2.2 Connective Tissue Flashcards
What are the 4 tissue types?
Nerve, Muscle, Epithelial and Connective tissue
What are the characteristics of connective tissue?
Extracellular matrix containing specialised cells
What are the functions of connective tissue?
Connects - cells to form tissues, tissues to form organs.
Protects - adipose cushion for organs
Transports - nutrients to epithelial cells
Defence - lymph contains immune cells
Storage- triglyceride storage in adipose
Wound healing- macrophages and fibroblasts
What is connective tissue made up of?
- Fibres
- Cells
- Ground substance
What fibre types are present in CT and how do they differ?
- Collagen - type 1, high tensile strength
- Elastin - fibrillin, allows recoil
- Reticular - type 3 collagen, supporting framework
What is the composition of ground substance?
Made of proteoglycans, which consist of a core protein and covalently bound glycosaminoglycans (GAGs) which are long chained polysaccharides. They attract water, giving it a high water content. Resists compression.
Hyaluronic acid = GAG in cartilage.
What are some of the fixed cells present in CT?
Melanocytes Macrophages Mast cells Fibroblasts Adipocytes
What are some wandering cells in CT?
Plasma cells, white blood cells, macrophages
Why are fibroblasts so important?
They secrete fibres and ground substance. E.g pro collagen
What is in the mast cell granules?
Heparin (anticoagulant) and Histamine
What are the 3 types of loose CT?
- Areolar
- Reticular
- Adipose
What are the characteristics of loose CT?
Allows free movement with minimal resistance.
How does areolar, reticular and adipose loose CT differ?
- Areolar lies beneath all epithelia.
- Reticular is dominated by reticular fibres and forms framework around organs and lymph nodes.
- Adipose has little extracellular space, filled with adipocytes which cushion organs.
What are the 3 types of dense CT?
Regular, Irregular and Elastic
Explain the structure and function of regular dense CT.
Parallel collagen fibres with mainly fibroblasts and little ground substance.
High tensile strength in one direction.