Lesson 4

Question 1

Hyaline Cartilage
Elastic Cartilage
Fibrocartilage

Answer 1

TYPES OF CARTILAGE

Question 2

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

Answer 2

CARTILAGE

Question 2

• Trachea, costal cartilage (attached to the sternum and rib)
  o found at the anterior or ventral portion of rib
  o provides extension

Answer 2

Hyaline Cartilage

Question 3

• The cartilage matrix endows the tissue with resilience that allows it to bear mechanical stresses without distortion.

Answer 3

CARTILAGE MATRIX

Question 4

• Epiglottis, external ear

Answer 4

Elastic Cartilage

Question 5

• Intervertebral disc
• Most dense among all cartilage

Answer 5

Fibrocartilage

Question 6

• Cartilage is avascular/nonvascular and gets nourishment from blood vessels in the outer part of perichondrium.
  o covers the cartilage
  o vascular part - perichondrium
• Vascularity refers to the presence of blood vessels.

Answer 6

CARTILAGE VASCULARITY

Question 7

• is the fibrous tissue surrounding the cartilage plate. It is a condensation of the deeper part of the tunica propia.
  o articular cartilage (cartilage in joints) lacks perichondrium – gets nutrients from synovial fluid (can be seen in joints)
  o hyaline cartilage cells metabolize glucose mainly by anaerobic (no presence of oxygen) glycolysis because of cartilage’s lack of vascularity

Answer 7

PERICHONDRIUM

Question 8

• protect bones from injury and damage,
• nourish cartilage through blood vessels, and
• facilitate cartilage growth
  (pic)
• diffusion (dispersal) of excretory products of chondrocytes – production of ECM and collagen

Answer 8

MAIN FUNCTIONS OF THE PERICHONDRIUM

Question 9

• It is characterized by a mass of cellular tissue and with a homogenous ground substance or matrix without demonstrable fibers.
• It contains chondrocytes within the lacunae (matrix cavities) in the matrix that are arranged in groups called cell nests found in the center of the plate.
  o hyaline – hylos = glass
  o chondrocytes - chondros = cartilage; kytos = cell
  o hyaline forms the temporary bones of babies
  o growth hormone (somatotropin) – major regulator of hyaline cartilage growth (somatomedin)
   main hormone that will act upon cartilage growth
   growth hormone will stimulate somatomedin (protein from liver) will directly stimulate the cells of hyaline cartilage (chondrocytes)

Answer 9

HYALINE CARTILAGE

Question 10

• The elastic cartilage is stained with Mallory’s Phosphotungstic Acid Hematoxylin.
• It consists of perichondrium, matrix, lacunae, chondrocytes and cell families.
  o same with hyaline cartilage but has elastic fibers
  o more flexible than hyaline cartilage
  o yellowish - elastic fibers
  o usually seen in the ears, auditory tubes, upper respiratory tract, epiglottis (flap in the throat, behind the tongue, and in front of larynx)
• It is differentiated from a hyaline cartilage by the presence of elastic fibers in the matrix not demonstrable by H&E stain.
• H&E Stain - Hematoxylin and Eosin stain
  o most used stain in histology
  o is not used in elastic cartilage

Answer 10

ELASTIC CARTILAGE

Question 11

• It has a dense fibrous nature in contrast to the other cartilage tissues.
• It is largely composed of dense collagenous connective tissues.
• Between the fiber bundles, there are small islands of hyaline cartilaginous matrix with lacunae and spherical chondrocytes occurring singly or in small groups.
• Usually found in intervertebral disc
  o per disc, there are intervertebral disc, which is composed of fibrocartilage
  o usually seen at attachments of certain ligaments and pubic symphesis
  o cushioning and providing tissue support for bones
  o hyaline + dense collagenous CT = fibrocartilage
• It has no perichondrium and it is avascular within the cartilage plate.
• Avascular means absence of blood vessels.
• It is a transition stage between cartilage and dense CT.
  o it consists of collagenous fibers, matrix, and cartilage cells

Answer 11

FIBROCARTILAGE