Connective Tissues and Cartilage

Question 1

What is connective tissue

Answer 1

widely separated cells, intercellular substance

consists of cells, fibres and ground substance

Question 2

Characteristics of connective tissue

Answer 2

cells often separated by ECM
ECM contains blood vessels and nerves
cells may communicate
often slow turnover
cells interact with ECM - adhesion molecules

Question 3

Cells of connective tissues

Answer 3

family of cells derived from mesenchyme:
fibroblasts: responsible for synthesis and maintenance of ECM
adipose cells: involved in storage plus mechanical effects
defence cells: mast cells, macrophages, other white blood cells

Question 4

Classification of connective tissue

Answer 4

mesenchyme - embryonic
loose areolar connective tissue - around outside of GI tract, respiratory and urinary organs
dense - mechanical support, irregular or regular
reticular - around liver and lymphoid tissue
adipose

Question 5

Components of cartilage

Answer 5

ECM: ground substance - GAGs, large proteoglycans
fibres - collagen
Cells: chondroblasts
chondrocytes

Question 6

Hyaline cartilage

Answer 6

chondroblast
GAGs and large proteoglycans
type II collagen
turgdity, tensile strength, tough, resists deformation

Question 7

General support

Answer 7

fibroblast
GAGs
type I + III collagen and elastic fibres
elastic, compressible, tough packing material

Question 8

Chondroblasts

Answer 8

from perichondrium, secrete matrix

Question 9

Chondrocytes

Answer 9

maintain matrix

Question 10

Growth and maintenance of cartilage

Answer 10

matrix permeable to water - dissolved O2 and nutrients delivered, waste products removed
mainly non-vascular, therefore relies on diffusion via extracellular fluid
grows by interstitial in matrix and appositional on surafce growth

Question 11

Types of cartilage

Answer 11

hyaline - articular surfaces, tracheal rings
fibrocartilage - intervertebral discs, pubic symphysis
elastic cartilage - external ear, auditory canal

Question 12

Why can cartilage resist compression?

Answer 12

Sulphated compounds in the ground substance and a high proportion of water trapped in the ground substance

Question 13

Why is cartilage difficult to repair?

Answer 13

it is avascular

Question 14

Why are bone and cartilage regarded as forms of specialised connective tissue?

Answer 14

both made of cells embedded in ECM