Cell and Tissue Architecture Flashcards
Cell types are
Diverse
Red Blood Cells
Biconcave to maximize surface area for gas exchange and ability to pass through veins
Liver Cells
High amount of rough ER for protein synthesis
Muscle Cells
Long, multinucleated specialized for contraction
Neurons
Long slender extensions let neurons communicate
Intestinal Cells
Microvilli increase absorptive surface area
Tissue
Collection of cells that work together to perform a specific function
Organ
Two or more tissues combine and function together
Basal Lamina
Also known as the basement membrane, it is a thin, dense layer of extracellular matrix that lines most tissues forming the supporting structure and scaffolding for epithelial tissue and separates different types of cells, such as nerve cells and muscle cells.
Epidermis
The top layer of the skin, made up of keratinocytes and melanocytes
Dermis
The second layer of skin
Cytoskeleton
Made up of Micortubules, microfilaments, and intermediate filaments. Cytoskeleton has a role in transport, maintaining shape and internal organization
Microtubule
A hollow tube formed from tubulin dimers. Largest tube in diameter. Have a role in transport. Associated with the centrosome and cell division, as well as organelle arrangement. Consists of an alpha and beta subunit.
Microfilament
A double helix of actin monomers, has a role in cell-cell attachment. Surrounds the circumference of the cell. Has a role in transport, muscle contraction, cell division, cytokinesis.
Intermediate Filament
A strong fiber composed of IMF proteins, of which there are a diverse high number. Give cells stability and structure. Made of lamins in the nucleus and keratins in the cytoplasm.
Microvilli
Increases cell surface area for absorption, has cross-linked actin-binding proteins
Dynamic Instability
Polymerization and de polymerization. Growing and looking for something to latch onto, and moving back when not finding it. Plus end assembles quickly, minus end assembles slowly. Microtubules and microfilaments.
Microtubule Transport
Kinesin carries cargo (vesicles) to the plus end, and Dynein to the minus end. This requires energy, ATP.
Fish embryos
Melanin is dispersed outwards by kinesin, making the embryo dark in the dark. Granules are moved toward the center by dynein, causing the embryo to be light colored.
H. V. Wilson
Broke sponges up into individual cells, then swirled back together and the cells were able to sort themselves out. This is due to cadherins, which are highly specific.
Cadherins
Transmembrane proteins that provide cell-cell attachment
Integrins
Transmembrane receptors that attach cells to proteins in the ECM.
Tight Junction
Made up of occludin and claudin proteins, which hold cells together. Prevents stuff from getting between the cells. Is not structural.
Adherens Junctions and Desmosomes
Involves intermediate filaments and cadherins. Cadherins between two cells will line up parallel with one another and hold the cells together, IMFs will attach to the parts of the cadherin within the cell. Cell-cell rigidity.
Hemidesmosomes
Anchors the epithelial cells to the basal lamina by integrin. Also involved intermediate filaments.
Gap Junctions and Plasmodesmata
Not structural, animals have gap junctions and plants have plasmodesmata. Allows molecules to pass between cells through small pores.
Extracellular Matrix (Animal)
Underlying the basal lamina, made up of elastin fibers, collagen fibers, fibroblast nuclei. A gel-like matrix. Cells reside in a complex meshwork of ECM fibers.
Extracellular Matrix (Plant)
“Secondary Cell Wall”, composed of cellulose (which is glucose molecules linked together) and lignin. Lignin provides support.
Collagen
Triple helices that are bundled like steel cable wires and are the most abundant in the ECM.
ECM and Cancer
Mesastatic cancer cells cross the capillary basal lamina twice, once to enter the circulatory system and again to leave it. Can cross the basal lamina through the use of specific kinds of integrins.
ECM Necessity
When cells are grown three-dimensionally compared to two, or grown in ECM protiens, they look like actual cells.
Joan Caron
There is more protein secretion (gene expression) of albumin when hepatocytes are in matrix proteins compared to just collagen, (especially laminin).
