CHONDROBLASTS CHONDROCYTES OSTEOBLASTS OSTEOCYTES OSTEOCLASTS

Cells of connective tissue

Cells of connective tissue

Blood cells are connective tissue cells 32583 Bone marrow cells https://www.youtube.com/watch?v=UTo4LnXonTk&list=PLQltfhuKi1sgtel3O9IpDsbgEWMY3JaX5&index=19

Slide 109: Skin, hand, monkey Fibroblasts Bundles of collagen fibers Smooth muscle cells Muscular artery Venule Endothelial cells

Slide 196: Spermatic cord Loose connective tissue Fat cells Fibroblasts Smooth muscle Nerve Endothelial cells Bundles of collagen fibers Valve in vein Fibroblasts

Slide 196 Vein of Spermatic cord Fat cells Large vein Smooth muscle Valve in a large vein Fibroblasts

Vein of Spermatic cord Slide 196 Smooth muscle cells Arteriole Fibroblasts

Slide 19716: Tail of epididymis Fibroblasts, Collagen fiber bundles Fat cells Fat cells

EM 8e: Fibroblasts Fibroblasts Collagen fibers

Slide 126:Bile duct with portal vein, monkey Loose connective tissue (many cells and few fibers), Adipose cells, Fibroblasts Bile duct Portal vein

Slide 195 Fetal jaw White fat cells Fibroblasts White fat cell cytoplasm can be seen surrounding the single fat droplet Brown fat cell cytoplasm can be seen surrounding multiple fat droplets Slide HISTO039

Slide HISTO42: Lung Mast cell Light blue granules Mast cells Mast cells Air sac

Cardiac stomach w/chronic infection 140 Cardiac stomach w/chronic infection Plasma cells 32409 Mast cell Mast cells epithelium Loose connect tissue

EM 8d: Mast cell Granules, Mitochondria, Golgi region

432 lung macrophages Lung Type II pneumocytes Air space Air space Air

Macrophage in lamina propria of rat intestine Slide 32409 Macrophage Slide 109

Note varied densities in Macrophage in vacuoles. aged rat testis EM 8h: Macrophage in testis; 30,000x Enlarged basal lamina Heterophagic vacuole Leydig cell cytoplasm Nucleolus Myoid cell

Kupffer cells EM 18 Slide 118 liver Hepatocytes Blood bathing of the hepatocytes travels through portal sinuses Slide 118 carbon deposits in the macrophages in the spleen

Slide 126: Bile duct with portal vein, monkey Loose connective tissue, plasma cells

Cardiac stomach w/chronic infection 140 Cardiac stomach w/chronic infection Plasma cells neutrophils eosinophils endothelium Fibroblasts in loose connect tissue Parietal cells of stomach

111 Skin Large bundles of collagen fibers running in different directions (irregular) and of high density (dense) = dense irregular connective tissue in the dermis of skin 111 Skin Epithelium ocotillo plant Nuclei of fibroblasts

Slide 109 skin High density of collagen fibers regularly or irregularly arranged Slide 202 tendon dermis fibroblasts With flexibility, high tensile strength, and impressive resistance to stretch, concentrations of these fibers are found where these attributes are crucially important.

Slide HISTO039: Larynx Bundles of collagen fibers Loose connective tissue of the lamina propria Dense irregular connective tissue in capsule Fibroblasts cartilage perichondrium Epithelium Bundles of collagen fibers

Fibroblast EM 10d: Schwann cell Collagen fibers

EM 8e: Fibroblasts Fibroblasts Bundles of collagen fibers 111 Skin

Slide 218 spleen with dark, branched reticular fibers

Slide 427: Aorta Elastin lamina Lumen Smooth muscle cells Muscle and elastic fibers

Slide 426: Renal artery and vein with nerves Elastin fibers Elastin lamina Smooth muscle

EM 9: Smooth muscle cells Elastic lamina

EM 10f: Arteriolar Wall Elastic fibers

Slide 32409 Intestine: Connective Cells

In summary Blood cells Marrow cells

Questions on Connective Tissue a. provides mechanical support and metabolic exchange for epithelia b. provides site of battle for blood borne immune cells c. stores energy in striated muscle cells d. a and b e. a, b, and c Classification of connective tissue proper is based on: a. ratio of cells to extracellular matrix b. arrangement of fibers c. the density of fibers in the extracellular matrix Cells of connective tissue that are progenitor (stem) cells are: a. adipose cells b. macrophages c. plasma cells d. fibroblasts e. mast cells

Many illustrations in these VIBS Histology YouTube videos were modified from the following books and sources: Many thanks to original sources! Bruce Alberts, et al. 1983. Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY. Bruce Alberts, et al. 1994. Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY. William J. Banks, 1981. Applied Veterinary Histology. Williams and Wilkins, Los Angeles, CA. Hans Elias, et al. 1978. Histology and Human Microanatomy. John Wiley and Sons, New York, NY. Don W. Fawcett. 1986. Bloom and Fawcett. A textbook of histology. W. B. Saunders Company, Philadelphia, PA. Don W. Fawcett. 1994. Bloom and Fawcett. A textbook of histology. Chapman and Hall, New York, NY. Arthur W. Ham and David H. Cormack. 1979. Histology. J. S. Lippincott Company, Philadelphia, PA. Luis C. Junqueira, et al. 1983. Basic Histology. Lange Medical Publications, Los Altos, CA. L. Carlos Junqueira, et al. 1995. Basic Histology. Appleton and Lange, Norwalk, CT. L.L. Langley, et al. 1974. Dynamic Anatomy and Physiology. McGraw-Hill Book Company, New York, NY. W.W. Tuttle and Byron A. Schottelius. 1969. Textbook of Physiology. The C. V. Mosby Company, St. Louis, MO. Leon Weiss. 1977. Histology Cell and Tissue Biology. Elsevier Biomedical, New York, NY. Leon Weiss and Roy O. Greep. 1977. Histology. McGraw-Hill Book Company, New York, NY. Nature (http://www.nature.com), Vol. 414:88,2001. Arthur C. Guyton,1971.Textbook of Medical Physiology W.B. Saunders company, Philadelphia, PA WW Tuttle and BA Schottelius 1969 Textbook of Physiology C.V. Mosby Co. A.L. Mescher 2013 Junqueira’s Basis Histology text and atlas, 13th ed. McGraw

ocotillo plant Mexico Big Bend TX, USA

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