NURS6501 (Week 1-6) NURS 6501 Midterm Exam Study Guide (Latest 2022) Advanced Pathophysiology

NURS 6501 MIDTERM EXAM REVIEW GUIDE (Weeks 1-6)

CELLULAR PROCESSES AND THE GENETIC ENVIRONMENT

• Describe cellular processes and alterations within cellular processes

 The eight specialized cellular functions are movement, conductivity, metabolic absorption, secretion, excretion, respiration, reproduction, and communication.

 The chief functions of the nucleus are cell division and control of genetic information

 Importantly, the ER is responsible for protein folding and sensing cell stress.

 Lysosomes are saclike structures that originate from the Golgi complex and contain digestive enzymes. These enzymes are responsible for digesting most cellular substances completely to their basic components, such as amino acids, fatty acids, and carbohydrates. A newly understood role of lysosomes is nutrient-dependent signal transduction. The signaling function cooperates with the known degradative role to mediate basic cell functions, such as nutrient sensing, metabolic adaptation, and quality control of proteins and organelles. 8. Four pathways of degradation in lysosomes include endocytosis, phagocytosis, macropinocytosis, and autophagy.

 . Mitochondria are found in great numbers in most cells and are responsible for cellular respiration and energy production. The enzymes of the respiratory chain (electrontransport chain), found in the inner membrane of the mitochondria, generate most of the cell’s ATP.

 The chemical tasks of maintaining essential cellular functions are referred to as cellular metabolism. Anabolism is the energy-using process of metabolism, whereas catabolism is the energy-releasing process. 2. ATP functions as an energy-transferring molecule. Energy is stored by molecules of carbohydrate, lipid, and protein, which, when catabolized, transfer energy to ATP. 3. Oxidative phosphorylation occurs in the mitochondria and is the mechanism by which the energy produced from carbohydrates, fats, and proteins is transferred to ATP.

• What is the impact of the genetic environment on disease?

 Family members share genes and a common environment; therefore, resemblance in traits, such as high blood pressure, reflects both genetic and environmental factors (nature and nurture, respectively).

 A genetic predisposition may interact with an environmentallifestyle factor to increase the risk of disease; this is called a gene-environment interaction.

 The complete human genome sequence will facilitate gene identification, diagnosis, and disease treatment.

 An individual’s genotype is the person’s genetic makeup, and the phenotype reflects the interaction of genotype and environment.

 Environmental factors, such as diet and exposure to certain chemicals, may cause epigenetic modifications.

• Explain how healthy cell activity contributes to good health and how its breakdown in cellular behaviour and alterations to cells lead to health issue.

• What are the roles genetics plays in disease processes?

 Changes in many genes, each with a small effect, may underlie susceptibility to many common diseases, including cancer, obesity, diabetes, heart disease, and mental illness. In people with a genetic predisposition, the risk of disease can depend on multiple factors in addition to an identified genetic change

• What is the relationship of how cells are involved in disease processes?

 All diseases are disturbances at the cellular level (Rudolph Virchow, 1858) To treat disease, we must understand its cause. To understand the cause of a disease, we must understand the alterations that occur at the level of individual cells.

 Systemic manifestations of cellular injury include fever, leukocytosis, increased heart rate, pain, and serum elevations of enzymes in the plasma.

 Manifestations of cellular injury include accumulations of water, lipids, carbohydrates, glycogen, proteins, pigments, hemosiderin, bilirubin, calcium, and urate.

Altered Physiology

• Evaluate cellular processes and alterations within cellular processes

 Cellular processes, such as transcription, DNA replication, and DNA repair, are regulated by an intimate and selfreinforcing crosstalk and interdependence between histonemodifying complexes and other histone-modifying activities, such as acetylation, phosphorylation, and methylation.

 Cellular processes are mediated through the complex action of several biological molecules through biochemical or biophysical interactions. Comprehensive understanding of the network will hence help to better understand the molecular mechanism underlying human diseases. Proteins “A” and “B” serve as hub proteins (schematic 1). An alteration (mutation) that removes one of the hub proteins (schematic 2) could lead to a significantly more severe outcome compared to an alteration that affects only a single edge (schematic 3), which could explain how different alteration in the same gene could lead to a different disease phenotype.

• Analyze alterations in the immune system that result in disease processes

 Autoimmune diseases originate from the coincidence of an initiating event in a genetically predisposed individual leading to an autoimmune mechanism that affects specific target tissues or cells. Central tolerance develops during the embryonic period. Peripheral tolerance is maintained in secondary lymphoid organs by regulatory T lymphocytes or antigenpresenting dendritic cells.

 Inappropriate immune responses are misdirected responses against the host’s own tissues (autoimmunity); directed responses against beneficial foreign tissues, such as transfusions or transplants (alloimmunity); exaggerated responses against environmental antigens (allergy); or insufficient responses to protect the host (immune deficiency).

• Identify racial/ethnic variables that may impact physiological functioning

 lower education levels, socioeconomic status, lack of health insurance, inadequate housing, and living near environmental hazards.

• What is the impact of patient characteristics on disorders and altered physiology?

• What is the association of genes in the development of disease?

 The more strongly inherited forms of complex disorders generally have an earlier age of onset (breast cancer, 

Alzheimer’s disease, heart disease) o These represents subsets of cases in which there is single-gene inheritance

o Laterality, is a component, the bilateral forms are more likely to cluster strongly in families (breast cancer, CL/P)

 Sex-specific threshold model fits some of the complex disorders

(pyloric stenosis, CL/P, autism, heart disease)

 If it fails to fit others (type 1 diabetes)

• What is the process of immunosuppression and the effect it has on body systems?

 Corticosteroids not only intervene at many points of the immune response, such as preventing lymphocyte recirculation and generation of antibody-producing and cytotoxic effector cells, but they also possess a remarkable anti-inflammatory potency. They inhibit neutrophil adherence to the vascular endothelium at an inflammatory site and suppress monocytic functions such as microbicidal activity, monocyte response to lymphokines, and release of monokines.

 An immunocompromised individual may particularly be vulnerable to opportunistic infections, in addition to normal infections that could affect anyone.[3] It also decreases cancer immunosurveillance, in which the immune system scans the body's cells and kills neoplastic ones.

CONCEPTS OF CADIOVASCULAR AND RESPIRATORY DISORDERS

• Common diseases and disorders that impact the Cardiovascular system

 Diseases of the Veins  

 Varicosities are areas of veins in which blood has pooled, usually in the saphenous veins. Varicosities may be caused by damaged valves as a result of trauma to the valve or by chronic venous distention involving gravity and venous constriction.  

Chronic venous insufficiency is inadequate venous return over a long period that causes pathologic ischemic changes in the vasculature, skin, and supporting tissues. o Superior vena cava syndrome most often results from compression of the SVC by tumors. 

 DVT occurs in individuals who have venous stasis (immobility, age, left heart failure), spinal cord injury, vein wall damage (trauma, intravenous medications), or hypercoagulable states (pregnancy, oral contraceptives, malignancy, genetic coagulopathies). DVT is often asymptomatic but may lead to fatal pulmonary emboli; prevention and careful assessment in individuals at risk are crucial. 

 Diseases of the Arteries 

o Hypertension is a sustained elevation of the systemic arterial blood pressure resulting from increases in cardiac output or total peripheral resistance, or both. Hypertension can be primary (without known cause) or secondary (caused by disease or drugs). Systolic hypertension is the most significant factor in causing target organ damage. 

 The risk factors for hypertension include a positive family history; male gender; advanced age; black race; obesity; high sodium intake; low potassium, calcium, and magnesium intake; diabetes mellitus; labile blood pressure; cigarette smoking; and heavy alcohol consumption. 

 Primary hypertension is the result of extremely complicated interactions of genetics and the environment mediated by a host of neurohumoral effects. These genes interact with diet, smoking, age, and the other risk factors to cause chronic changes in vasomotor tone and blood volume. The most frequently cited theories of the pathogenesis 

of primary hypertension include overactivity of the SNS; overactivity of the RAAS; alterations in other neurohumoral mediators of blood volume and vasomotor tone such as ANP, BNP, and adrenomedullin; inflammation; a complex interaction involving insulin resistance and endothelial function; and obesity-related hormonal changes. 

 Clinical manifestations of hypertension result from damage of organs and tissues outside the vascular system. These include heart disease, renal disease, CNS problems, and retinal changes. 

 Hypertension is managed pharmacologically, using diuretics, adrenergic blockers, calcium channel blockers, ACE inhibitors, and Ang II receptor blockers.

• Nonpharmacologic methods include cessation of smoking, dietary modifications, and exercise. 

o Orthostatic hypotension is a drop in blood pressure that occurs on standing. The compensatory vasoconstriction response to standing is altered by a marked vasodilation and blood pooling in the muscle vasculature. 

 Orthostatic hypotension may be primary or secondary. The primary form is caused by neurologic changes that affect the autonomic reflexes that control blood pressure upon standing. 

 The clinical manifestations of orthostatic hypotension include fainting and may result in falls and significant injury. 

o An aneurysm is a localized dilation of a vessel wall to which the aorta is particularly susceptible. 

o A thrombus is a clot that remains attached to a vascular wall.  

o An embolus is a mobile aggregate of a variety of substances that occludes the vasculature. Sources of emboli include thrombi, air, amniotic fluid, bacteria, fat, and foreign matter. 

 The most common sources of arterial thrombotic emboli from the heart are mitral and aortic valvular disease and atrial fibrillation. 

 Tissues affected include the lower extremities, the brain, and the heart. 

 Emboli to the central organs cause tissue death in lungs, kidneys, and mesentery 

 The generation of air emboli requires a connection between the vascular compartment and a source of air. These emboli cause ischemia and necrosis when a vessel is totally blocked. 

 Amniotic fluid may be forced into the bloodstream and generate an embolus during the labor and delivery of pregnancy. 

 Aggregates of bacteria in the vasculature may be large enough to form an embolus. 

 Fat emboli are caused mainly by trauma to the long bones, either through defective fat metabolism after trauma or through the release of fat globules from bone marrow exposed by fracture. 

 The introduction of foreign matter into the vasculature can occur with trauma and also can occur in a hospital setting in which intravenous and intraarterial lines are being used. 

o Vasospastic disorders include thromboangiitis obliterans and Raynaud disease, involving arterioles of the extremities. 

o Atherosclerosis is a form of arteriosclerosis and is the leading cause of coronary artery and cerebrovascular disease.