IMMS: Histology Flashcards
Epithelia; Epithelial junctions; Connective tissue
What shape are smooth muscle cells?
Fusiform (spindle shaped).
What do polygonal cells look like?
Irregular shape, lots of soft cells squished together.
Why might a cell have a large nucleus?
Metabolically active; transcribing DNA to make proteins. Often also have nucleolus.
What filaments are microfilaments made of?
Actin.
What filaments are microtubules made of?
Tubulin.
What are intermediate filaments?
Made of proteins, spread forces through tissues. Different types of cells have different ones.
What sort of cells look like fried eggs?
Squamous cells! Nucleus projects up from cell.
What organelle can appear as a pale area in a cell?
Golgi body.
What filament in cytoskeleton has the smallest diameter?
Actin (5 nanometers).
What has a larger diameter: intermediate filaments or microtubules?
Microtubules (tubulin has 25 nanometer diameter).
Intermediate filaments (e.g. nuclear laminin) have 10 nanometer diameter.
What intermediate filament is predominantly found in muscle?
Desmin.
What sort of muscle cells are striated?
Skeletal or cardiac.
What is the difference between nucleus in cardiac muscle cells versus skeletal muscle?
Cardiac muscles cells: single nucleus, rounded in middle of cell, branching.
Skeletal muscle: can have multiple nuclei, pushed and flattened towards edge of cell.
What type of epithelium is this?
Single layer of flattened plate-like cells on basement membrane, nucleus standing proud of surface of cells, thin layer of cytoplasm.
Simple squamous epithelium.
What type of epithelium is found lining renal tubules?
Simple cuboidal epithelium.
Where might you find simple columnar epithelium?
Lining of small intestine, for example.
What is the difference between microvilli and cilia?
Microvilli = for absorption - increase luminal surface area of cells, fuzzy appearance on light microscopy.
Cilia = for movement - propel material along surface of epithelium, long hair-like projections containing contractile protein.
What type of epithelium would you find in the skin?
Stratified squamous keratinising epithelium.
Why might an epithelium be pseudo-stratified?
In an epithelium which needs to stretch and contract, when stretched epithelium is single layer of cells (simple), when contracted it can look multi-layered (stratified), but all cells are still in contact with basement membrane. For example, in respiratory epithelium in bronchi.
Where would you find hemidesmosomes and why?
Joining basal cells to basement membrane - spread forces across several cells in epithelium to resist mechanical forces.
What two proteins are principally involved in generation of ciliary movement?
Tubulin and dynein.
What type of collagen is found in the basement membrane?
Type IV collagen
What type of secretion releases entire cells?
Holocrine, type of exocrine secretion.
What do mesenchymal cells develop into?
Connective tissue, blood vessels, and lymphatic tissue.
What type of cells make up connective tissue?
Fibroblasts/cytes + adipocytes + visible fibres (collagen/elastin/reticulin) + ground substance (e.g. glycosaminoglycans, invisible fibres).
Where would you find Type I collagen?
Bone, tendon, ligaments, skin.