Patho Exam 1 (Maryville University - NURS611) QUESTIONS WITH COMPLETE SOLUTIONS

Patho Exam 1 (Maryville University - NURS611) QUESTIONS WITH COMPLETE SOLUTIONSNucleus Contains the nucleolus, a small, dense structure composed largely of RNA; most of the cellular DNA; and the DNA-binding proteins, the histones, that regulate its activity. Therefore, the histones binding to DNA cause DNA to fold into chromosomes. The wrapping of DNA into tight packages of chromosomes is essential for cell division in eukaryotes. Ribosomes RNA-protein complexes that are synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore complexes. These tiny ribosomes may float free in the cytoplasm or attach themselves to the outer membrane of the endoplasmic reticulum. THEIR CHEIF FUNCTION IS TO PROVIDE SITES FOR CELLULAR PROTEIN SYNTHESIS. Golgi Complex a network of flattened, smooth membranes and vesicles frequently located near the nucleus of the cell. Proteins from the endoplasmic reticulum are processed and packaged into small membrane-bound sacs or vesicles called secretory vesicles, the Golgi complex is a refining plant and directs traffic (i.e. protein, polynucleotides, polysaccharide molecules) in the cell. Lysosomes Maintain cellular health through: -efficient removal of toxic cellular components -removal of useless organelles -termination of signal transduction -signals cellular adaptation Mitochondria organelles found in large numbers in most cells and responsible for cellular respiration and energy production. The inner membrane contains the enzymes of the respiratory chain and these enzymes are essential to the process of oxidative phosphorylation that generates most of the cells ATP. Apoptosis Programmed cell death. Cellular self-destruction for elimination of unwanted cell populations. Necrosis Characterized by rapid loss of the plasma membrane, organelle swelling and mitochondrial dysfunction. Hypoxia #1 cause of cellular injury leading to necrosis (especially in kidneys and heart) Physiologic Atrophy -occurs with early development -example: the thymus gland undergoes physiologic atrophy during childhood Pathologic Atrophy occurs as a result of decreases in workload, pressure, use, blood supply, nutrition, hormonal stimulation, and nervous stimulation Hypertrophy increase in cell size Physiologic Hypertrophy hypertrophy of myocardial cells secondary to endurance training Pathologic Hypertrophy hypertrophy of myocardial cells secondary to HTN Hyperplasia increase in number of cells Compensatory Hyperplasia liver regenerates in 2 weeks after 70% is removed Pathologic Hyperplasia endometrial hyperplasia Metaplasia Replacement of cells Example: normal columnar ciliated cells of the bronchial lining have been replaced by stratified squamous epithelial cells. CAN BE REVERSED IF IRRITANT STOPS Cellular Metabolism ATP functions as the energy transferring molecule (Very important). Ischemia effects on ATP A reduction in ATP levels causes the plamsa membrane's Na+/K+ pump and sodium-calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. Sodium and water then enter the cell freely - causing cellular swelling. Sodium-Potassium Pump Three Na+ ions bind to the sodium-binding sites on carrier's inner face, at the same time, an energy-containing ATP molecule produced by the mitochondria binds to the carrier. The ATP dissociates, transferring its stored energy to the carrier and the carrier then changes shape. The 3 Na+ ions are then released to the outside of the cell and 2 K+ ions are attracted to potassium binding sites. The carrier returns to its original shape and releases the two K+ ions and remaining ATP inside the cell. Free Radical An electrically uncharged atom or group of atoms having an unpaired electron. To stabilize, the free radical gives up an electron to another molecule or steals one, causing injurious chemical bonds with proteins, lipids, carbohydrates which are key molecules in membranes and nucleic acids.