Connective tissue

Question 1

Tissue

Answer 1

A collection of cells to do a similar job

Question 2

4 principle groups of tissues

Answer 2

Epithelial :
covers body-surface lines hollow organs body cavities ducts and forms glands

Connective tissue;
protects and supports body and organs binds organs together, stores energy reserves such as fat, helps provide body with immunity.
includes skeletal tissue cartilage and bone

Muscular tissue:
cells specialised for
contraction and generating force

Nervous system:
detects change in a variety of conditions responds by generating electrical signals e.g. action potentials

Question 3

Functions of connective tissue

Answer 3

Bind together

Support

Strengthen other body tissues

Protect and insulate internal organs

Compartmentalise structures such as skeletal muscle

Major transport system e.g. blood

Store energy reserves – adipose

Main source of immune response

Question 4

Components of connective tissue

Answer 4

1)Cells:
Chondroplasts:
immature cells — Produce extracellular matrix

Chondrocytes:
Mature cells — maintain extracellular matrix

2)Extracellular matrix:
Fibres- collagen (main protein),elastin,reticulin
Ground substance

Question 5

Resident and fluctuating cells

Answer 5

Resident cells:

Fibroblasts-secret collagen active during wound repair forms granulated tissue

Lipocytes- store and synthesis fat

Fluctuating cells:

Macrophages- phagocytosis
Lymphocytes- phagocytosis
Mast cells- defence mechanism
Plasma cells- secret antibodies

Question 6

Extracellular matrix

Fibres

Answer 6

Collagen

Secreted by fibroblasts flexible with high tensile strength orientation of fibres depends on stresses which act on tissue. Found in ligaments tendons and joint capsule

Elastin

Smaller and less numerous yellow and branched. Found in lungs skin arteries and veins

Reticular:

Form supporting structures of many glands and basement membrane of epithelial tissues supporting frame of many organisations

Question 7

Extracellular matrix

Ground substance

Answer 7

Ground substance: Composed of water and large organic molecules gel like substance

• Complex combination of polysaccharides and proteins
• Polysaccharide – glycosaminoglycans
• Proteins – proteoglycans

Water molecules are trapped within the meshwork of these complexes producing viscous nature of gel

Acts as a mechanical barrier and means of diffusion of metabolites, electrolytes and gases between the tissues and capillaries

Question 8

Epithelial tissue vs connective tissue

Answer 8

Epithelial tissue

• Little or no extracellular matrix
• Many cells tightly packed
• No blood vessels
• Form surface layer not covered by another tissue

Connective tissue

• Large amount of extracellular material
• Cells usually widely scattered
• Significant network of blood vessels not cartilage