Lecture 5 - Connective Tissue Proper Flashcards
def: a matrix that links and supports other tissue types
connective tissue
what are the 2 main functions of connective tissue?
- structural support and organization
- metabolic support and transit
by volume, what does connective tissue consist of :
- few resident cells that are embedded in ECM
- protein fibers (collagen and elastin), ground substance
what are the 3 types of protein fibers in ECM?
- elastic fiber
- collagen fiber
- reticular fiber
def: more fibers, less ground substance, fewer cells
dense CT
def: few fibers, more ground substance, more cells (greater variety of cells)
loose (areolar) cells
def: found predictably in CT in stable numbers
fixed cells
def: enter connective tissue in response to a cue (infection or injury)
wandering/transient cells
def: immature cells, high division potential, multiple phenotypic fates, often produce and maintain ECM
-blasts
def: mature cells, lower division potential and more determined phenotypic fates
-cytes
def: often prune/remodel the ECM
-clasts
def: most numerous and critical cellular component of connective tissue, very common in loose CT and only cell of dense CT, large nuclei, abundant rER, surrounded by collagen
fibroblasts
def: synthesize collagen, elastic fibres, most carbohydrates of the ground substance, and reticulin
fibroblasts
what are fibroblasts nuclei like?
elongated, elliptical nuclei
what are fibroblast characteristics on EM?
- euchromatic nucleus
- prominent nucleolus
how are fibroblasts activated?
- by injury
- build basement membrane and sense tension
def: most abundant protein in the human body
collagen
def: type of collagen responsible for skin, tendon, vasculature, organs, bone
Type I
def: type of collagen responsible for cartilage
Type II
def: type of collagen responsible for reticulin, commonly found alongside Type I
Type III
what type of collage in the majority of collagen in the body?
Type 1, 90%
def: heterogenous group of inherited connective tissue disorders characterized by joint hyper mobility, cutaneous fragility, and hyperexternsibility
elhers-danlos sysndrome
def: CT in skin, aponeurotic fascia, tendons, ligaments, collagen fires are oriented in one direction and tightly packed, for maximum tensile strength
dense, regular connective tissue
def: modified dense CT that contains substantial amounts of elastin
elastin CT
def: fibres that stretch under tension but produce recoil, prominent in large arteries
elastin
is elastin eosinophilic or basophilic?
eosinophilic, wave like confomration
def: contains bundles of collagen fibers that are more randomly interwoven, with no definite orientation
dense, irregular connective tissue
what is the difference between dense irregular and regular CT in terms of how they provide resistance to stress?
regular = single axis
irregular = all directions
where is DICT found?
dermis layer of the skin and capsules surrounding most organs
def: delicate and contains cells, fibers, and ground substance equally
loose connective tissue (areolar)
fibroadipose tissue can be found in the _________
finger, but most common type of CT in the body
def: modified loose CT, characterized by delicate matrix of type III collagen (reticulin)
reticular CT
where is reticular CT found?
support structure in many organs: endocrine glands, lymph nodes, bone marrow, liver, reticular lamina of BMs
