•Specialized connective tissue

•Rigid, Elastic, Resilient -

RESISTS COMPRESSION

•AVASCULAR –

nutrients diffuse through matrix

Hundreds of Eyes Staring Back at YOU!

PERICHONDRIUM

• Dense irregularly arranged connective tissue (type I collagen)

• Ensheaths the cartilage• Houses the blood

vessels that nourish chondrocytes

CHONDROBLAST

• Progenitor of chondrocytes

• Lines border between perichondrium and matrix

• Secretes type II collagen and other ECM components

• Chondroblasts build

CHONDROCYTE

• Mature cartilage cell

• Reside in a space called the lacuna

• Clear areas = Golgi and lipid droplets

• Chondrocytes completely fill their lacunae

• RER and euchromatic nuclei

• Synthetically active, secrete matrix

Cartilage matrix

RER

N

MATRIX• Provides the rigidity,

elasticity, & resilience• FIBERS

– Collagenous and elastic

• GROUND SUBSTANCE– Glycosaminoglycans

(chondroitin sulfates, keratin sulfate, hyaluronic acid)

– Proteoglycans: GAGs + core protein

– Water

• Basophilic• Territorial matrix - high [ ] of

sulfated proteoglycans

CARTILAGE GROWTH• Appositional

– Increasing in WIDTH; chondroblasts deposit matrix on surface of pre-existing cartilage

• Interstitial– Increasing in

LENGTH; chondrocytes divide and secrete matrix from w/in lacunae

TYPES OF CARTILAGE

• HYALINE

• ELASTIC

• FIBROUS

HYALINE CARTILAGE• FUNCTION

– Support tissue and organs– Model for bone development

• MATRIX– Type II collagen (thin

fibrils)– Chondroitin sulfate, keratin

sulfate, hyaluronic acid– Water

• LOCATION– Tracheal rings, nasal septum,

larynx, articular surfaces of joints

ELASTIC CARTILAGE

• FUNCTION– Support with flexibility

• MATRIX– Normal components of hyaline

matrix plus ELASTIC fibers

• LOCATION– External ear, external auditory

canal, epiglottis

• STAINS – Elastic fibers stain BLACK

with Weigert stain

perichondrium

FIBROCARTILAGE

Orcein van Giesen Elastic stain - fibrocartilage - reddish brown hyaline cartilage - yellow

FIBROCARTILAGE

• FUNCTION– Support with great

tensile strength

• MATRIX– Type I collagen -

Oriented parallel to stress plane

• LOCATION– Intervertebral disks,

pubic symphysis

FIBROCARTILAGE

• Chondrocytes align between collagen fibers

• Collagen fibers lie parallel to lines of stress

How many types of cartilage do you see?

SYNOVIAL (DIARTHRODIAL) JOINTS

JOINT DEFINITIONS

• SYNOVIAL CAVITY– Fluid filled space b/t 2 bones

• SYNOVIAL FLUID – Water and GAGs; provides

nutrients for cartilage

• SYNOVIAL MEMBRANE– Continuous with the

perichondrium

SYNOVIAL “MEMBRANE”

Not a true membrane -

Why?

• Specialized secretory CT • Loose (areolar) CT• Formed by layers of

collagen and fibroblasts• Highly vascular

• No perichondrium• Joint capsule

composed of DIACT

• Why does the cartilage at the joint stain so acidophilic (i.e. pink)?

A

BC

Question 1

Panel C is a low magnification micrograph of the tissue shown in Panel B.Provide the letter or letters (A and/or B) (or none) of the panel to which the following apply.normally calcifiedvascularizedcollagen type IIcells capable of divisionmatrix contains proteoglycanslacunae present

A

B

C

Questions 2 and 3:

2. The three tissues shown have all of the following properties in common EXCEPT:

a. They contain capillaries.b. They contain proteoglycans.c. They can increase in size by interstitial growth.d. They can increase in size by appositional growth.

3. Which tissue is the most highly specialized to resist compression?

a. Ab. Bc. C

Question 4

4. What cartilage nourishing tissue is missing at the interface shown?

a. Synovial fluidb. Perichondriumc. Synovial

membraned. Chondroblasts