Histology Flashcards
THIN and SPARSE collagen fibers, abundant ground substance
osurrounds small blood vessels
oSITE of INFLAMMATORY/IMMUNE RXN
ex. Lamina Propia
Loose CT
Abundant collagen fibers and Little ground substance/Few fibroblasts (provides STRENGTH)
- bundles running in various directions
ex. submucsa of organs and reticular layer beneath the dermis
Dense Irregular CT
main fxnl component of TENDONS, LIGAMENTS, and APONEUROSES aka flat tendon (very pink on the right)
o Fibers arranged in parallel & densely packed to provide strength
Dense Regular CT
o Each collagen molecule is a triple helix composed of
3 intertwined polypeptide chains
Loose/Dense c.t. seen in bone, tendon, ligaments, etc
Type I collagen
Hyaline/Elastic Cartilage
Type II collagen
Reticular fibers/Meshwork aka Granulation tissue
Type III collagen
BM
Type IV collagen
provide supporting framework for the cellular constituents of various tissues/organs & are similar to collagen _______ but composed of _______ collagen
Reticular Fibers, type I, type II
Type I collagen to limit distensibility & prevent tearing/excessive stretch, fibroblasts & vascular smooth muscle cells, MAJOR Extracellular substance in ligamens, larynx, elastic arteries
Elastic Fibers
most abundant glycoprotein in c.t. & fxns in cell attachment to ECM, and is a type of ______
fibronectin, glycoprotein
binds osteoclasts and ataches them to underlying bone surface (Also sequesters calcium/promoting calcification of ECM), and is a type of ______
Osteopontin, Multiadhesive glycoprotein
basal/external laminae & has binding sites for type IV collagen molecules
laminin
GAG + Core Protein & look like a brush (syndecan and Aggrecan)
Proteoglycans
principal cell of c.t. and responsible for synthesis of collagen, elastic and reticular fibers, & complex carbs of ground substance (Purple cells)
fibroblasts
elongated, spindly c.t. consisting of bundles of actin filament w/ associated actin motor proteins like non-muscle myosin, regulating the shape and emptying of the glands and wound contraction and closure
myofibroblasts
phagocytic cells derived from monocytes & are also known as tissue histiocytes
macrophages
spherical nucleus & basophil granules
Responsible for anaphylactic rxns: antibodies can bind to mast cells and release their contents/histamine
mast cells
spherical nucleus & basophil granules
Responsible for anaphylactic rxns: antibodies can bind to mast cells and release their contents/histamine
cartilage
chondroblasts are formed by the inner layer of perichondrium (cells produce collagen type I), they produce matrix (collagen type II) and turn to chondrocytes aka forming NEW cartilage AT surface of existing cartilage
apositional growth
division of chondrocytes within the lacunae – isogenous groups aka forming new cartilage WITHIN cartilage mass
interstitial growth
o Resting cell that can differentiate into osteoblast and secrete bone matrix
appositional bone formation
flattened cells that resemble fibroblasts
Osteoprogenitor cells
lining internal bone surfaces
line external bone surfaces
Endosteal
Periosteal
____ increases osteoclast activity, ______ decreases it
PTH, calcitonin
summarize intramembranous ossification
`mesenchymal cells, osteoblasts, secrete osteoid, mineralize, enclose into lacunae to become osteocytes, growth via appositional growth via osteoprogenitor cells
plate forms bone towards the opposite directions lengthening the bone – eventually it calcifies in the age of 20s
Epiphyseal Plate
Layers of the epiphyseal cartilage
Reserve, Proliferation, Hypertrophy, Calcified Cartilage, Resorption
Increases in diameter with apositional growth and osteoclasts continually remodel the bone
In bone growth and remodeling, what two things help keep levels of calcium and phosphate high in order for crystalization and mineralization to occur
Osteocalcin and ALP/Alkaline phosphatase
_____ crystals: initiate matrix mineralization by formation/deposition of _________crystals (Ca10(PO4)6(OH)2) into the matrix surrounding the osteoblasts
CaPO4, hydroxyapatite
o ________ transmits info about degree of stretching in a muscle fiber/length
o SENSORY________ nerve fibers: carry info from muscle spindle to CNS
o ___________nerve fibers: from brain/SC that innervate spindle cells and regulate sensitivity of stretch receptor by ___________________in muscle spindle so it can sense stretch
Muscle spindle, afferent Ia, ϒ-motor efferent, keeping intrafusal fibers taut
____________in tendons responds to increased tension via ______nerve fibers
golgi tendon organ, sensory afferent Ib
