Connective Tissue

Question 1

What is connective tissue made up from?

Answer 1

Cells

Extracellular matrix

Question 2

What are the three different fibre types found in the Extracellular matrix of connective tissue?

Answer 2

Reticular, elastic, collagen.

Question 3

List some of the properties of mesenchymal connective tissue.

Answer 3

In this tissue cells have a tapering appearance. There is abundant ground substance, and cells are similar but are able to differentiate giving rise to new cell types.

Question 4

What cell types can mesenchymal cells differentiate into?

Answer 4

Chondroblasts, lipoblasts, fibroblasts, osteoblasts, myoblasts.

Question 5

Where is mucous connective tissue found?

Answer 5

Mucous connective tissue is found in the umbilical cord. Gelatin like ground substance surrounds spindle shaped mesenchymal cells. It contains blood capillaries bearing blood cells.

Question 6

Describe the structure of a peptidoglycan monomer

Answer 6

This contains a core protein which has approximately 100 GAG glycosaminoglycan units joined. Hyaluronic acid molecules have these attached.

Question 7

Beside Hyaluronic acid molecules and peptidoglycan monomers, what other substance is found in ground substance of connective tissue?

Answer 7

Collagen fibrils.

Question 8

Why does ground substance in connective tissue remain hydrated?

Answer 8

GAG molecules have a negative charge and they therefore Stacy water molecules.

Question 9

What are the four different types of collagen?

Answer 9

1 - forms fibrils and bundles (tendons organs skin dermis)
2 - fibrils don’t form bundles (hyaline/elastic cartilage)
3- recticulin (fibres around nerve/muscle cells)
4 - basement membrane

Question 10

Describe the structure of type 1 collagen.

Answer 10

It is made up of staggered collagen molecules which is what gives the banding pattern. Each molecule is made up from a triple helical arrangement of a chains. Gly-X-Y is the amino acid pattern. Where X and Y are small.

Question 11

How do fibroblasts secrete collagen to be formed into bundles?

Answer 11

Fibroblasts secrete pro collagen which is assembles into collagen fibrils. These then form aggregates which form bundles in the same direction.

Question 12

Describe the structure of a lymph node.

Answer 12

Lymph nodes have a mesh of reticular fibres with lymphocytes densely packed in the spaces inbetween.

Question 13

What is the name for a fibre made up primarily of elastin but then enfolded and surrounded by fibrillin?

Answer 13

Elastic fibre.

Question 14

What is Marfans syndrome? Why can it be fatal?

Answer 14

It is a disorder of the elastic tissue caused by abnormal expression of the fibrillin gene. It can lead to aortic rupture.

Question 15

Name the three layers of a small elastic artery

Answer 15

Tunica intima - endothelium
Tunica media - elastic lamellae
Tunica adventitia - collagen (loose connective tissue)

Question 16

State the differences in collagen and fibroblasts between loose and dense irregular connective tissue.

Answer 16

In loose irregular, there is less collagen an abundant fibroblasts. In dense irregular, there is abundant collagen and fewer fibroblasts.

Question 17

What type of connective tissue is the dermis and what are some of its properties?

Answer 17

It is dense irregular connective tissue. Collagen bundles go in different directions which prevents tearing, and elastic fibres allow the skin to stretch.

Question 18

Connective tissue has protective properties with organs and glands. Where can it be found?

Answer 18

Loose or dense irregular connective tissue forms capsules around organs and glands, and is also responsible for splitting glands into lobules.

Question 19

What type of connective tissue is found in tendons?

Answer 19

Dense regular. Collagen bundles lie in the same direction as the tensile force, and flattened fibroblasts lie between these bundles.

Question 20

What is a myotendious junction?

Answer 20

It is the point where tendon collagen fibres join skeletal muscle fibres.

Question 21

What is the difference between a tendon and a ligament?

Answer 21

Tendons connect muscle to bone whilst ligaments connect bone to bone.

Question 22

How is collagen arranged in ligaments?

Answer 22

Collagen is packed in a parallel arrangement and is arranged into fascicles which are separated by loose connective tissue.

Question 23

What are fibroblasts responsible for and therefore what can be said about their cell ultrastructure?

Answer 23

Fibroblasts lay down collagen and ground substance. They therefore need abundant RER. These cells are very important for healing.

Question 24

When do macrophages move into connective tissue?

Answer 24

During inflammation. They are phagocytic and breakdown foreign material and organisms.

Question 25

What is a mast cell?

Answer 25

Mast cells are found near blood vessels in connective tissue. They contain granules which are released during trauma.

Question 26

What three substances do mast cell granules contain?

Answer 26

Heparin - anticoagulant
Histidine - increases blood vessel permeability
Substances to attract eosinophils and neutrophils.

Question 27

Why do adipocytes show as empty white circles under micro graphs?

Answer 27

The fat is washed away during the preparation process.

Question 28

Give three functions of adipose tissue.

Answer 28

Fuel reserve, thermal insulation, shock absorption.

Question 29

What is connective tissue?

Answer 29

Connective tissue is the tissue which connects other types of tissue such as muscle, nerve, epithelial and offers structural but also metabolic and physiological support.