Tissues 1 (Epithelial Cells) Flashcards
What are the 3 connective tissue cells?
- fibroblasts
- chondrocytes (cartilage)
- osteocytes (bone)
What are the 3 contractile tissues?
- skeletal muscle
- cardiac muscle
- smooth muscle
What are haematopoetic cells?
- blood cells
- tissue-resident immune cells
- bone marrow cells
What are the 2 neural cells and their functions?
- neurones (carry electrical signals)
- glial cells (support cells)
What are the functions of epithelial cells
- form continuous layers
- line surfaces
- separate tissue compartments
What is a mesenchymal cell?
- connective tissue
- fibroblasts, chondrocytes & muscle cells
Which cells do carcinomas, sarcomas, leukaemias & neuroblastomas originate from?
- carcinoma: epithelial
- sarcoma: mesenchymal
- leukaemia: haemopoetic
- neuroblastoma: neural
What features does a nucleus contain?
- nucleoplasm
- nuclear pores
- nucleolus (site of ribosome production)
- nuclear envelope
What is a cisternae?
stack of endoplasmic reticulums
What do peroxisomes contain?
enzymes for lipid & oxygen metabolism
What comprises a cytoskeleton?
- microtubules
- intermediate filaments
- microfilaments
What are microtubules made of and what is the diameter of a microtubule?
- alpha and beta tubulin
- 20nm
What are the functions of a microtubule?
- involved in cell shape
- tracks for movement of organelles & other components
- form mitotic spindle
What is a major structural & motor component of cilia & flagellae
microtubules
Which cytoskeletal filament gives mechanical strength to a cell?
intermediate filament
What is an intermediate filament?
group of filamentous proteins forming rope-like filaments
What are the different type of intermediate filaments in different cell types?
- epithelial: cytokeratin
- mesenchymal: vimentin
- muscle: desmin
- neurons: neurofilament protein
What is the diameter of an intermediate filament?
10-15nm
How are desosomes connected?
via intermediate filaments
What is a nuclear lamins and its function
type of intermediate filament, stabilises nuclear envelope
What is a microfilament?
polymers of globular protein actin
What do microfilaments associate with?
- adhesion belts (epithelia)
- endothelia proteins
- plasma membrane proteins
What are the functions of microfilaments?
- involved in cell shape & movement
- contraction of non-muscle cells
What type of structure does a microfilament have?
helical (actin)
What is a tissue?
a group of cells whose type, organisation & architecture are integral to its function
What are the 3 major cell-cell junctions?
- zonula adherens
- zonula occludens
- macula adherens
What is a zonula adherens?
- adhesion belt
- e.g. cadherin (binds to similar molecules on adjacent cells)
- closely associated to actin cytoskeleton
Why are cell-cell junctions important?
key to formation & maintenance of epithelial layers
What is a zonula occludens?
- tight junction
- prevents ion diffusion so allows polarity establishment
- blocks paracellular pathways
What is a macula adherens?
- cluster of pores formed by membrane proteins
- allows passage of ions (relatively small & water)
- 1.5nm diameter
What happens in the nucleolus?
ribosomal subunits are synthesised
What is the organisation of microtubules in cells?
originate from point called the microtubule organising centre (MTOC)
What is the definition of extracellular matrix?
the insoluble material found extracellularly
What are the four main types of cell-cell junctions (in order of apical to basal)?
- tight
- adhesion belt
- desmosomes/gap junctions
What is the role of gap junctions?
allows transport of small molecules between cells
