Introduction to Cytology Lab Flashcards
What is the structure in the center green circle?
nucleolus
EM
What is the image in the black circle?
intercellular space between two lipid bilayers
EM
What is the black arrow pointing to?
intercellular space
LM
What is the structure outlined in white?
nucleolus
EM
What is the black arrow pointing at?
nuclear pore
What are the black arrows pointing at?
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?
mitochondria
What are the black arrows pointing to?
- 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?
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?
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?
glycogen in EM
What is the black arrow pointing to?
Glycogen in LM
stained with Best Carmine Stain
What are the arrows pointing to?
lipid droplet in EM
What is the white arrow pointing to?
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?
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?
- 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?
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?
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?
centriole
What are the dark structures in this image?
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?
cilia
What is this an image of?
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?
- left = microvilli (tight and uniform packed)
- right = cilia
What are the black arrows pointing to?
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?
hemidesmosome
- attaches epithelial cell to connective tissue
What are the black arrows pointing to?
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)
