Histology II Flashcards
(265 cards)
- What are the 3 types of epithelial tissues?
Contiguous cells, mucosa membrane and serous membrane
- Definition of Histology
Histology is the study of the microscopic structure of biological material and the ways in which individual components are structurally and functionally related.
- What are the characteristics of epithelium cells?
- A vascular
- Closely packed
- Have basal lamina
- What are the epithelium tissues derived from Ectoderm?
Skin, oral mucosa, glands of skin, mammary glands
- What are the epithelium tissues derived from Endoderm?
Liver, pancreas, respiratory and gastrointestinal tracts
- What are the epithelium tissues derived from Endoderm?
Liver, pancreas, respiratory and gastrointestinal tracts
- Definition of Tissue and the four main types
Tissue: collections of cells having similar morphological characteristics The four main types are: Epithelial Tissues Connective Tissue Muscular Tissues Nervous Tissues
- What composes the basement membrane?
Basal lamina -> lamina lucida + lamina densa
Lamina Retricularis
- What composes the lamina lucida?
Laminin, entactin
Laminin Receptors: integrins + dystroglcans
- What composes the lamina densa?
Collagen type 4 - anchoring
Collagen type 7 - fibrils
- What composes the lamina retricularis?
Fibroblasts, collagen 1+3
- Where can we find simple cuboidal epithelium?
Ducts of glands, Ovary covering, Kidney tubules
- Tissue preparation for TEM
- Fixation: glutaraldehyde and osmium tetraoxide
- Dehydrate and infiltration with some specific metal tissues.
- Embed and block fixed tissues in plastic.
- Cut into ultra-thin slices (50 nm thick)
- Stain sections with heavy metal salts (lead citrate and uranyl acetate) that bind nucleic acids & proteins.
- Where can we find stratified squamous epithelium?
Lining of mouth, oral pharynx, Vagina, Skin + keratinized
- Where can we find simple columnar epithelium?
Digestive tract, gall bladder, ducts
- Light microscopy description.
The light of the microscope is projected through the mirror to the condenser lens and to the specimen.
Objective lens magnifies the image of specimen (can be 4X, 10X, 40X to 100X).
The ocular lens projects to the eyes (10X).
- Magnification of Light Microscopy (formula)
Magnification = Ocular Lens x Objective Lens
- Resolution of Light microscopy
Anything smaller than 0.2 μm is out of resolution. (e.g. cellular membrane)
- Tissue preparation for light microscopy
- Stabilize cellular structures by chemical fixation.
- Dehydrate and infiltrate tissues with paraffin or plastic.
- Embed fixed tissue inside paraffin or plastic box.
- Cut into thin slices of 3-10 micrometer thick.
- Rehydrate and stain with Hematoxylin.
- Counter-stain with Eosin.
- Description of TEM (Transmission electron microscope)
The source of electrons is the cathode.
The electrons pass through the specimen and hit the bottom of the microscope, where the image viewing screen is.
- Alcian blue / Periodic acid-Schiff (PAS) Staining
- Strongly acidic mucins : blue
- Nuclei: pink, red
- Cytoplasm: pale pink
PAS detects polysaccharides as well as neutral and acidic mucins, allowing identification of hepatic glycogen, intestinal goblet cells and basal laminae.
- Where can we find trasitional epithelium?
Urinary system
- Where can we find Columnar pseudo-stratified epithelium?
Respiratory airways.
Usually contain cilia.
- What are the 3 cell surface specializations?
Brush border/microvilli, streocilia, cilia