Connective Tissue

Question 1

What is connective tissue and what is it made of?

Answer 1

Non-living material between cells that supports, connects and separates organs and tissues.
Made from Extracellular Matrix and cells of the connective tissue

Question 3

What is ground substance made of?

Answer 3

Long chain of hyaluronan molecules with proteoglycans attached by linker proteins on each side.
Proteoglycans made of core proteins and GAGs (Glycoaminoglycans)
These molecules attract water making the ground substance very hydrophillic

Question 4

What is the specific function of ground substance and how do they achieve this?

Answer 4

Resist compression and allow diffusion.

Made of hydrophillic macromolecules

Question 5

What are the fibres of Extracellular Matrix?

Answer 5

Collagen
Reticulum
Elastin

Question 6

Describe features of collagen?

Answer 6

Formed from type I collagen (triple helix of alpha-chains)

Flexible but with a high tensile strength

Question 7

Describe features of reticulum?

Answer 7

Formed from type III collagen (thin delicate fibres) —> cross-linked meshwork
Provide support framework

Question 8

Describe features of elastin?

Answer 8

Formed from folded elastin surrounded by fibrillin (provides scaffold)
Allow recoil after stretching/distension

Question 9

What are the cells of connective tissue?

Answer 9

Fixed:
Fibroblasts, Mast cells, Melanocytes, Macrophages, Adipocytes, Stem (mesenchymal) cells

Wandering: (immune cells)
Leukocytes, Plasma cells, Monocytes, Eosinophils, Basophils

Question 10

What are the types of fibroblasts and what are their specific function?

Answer 10

Fibrocytes (inactive): maintain the ECM
Fibroblasts (active): secrete fibres and ground substance forming ECM
Myofibroblasts: wound contraction (form scar tissue) using actin filaments

Question 11

What is the specific function of mast cells in connective tissue?

Answer 11

Found near blood vessels and coated in IgE (Immunoglobulin E), which binds to allergens to release granules

Question 12

What is contained within the granules of mast cells?

Answer 12

Histamine: increases the permeability of capillaries
Heparin: anticoagulant (naturally occurring GAG activates antithrombin)
Substances to attract eosinophils and nuetrophils

Question 13

What are the basic types of tissue?

Answer 13

Basic:

Epithelial
Muscle
Nerve
General Connective

Question 14

What are the specialised types of connective tissue?

Answer 14

Adipose
Lymphatic
Blood
Haemopoetic
Cartilage
Bone

Question 15

What are the specific functions of connective tissue?

Answer 15

Connects cells to form tissue, tissues to form organs, organs to form the body
Provides the medium for diffusion
Protects organs and tissues
Stores energy and nutrients (insulation)
Defends against infection and is involved with wound healing

Question 16

What are the types of general connective tissue (CT Proper)?

Answer 16

Loose

Dense

Question 17

Describe the features of loose CT

Answer 17

Many cells
Sparse collagen fibres
Much ground substance
Facilitates diffusion

Question 18

Describe the features of dense CT

Answer 18

Few cells
Many collagen fibres
Little ground substance
Designed to withstand stress

Question 19

What are the types of dense CT?

Answer 19

Regular

Irregular

Question 20

What is Extracellular Matrix made of?

Answer 20

Extracellular Matrix is formed from ground substance and fibres.

Question 21

Where is dense irregular CT found and what is it’s specific function?

Answer 21

Fibres are multi-directional

Found in the skin and intestines (below loose CT)

Question 22

Where is dense regular CT found and what is it’s specific function?

Answer 22

Fibres are parallel and densely packed

Found in tendons, ligaments and aponeuroses

Question 23

What is Marfans syndrome?

Answer 23

Genetic disorder of the gene that makes fibrillin which causes abnormal connective tissues formation and growth