Connective & Adipose Tissue Flashcards
What does all connective tissue develop from?
Embryonic mesenchyme tissue.
What are some examples of connective tissue?
Adipose, Blood, Cartilage, Bone, Lymphatic
What are some functions of connective tissue?
Storage.
Insulation.
Connects cells, tissues, organs etc.
Transportation.
Defence.
What is the basic composition of all CT? (3 things)
1) Cells
2) Fibres
3) Ground Substance
What are the 3 types of fibres found in connective tissue?
Collagen.
Reticular.
Elastin.
What are some features of collagen fibres in CT?
Flexible, high tensile strength.
What are some features of reticular fibres in connective tissue?
Provides a supporting framework/sponge. (Type of collagen)
What are some features of elastin fibres in tissue?
Allows tissues to recoil after stretching.
What is the ground substance of CT?
A viscous, clear substance composed of proteoglycans. High water content.
What is a proteoglycan?
Makes up the ground substance.
Large macromolecule with a core protein and many bound GAGs.
What is a glycosaminoglycan (GAG)? What are some of its features?
Long-chained polysaccharide
Attracts water to form a hydrated gel for rapid diffusion and resistance to compression
What makes up the extracellular matrix in CT?
Fibres and ground substance.
What are the 2 types of CT proper?
Loose
Dense
What are some features of loose CT?
Many cells.
Sparse collagen fibres.
Abundant ground substance.
What is a important function of loose CT?
Allows rapid diffusion of molecules so important role in transport.
What are some features of dense CT?
Few cells.
Many collagen fibres.
Little ground substance.
Nearly all of the cells in dense CT are…
Fibroblasts
What are two types of dense CT?
Dense REGULAR CT
Dense IRREGULAR CT
Name 3 places loose CT is usually located and why?
Beneath epithelia - to facilitate diffusion.
Associated with the epithelium of glands.
Around small blood vessels.
How are collagen fibres arranged in dense regular CT?
Densely packed in parallel bundles.
What is found between bundles of collagen fibres in both regular and irregular dense CT?
Fibroblasts
Where is dense regular CT found?
Tendons, Ligaments
How are the collagen fibres in dense irregular CT arranged?
Arranged in bundles in various directions.
Where is dense irregular CT found?
Submucosa of intestine. Deeper levels of dermis.
Dense regular CT withstands stress in ….. direction(s)
1 direction
Dense irregular CT withstands stress in ….. direction(s)
Multiple directions
Cells found in CT can be categorised into which 2 categories?
Fixed and Wandering Cells.
Give some examples of fixed cells in CT.
Fibroblasts.
Mast Cells.
Macrophages.
Adipocytes.
Give some examples of wandering cells in CT.
Leucocytes. Plasma Cells. Monocytes. Eosinophils. Basophils.
What is the function of fibroblasts?
Synthesises and secretes both the ground substance AND fibres of the ECM.
In particular what organelle do fibroblasts have lots of and why?
RER.
For production of secretory vesicles of procollagen.
What cells are responsible for the formation of scar tissue in the wound healing process?
Fibroblasts
What cells are macrophages derived from?
Monocytes
What does the cytoplasm of mast cells contain?
Abundant granules of histamine and heparin.
Mast cells are particularly found in mast cells where?..
CT near blood vessels.
What prompts the release of granules from mast cells?
Allergens binding to Immunoglobulin E.
What are the main functions of histamine and heparin respectively?
Increase blood vessel wall permeability.
Anticoagulant.
Where does elastic fibres (elastin) play an important role in the body?
Sites with elastic cartilage.
Dermis, artery walls, lungs.
What is the most common type of collagen?
Type 1 collagen. (90% of all collagen)
Where is type 1 collagen typically found?
Tendons, skin dermis.
What is a difference between type 1 and type 2 collagen? Where is type 2 collagen found?
Type 2 collagen fibrils do not form fibres.
Found in hyaline and elastic cartilage.
What is type 3 collagen? Where is it typically found?
Reticulin.
Found AROUND muscle/nerve and in the lymphatic system.
Where is type 4 collagen found?
The basal lamina of basement membrane
What is vitamin C required for in relation to collagen? What does a deficiency in vitamin C result in?
Required for the intracellular production of procollagen.
Scurvy.
What are 2 symptoms of scurvy?
Poor wound healing.
Poor bone function.
What is osteogenesis imperfecta? What is it a result of?
Genetic disorder where bones are broken more easily.
Due to abnormal type 1 collagen.
What are two types of fat cells? Which type makes up the majority of adipose tissue?
White and Brown
Majority is white fat cells.
What does a white adipose cell consist of?
Contains fat. Almost completely filled by a single lipid droplet.
Why do white cells look empty when H + E stained? What are 2 functions of white cells?
Toluene and xylene have dissolved away the lipid.
Insulation. Shock-absorption.
What is the structure of brown adipose cells?
Contain many lipid droplets and a central nucleus.
What contributes to the brown colour of brown cells?
Rich vascular supply and many mitochondria.
