(Pt.1) Connective Tissue Flashcards
What is Connective tissue
- Prevalent in the body, but amount in certain organs vary
- Skin mostly CT, but brain is very little
What are the four main classes of Connective tissue
- Connective Tissue proper
- Cartilage
- Bone
- Blood
What are the major functions of Connective Tissue
DO NOT only connect body parts
- binding/ supporting
- protecting
- Insulating
- Storing reserve fuel
- Transporting substances w/in the body
What are common characteristics of Connective Tissue
Two characters (set them apart from others)
- extracellular matrix
- common origin
What is Extracellular matrix of the common characteristics
- Large nonliving, which separate often widely, living cells of connective tissue
- Due to matrix, CT can bear weight, w/stand great tension & endure abuses like physical trauma/ abrasion, that no other tissue can tolerate
What is Common origin of the common characteristics
- All CT come from mesenchyme (embryonic tissue)
What are the three main structural components of Connective Tissue
- ground substance
- fibers
- cells
What is Ground Substance
- Unconstructed material that fill the space between cells that set them apart from other tissues
What are the three components of Ground substance
- Interstitial fluid
- Cell adhesions
- Proteoglycans
What is interstitial fluid
- Ground substance made of large amounts of liquid fluid/ functions as molecular sieve which nutrients and other dissolved substances can diffuse between the blood capillaries and cells
What are Cell adhesions
- Connective Tissue glue that allow connective tissue cells to attach to the extracellular matrix
Explain Proteoglycans
- Protein core with large polysaccharides attached called glycosaminoglycans (GAG)
- The strandlike GAG’s, chrondroitin sulfate and hyaluronic acid stick out of the protein core like fiber of a bottle brush
- form huge aggregates
- High GAG content = more viscous the ground substance
What are Connective Tissue fibers
- fibers that give support (strongest/ most abundant as well)
Three types of connective tissue fibers in the matrix
- collagen
- elastic
- reticular
What are collagen fibers
- primarily protein collagen
- collagen molecules are secreted into extracellular space and build cross linked fibrils spontaneously, then are bundled together into thick collagen fibers seen with a microscope
- white
- extremely tough/ high tensile strength to the matrix (ability to resist being pulled apart)
What are elastic fibers
- long thin and create branching networks in the ECM
- rubberlike protein, elastin that allow recoil and stretching like rubber bands
- connective tissue can only stretch so much, before thick rope like collagen fibers become taut. when tension lets up elastic fibers snap CT
- Found where greater elasticity is needed (lungs, skin, blood vessel walls)
What are reticular fibers
- short, thick type made of different collagen than the thicker type
- connect to coarser collagen fibers, but branch extensively forming delicate networks (reticul 5 network) that surround small blood vessels and support the soft tissue organs
- particularly abundant where CT is next to other tissue types
Ex:
- in basement membrane of epi tissues and around capillaries where they form fuzzy “nets” that allow more stretch than the larger collagen fibers
Explain Connective Tissue cells
- Each CT major class has a resident type that exist in immature (-blast) / mature (-cyte) forms
Ex:
- fibroblast –> fibrocytes
- Chondroblast —> chondrocyte
Which major class of CT is an exception to the CT cells rules of mature (-cyte) and explain
blood:
- immature, hemocytoblast is called a hematopoietic stem cell
- not located in its tissue (blood) and do not make fluid matrix (plasma) of that tissue
What takes place with CT cells
- immature blast cells are actively miotic
- each blast cell secrete ground substance/ fiber characteristics of particular matrix
- Once matrix is synthesized, blast cells are mature (less active -cyte)
- mature cells maintain health of matrix
- if matrix injured they can revert back to more active -blast form and repair/ regenerate matrix
Connective tissue is home to what other cells
- Adipocytes
- White blood cells
- Mast cells
- Macrophages
What are adipocytes
- called adipose/ fat cells
- store energy as fat
what are white blood cells
- (WBC’s, leukocytes, neutrophils, eosinophils, lymphocytes) also other cell types dealing with tissue response to injury
What are Mast cells
- typically cluster along blood vessels
- ova cells that detect foreign microorganisms (bacteria, fungi) and start local inflammatory responses against them
chemicals:
- heparin (anticoagulant)
- proteases (enzyme)
What are Macrophages
- large, irregularly shaped cells
- devour a broad variety of foreign materials from molecules to entire bacteria
- attached to CT fibers/ move through matrix freely
LOCATION: loose CT - dispose of dead tissue cells and central actors in the immune system
