STUDY GUIDE FOR QUIZ 1 Advanced Pathophysiology 2022, Exams of Nursing

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Study the process of meiosis – specifically what occurs when homologous chromosomes fail to separate Human cell can be categorized into gametes (Sperm & egg cells) and somatic cells, which include all cells other than gametes. Each somatic cell nucleus has 46 chromosomes in 23 pairs. These are diploid cells, and the individual’s father and mother each donate on chromosome per pair. New somatic cells are formed through mitosis and cytokinesis. Gametes are haploid cells : they have only 1 member of each chromosome pair, for a total of 23 chromosomes. Haploid cells are formed from diploid cells by meiosis. A somatic cell has 23 pairs of chromosomes In meiosis I, chromosomes in a diploid cell resegregate, producing four haploid daughter cells. It is this step in meiosis that generates genetic diversity. DNA replication precedes the start of meiosis I. During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. In meiosis a haploid cell is created from a diploid cell. What are the 8 stages of meiosis in order? Aneuploidy is caused by nondisjunction, which occurs when pairs of

homologous chromosomes or sister chromatids fail to separate during meiosis. The loss of a single chromosome from a diploid genome is called monosomy (2n-1), while the gain of one chromosome is called trisomy (2n+1). Know the risk factors for down syndrome Nondisjunction occurs when homologous chromosomes ( meiosis I) or sister chromatids ( meiosis II ) fail to separate during meiosis The most common trisomy is that of chromosome 21, which leads to Down syndrome. Down syndrome is a chromosomal disorder Down syndrome Best known example of aneuploidy Trisomy 21 1:800 live births Mentally retarded, low nasal bridge, epicanthal folds, protruding tongue, poor muscle tone Risk increases with maternal age > People who have down syndrome are at a higher risk for developing Alzheimer disease because of involvement of chromosome 21. 1 in 800 to 1 in 1000 live births are affected with Down syndrome. RISK FACTORS – increases greatly with material age. Younger than 30 have

a risk of 1 – 1000 to 1 in 2000. After 35 risk increases greatly. By 45 and older a risk of 3% to 5% of children born will have down syndrome. This increase in risk is caused by the age of maternal egg cells, which are held in an arrested state of prophase 1 from the time they are formed in the female embryo until they are shred in ovulations. Thus, an egg cell formed by a 45-year woman is inself 45 years old. This long suspended state may allow defects to accumulate in the cellular proteins responsible for meiosis, leading to nondisjunction. The risk of Down syndrome, as well as other trisomies, does not increase with paternal age. Genetic diseases caused by single genes usually are autosomal dominant, autosomal recessive or X-linked recessive X-linked recessive disease are seen more often in males than in females. If the cells have three copies of each chromosome triploidy is present. Loss of chromosome material usually has more serious consequences than duplication of chromosome material. A Barr body is an inactivated X chromosome that is seen in normal female cells. Study transmission factors associated with Huntington’s disease Recurrence risk for autosomal dominant inheritance like Huntington’s Disease. Recurrence risk for autosomal dominant inheritance would be

50% if one parent was heterozygous for the trait, 75% if both parents were heterozygous, and 100% if either parent was homozygous for the trait. Autosomal dominant inheritance pattern Huntington disease is a single-gene disorder. Huntington's disease is caused by an inherited defect in a single gene. Huntington's disease is an autosomal dominant disorder, which means that a person needs only one copy of the defective gene to develop the disorder Study Turner’s syndrome – specifically what karyotype is associated with it A sex chromosome aneuploidy (a cell that does not contain a multiple of 23 chromosomes) condition that lead to somewhat more serious problems is the presence of a single X chromosome and no homologous X or Y chromosome, so that the individual has a total of 45 chromosomes. The Karyotype is usually designated 45,X and it cases a set of symptoms know as Turner syndrome. Turner syndrome Females with only one

X chromosome Characteristics: Underdeveloped ovaries (sterile) Short stature (~ 4'7") Webbing of the neck Edema Underdeveloped breasts; wide nipples High number of aborted fetuses X is usually inherited from mother Turner’s syndrome is a chromosome disorder Aneuploidy is usually the result of nondisjunction (an error in which homoloegous chromosomes or sister chromatids fail to separate normally during meisosis or mitosis) A karyotype or karyogram is an ordered display of chromosomes. A display of chromosomes ordered according to length and centromere locations is called a karyotype Study Klinefelte disorder. Specifically, what karyotype is associated with it Individuals with at least two X chromosomes and 1 Y chromosomes in

each cell (47, XXY karyotype) have a disorder known as Klinefelter syndrome. Klinefelte is a chromosome disorder People who have the 47, XXY karyotype have klinefelte disorder Klinefelter syndrome Individuals with at least two Xs and one Y chromosome Characteristics Male appearance Develop female- like breasts Small testes Sparse body hair Long limbs Some individuals can be XXY and XXXY The abnormalities increase with each X Know the basics of CF (you should all know this well given our excellent discussion posts last week) but know if it’s dominant, recessive etc CF is autosomal recessive and a single gene disorder

A recessive gene will be expressed only if it is present in two copies. The gene repressible for CF encodes a chloride ion channel in some epithelial cells. Defective transport of chloride ions lead to a salt imbalance that results in secretions of abnormally thick, dehydrated mucus. Some digestive organs, particularly the pancreases, become obstructed, causing malnutrition, and the lungs become clogged with mucus, making them highly susceptible to bacterial infects. Death from lung disease or heart failure occurs before 40 years of age in about half of person with CF. The important criteria for discerning autosomal recessive inheritance include the following.

1. Males and females are affected in equal proportions.
2. Consanguinity (marriage between related individuals) is sometimes present especially for rare recessive disease/
3. The disease may be seen in siblings of affected individual but usually not in their parents.
4. On average one fourth of the offspring of carrier’s parents will be affected. Know the difference between adaptive (specific immunity) and Innate Immunity Innate immunity is something already present in the body. INNATE IMMUNITY

Physical barriers: Innate, or nonspecific, immunity is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response. Examples of innate immunity include: Innate immunity also comes in a protein chemical form, called innate humoral immunity. Examples include the body's complement system and substances called interferon and interleukin-1 (which causes fever). If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system. Adaptive immunity is created in response to exposure to a foreign substance. Once activated against a specific type of antigen, the immunity remains throughout the life .................................................... Adaptive immune system is composed of B cells and T cells a. Purposes: ➢ Destruction of infectious microorganisms that are resistant to inflammation ➢ Long-term, highly effective protection against future exposure to the same microorganism

Overview of human defenses Characteristic s Physical and Biochemical Barriers and the Human Microbiome Innate Immunity Adaptive (Acquired) Immunity Level of defense First Line of defense against infection and tissue injury Second line of defense, occurs as response to tissue injury or infection (inflammatory response) Third line of defense, initiated when innate immune system signals cells of adaptive immunity Timing of defense Constant Immediate response Delay between primary exposure to antigen and maximal response, immediate against secondary exposure to antigen Specificity Broadly specific Broadly specific Response is very specific toward antigen Cells Epitheli a cells Microbi Mast cells, granulocytes (Neutrophils, T lymphocytes, B lymphocytes, macrophages,

ome eosinophils, basophils) monocytes/mac rophages, natural killer (NK) cells platelets, endothelial cells. dendritic cells Memory No memory involved No memory involved Specific immunologic memory by T and B lymphocytes Active molecules Defensins, cathelicidins, collectins, lactoferrin, bacterial toxins Complement, clotting factors, kinins, cytokines Antibodies, complement, cytokines Protection Protection includes anatomic Physical barriers (i.e. skin and mucous membranes) Epithelial Cell - Protection includes vascular responses, cellular components (e.g. mast cells, neutrophils, macrophages), Protection includes activated T and B lymphocytes, cytokines, and antibodies.

Derived chemicals: Cell and secretory molecules (e.g. lysozymes, low pH of stomach and urine), and ciliary activity Normal Microbiome secretory molecules or cytokines, and activation of plasma protein systems. Clotting system Study immune reactions. You will be given a scenario and asked to specify if it’s IgE, Tissue specific, cell mediated, immune complex…so know your immune reactions

Immunoglobulin E ( IgE ) is an antibody that is produced by the body’s immune system and is associated with allergic responses, including asthma, and to a lesser degree with immunity to parasites. The total IgE test may be used to screen for and detect allergic diseases. Least concentrated of the immunoglobulin classes in the circulation Mediator of many common allergic responses Defender against parasites a. Provides protection from large parasites ➢ Initiates an inflammatory reaction to attract eosinophils b. When produced against innocuous environmental antigens, they are a common cause of allergies ➢ Fc portions of IgEs are bound to mast cells The tissue-specific genes are a group of genes whose function and expression are preferred in one or several tissues/cell types. Identification of these genes helps better understanding of tissue–gene relationship, etiology and discovery of novel tissue-specific drug targets. Tissue Specific Promoters are active in a specific type of cells or tissues such as B cells, monocytic cells, leukocytes, m acrophages, muscle, pancreatic acinar cells, endothelial cells, astrocytes, lung ... Cell - mediated immunity is an immune response that does not involve

antibodies, but rather involves the activation of phagocytes, antigen- specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. Action by the immune system involving T cells ( T LYMPHOCYTES ) and concerned with protection against viruses, fungi, TUBERCULOSIS and cancers and rejection of foreign grafted material. Cell-mediated immunity is not primarily effected by ANTIBODIES. Immune complex is the term used to refer to the combination of an antibody with its antigen. Immune complexes must be removed from tissues and kept from accumulating in the circulation and forming deposits throughout the body. Failure to clear immune complexes can lead to autoimmune disease. Study color blindness and risk factor for developing it (look for more in book). Color deficiency is usually a hereditary condition. The trait is passed on the X chromosome, and because males only have one X chromosome, it is easier for them to inherit color vision deficiency. A mother who carrier’s one normal X chromosome and one X chromosome with a mutation of red and/or green pigments is not affected, but her son has a 50% chance of having a color vision deficit. Fathers cannot pass it to their sons, because they supply only a Y chromosome to the genetic mix, but they can pass the gene to their daughters who carry the gene but do not manifest a color deficit.

Abnormal color vision also may be caused by color blindness and is an X- linked genetic trait. Color blindness affects 6 to 8% of the male population and about 0.5% of the female population. Although many forms of color blindness exist, most commonly the affected individual cannot distinguish red from green. In the most severe form individuals see only shades of grey, black, and white. Study cellular adaptation (anaplasia, hyperplasia, metaplasia, dysplagia, etc)

1. See study guide Chapter 4 Anaplasia – one of the microscopic hallmarks of cancer is anaplasia, the loss of cellular differentiation. You will be given scenarios with ABG values and asked to pick which it is. See sheets with case studies to practice. Know how to differentiate between cell types (eosinophils, neutrophils, leukotrienes, monocytes, mast cells). In other words know what they each are responsible for. Eosinophils are a type of disease-fighting white blood cell. This condition most often indicates a parasitic infection, an allergic reaction or cancer. You can have high levels of eosinophils in your blood (blood eosinophilia ) or in tissues at the site of an infection or inflammation (tissue eosinophilia ). Eosinophils Defend against parasites, degrade vasoactive substances

released by mast cells. ● Eosinophils ➢ Mildly phagocytic ➢ Defense against parasites and regulation of vascular mediators Eosinophils do many things, including:

• fend off bacteria and parasites
• kill cells
• participate in allergic reactions
• play a part in inflammatory responses
• "respond" to areas of inflammation Although eosinophils are part of the immune system, some of their responses aren't always healthy for the body. Sometimes they play a part in conditions such as food allergies and inflammation in the body's tissues. Neutrophils – phagocytize microorganisms and cellular debris soon after injury; secrete chemicals that call in longer- acting phagocytes ● Neutrophils ➢ Also referred to as polymorphonuclear neutrophils (PMNs) ➢ Predominate in early inflammatory responses ➢ Ingest bacteria, dead cells, and cellular debris

➢ Cells are short lived and become a component of the purulent exudate They are a type of white blood cell (WBC or granulocyte) that protect us from infections, among other functions. They make up approximately 40 percent to 60 percent of the white blood cells in our bodies and are the first cells to arrive on the scene when we experience a bacterial infection Neutrophils are a type of white blood cell that helps heal damaged tissues and resolve infections. Neutrophil blood levels increase naturally in response to infections, injuries, and other types of stress. They may decrease in response to severe or chronic infections, drug treatments, and genetic conditions. Neutrophils help prevent infections by blocking, disabling, digesting, or warding off invading particles and microorganisms. They also communicate with other cells to help them repair cells and mount a proper immune response. Inflammatory molecules called leukotrienes are one of several substances which are released by mast cells during an asthma attack, and it is leukotrienes which are primarily responsible for the bronchoconstriction. Leukotrienes are potent pro-inflammatory mediators that appear to contribute to pathophysiologic features of asthma. ● Leukotrienes

➢ Product of arachidonic acid from mast cell membranes ➢ Similar effects to histamine in later stages Monocytes are a type of leukocyte, or white blood cell. They are the largest type of leukocyte and can differentiate into macrophages and myeloid lineage dendritic cells. As a part of the vertebrate innate immune system monocytes also influence the process of adaptive immunity. Monocytes are a type of white blood cell. Like other white blood cells, monocytes are important in the immune system’s ability to destroy invaders, but also in facilitating healing and repair. Monocytes are formed in the bone marrow and are released into peripheral blood, where they circulate for several days. They comprise about 5-10 percent of the circulating white blood cells in healthy individuals. Monocytes are probably best known for their role in serving as something akin to reserve forces in the military. Some of them may be called up if needed, to form the precursors of two other types of white blood cells: tissue macrophages and dendritic cells. But monocytes also have other roles in infection and disease, some of which have nothing to do with tissue macrophages and dendritic cells. Mast cells are cells found in connective tissue throughout our bodies as part of our immune system. Mast cells are particularly prominent in tissues of our bodies that interact with our external world, such as those found on our skin and in our respiratory and digestive tracts. Mast cells can also be found in the organs and tissue of our circulatory and nervous systems. Mast cells play an important role in protecting our health by

providing a line of defense against pathogens. Mast Cell Functions Release chemicals that initiate the inflammatory response ● Mast cells are cellular bags of granules located in the loose connective tissues close to blood vessels ➢ Skin, digestive lining, and respiratory tract ➢ Contain histamine, cytokines, and chemotaxic factors In response to exposure to a perceived pathogen, mast cells set off a rapid inflammatory response to outside invaders, such as germs, viruses, and parasites. Mast cells have the capacity to directly kill these organisms or to stimulate the production and release of substances that will destroy the pathogen. Mast cells play a prominent role in the activation of the allergy response. When a person has an allergy, mast cells are responding to harmless triggers as if they were a threat. In addition to their protective and immune system effects, mast cells are also involved in:

• Homeostasis of blood vessels and bronchial functioning
• Injury healing
• Formation of new blood vessels
• Regulate functioning of cells throughout the body
• Regulation of bone growth

Malaria is one of the most common infections worldwide. In 2012, the World Health Organization (WHO) estimated that there were 207 million cases of malaria with an estimated 627,000 deaths; 90% were min Africa where 82% of the deaths were children younger than age 5. Malaria is caused by Plasmodium falciparum, a protozoan (unicellular) parasite. Many protozoan parasites are transmitted through vectors or ingested. Transmission of Plasmodium is through the bite of an infected female Anopheles mosquito, where the parasite grown in the salivary glands. The initial attachment to cells depends on the presence of the microorganism in the bloodstream or gastrointestinal tract. Microorganisms in the bloodstream have surfaced proteins that allow them to attach to various receptors to infect macrophages, red blood cells, or organ cells such as the liver. For example, multiplication of Plasmodium occurs in erythrocytes and results in the release of additional parasites that infect other erythrocytes. Periodic (48-72 hours) lysis of the erythrocytes results in anemia and induction of cytokines that provoke fever, chills, sweating, headache, muscle pain, and vomiting. Severs symptoms include anemia, pulmonary edema, and other complications causing death. Neurologic complications may result from infected red blood cells adhering to endothelium in capillaries of the brain. Tetanus some bacterial pathogens are not invasive, but colonize mucosal membranes or wounds and release potent exotoxins that act locally or

systemically. Vaccinations against systemic exotoxins (e.g. Tetanus) has been achieved using toxoids (purified exotoxins that have been chemically detoxified without loss of immunogenicity. One of the first licensed vaccine mixtures was DPT, which now usually contains diphtheria (D) and tetanus (T) toxoids and acellular pertussis vaccine (aP). More recent mixtures include DTaP with inactivated poliovirus, either with Hib conjugate to tetanus toxoid or with hepatitis B antigen. Through vaccinations active immunization – Primary immune response is activated. They are biologic preparations of antigens that when administered stimulate production of protective antibodies or cellular immunity against a specific pathogen without causing potentially life- threatening disease. Smallpox (varioloa) was a highly contagious and deadly, but also preventable, disease caused by poxvirus variolae. Smallpox was eradicated worldwide in 1977. Routine vaccination in the US was discontinued in 1972, and a new vaccine, ACAM2000, has been produced from the US. In the early 1950’s an estimated 50 million cases of smallpox occurred each year, with 15 deaths. WHO conducted an aggressive immunization campaign from 1967 to 1977 that resulted in the global eradication of smallpox by 1979. Hepatitis B and C viruses (HBV, HCV) are associated with about 15% of all human cancers worldwide. Chronic Hep B infections are common in parts of Asia and Sub-Saharan Africa and confer up to a 200-fold increased risk of developing liver cancer. Chronic Hep C infections have become

increasingly recognized in Western countries. Up to 80% of liver cancer cases worldwide are associated with chronic hep caused either by HBV or by HCV. The initial infection with hep B or C is not associated with cancer; instead, it is acquisition of a chronic viral hepatitis that markedly increases cancer risk. In both cases, it appears that a lifetime of chronic liver inflammation predisposes to the development of hepatocellular carcinoma. Widespread use of the HBV vaccine is expected to significantly decrease the incidence of chronic hep B and hence hepatocellular carcinoma. No vaccine for HCV. QUESTIONS: A 50 – year – old male intravenous drug user is diagnosed with Hep-C. Examination of the liver reveals cell death secondary to: a. Fat necrosis b. Physiologic apoptosis c. Infection-induced apoptosis d. Pykn osis ANS. C With Hepatitis, the liver will demonstrate apoptosis that is a result of the viral infection. What is the result homologous chromosomes failing to separate during meiosis?

a. Neurofibromatosis b. Nondisjunction c. Polypoloidy d. Conjoine d twins ANS. B Nondisjunction is an error in which homologous chromosomes or sister chromatids fail to separate normally during meiosis or mitosis. A cell that does not contain a multiple of 23 chromosomes is called a cell. a. Diploid b. Euploid c. Polyploid d. Hapl oid ANS. C A polypoloid cell is one in which a euploid cell has more than 23 pairs of chromosomes. What is the most common cause of Down syndrome? a. Paternal nondisjunction b. Maternal translocations

c. Maternal nondisjunction d. Paternal translocation ANS. C The most common cause of Down syndrome is maternal nondisjunction A patient wants to know the risk factors for Down syndrome. What is the nurse’s best response? a. Fetal exposure to mutagens in the uterus b. Increased paternal age c. Family history for down syndrome d. Pregnancy in woman over age 35 ANS. D The primary risk for down syndrome is pregnancy in women over 35. Down syndrome is a trisomy chromosomal abnormality. Down syndrome is characterized by distinctive characteristics: Low nasal bridge, epicanthal folds, protruding tongue, and low-set ears. A 13-year-old girl has a karyotype that reveals an absent homologous X chromosome with only a single X chromosome present. What medical diagnosis will the nurse observe on the chart?

a. Down syndrome b. Cri du chart syndrome c. Turner Syndrome d. Fragile X syndrome ANS. C A condition with the presence of a single X chromosome and no homologous X or Y chromosome, so the individual has a total of 45 chromosomes, is known as Turner syndrome. What genetic disorder is the result if an individual possesses an XXY chromosome configurations? a. Turner b. Klinefelter c. Down d. Fragi le X ANS. B Individuals with at least two X chromosomes and one Y chromosome in each cell 47 XXY karyotype, have a disorder known as Klinefelter syndrome. Klinefelter syndrome is characterized by small testes, some

development of the breast, sparse body hair, and long limbs. Cystic fibrosis is caused by what gene abnormality? a. X-linked dominant b. X-linked recessive c. Autosomal dominant d. Autosomal recessive ANS. D Cystic fibrosis is an autosomal recessive disorder. A child is diagnosed with cystic fibrosis. History reveals that the child’s parents are siblings. Cystic fibrosis was most likely the result of: a. X-inactivation b. Genomic imprinting c. Consanguinity d. Obligate carriers ANS. C Consanguinity refers to the mating of two related individuals, and the offspring of such mating are said to be inbred. Consonguineous mating produces a significant increase in recessive disorders and are seen most often in pedigrees for rare recessive disorders.