Connective Tissue Flashcards
What is connective tissue?
Characterized by large amounts of intracellular substance with very few cells
Connective tissue consists of…
- cells
- extracellular fibers
- ground substance
What are the 3 types of connective tissue?
- embryonic connective tissue
- connective tissue proper
- specialized connective tissue
What are the types of embryonic connective tissue ?
- mesenchyme
- mucus
What are the types of connective tissue proper?
Loose connective tissue
Dense connective tissue
-irregular
-regular
What are the types of specialized connective tissue ?
Adipose tissue
Blood
Bone
Cartilage
What are loose (areolar) connective tissue ?
- Contains more cells than collagen fibers
- Located in mucosa and submucosa of various organs
- Surrounds:
- muscles
- nerves
- blood vessels
Describe connective tissue proper
-dense connective tissue
- contains more collagen fibers than cells
- regular dense connective
Tissue
-collagen fibers are preferentially oriented
- regular dense connective tissue
- collagen fibers
- randomly oriented
- collagen fibers
- reticular fibers
- found in dermis of skin
Where are connected tissue proper found?
- Tendons
- ligaments
- cornea
What are the most abundant fibers of connective tissue?
Collagen fibers
How does collagen fibers appear?
Appear wavy
-variable width
-intermediate length
Stain easily with Eosin (Acid dye)
What are the functions of reticular fibers?
Supporting framework for cellular constituents of tissue & organs
Form supporting stroma in hemopoietic and lymphatic tissues (not thymus)
In these cases: fibers surround the cells and isolate them
What are reticular fibers?
-closely related to collagen
- composed of type III collagen
- Also may have some type IV collagen
Fibers are about 20 nm diameter
What are the function elastic fibers?
Enable tissues to stretch and distend
Prevents tearing
What are elastic fibers ?
Elastic fibers are thinner than collagen
-In large amounts, give a yellowish color to tissues
-fibers are interwoven with collagen
Prevents tearing
What are the functions of ground substance?
“Glue”- binds cells to fibers
“Lubricant” - allows ease of motion (pathway for cell migration)
“Barrier” - physical prevention of bacteria and microorganisms
Tissue tensile strength
What is ground substance?
-occupies the space between cells and fibers
- clear, viscous substance
- high water content
- Appears amorphous in light micrographs
- stains with PAS stain
- always lost in H &E preps
Consists largely of:
- Proteoglycans
- Hyaluronic acid
Types of cells and their numbers reflect their…
Functional activity
Connective tissue cells are classified as:
- Fixed
- Wandering
What are the functions of fibroblasts ?
Principal cell of connective tissue
-Main cell involved in wound repair
Synthesize
-collagen
- elastin
- reticular fibers
- complex carbohydrates of ground substance
Describe macrophages
- possess a large indented or kidney-shaped nucleus
- ingestion and degradation of foreign matter
- Stimulation of the immune response by immune presentation
- fixed and wandering
Where are macrophages derived from?
Derived from monocytes in the bone marrow
Macrophages are difficult to identify unless…
They display obvious phagocytosis
What are mast cells?
- Oval, cytoplasm filled with basophilic granules
- Storage of chemical mediators of inflammatory response
