McKenna's Pharmacology for Nursing, 2e

7

Introduction to cell physiology

Learning objectives Upon completion of this chapter, you should be able to: 1. Identify the parts of the human cell. 2. Describe the role of each organelle found within the cell cytoplasm. 3. Explain the unique properties of the cell membrane.

4. Describe three processes used by the cell to move things across the cell membrane. 5. Outline the cell cycle, including the activities going on within the cell in each phase.

Test your current knowledge of cell physiology with a PrepU Practice Quiz!

Glossary of key terms cell cycle: life cycle of a cell, which includes the phases G 0 , G 1 , S, G 2

and M; during the M phase, the cell divides into two identical

daughter cells cell membrane: lipoprotein structure that separates the interior of a cell from the external environment; regulates what can enter and leave a cell cytoplasm: lies within the cell membrane; contains organelles for producing proteins, energy and so on diffusion: movement of solutes from an area of high concentration to an area of low concentration across a concentration gradient endocytosis: the process of engulfing substances and moving them into a cell by extending the cell membrane around the substance; pinocytosis and phagocytosis are two kinds of endocytosis endoplasmic reticulum: fine network of interconnected channels known as cisternae found in the cytoplasm; site of chemical reactions within the cell exocytosis: removal of substances from a cell by pushing them through the cell membrane genes: sequences of DNA that control basic cell functions and allow for cell division Golgi apparatus: a series of flattened sacs in the cytoplasm that prepare hormones or other substances for secretion and may produce lysosomes and store other synthesised proteins histocompatibility antigens: proteins found on the surface of the cell membrane; they are determined by the genetic code and provide cellular identity as a self-cell (i.e. a cell belonging to that individual) lipoprotein: structure composed of proteins and lipids; the bipolar arrangement of the lipids monitors substances passing in and out of the cell lysosomes: encapsulated digestive enzymes found within a cell; they digest old or damaged areas of the cell and are responsible for destroying the cell when the membrane ruptures and the cell dies mitochondria: rod-shaped organelles that produce energy within the cell in the form of adenosine triphosphate (ATP) nucleus: the part of a cell that contains the DNA and genetic material; regulates cellular protein production and cellular properties organelles: distinct structures found within the cell cytoplasm osmosis: movement of water from an area of low solute concentration to an area of high solute concentration in an attempt to equalise the concentrations phagocytosis: the engulfing of pathogens or other particles by phagocytes (white blood cells) pinocytosis: the introduction of fluids into a cell by invagination of the cell membrane, followed by formation of vesicles within the cells ribosomes: membranous structures that are the sites of protein production within a cell selective toxicity: ability of a chemical or drug to kill a microorganism without harming its host. See Chapter 2