BIOMED 10/16b CT Histology Flashcards
Roles of Connective tissue
- maintains/supports structure (dermal layer) - extensive amount of communication (mechanobiology) that allows it to respond through gap junctions
- mediates exchange of metabolites, waste, etc. - into and out of it and through it
- immune response, inflammation, and tissue repair
classifications of connective tissue?
- CT proper
- Loose (areolar)
- Dense (irregular and regular) - Specialized CT
what is loose CT proper?
- most abundant CT in the body, bundles in two types of tissues
- sparse fibers
- increased cells and ground substance
- vehicle by which blood vessels, nerves and lymph get to the target tissue
- allows space for things to travel into, through, and out of
- has elastin and collagen, but not as much as the gel-like ground substance
major functions of loose CT
- allow for space for things to travel where they need to go
- space packing, occupying materials, shock absorbers
what does loose CT have the most of?
ground substance and cells
what are two types of dense connective tissue?
- irregular
2. regular
what is dense irregular connective tissue?
- dermal layer of the skin
- withstands tension from different directions
- has the presence of elastic fibers
- responsive in any direction of stress
- densely packed with collagen, not arranged in parallel bundles
- sheaths around tendons and nerves
what kind of tissue is the dermal layer of the skin?
dense irregular connective tissue
what is the main purpose of dense irregular connective tissue?
withstand tension from different directions
what kind of bundles does dense irregular tissue form and what’s its purpose?
- densely packed with collagen
- not arranged in parallel bundles
- sheaths around the tendons and nerves are for protection so they can withstand stresses from various forces
what is dense regular connective tissue?
- collagen is bundled and in parallel arrangement
- only resist tension that’s built in its direction
- has ability to relay and respond to tensile stress
- found in ligaments, muscles, and aponeurosis (sheets layered in multiple directions)
can dense regular connective tissue withstand stress in any direction?
NO!
- it can only resist tension that’s built in it’s direction
- parallel bundles
what are some examples of specialized connective tissue?
- adipose - modified loose CT
- cartilage
- bone
- hematopoetic tissue (bone marrow)
what are the components of CT proper?
- ECM (fibers are functional part of ECM)
2. Cells (resident vs visiting)
two major components of ECM
- ground substance - largely proteoglycans
2. fibrous proteins - embedded throughout the ground substance
what is the purpose of proteogolycans in ground substance of CT proper
attract water to create a hydrated gel
what does the ECM dictate?
- amount of water
- types of fibers produced
- amounts of fibers produced
how will ECM vary?
it depends on the actual type o CT
- tendon is type I collagen and basically no ground substance
- -> lined up in parallel bundles, because it reacts to tensile stress
what is the ground substance made of
- GAGs - glycosaminoglycans
2. Structural Glycoproteins
what are GAGs
- collections of long chain sugars/polysaccharides (same as proteoglycans)
- highly negatively charged (can attract water)
- gel/mousse like substance
when will you have more watery GAGs
depends on the function
-Loose connective tissue has a much higher degree of water than a tendon
what is the purpose of structural glycoproteins in ground substance?
- BINDING proteins
- bind fibers to the ground substance
- bind fibroblasts (cells) to fibers
- the way things from the external surface get relayed to the nucleus
what are some examples of structural glycoproteins?
fibronectin
fibrillin
most common fibers in CT proper components
- collagen
2. elastin