NU545 Patho Study Guide Unit 1 Rated A+

NU545 Patho Study Guide Unit 1 Rated A+ What is metabolic absorption? (p.2) • 1 of 8 cellular functions of eukaryote cell • Chief function is to take in & use nutrients or other substances from surroundings • Ex: kidney (fluid absorption and synthesize proteins) and Intestinal epithelial cells (fluid absorption/protein enzyme synthesis) What uses oxygen to remove hydrogen atoms in an oxidative reaction? (p.8) • Peroxisomes contain enzymes that use O2 to remove H+ in oxidative reactions that produces hydrogen peroxide which is then used by catalase to further oxidize other substances like: phenols, formic acid, formaldehyde, and alcohol During cell injury what is released that is capable of cellular autodigestion? (p. 8) enzymes (hydrolases), or the digestive enzymes within the lysosome • Autolysosomes, or autophagosomes Where is the genetic info contained in the cell? (p. 2) • Lysosomal Nucleus, specifically the nucleolus Cell membranes contain which major chemical components? (p. 12) complex lipid bilayer What allows potassium to diffuse in and out of cells? (p. 31-32) Lipids & Proteins in a • The Na+-K+-ATP pump. Uses direct energy of ATP; found in excitable tissues (muscles/nerves) & also in kidneys & salivary glands. Involves the movement of Na+ & K+ against a concentration gradient. • Protein enzyme ATPase allows potassium to move in and out of the cell. • Mediated transport = channel protein through which ions can diffuse (K+ leak channel). How is a cell protected from injury? (p.12) • Plasma membrane - Acts as a barrier to toxic molecules, macromolecules, & foreign organisms/cells. • Exists in a state of change & modulation. Alternates receptor numbers & patterns. • Gating protects cells from release of Ca from injured cells by sealing off or decreasing permeability at junctional complexes. In cirrhosis, what does cholesterol have to do with the erythrocytes? (p.68) • Associated with chemical changes that result in structural & metabolic abnormalities of the erythrocyte membrane leading to cell shape changes & hemolytic anemia. • Increase in unesterified serum cholesterol owing to lecithin cholesterol acyl transferase (LCAT) deficiency in cirrhosis leads to expansion of the lipid bilayer & macrocytosis without megaloblastic changes in precursors. Substitutions of phosphatidyl choline (PC) moieties in the erythrocyte lipid bilayer lead to echinocytes (disaturated PC) or to stomatocytes (diunsaturated PC). In some patients, high density lipoprotein (HDL) abnormalities lead to erythrocyte surface changes causing rapid formation of echinocytes. (Ann Clin Lab Sci. 1990 May-Jun;20(3):169-74.Mechanisms of hemolysis in liver disease.Morse EE1. Department of Laboratory Medicine, University of Connecticut School of Medicine, Farmington 06032) • Alters fluidity & function of cell membrane as well as intercellular transport What is platelet-derived growth factor? (p.39) neuroglial cells Stimulates production of connective tissue cells & What is cell communication? How does it occur? (p.20) • Required for homeostasis, regulate cellular growth/division & development/organization into tissues, & coordinate cellular function. • Occurs in 3 ways: -via protein channels & gap junctions that directly coordinate activities of adjacent cells (must be touching) -via plasma membrane-based signaling molecules (receptors) that affect the cell itself & cells that come in direct contact -via chemical signals that must enter the distant cells to affect the receptors inside of the distant cell (the most common means of communication). • Primary modes of intercellular signaling are hormonal, neurohormonal, paracrine, contact dependent, & neurotransmitters. There is also Autocrine signaling where the cell signals itself. What is chemical signaling? (p.20) Involves the secretion of chemicals, such as hormones, neurohormones, paracrine, autocrine, and neurotransmitters. Chemical signaling may occur through the bloodstream or in small discrete spaces How is glucose transported from the blood to the cell? (p. 33) Passive protein channels. Passive mediated transport or facilitated diffusion moves the glucose via a uniport mechanism into the cell. When all glucose-specific receptors are occupied, the transport system is saturated and operating at maximal capacity. Direction of movement is the same as passive simple diffusion-down the concentration gradient, from an area of high concentration to low concentration until equilibrium is achieved. Understand the transportation of potassium and sodium across plasma membranes. (p. 29-32) The Na+ K+ antiport (opposite directions) system uses direct energy of ATP to move cations. • ATPase is transporter protein. • Concentration of ATPase in plasma membranes is directly related to Na+ K+ transport activity. • Process: - 3 Na+ ions bind to Na-binding sites on carrier's inner face. - ATP molecule produced by cell's mitochondria binds to carrier. • - Carrier changes shape, releases 3 Na+ ions to outside of cell, & attracts 2 K+ ions to K-binding sites. - Carrier returns to original shape, releasing 2 K+ ions & the leftover ATP molecule to inside of cell. - Carrier can now repeat cycle. What is active transport? (p. 31-33) ch.1 • The movement of a substance across a membrane by a carrier protein. Requires metabolic energy (ATP) to move the molecules against the concentration gradient. • Active transport also occurs by endocytosis (vesicle formation), where substances are engulfed by a segment of the plasma membrane, forming a vesicle that moves into the cell. What are cytokines? (p.38-39) Or cytokinesis? (p.37) • Cytokines are peptides that transmit signals within/between cells to stimulate tissue growth & development. Do all cells continue to replicate or divide? (p. 39) • No, all types of cells undergo mitosis during formation of the embryo, but adult cells including: nerve cells, lens cells, & muscle cells, lose the ability to replicate. • When a need arises for new cells, as in the repair of injured cells, previously non-dividing cells must be rapidly triggered to reenter the cell cycle. • Neurons are fixed at birth & are unable to be replaced. When normal columnar ciliated epithelial cells of the bronchial lining are replaced by stratified squamous cells, the process is called? (p. 54) • Metaplasia: the reversible replacement of one mature cell by another, sometimes less differentiated cell type. • However, lose protective ability, because new cells don't secrete mucus or have cilia. • Bronchial metaplasia can be reversed if inducing stimulus is removed, such as cigarette smoking. What is the relationship between ischemia and ATP? (p. 55-57) • When a hypoxic injury occurs to myocardium, which causes an abrupt lack of contraction (caused by quick decline in mitochondrial phosphorylation), causing insufficient ATP production. • Lack of ATP leads to increase in anaerobic metabolism, which generates ATP from glycogen when there is insufficient oxygen. • When glycogen stores are depleted, even anaerobic metabolism ceases. When does sodium enter the cell and cause swelling? (p. 57) plasma membrane's Na-K pump & Na-Ca exchange to fail. • A reduction in ATP levels cause the • Causes intracellular accumulation of Na & Ca & diffusion of K out of cell. • Na & H2O enter cell freely, leading to cellular swelling. What are free radicals in relation to cell damage? Progression of diseases? (p. 59-61) Membrane damage is initiated by injury induced by free radicals, primarily by excess reactive oxygen species (ROS) called oxidated stress. Free radical is an electrically uncharged atom or group of atoms having an unpaired electron; thus causing the molecule to be unstable. To stabilize the molecule, it gives up an electron or steals one. This process is capable of injuries through chemical bond formation with proteins, lipids, & carbs. Free radicals aren't easily controlled & they initiate chain reactions. These reactive species are important in regard to cell injury by lipid peroxidation, alterations of proteins causing fragmentation of polypeptide chains, & alterations of DNA (breaking single strands). Diseases & disorders have been linked directly & indirectly to these reactive species. Know all about lead poisoning. How does it cause damage within the cell? (p. 65-67) metal, primary hazard to children. • Can cause learning disabilities, hyperactivity, & ADD • A heavy • Found in paint, soil, dust, debris from houses, baby formula mixed with lead contaminated water, newsprint, water that flows through lead pipes, hair dyes, gasoline, & tin cans or pottery made with lead based glaze. • Nervous system, hematopoietic system, & kidneys are primarily affected • Interferes with Ca. Can increase intracellular Ca concentrations & become a substitute & some Ca binding proteins are capable of binding with lead. PKC (protein kinase C) mediated lead induced rise in intracellular free Ca causing cellular disruption. • Inhibits enzymes involved in hemoglobin synthesis (ie anemia) • Other s/s: convulsions, delirium, & peripheral nerve involvement to the wrist, fingers, & feet, glycosuria, aminoaciduria, & hyperphosphaturia, n/v, loss of appetite, wt loss, & abd cramps. Know about the affects of fetal alcohol syndrome on infants. (p. 68-69) • Can lead to growth retardation, cognitive impairment, facial anomalies, & ocular disturbances. How does alcohol affect the nervous system? (p.67-68) • Acts as a depressant affecting the subcortical structures first (brainstem reticular formation). Motor and intellectual activities then become distorted. At high levels, medullar centers become depressed, affecting respirations. Where do lipids accumulate? (p. 63, 75, 84-85) • During chemical injury lipids accumulate within the cytoplasm, starting within cisternae of the endoplasmic reticulum (p.63). • Lipids primarily accumulate in the cells of the spleen, liver, CNS (p.84). • The most common site of intracellular lipid accumulation also known as fatty change is liver cells (p.85). • Heart, liver, & muscle in hyperlipidemia (p.75). What is hemosiderosis? (p. 86) • Excess iron is stored as hemosiderin in the cells of many organs