1.03 - Connective Tissue Flashcards
Define: Tissue
A group of similar cells specialised in a particular way for the performance of a common function
Define: Connective Tissue
Supports the various organs and fills the spaces between different tissue types. Binds tissue systems together.
What does connective tissue do?
Structural (binds together, protects and support other tissues)
Mediate exchange of nutrients, metabolites and waste products between cells and the circulatory system
Repair
Defence
What two components form connective tissue?
Extracellular matrix (made up of ground substance & fibres) Cells: Indigenous (fibroblasts, adipocytes & reticulocytes) & Migratory (cells of the immune system)
What are the two different types of connective tissue in the body and their respective subtypes?
Connective tissue proper
Special: vascular connective tissue, cartilage, bone
What are the types of indigenous cells that form part of connective tissue?
Fibroblasts
Reticulocytes
Adipocytes
Describe Fibroblasts
The active form of the cell
Responsible for maintenance and synthesis of extracellular matrix
Contain large amounts of organelles
Easily found in healing wounds
What is a Fibrocyte and how is it different to a Fibroblast?
Fibrocytes are the mature inactive form of fibroblasts. They are larger than fibroblasts and their nuclei typically stains lighter
They also have irregular cytoplasms
Describe Adipocytes
Adapted for storage of fat Immature form in known as lipoblast Very long lived cells Large in size due to fat accumulation Nucleus pushed to periphery
Describe the differences between White Adipose and Brown Adipose Tissue
White: 20-25% of total body weight in humans. Important for energy storage. Thermal insulator. Cushion against mechanical shock for deep organs.
Brown: Typically found in newborns. Temperature regulation
Name the Migratory cells of the immune system
Macrophages Mast Cells Plasma Cells Eosinophils Lymphocytes
Describe Macrophages
Precursor: monocytes
Originate in bone marrow and enter blood stream. Enter tissue and differentiate into macrophages
Life span: months to years
Main function is defence: act as tissue scavengers as they phagocytose foreign materials
Antigen presenting cell to lymphocytes and other cells
Describe Mast Cells
Derived from basophils in the bone marrow
Migrate to peripheral tissues such as the skin and GIT and develop and differentiate.
Cytoplasm filled with numerous large vesicles
Present in healthy connective tissue - they stand guard and monitor local situation
Function: defence against protein containing foreign material like bacterium or allergens
Discharge contents of vesicles (heparin and histamine) on contact which causes capillaries to leak, vasodilation and improve blood flow to the area
Describe plasma cells
main function: defence
Produce antibodies. cytoplasm increases when producing antibodies
Describe Eosinophils
Originate in bone marrow
Rounded or oval cells with a bilobed nucleus
Contain large amounts of bright red granules in the cytoplasm.
Found in healthy connective tissue
8-12 day life span
Main Function: Defence against parasites and in some allergic disorders - either phagocytose or release their granule content