Introduction to Cytology Lab Flashcards
What is the structure in the center green circle?
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nucleolus
EM
What is the image in the black circle?
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intercellular space between two lipid bilayers
EM
What is the black arrow pointing to?
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intercellular space
LM
What is the structure outlined in white?
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nucleolus
EM
What is the black arrow pointing at?
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nuclear pore
What are the black arrows pointing at?
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nuclear pores
Function and structure of cell membrane:
- Barrier between two aqueous compartments
- Phospholipid bilayer (5-10nm in width)
- composed of cholesterol, glycolipids, phospholipids, proteins
Function of nucleolus:
- Synthesis of ribosomal rRNA and assembly of ribosomal subunits
Function of nuclear pore:
- Communication gates for macromolecules between cytoplasm and nucleus
The inner nuclear membrane is associated with:
nuclear lamins
The outer nuclear membrane is continuous with:
endoplasmic reticulum
What are the black arrows pointing to?
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mitochondria
What are the black arrows pointing to?
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- left arrow = mitochondria double membrane
- top arrow = mitochondria cristae
Mitochondria structure and function:
- ATP production
- double membrane
- cristae = folds of inner membrane
Golgi function:
- Modifying, Sorting and Packaging of proteins
- Targeting enzymes to lysosomes
What is the white arrow pointing to?
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Golgi apparatus
- left = EM; stacks
- right = LM; used silver stain
Golgi can only be visualized with what type of stain?
silver stain
will not be visualized in LM with H&E
What is the red arrow pointing to?
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unstained Golgi in LM with H&E
Lysosome function:
- Membrane bound granules containing hydrolytic enzymes
- Very difficult to recognize under EM
- Can be identified using immunocytochemistry
Cell inclusions are:
- Structures in cytoplasm formed from metabolic products of cell.
- Considered nonliving components of cell.
- Glycogen (no membrane)
- Lipid droplets (no membrane)
- Pigment granules (membrane)
What are the black arrows pointing to?
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glycogen in EM
What is the black arrow pointing to?
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Glycogen in LM
stained with Best Carmine Stain
What are the arrows pointing to?
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lipid droplet in EM
What is the white arrow pointing to?
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lipid droplets in LM
stained with toluidine blue
Lipid content is usually _____ during the dehydration process of embedding sections.
- washed out
- lipid droplets appear empty in the H&E sections
Secretory granules are:
- membrane bound packets of stored products which have gone through the biosynthetic pathway
What are the arrows pointing to?
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secretory granules
- left = EM (dark spots, constant shape)
- right = LM (red spots, constant shape)
Cells storing many granules is indicative of:
regulated secretion
What are the green and black arrows pointing to?
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- green arrow = secretory vesicles
- black arrow = rough ER
Rough ER function and structure:
- Membrane system studded with ribosomes
- Responsible for:
- Protein synthesis
- Glycosylation of glycoproteins
Smooth ER structure and function:
- System of vesicles and tubules
- Lipid and steroid biosynthesis
- Detoxification of drugs
- Ca++ storage,
What are black arrows pointing to?
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smooth ER
- right = EM
- left = LM
Functions of cytoskeleton:
- Cell movement
- Support and strength for the cell
- Phagocytosis
- Cytokinesis
- Cell-cell and cell-extracellular matrix adherance
- Changes cell shape
Can Microfilaments, microtubules, or intermediate filaments be seen under LM?
no
What are the black arrows pointing to?
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Actin filaments of microvilli
What is this an image of?
cross-section of actin microfilaments of microvilli
Actin forms the structural basis of:
- Microvilli
- Steriocilia
- Adherent junctions
- Anchorage and movements of membrane proteins
Microvilli:
- Extension of the cell membrane whose core is actin filaments
Microtubules:
- Small cylindrical structures composed of tubulin
- 25nm diameter
Microtubules form the structural basis of:
- Centrioles
- Cilia
- Basal bodies
- Mitotic spindles Involved in intracellular traffic of vesicles
What is this an image of?
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centriole
What are the dark structures in this image?
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centrioles
Centrioles:
- 9 triplets of microtubules
- Usually paired structures
- Important association with microtubule-organizing center of cells
- Mitotic activity
- Unable to see under LM
What is the green arrow pointing to?
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cilia
What is this an image of?
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cross-section of cilia
Cilia:
- Extension of the cell membrane whose core is microtubules
- Core of 9 doublets + 1 central doublet of microtubules
What is on the left and what is on the right?
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- left = microvilli (tight and uniform packed)
- right = cilia
What are the black arrows pointing to?
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intermediate filaments
Intermediate filaments:
- Provide mechanical support for the cell
- 10nm diameter
Location of intermediate filaments:
- Hemidesmosomes
- Epidermis of skin
- Skeletal muscle cells
- Astrocytes
- Nuclear lamins
What is pictured in this image?
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hemidesmosome
- attaches epithelial cell to connective tissue
What are the black arrows pointing to?
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Junctional Complexes in LM with H&E
(terminal bar)
What are the three domains of a junctional complex?
- zonula occludens (top)
- zonula adherens (middle)
- macula adherens (bottom)
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