1.introduction to IMMS Flashcards
what colour does Haematoxylin and Eosin (H&E) stain the nucleus, cytoplasm and extra-cellular structures
nucleus - blue
cytoplasm - pink (colour depends on contents)
extra-cellular - pink
how is tissue prepared for microscopy
preserved by fixing in formalin (prevents it from rotting)
then embedded in paraffin
thin slices made
for bone it must be de-mineralised or ground down
other types of stains
PAS (sugars), Van Gieson (elastic), Trichrome (3 types of cell), Alcian blue (mucins)
shapes of cells
rounded polygonal (irregularly shaped) fusiform (spindle shaped/elliptical) squamous (flattened) cuboidal columnar
activity of cells
metabolically inactive (dormant cells) are smaller than metabolically active - needs less machinery so has less cytoplasm metabolically active cells often have nucleoli
cell life spans
lining of gut - days
red blood cells - 120 days
cardiac muscle - whole life
nucleus ultrastructure
houses DNA
nucleolus - 1-3 microns in diameter, sites of ribosomal RNA formation
Euchromatin is lighter - less electron dense due to transcription than heterochromatin
mitochondria
powerhouse, site of oxidative phosphorylation, have their own DNA, double membrane (inner is highly folded)
rough endoplasmic reticulum
site of protein synthesis, highly folded flattened membrane sheets with ribosomes
smooth endoplasmic reticulum
site of membrane lipid synthesis, processes synthesised proteins, highly folded membrane sheets
golgi apparatus
parallel stacks of membrane, processes macromolecules synthesised in the ER, particularly prominent in plasma cells
vesicles
small, spherical, membrane-bound organelles used for transport, storage and exchanging cell membrane between compartments
lysosomes
derived from golgi apparatus, low internal pH due to H+-ATPase on membrane, contain acid hydrolases that degrade proteins, dangerous to cell so separation between two chemicals, initial hydrolase vesicles fuse with endosomes with the correct membrane proteins to produce endolysosomes
peroxisomes
small vesicle, contain enzymes which oxidise long-chain fatty acids
cytoskeleton
has lots of different filaments e.g. intermediate filament
desmin-myocytes
neurofilament protein neurons
call death
programmed - apoptosis (cell shrinks, becomes fragmented and is ingested by adjacent cells)
unprogrammed cell death occurs as a result of tissue necrosis
storage products and inclusions
lipid- non-membrane bound, appear as empty space as dissolve in processing, adipocytes and liver
glycogen - CHO polymer in cytoplasm, seen on electron microscopy, accumulates in some cells and diseases
composition of tissues
interstitial fluid (water, salts in solution, peptides and proteins) extracellular material (fibrillar proteins, inorganic salts and solids)
types of tissues
epithelia: protection, adsorption, secretion, form solid glands such as salivary glands
muscle: smooth, skeletal, heart, have contractile properties
supporting tissues: cartilage, bone, tendons, blood
nerves: brain, peripheral, visceral
germ cells: ova . sperm
what is chromatin
nuclear DNA + proteins
what is the function of the nucleolus
DNA transcription
what is the function of rough endoplasmic endoplasmic reticulum
site of protein synthesis
what intermediate filament is predominantly found
Desmin
where is cytokeratins found
epithelial cells
Glial fibrillary acidic protein
astrocytic glial cells
neurofilament
neurons
nuclear laminin
nuclei of all cells
vimentin
mesodermal cells
