plasma cell
(noun)
a form of lymphocyte that produces antibodies when reacted with a specific antigen; a plasmacyte
Examples of plasma cell in the following topics:
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Immunological Memory
- However, if the host is re-exposed to the same pathogen type, circulating memory cells will immediately differentiate into plasma cells and TC cells without input from APCs or TH cells.
- Memory B cells that differentiate into plasma cells output ten to hundred-fold greater antibody amounts than were secreted during the primary response .
- As a result, memory B cells and plasma cells are made.
- In the primary response to infection, antibodies are secreted first from plasma cells.
- Upon re-exposure to the same pathogen, memory cells differentiate into antibody-secreting plasma cells that output a greater amount of antibody for a longer period of time.
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Components of Plasma Membranes
- The plasma membrane protects the cell from its external environment, mediates cellular transport, and transmits cellular signals.
- The plasma membrane (also known as the cell membrane or cytoplasmic membrane) is a biological membrane that separates the interior of a cell from its outside environment.
- The primary function of the plasma membrane is to protect the cell from its surroundings.
- Plasma membranes must be very flexible in order to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries.
- The plasma membrane also plays a role in anchoring the cytoskeleton to provide shape to the cell, and in attaching to the extracellular matrix and other cells to help group cells together to form tissues.
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Injuring the Plasma Membrane
- The plasma membrane or cell membrane is a biological membrane that separates the interior of all cells from the outside environment.
- The plasma membrane is selectively permeable to ions and organic molecules.
- Plasma membranes are involved in a variety of cellular processes such as cell adhesion, ion conductivity, and cell signaling.
- The plasma membrane also plays a role in anchoring the cytoskeleton to provide shape to the cell and in attaching to the extracellular matrix and other cells to help group cells together to form tissues .
- Diagram of a typical gram-negative bacterium, with the thin cell wall sandwiched between the red outer membrane and the thin green plasma membrane.
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The Plasma Membrane and the Cytoplasm
- The plasma membrane is made up of a phospholipid bilayer that regulates the concentration of substances that can permeate a cell.
- Despite differences in structure and function, all living cells in multicellular organisms have a surrounding plasma membrane (also known as the cell membrane).
- The plasma membrane's main function is to regulate the concentration of substances inside the cell.
- The cell's plasma membrane also helps contain the cell's cytoplasm, which provides a gel-like environment for the cell's organelles.
- Explain the structure and purpose of the plasma membrane of a cell
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Plasma Membrane Hormone Receptors
- Hormones that cannot diffuse through the plasma membrane instead bind to receptors on the cell surface, triggering intracellular events.
- Amino acid-derived hormones and polypeptide hormones are not lipid-derived (lipid-soluble or fat-soluble); therefore, they cannot diffuse through the plasma membrane of cells.
- Lipid-insoluble hormones bind to receptors on the outer surface of the plasma membrane, via plasma membrane hormone receptors.
- The amino acid-derived hormones epinephrine and norepinephrine bind to beta-adrenergic receptors on the plasma membrane of cells.
- Describe the events that occur when a hormone binds to a plasma hormone receptor
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Exocytosis
- Exocytosis is the process by which cells release particles from within the cell into the extracellular space.
- In exocytosis, waste material is enveloped in a membrane and fuses with the interior of the plasma membrane.
- Exocytosis is used continuously by plant and animal cells to excrete waste from the cells.
- Some examples of cells using exocytosis include: the secretion of proteins like enzymes, peptide hormones and antibodies from different cells, the flipping of the plasma membrane, the placement of integral membrane proteins(IMPs) or proteins that are attached biologically to the cell, and the recycling of plasma membrane bound receptors(molecules on the cell membrane that intercept signals).
- In exocytosis, vesicles containing substances fuse with the plasma membrane.
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Plasma and Serum
- Plasma is the liquid component of blood after all of the cells and platelets are removed; serum is plasma after coagulation factors have been removed.
- Plasma, the liquid component of blood, comprises 55 percent of the total blood volume.
- The blood cells and platelets that make up about 45 percent of the blood are separated by centrifugal forces to the bottom of a specimen tube, leaving the plasma as the upper layer.
- The plasma also contains the coagulation factors and antibodies.
- Human serum albumin, the most abundant protein in human blood plasma, is synthesized in the liver.
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Fluid Mosaic Model
- Nicolson in 1972 to explain the structure of the plasma membrane.
- Plasma membranes range from 5 to 10 nm in thickness.
- For comparison, human red blood cells, visible via light microscopy, are approximately 8 µm wide, or approximately 1,000 times wider than a plasma membrane.
- The proportions of proteins, lipids, and carbohydrates in the plasma membrane vary with cell type.
- The fluid mosaic model of the plasma membrane describes the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins.
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Intercellular Junctions
- In general, long stretches of the plasma membranes of neighboring plant cells cannot touch one another because they are separated by the cell wall that surrounds each cell.
- Plasmodesmata are numerous channels that pass between cell walls of adjacent plant cells and connect their cytoplasm; thereby, enabling materials to be transported from cell to cell, and thus throughout the plant .
- Short proteins called cadherins in the plasma membrane connect to intermediate filaments to create desmosomes.
- Gap junctions develop when a set of six proteins (called connexins) in the plasma membrane arrange themselves in an elongated doughnut-like configuration called a connexon.
- A plasmodesma is a channel between the cell walls of two adjacent plant cells.
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Blood Plasma
- Plasma comprises about 55% of total blood volume.
- About 55% of blood is blood plasma, a straw-colored liquid matrix in which blood cells are suspended.
- One percent of the plasma is salt, which helps with pH.
- Human blood plasma volume averages about 2.7–3.0 liters.
- However, during endothelial injury, damaged cells will release tissue factor, another type of clotting factor that causes a cascade of thrombin production that will overpower the anticoagulants and cause a clotting response.