chapter twenty-one Flashcards
tissues are constructed on a _____
matrix
how are tissue types categorized? 4 ways
connective, epithelial, nervous and muscular
______ tissue is mostly extracellular matrix material with cells interspersed within
connective
________ tissue is mostly composed of collagen fibers
connective
collagen proteins assemble into _____ _____ _______
triple helix coiled-coils
to avoid premature assembly, collagen is secreted from cells as _______
procollagen
procollagen contains sequences that block _______
assembly
in the extracellular space ______ cleave the prosequences, allowing assembly of collagen
proteases
_____ ______ links cells to the extracellular matrix
integrin adhesion
integrin adhesion also influences the cells by activating _____ _______ processes to the cell interior
signal transduction
protein molecules that are highly modified with ____ ______ fill space in the extracellular matrix
carbohydrate structures
carbohydrate molecules bind a lot of _____ and make a gel material between collagen fibers
water
_____ cells seperate biological compartments and regulate their composition by transport processes
epithelial
epithelial cells sit on a ____ ____
basal lamina
_______ epithelia have distinct domains with different compositions
transporting
domains of epithelia are separated by _____ ____, producing the apical and basal domains
tight junctions
the ______ _____ prevents ions and solutes from leaking between cells
tight junction
tight junctions are composed of ____ and _____ proteins that form from interlacing strands
occludin and claudin
______ cell adhesion molecules create small links that are strong in large patches
cadherin
linker proteins connect adhesion molecules to the _____ cytoskeleton
actin
the adherens junction is mediated by _____
cadherin
constricting ___ ____ can change epithelial shape producing tissue morphogenesis
adherens junctions
differentisl cell adhesion produces ___ ___
cell sorting
_____ ____ are channel proteins that link with another cell, creating a cytoplasmic bridge between cells
gap junctions
____ ____ have the instructions to continuously renew our tissues
stem cells
3 factors that control cell renewal
communication, selective cell adhesion and cell memory
the stem cells are located where
base of the crypt
stem cell niche in the crypt regulates _____ and ______
proliferation and differentiation
Hematopoietic stem cells produce what
blood cells
______ _____ _____ are derived from the inner cell mass of the blastocyst stage mammalian embryo
embryonic stem cells
embryonic stem cells are _______ which means that they can produce 3 germ layers
pluripotent
what are the 3 germ layers
ectoderm, mesoderm, endoderm
cancer is a ____ cell disease
stem
abnormal stem cells produce ___ _____ that propagate and spread
abnormal tissues
altered versions of normal cellular genes (typically gain-of-function)
oncogenes