Connective tissue lab

• Uric acid


  Resides in cartilages = gout
• Connective tissue


  • Connects other muscle, organs (e.g. ear, pubic symphysis)
• Classifications of connective tissue

  • Loose (areolar) connective tissue
  • Dense irregular connective tissue
  • Dense regular connective tissue
• Loose (areolar) connective tissue

  • Much ground substance; many cells and little collagen, randomly distributed; supports microvasculature, nerves, and immune defense cells; e.g. lamina propria beneath epithelial lining of digestive tract
• Dense irregular connective tissue

  • Little ground substance; few cells (mostly fibroblasts); much collagen in randomly arranged fibers; protects and supports organs; resist tearing; e.g. dermis of skin, organ capsules, submucosa of digestive tract
• Dense regular connective tissue

  • Almost filled with parallel bundles of collagen; few fibroblasts, aligned with collagen. E.g. ligaments, tendons, aponeuroses, corneal stroma
• Cartilage


  A tough, durable form of supporting connective tissue, characterized by an ECM with high concentration of GAGs and proteoglycans, interacting with collagen and elastic fibers
• Cartilage ECM


  • Has firm consistency that allows tissue to bear mechanical stresses without permanent distortion
• Types of cartilages


  • Hyaline cartilage
  • Elastic cartilage
  • Fibrocartilage
• Hyaline cartilage


  • Lightly stained; most common among the three types; found majority in joints; provides smooth, low-friction surfaces in joints; structural support for respiratory tract. Has presence of perichondrium (except at epiphyses and articular cartilage)
• Elastic cartilage


  • Dark stain; provides elasticity; Type II collagen; provides flexible shape and support of soft tissue; location: ear, external acoustic meatus, auditory tube; epiglottis
• Fibrocartilage


  • Has area of light and dark stain; mixture of hyaline and elastic cartilage; no perichondrium; provides cushioning, tensile strength, and resistance to tearing and compression; location: intervertebral discs, pubic symphysis, meniscus, other joints, insertions of tendons
• Chondrogenesis


  Formation of cartilage cells
• Mesenchyme


  Precursor cell of all types of cartilage
• Chondrocyte


  Cartilage cell
• Chondroclast


  Breakdown of cartilages
• Stains used


  • H&E stains
  • Romanowsky-type stain
• Blood


  Specialized connective tissue
• Progenitor cells


  Found in bone marrow
• Components of whole blood

  • Plasma
  • Erythrocytes (RBC)
  • Buffy coat
• Plasma


  • 55% of whole blood; Water 92% by weight; Proteins 7% by weight: Albumin 58% - major protein; protein made in blood; Globulins 37%- antigens; Fibrinogen 4%; Regulatory proteins <1%; Other solutes 1% - Electrocytes, nutrients, respiratory gases, waste products
• Erythrocytes (RBC)


  • 44% of whole blood; 4.2-6.2 million per cubic mm
• Buffy coat


  • <1% of whole blood; platelets – 150-400 thousand per cubic mm; leukocyte – 4.5-11 thousand per cubic mm
• Globulin types


  • IgG – past infection; immunity (vaccine)
  • IgA – secretion; colostrum
  • IgM – recent infection
  • IgD
  • IgE – allergy
• Fibrinogen


  Proteins in blood; for clotting proposes
• Heparin


  Natural anticoagulant in the body; produced in liver; helps check the clotting in the blood inside blood vessels
• RBC


  • Provides oxygen in tissues; concave
• Anemic


  Not enough (healthy) RBC
• Polycythemia vera


  Bone marrow produces too many RBC; consistency of blood is viscous
• WBC (leukocyte) types


  • Neutrophil
  • Lymphocyte
  • Monocyte
  • Eosinophils
  • Basophil
• Neutrophil


  Fights bacteria; granules: faint/light pink
• Lymphocyte


  No granules; effector and regulatory cells for adaptive immunity
• Monocyte


  No granules; horse-shoe/kidney shaped; precursor of macrophages and other mononuclear phagocytic cells
• Eosinophils


  Granulated – red/dark pink; bilobed; kills helminths, parasites; modulate local inflammation
• Basophil


  Granulated - dark blue/purple; modulate inflammation, release histamine during allergy (allergic reaction)
• Progenitor cells


  • RBC – Prono-ormoblast
  • WBC – Myeloblast
  • Platelets – megakaryoblast
• 120 days – lifespan of RBC; frequency of donation – 24 months
• HbA1c


  Recently used for diabetic testing; prefered indicator for glucose; no need for FBS (fasting blood sugar); more accurate than FBS
• Rouleaux


  Stacking of coins (RBC); not ideal
• Poikilocytosis


  Irregular shape of RBC; sickle cell – cannot maintain its function