Histology Of Connective Tissue I Lecture PDF

HISTOLOGY OF CONNECTIVE TISSUE I VPP3214 (Veterinary Histology and Developmental Anatomy )  CONNECTIVE TISSUE (CT) One of four basic animal tissue (epithelium, muscle and nerve) Integrating three basic animal tissue to physiologically function...

HISTOLOGY OF CONNECTIVE TISSUE I VPP3214 (Veterinary Histology and Developmental Anatomy )  CONNECTIVE TISSUE (CT) One of four basic animal tissue (epithelium, muscle and nerve) Integrating three basic animal tissue to physiologically function Connective Tissue Classification CT Proper Dense Regular Collagenous CT Specialized CT Dense Regular Elastic CT Loose CT Cartilage Dense Regular CT Bone Dense CT Dense Irregular CT Blood CONNECTIVE TISSUE  CONNECTIVE TISSUE PROPER Derived from mesoderm of embryonic germ layers Differentiated from pluripotent mesenchymal cells Connective Tissue Cellular Extracellular Matrix (ECM) 1 2 Fibroblast Adipocyte Fibers Plasma Cell Mast Cell 3 4 Ground Substances 5 Macrophage  (1) FIBROBLAST Most abundant and widely distributed in animal tissue Important for fibers (collagen and elastic) andground substance synthesis (GAG, proteoglycan and glycoprotein) Elongated and fusiform cell with irregular cytoplasmic projections Darker-stained, oval nucleus with numerous euchromatin Weak eosinophilic and pale cytoplasm stained with H&E Abundant rough endoplasmic reticulum (rER) and Golgi apparatus (GA)  (1) FIBROBLAST Cytoplasmic Collagen Process Phagosome Heterochromatin Fibroblast Collagen Fibrils Esophageal Lamina Propria Euchromatin  (2) ADIPOCYTE Crucial in synthesis and storage of lipid Two types of adipocytes, including multilocular (brown) and unilocular (white) adipocytes 1. Multilocular adipocytes: Small spherical cell morphology (15-25 µm) Cytosol contained numerous varying size of lipid droplets Round nucleus and centrally located Numerous of mitochondria and cytochrome Innervated with adrenergic nerve fibers of autonomic nerve plexus Accompanied with dense capillaries network Predominantly found in birds, rodent and newborn mammals (thyroid glands and renal hilus)  (2) ADIPOCYTE Lipid Droplets Nucleus Brown Fat  (2) ADIPOCYTES 2. Unilocular adipocytes Large spherical to polyhedral cells (25-100 µm) Cytosol contained single, large lipid droplet (lipoblast) Lipid droplet stabilized with microfilament Carotenoids determines lipid droplet color Flattened nucleus displaced to the periphery (signet ring) Small GA, few mitochondria, sparse rER and abundance of free ribosomes Plasma membrane possess insulin, growth hormone, cortisol and noradrenaline receptors Surrounded by dense capillary network and collagen type III (reticular fiber) (2) ADIPOCYTES Polyhedral Nucleus  (3) PLASMA CELL Differentiated B-lymphocytes (humoral immunity) Morphologically, large and ovoid cells (20 µm) Eccentrically located nucleus Heterochromatin concentrated in peripheral clump (clock face, spoke wheel or cartwheel) Intense basophilic cytoplasmic staining Well-developed rER with closely packed cisternae Few scattered mitochondria and numerous free ribosome Found in lamina propria of gastric and enteric mucosa (3) PLASMA CELL Cartwheel Nucleus Mitochondria rER  4. MAST CELL Large, ovoid cell (20-30 µm) in loose connective tissue Centrally located nucleus with ellipsoid shape Basophilic cytoplasm Numerous vary sizes of metachromatic granules (0.3-0.8 µm) Granule contained histamine, heparin and chemotactic factors (ECF and NCF) Expressing IgE receptors (hypersensitivity type I) Long lifespan (weeks-months)  4. MAST CELL Basophilic Cytoplasm Metachromatic Granule Granules  5. MACROPHAGE Derived from hematopoietic stem cell Also known as histiocytes Circulating monocytes to macrophage (diapedesis) 1. Resident macrophages (Kupffer cell, Langerhans cell, dust cell) 2. Free macrophage (loose connective tissue) Phagocytose damaged, dead, cellular debris and antigenic substances Serves as an antigen presenting cell (APC) via MHC class II Amoeboid, irregular cell morphology (10-30 µm)  5. MACROPHAGE Possess vary length and blunt projections (pseudopodia) Activated macrophage appeared prominent membrane folding Indented nucleus (kidney-shaped nucleus) Basophilic cytoplasm with small vacuoles and granules Abundance lysosomes (azurophilic granules) Well-developed Golgi apparatus and prominent rough endoplasmic reticulum  5. MACROPHAGE Phagolysosomes Nucleus Macrophage Pseudopodia Lysosome THANK YOU