0404 - Connective Tissue - RM Flashcards
What is connective tissue?
A group of similar, specialised, cells that collectively perform the common functions of: supporting and protecting organs, filling space between other tissues binding tissue systems together.
What are the four functions of connective tissue?
Structural (binding, protecting, supporting). Mediating (exchange of nutrients, intermediates, waste products between cells and circulatory system). Repair (including scarring) Defence (immune cells in blood)
What is the common origin of all connective tissue?
Embryonic mesenchyme.
What are the two basic forms of connective tissue?
Extracellular matrix (ground substance and fibres) Cellular (indigenous and migratory)
What cell type is the arrow pointing to?
Reticular CellIndigenous - Found in reticular connective tissue. Larger than fibrocyte. Large, lightly stained nuclei Irregular cytoplasm.Do not confuse with ‘reticulocyte’ - immature erythrocyte.
What are the two components of the extracellular matrix?
Ground substance (protein-based ‘gel’ between fibres)Fibres (collagen, elastin, or reticular)
What are the wavy pink fibres?
Collagen fibresMost CT fibres are made of collagen. Provides strength and support. Thick bundles with an elongated, wavy, pink appearance. Individual fibres 1-10µm wide. Fibres composed of fibrils and microfibrils. Striated appearance may be visible on electron microscopy.
What are the fibres in this image?
Reticular FibresTiny collagen fibres in loose CT and blood vessels. Form delicate networks that support cells, rather than bundles.Demonstrated by using silver stains (hence dark, not pink).
What lies between the two arrows?
Basement membraneSheet of ECM proteins that divides epithelial and functional cells. Provides anchor for epithelium. Controls growth of epithelial cells.
What are the two types of connective tissue? What are their sub-types?
Dense (fibrous) - more fibres, less cellsRegularIrregularLoose (areolar) - lots of small spacesMucoidReticularAdipose
Dense irregular connective tissue
Dense irregular connective tissueNo clear orientation of fibres. Bundles for a mesh, with fibrocytes scattered between. Found in dermis of skin, and capsules of organs.
What type of tissue is in the picture?
Mucoid connective tissueA few nuclei scattered between loosely-spaced fibres. Large amount of ground substance – may be jelly-like. Found in umbilical cord and dental pulp.
What tissue type is this?
Reticular connective tissueConsists of reticular cells and surrounding reticular fibres (delicate networks). Form a structure to suspend organ cells, assisting diffusion and cell movements. Found in liver, lymph nodes, spleen.
What are the two forms of adipose tissue? What are their functions?
White fat – one large droplet of fat provides energy storage.Brown fat – many small droplets of fat provides thermal regulation via mitochondria. Generally found in infants.
