histology Flashcards
what are organelles
small intracellular organs
are inclusions dispensable
yes
what are inclusions
components that have been synthesised by the cell itself or taken up from the extracellular environment
what are microfilaments composed of
actin
are microtubules polar
yes - radiate outwards rom central portion of the cell
what proteins move along microtubules to drag organelles etc along the microtubule
dynein and kinesin
which direction does dynein move
towards cell centre
which direction does kinesin move
toward cell periphery
describe the layers of the nucleus
outer and inner nucelar memerbane in-between these perinuclear cistern
what is euchromatin
DNA actively undergoing transcription
what is heterochromatin
DNA that is condensed and not undergoing transcription
where are ribosomes formed
nucleolus
why is the RER rough
studded with ribosomes
what does the RER synthesise
proteins destined for secretion, membranes or lumen of other organelles
what does the SER do
synthesis steroid hormones and lipids
golgi apparatus function
modification and packing of macromolecules that were synthesised in the ER
anchoring junctions
provide mechanical strength
occluding junctions
link cells to form a diffusion barrier
communicating (gap) junctions
allow movement of molecules between cells
what are tight junctions
occluding
what are desmosomes
anchoring junctions - found in between cardiac cells
what are pores in gap junctions produced by
connexon proteins
what does H&E stain stand for
haematoxylin and eosin
define pseudostratified
tissue appears to have multiple layers but in fact all layers are in contact with a basal lamina
