37 Questions
Which stain highlights acidic mucosubstances and is commonly used to identify glycogen and mucin?
Periodic acid-Schiff stain (PAS)
Which type of epithelial tissue is commonly found in the urinary bladder and undergoes changes in shape when stretched?
Transitional epithelium
Which cell junction forms a barrier that prevents the passage of substances between cells and is commonly found in epithelial tissues?
Tight junctions
Which type of cilia is involved in moving substances along the cell surface, such as in the respiratory tract?
Motile cilia
Which type of connective tissue proper contains minimal collagen fibers and is commonly found under the epithelial lining of tissue?
Loose connective tissue
What is the main component of gluten that individuals with celiac disease mount an immune response to?
Gliadin
What structural damage occurs in the small intestine of individuals with celiac disease?
Flattening of the villi
What protein does gliadin bind to, leading to the release of zonulin in individuals with celiac disease?
Chemokine receptor CXCR3
What is the consequence of the disassembly of claudin and occludin proteins at the tight junction in individuals with celiac disease?
Leakage of gliadin into the lamina propria
What is the role of Larazotide acetate in the context of celiac disease?
Tight junction regulation
Which type of junction strengthens and stabilizes tight junctions, participating in cell-cell signaling that regulates cell division and proliferation?
Adherens junctions
What type of cells serve a protective function for mucous membranes and the skin, and facilitate the absorption of water, nutrients, and electrolytes?
Simple epithelial cells
Which proteins help in tight junction formation and interaction with the cytoskeleton?
Claudins
Where are tight junctions located in epithelial cells?
Apical aspect
Which type of cells have specialized functions such as secretion of substances into ducts or hormones into the blood?
Epithelial cells
Which cellular structure is responsible for binding to laminin in the basement membrane?
Integrin
What is the primary function of hemidesmosomes?
Link to intracellular intermediate filaments
What is the primary component of dense regular connective tissue?
Collagen oriented in one direction
What is the composition of the basement membrane?
Type IV collagen, proteoglycans, and laminin
What is the main intermediate filament in keratinocytes?
Keratin
Which structure in the skin is responsible for bringing nutrients and exchanging gases and wastes?
Capillary loops in the dermis
What is the function of the simple columnar epithelium in the intestinal mucosa?
Absorption of nutrients and water
Which cells have a protective and digestive role in the intestinal mucosa?
Goblet cells
Which protein is responsible for compacting keratin and attracting water to aid in skin moisturization?
Filaggrin
What is the main intermediate filament in keratinocytes?
Keratin
Which structure in the skin is responsible for bringing nutrients and exchanging gases and wastes?
Capillary loops in the dermis
What is the function of the apical microvilli in the intestinal mucosa?
Absorption of nutrients and water
Which type of collagen is found in the skin and provides structural support?
Type I collagen, forming thick fibers for strength and structure
Which two major components of ground substance play a crucial role in connective tissue function?
Proteoglycans for hydration and glycoproteins for ECM bonding
Which staining procedure is specifically effective in highlighting glycogen and glycoproteins in tissues?
Periodic acid-Schiff stain
What is the main advantage of confocal microscopy over light microscopy?
Confocal microscopy provides better depth resolution and can visualize structures in a particular plane
What is the purpose of fixation in histological tissue preparation?
To cross-link proteins and inactivate degrading enzymes while retaining tissue characteristics for staining
What is the minimum size of structures that can be visualized using light microscopy?
0.2 microns
What is the minimum size of structures that can be visualized using electron microscopy?
3 nm
Which staining procedure is commonly used in tissue preparation and binds to negatively-charged molecules?
Hematoxylin
What is the purpose of histology at the junction of anatomy and physiology?
Deducing the function of a cell or tissue by its microscopic structure
What is the significance of histological examination in the diagnosis of diseases and conditions?
Revealing abnormalities in cells and tissues
Study Notes
Cellular Structures in Histology
- Desmosomes and hemidesmosomes provide structural stability to cells
- Integrin is the transmembrane "linking" protein in hemidesmosomes, binding to laminin in the basement membrane
- Hemidesmosomes do not have important intracellular signaling functions but link to intracellular intermediate filaments
- Cellular junctions contribute to paracellular transport, barrier function, strength, polarity determination, signaling, and anchoring
- Motile cilia in epithelial cells have a 9 + 2 structure and propel fluids in a single direction
- Primary cilia are non-motile, longer than microvilli, and important in sensing environmental information
- Loose connective tissue contains ground substance, many cells, and relatively little collagen
- Dense irregular connective tissue has fewer cells, less ground substance, and more collagen arranged in multiple directions
- Dense regular connective tissue has collagen oriented in one direction, resisting stresses along one line or plane
- Different types of collagen have specific functions, such as resisting tension or absorbing shock
- Type IV collagen forms the basement membrane, linking epithelial and connective tissue layers
- The basement membrane is composed of type IV collagen, proteoglycans, and laminin, to which integrins bind
Introduction to Histology and Tissue Preparation
- Histology is the study of tissues under a microscope, often prepared using light microscopy or electron microscopy.
- Light microscopy can visualize structures as small as 0.2 microns, while electron microscopy can visualize structures as small as 3 nm.
- The process of tissue preparation for examination involves fixation, dehydration, clearing, infiltration, embedding, and trimming.
- Living and dead cells can be stained with dyes to improve visualization, highlighting specific molecules with particular chemical properties.
- Hematoxylin and eosin staining is commonly used in tissue preparation, binding to negatively-charged and positively-charged molecules, respectively.
- Other staining procedures include DAPI, AO/EB, Masson's trichrome, methylene blue, PAS, and acid fuchsin, each highlighting different molecules and organelles.
- Histology is useful at the junction of anatomy and physiology, as the function of a cell or tissue can be deduced by its microscopic structure.
- Histological examination can reveal abnormalities in cells and tissues, aiding in the diagnosis of various diseases and conditions.
- The text also includes descriptions of connective tissue types, collagen types, ground substance components, and the structure and composition of the skin and intestinal mucosa.
- It also briefly describes the epidemiology, etiology, common symptoms, and pathophysiology of atopic dermatitis and celiac disease.
- The text provides information on the use of confocal microscopy and electron microscopy, including the University of Saskatchewan's confocal microscope and an electron microscope image.
- It also explains the purpose and significance of histology, emphasizing its role in understanding cellular and tissue pathology.
Test your knowledge of cellular structures in histology and tissue preparation, including desmosomes, hemidesmosomes, cilia, connective tissues, staining procedures, and the role of histology in understanding cellular pathology.
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