Lesson 5- Cartilage, Bone, Blood Tissues

• Types of Cartilage


  • Hyaline Cartilage
  • Elastic Cartilage
  • Fibrocartilage
• Cartilage


  Specialized form of connective tissue consisting of chondrocytes and extracellular fibers embedded in an amorphous, gel-like matrix
• Chondrocytes


  Cells in the cartilage
• Cartilage matrix


  • Endows the tissue with resilience that allows it to bear mechanical stresses without distortion
  • Cartilage is vascular and gets nourishment from blood vessels in the outer part of perichondrium
• Vascularity


  Refers to the presence of blood vessels
• Perichondrium


  Fibrous tissue surrounding the cartilage plate, a condensation of the deeper part of the tunica propia
• Hyaline Cartilage


  • Characterized by a mass of cellular tissue and with a homogenous ground substance or matrix without demonstrable fibers
  • Contains chondrocytes within the lacunae in the matrix that are arranged in groups called cell nests found in the center of the plate
• Elastic Cartilage


  Stained with Mallory's Phosphotungstic Acid Hematoxylin, consists of perichondrium, matrix, lacunae, chondrocytes and cell families
• Elastic Cartilage


  • Differentiated from hyaline cartilage by the presence of elastic fibers in the matrix not demonstrable by H&E stain
• H&E Stain


  Hematoxylin and Eosin stain
• Fibrocartilage


  • Has a dense fibrous nature in contrast to the other cartilage tissues, largely composed of dense collagenous CT, with small islands of hyaline cartilaginous matrix with lacunae and spherical chondrocytes occurring singly or in small groups
  • Has no perichondrium and it is avascular within the cartilage plate
  • A transition stage between cartilage and dense CT
• Avascular


  Absence of blood vessels
• Components of Fibrocartilage


  • Collagenous fibers
  • Matrix
  • Cartilage cells
• Bones


  • The most highly differentiated connective tissues, rigid and makes up our skeletons
  • Second to cartilage in its ability to withstand stress, consists of osteocytes, fibers and ground substance (matrix) which are calcified to make it hard and brittle
• Osteocytes


  Cells of the bone
• Types of Bones


  • Spongy bone
  • Compact bone
• Ground Bone


  Consists of the Haversian lamellae which surrounds the small Haversian canals, with osteocytes lodged in the lacunae
• Artifacts


  Black spots in the lacunae that accumulated when the bone was washed during specimen preparation
• Components of Compact and Spongy Bone


  • External circumferential lamellae
  • Internal circumferential lamellae
  • Haversian lamellae
  • Haversian canal
  • Lacunae
  • Bone canaliculi
• Compact Bone


  • Binds, supports and protects organs
  • Comes together to form the skeleton
• Osteon


  Compact bone tissue consists of units called osteons or Haversian systems, cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood
• Hematopoiesis


  The production of blood cells
• Bone Marrow


  Responsible for hematopoiesis, consists of hematopoietic cords, blood vessels, and adipose cells
• Adipose cells


  Seen using sudanophilic stain
• Blood


  Transports hormones, nutrients and cells all over the body, formed from the hematopoietic CT found inside the bone marrow, a fluid CT
• Different types of blood cells and their functions


  • Red blood cells (transport O2 and CO2)
  • Neutrophils (elevated in bacterial infections)
  • Eosinophils (elevated in parasitic infections)
  • Basophils (elevated in allergic reactions)
  • Lymphocytes (produce antibodies)
  • Monocytes (convert into macrophages which engulf pathogens)
  • Platelets (responsible for blood clotting during wounds)
• Stages of Hematopoiesis


  • Yolk sac
  • Liver
  • Bone marrow
• Marfan Syndrome


  An inherited disorder that affects connective tissue, the connective tissue lacks strength and affects all connective tissues