How does air get from the nostrils to the lungs?

In order for respiration to occur, gases must be exchanged between the human and the environment. Oxygen must be inhaled while carbon dioxide must be exhaled as a waste.

When we inhale, air enters the nose where it is moistened and filtered due to hairs that can trap dust and other particles. Next, air passes into the pharynx, the tube inside the throat.  Next, air passes into the trachea, a tube which has cartilaginous rings to strengthen it and to help it remain open. At the top of the trachea are the vocal cords as well.

Next, the trachea branches into two large tubes called the bronchi and air continues on its journey. Each of these bronchi lead to one of the two lungs. Inside our lungs, the bronchi divide into smaller tubes called bronchioles. These continue to get smaller and smaller, with their ends culminating in tiny alveoli or air sacs. These are the organs of gas exchange. They are surrounded by tiny capillaries from the circulatory system which allow the exchange of gases between the alveoli and the blood stream. Oxygen in the air sacs enters the capillaries by diffusion, and can be transported in the circulating blood to the cells, while carbon dioxide in the bloodstream enters the air sacs by diffusion and can be exhaled.

Breathing is regulated by carbon dioxide levels in the blood. Higher levels mean that the brain sends impulses to the diaphragm (a muscular organ between the chest and abdomen) to cause it to contract. When this occurs, the air pressure inside the chest cavity is lower than the surrounding air. This change in pressure pushes air into the nose and it begins its journey to the lungs.

When we exhale, the diaphragm relaxes. This  causes the air pressure inside the chest cavity to become higher than in the surrounding air. This pushes air out of the lungs and, eventually, we exhale.

I have included a link to a labeled diagram of the human respiratory system.

What are developmental disorders?

Causes and Symptoms

According to the revised fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (known as the DSM-IV-TR), published in 2000 by the American Psychiatric Association, the developmental disorders may be categorized into five distinct disorders that all share the central feature of childhood development that is outside the norm in some manner. These disorders are included under the heading of pervasive developmental disorders in the DSM-IV-TR. The term pervasive is used to indicate the extensive developmental deficits found among these disorders. The five pervasive developmental disorders in the DSM-IV-TR are autistic disorder, Rett syndrome, childhood disintegrative disorder, Asperger syndrome, and pervasive developmental disorder not otherwise specified (PDD-NOS).

Autistic disorder is probably the best known of the disorders in the developmental disorders group. The disorder has an onset before age three but may not be formally diagnosed until some years later. Children with autistic disorder do not commonly show any unusual physical characteristics, but they demonstrate a number of behavioral, social, and affective symptoms. There are usually major deficiencies in the capacity to show social relatedness to others, including parents. The social smile is absent during infancy, and autistic children continue to show deficits in play activities and social attachments throughout their lives. There is an inability to understand or infer the feelings and mental state of other people around them. Language development is usually limited, with difficulties in communicating ideas even when the vocabulary is present. Delayed mental development occurs in a high percentage of children with autism, with greatest deficits in abstract reasoning and social understanding. Children from an early age do not show interactive play activity but rather engage in repetitious actions such as rocking and other unusual mannerisms. Children with autism usually form attachments to inanimate objects rather than to people. Their mood is usually marked with sudden changes and potentially aggressive outbursts. Although the exact cause in unknown, autistic disorder is considered to have a biological cause with a high genetic vulnerability. Research has indicated that two regions on chromosomes 2 and 7 contain genes involved with autistic disorder. Studies suggest that abnormal levels of serotonin and other neurotransmitters in the brain are found because there is a disruption of normal brain development early in fetal development caused by defects in the genes. The temporal lobe area of the brain has been implicated in the development of autism since this area is strongly associated with social development.

Rett syndrome features a period of normal development for approximately six months after birth that is followed by deterioration of functioning. Symptoms such as encephalopathy, seizures, breathing difficulties, loss of purposeful hand movements, loss of social engagement with others, poor coordination, and severely impaired language development then develop. The growth of the head circumference slows and produces microcephaly. The child begins to show repetitious movements such as hand-wringing and problems walking. The condition is progressive, and the skill level remains at the level of the first year of life. Children may live for ten years or more but must use a wheelchair as a result of muscle wasting. The cause of Rett syndrome has been identified as related to a genetic mutation. The gene is located at the Xq28 site on the X chromosome. Only one of the two X chromosomes need have the mutation in order for it to cause the disorder. This means that it is an X-linked dominant disorder. Rett syndrome is a rare condition usually found in females.

Childhood disintegrative disorder is diagnosed when there is marked regression or deterioration in a number of areas of functioning after age two. Children with this disorder begin to lose language and social skills previously developed in the first two years of life. Both bowel and bladder control as well as manual skills can be lost. It is common for these children to exhibit high levels of anxiety as the deterioration progresses. Children with this disorder also typically develop seizures. The cause of childhood disintegrative disorder is unknown, but it is considered to be related to some central nervous system pathology.

Asperger syndrome is marked with symptoms of severe and sustained impairments in social interactions. Repetitive patterns of behavior are commonly seen. In contrast to autism, children with Asperger syndrome do not exhibit significant delays in language or cognitive development. Common characteristics of Asperger syndrome include a lack of empathy toward the feelings of others, minimal social interactions, limited ability to form friendships, pedantic and monotonic speech, and intense fascination with trivial topics learned in rote fashion. The cause of Asperger syndrome is unknown but is believed to have a genetic base. Current research suggests that a tendency toward the condition may run in families. Children with Asperger syndrome are also at risk for other psychiatric problems, including depression, attention-deficit disorder, schizophrenia, and obsessive-compulsive disorder. Persons with Asperger syndrome have a variable
prognosis depending upon their cognitive abilities and language skills, but all continue into adulthood showing an awkward manner toward other adults and lack of comfort in social settings. Asperger syndrome is usually first diagnosed in children between the ages of two and six.

PDD-NOS is the fifth developmental disorder described in the DSM-IV-TR. It is viewed as a severe impairment in communication skills with deficiencies in social behavior. It differs from autistic disorder in terms of the severity of symptoms, and persons diagnosed with this disorder experience better functioning into adulthood than those with autistic disorder.

Treatment and Therapy

The goal for treatment of autistic disorder is to increase socially acceptable behaviors and decrease or extinguish unusual actions such as rocking and self-injurious behaviors. Therapy attempts to improve verbal and nonverbal communication skills to enhance interactions with other people. Therapy usually involves both educational and behavioral interventions with structured classroom training using behavioral techniques that employ rewards or positive reinforcements. Treatments for children with autistic disorder require a great deal of structure and repetition. Family members often participate in counseling sessions to help with the stressors of raising a child with autistic disorder. Medications are used as an adjunct to educational and behavioral treatments to diminish temper tantrums, self-injurious behaviors such as head banging, and hyperactivity. Antipsychotic medications such as risperidone and haloperidol are the most commonly used adjunctive treatments.

Rett syndrome has limited treatment options. The focus is on providing symptomatic relief whenever possible and structured behavioral techniques of positive rewards to concentrate on positive behaviors. Anticonvulsive medications are used to control seizures that can develop in this disorder and also diminish self-injurious behaviors. Physical therapy can assist with the distress associated with muscle deterioration.

Childhood disintegrative disorder is treated with similar methods as used in autistic disorder. Highly structured educational and behavioral programs are used to maintain the limited language and cognitive skills that had developed prior to the onset of the disorder.

Asperger syndrome treatments depend upon the level of functioning present among those with this disorder. Emphasis is usually placed upon improving social skills and adaptive functioning in social situations.

Treatment for PDD-NOS is largely the same as used with autistic disorder. Children with this disorder have a higher functioning of language skills than found with autistic disorder; consequently, the educational and behavioral treatments are supplemented with individual psychotherapy.

Perspective and Prospects

Autistic disorder was initially identified in 1867 by psychiatrist Henry Maudsley, but it was not until 1943 that Leo Kanner coined the term infantile autism and carefully described the associated signs and symptoms of the condition. Even with this description, many children with autism received the diagnosis of childhood schizophrenia. This tendency toward misdiagnosis continued into the 1980s. When considering the causes for the development of infantile autism, Kanner initially hypothesized that infantile autism was caused by emotionally unresponsive or “refrigerator” mothers who were unable to provide nurturance and emotional warmth to their newborn infants. Some children reacted to this emotional coldness by turning inward as a defense mechanism. Because of this defense, the child with autism focused on his or her inner world and did not develop communication skills. The child with autism usually focuses on inanimate objects rather than people and exhibits repetitious or self-stimulating behaviors such as rocking to gain personal satisfaction. Additions to this theoretical idea focused on the unresponsiveness of both parents toward the child and feelings of rage directed toward the child. Theories focusing on parental factors have since been discarded in favor of the current emphasis on identifying biological and genetic factors in the development of autism.

Rett syndrome was first identified by pediatrician Andreas Rett in 1966. Practicing in Austria, Rett based his descriptions on a pool of twenty-two girls who had developed normally until they were around six months of age. Rett published his findings in several German medical journals, but the information was largely ignored in the rest of the world. Awareness about the disorder increased when Rett published a description of the disease in English in 1977, but it was a 1983 article that appeared in the mainstream English-language journal Annals of Neurology that finally raised the recognition of this disorder.

Childhood disintegrative disorder was first described in 1908 by Viennese remedial teacher Theodor Heller. He described six children who had unexpectedly developed a severe mental deterioration between their third and fourth years of life, after previously normal development. Heller termed the condition dementia infantilis, and it was subsequently called Heller’s syndrome. The disorder is more often diagnosed in males than in females. Although the DSM-IV-TR uses two years of age as the standard for its diagnosis, most cases emerge when a child is between three and four years of age.

Asperger syndrome was first described in 1944 by Austrian pediatrician Hans Asperger, who called the condition autistic psychopathy. Asperger described a number of children, and his descriptions were close to Kanner’s idea of infantile autism. Asperger’s portrayals differed from Kanner’s, however, in that speech was less commonly delayed and the onset appeared to be somewhat later. The children that Asperger described were seen to have social behavior that was labeled as odd or unusual. Asperger called the children with this condition “little professors” because of their formal manner when talking about their favorite topics using great detail. Asperger also suggested that similar problems could be observed in the children's family members, particularly their fathers. Most of the scientific literature concerning Asperger’s discovery initially appeared in European professional journals until Asperger syndrome was made official in 1994, when the diagnosis was added to the DSM-IV.

In 2013, the American Psychiatric Association published the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, known as DSM-5. This edition made significant changes to a number of classification systems, perhaps most notably the classification of pervasive developmental disorders. Autistic disorder, Asperger syndrome, childhood disintegrative disorder, Rett syndrome, and PDD-NOS were subsumed under the category autism spectrum disorder. This change was met with criticism from some members of the medical community; however, others argued that the new system would aid medical professionals in making diagnoses.

Bibliography:

Aman, M., et al. “Medication and Parent Training in Children with Pervasive Developmental Disorders and Serious Behavior Problems: Results from a Randomized Clinical Trial.” Journal of the American Academy of Child and Adolescent Psychiatry 23 (October, 2009): 1025–38.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, D.C.: American Psychiatric Publishing, 2013.

Bopp, K., et al. “Behavior Predictors of Language Development over Two Years in Children with Autism Spectrum Disorders.” Journal of Speech, Language, and Hearing Research 52 (October, 2009): 1106–20.

Elder, J., et al. “Supporting Families of Children with Autism Spectrum Disorders: Questions Parents Ask and What Nurses Need to Know.” Pediatric Nursing 35 (July/August, 2009): 240–45.

National Institute of Mental Health. "Autism Spectrum Disorders (Pervasive Developmental Disorders." National Institutes of Health, May 23, 2013.

National Institute of Neurological Disorders and Strokes. "NINDS Pervasive Developmental Disorders." National Institutes of Health, May 7, 2013.

Noterdaeme, M., et al. “Asperger’s Syndrome and High-Functioning Autism: Language, Motor, and Cognitive Profiles.” European Child and Adolescent Psychiatry 8 (October, 2009): 875–925.

What adjectives appear in the poem "I Stood Tip-Toe Upon a Little Hill" by John Keats?

Adjectives are words that modify (describe) nouns. This means that adjectives are extremely common in most kinds of writing, including poetry. "I Stood Tip-Toe Upon a Little Hill" is full of adjectives. Consider the first two lines of the poem: 

"I stood tip-toe upon a little hill, / The air was cooling, and so very still..." 

The bolded words are adjectives. Why? Because "little" describes the hill, and "still" describes the air. 

Think about the next few lines, which get a little more complicated: 

"That the sweet buds which with a modest pride / Pull droopingly, in slanting curve aside..." 

Again, the adjectives are bolded: "sweet" describes the buds, "modest" describes the pride, and "slanting" describes the kind of curve that the buds follow. "Droopingly" is an adverb, meaning that it describes a verb ("pull") in the same way that adjectives describe nouns.

What is bedwetting?

Causes and Symptoms

Primary enuresis is defined medically as the inability to hold one’s urine during sleep. The condition is quite common and occurs most often in children; between 15 and 20 percent of children under the age of six suffer from the condition. These percentages decrease to about 5 percent at age ten, 2 percent at age fifteen, and only about 1 percent of adults. Secondary enuresis is bed-wetting in a child who had previously achieved bladder control. (These terms do not apply, however, to urination problems caused by physical illness, disease, or anatomical defect.) The condition is more common in boys than in girls. Bed-wetting usually occurs during the first third of sleep, although it can occur during all sleep stages and without relation to awakening periods.

It is important to realize that enuresis is considered to be a developmental concern rather than an emotional, behavioral, or physical one. Donald S. Kornfeld and Philip R. Muskin report in The Columbia University College of Physicians and Surgeons Complete Home Medical Guide (rev. ed., 1989) that “enuresis is due to a lag in development of the nervous system’s controls on elimination.” Many parents fail to understand this neuropsychological element and thus punish the child for a wet bed. Punishing, ridiculing, or shaming the child does not correct the situation; in fact, in many cases, it may prolong the problem as well as cause other unnecessary and undesirable psychological problems. Emotional problems have resulted from enuresis, as the child may be too embarrassed to partake in normal childhood activities such as camping or sleepovers.

Treatment and Therapy

Techniques for helping the enuretic child achieve dryness range from withholding liquids near bedtime to alarm systems to medical intervention. Generally, restriction of liquid intake after dinner is the first course of action. This treatment method, however, does not have a very high success rate. Should this treatment fail after a trial period of a few weeks, other methods may be employed.

Alarm therapy can help a child achieve control within four months, sometimes in only a few weeks. A beeper- or buzzer-type alarm sounds when moisture touches the bedding or underwear; the desired result is that the child, while sleeping, will eventually recognize the need to urinate and awaken in time to get to the bathroom. Electronic alarms are generally of two types. The first is a wired pad, consisting of two screens, which is placed under the sheets to detect wetness; when the child wets, the moisture activates the battery-operated alarm. The second is a device worn on the body, either in the underpants and connected by a wire to an alarm or a wristwatch-type alarm; the underwear serves as a separating cloth for the contact points. In either case, as wetness occurs, the alarm sounds, thus wakening the child; the child can then be directed to the bathroom to complete urination.

Barry G. Powell and Lynda Muransky cite several case histories in which alarm therapy proved to be effective in stopping enuresis. For example, a six-year-old who never had a dry bed achieved dryness within a week through the use of an alarm. In another case, a fifteen-year-old had been trying to overcome his bed-wetting problem for ten years. Several trips to the doctor showed that he had no physical cause for enuresis. His parents labeled him “lazy, inconsiderate, and difficult.” His desire to join his hockey team in overnight travel gave him the impetus to seek help. Powell and Muransky found his problem to be primary enuresis aggravated by family ridiculing. Through the use of his alarm, he achieved dryness within two weeks.

A case involving secondary enuresis is described as well. A child who had suffered through primary enuresis, then achieved dryness, was found to be wetting again. This second bout of bed-wetting seems to have been the result of his parents’ marital separation. After a medical examination revealed no physical problems, it appeared the problem was psychological, caused by emotional upset. He resumed dryness in three weeks (although an alarm system on his bed for six months gave him more confidence). It is important to note, however, that alarms can take up to several months’ time before a child feels comfortable in stopping its use. Also, parental supervision is imperative for this type of therapy to work properly.

Chiropractic spinal manipulation has been found to be effective in the treatment of some cases of enuresis. Some believe that a spinal reflex is involved in bed-wetting. As nighttime breathing slows down (a normal reaction), carbon dioxide builds up in the body. When the carbon dioxide buildup reaches a certain level, a breathing mechanism called the
phrenic reflex is triggered. This mechanism normally causes the diaphragm to return breathing to its normal pattern. If the mechanism does not work properly, however, the carbon dioxide continues to increase, resulting in an involuntary relaxation of the sphincter muscle at the opening to the bladder. Fluid (urine) is released and leaks out of the bladder. A child in a deep state of sleep does not recognize that the bed has been wet. Generally, chiropractors believe that the bed-wetting child sleeps in a state of high carbon dioxide intoxication.

While immature development of the phrenic reflex is the most common cause of bed-wetting, in some children a misalignment of the bones in the neck and spine (referred to as “subluxation” by chiropractors) is thought to cause pressure on the nerves that are related to the phrenic reflex. Through chiropractic adjustments, it is argued, the subluxation can be corrected, thus relieving pressure on the nerves. With the spine realigned and bodily functions working normally, enuresis can be eliminated. One child had never had a dry bed in his first ten years of life; after only two spinal adjustments by a licensed chiropractor, the child stopped wetting immediately. Chiropractors usually recommend a series of adjustments in order to realign the spine and nerves and keep them in the proper position.

Drug therapy solely for the treatment of enuresis is controversial. However, when an illness such as diabetes mellitus is the underlying cause of the bed-wetting, the use of drugs may be indicated. The drug imipramine hydrochloride (an antidepressant agent) has been studied to assist in contraction of the sphincter; however, because of the high toxicity and limited effectiveness of such antidepressants, its use is not widespread. Relapse rates are high, and cure rates are relatively low. More success has been achieved with desmopressin acetate, an antidiuretic drug. There is an immediate improvement in 70 percent of treated children. Relapse rates are lower than those associated with imipramine but higher than with the use of bed-wetting alarms, probably because the sphincter muscle is not fully developed in the enuretic child. In general, drug therapy yields a final success rate of about 25 percent.

Perspective and Prospects

The history of bed-wetting is probably a lengthy one. The term “enuresis” was coined around 1800, and the condition has plagued children from every ethnic background and socioeconomic level around the world. It continues to be a problem for many children today and probably will be so in the future as well.

Most enuretics are deep sleepers who are usually quite active during their waking hours. This sleeping pattern, combined with urinary systems that are not yet fully developed, is generally the main cause of bed-wetting. There are some indications that enuresis is hereditary; many children who suffer from the condition have a parent who was enuretic as a child. It is reassuring to know that almost all affected children outgrow the problem by adulthood. While no immediate cure is available, continued experiments with alarm systems and drugs will certainly alleviate the discomfort and embarrassment until the body’s lag in development corrects itself.

Bibliography

A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; ©2005. Bedwetting; [updated 2011 Aug. 2; cited 2013 Aug. 29]; about 3 p.

“Alarm Bells for Enuresis.” The Lancet 337 (March 2, 1991): 523.

American Medical Association. American Medical Association Family Medical Guide. 4th rev. ed. Hoboken, N.J.: John Wiley & Sons, 2004.

“Defining Enuresis.” FDA Consumer 23 (May, 1989): 10.

Hurl, C. "Urine Trouble: A Social History of Bedwetting and Its Regulation." History of the Human Sciences 24.2 (2011): 48–64.

Kemper, Kathi J. The Holistic Pediatrician: A Pediatrician’s Comprehensive Guide to Safe and Effective Therapies for the Twenty-five Most Common Ailments of Infants, Children, and Adolescents. 2d ed. New York: Quill, 2007.

Kornfeld, Donald S., and Philip R. Muskin. “Enuresis, or Bed-Wetting.” In The Columbia University College of Physicians and Surgeons Complete Home Medical Guide, edited by Donald Tapley et al. Rev. 3d ed. New York: Crown, 1995.

Morison, Moya J. “Living with a Young Person Who Wets the Bed: The Families’ Experience.” British Journal of Nursing 9, no. 9 (May 11–24, 2000): 572.

Rogers, June. “Child Centered Approach to Bed-Wetting.” Community Practitioner 76, no. 5 (May, 2003): 163–65.

Ronen, T., L. Hamama, and M. Rosenbaum. "Enuresis: Children’s Predictions of Their Treatment’s Progress and Outcomes." Journal of Clinical Nursing 22 no. 1–2 (January, 2013): 222–32.

What is XYY syndrome?

Risk Factors

Only males are at risk for XYY syndrome. Most cases of the disorder are not inherited but result from a random event during the formation of sperm cells.

Etiology and Genetics

All normal human cells contain forty-six chromosomes consisting of twenty-three pairs; one member of each pair is contributed by the female parent and one by the male. Of these forty-six chromosomes, two chromosomes, designated X and Y, are known as the sex chromosome pair. Individuals with an XX pair are female, while those with an XY pair are male. Unlike the other twenty-two chromosome pairs, the X and Y chromosomes are strikingly different from each other in both size and function. While the Y chromosome is primarily concerned with maleness, the X chromosome contains information important to both genders.

During formation of sperm and eggs in the testes and ovaries, respectively, a unique form of nuclear division, known as meiosis (or reductional division), occurs during cell division that halves the chromosome number from forty-six to twenty-three. Sperm and eggs thus carry only one member of each pair of chromosomes, and the original number will be restored during fertilization. Because females have an XX pair, their eggs can have only an X chromosome, while males, having an XY pair, produce sperm bearing an X or a Y chromosome.

A common genetic error during sperm or egg production is known as nondisjunction, which is the improper division of chromosomes between the daughter cells. Nondisjunction in the production of either gamete can result, at fertilization, in embryos without the normal forty-six chromosomes. XYY syndrome is one of several of these aneuploid
conditions (possession of one or a few more or less than the normal number of chromosomes) that involve the sex chromosome pair. While Klinefelter syndrome (an XXY male) and Turner syndrome (an X female) are more widely studied and recognized genetic diseases, the XYY male occurs with a frequency of 1 in 1,000 male births in the United States, according to the National Institutes of Health. Caused by a YY-bearing sperm fertilizing a normal X-bearing egg, the XYY embryo develops along a seemingly normal route and, unlike most other sex chromosome diseases, is not apparent at birth. The only physical clue is unusually tall stature; otherwise, an affected male will be normal in appearance. The XYY male is also fertile, unlike those with aneuploidies involving other combinations of sex chromosomes, which usually result in sterility.

Symptoms

Boys with XYY syndrome are usually tall, have difficulties with language, and may have slightly lower intelligence quotients (IQs) than other members of their families. They may also develop learning disabilities, hyperactivity, attention deficit disorder, and minor behavioral disorders.

Interest in the association between aggression and the Y chromosome began in the years following World War II. Both psychologists and geneticists began intensive scrutiny of the genes that were located on the male sex chromosome. Men with multiple copies of the Y chromosome thus became the subjects of much of this research. Genetic links to violent, aggressive, and even criminal behavior were found, although many argued that below-average intelligence played a greater role. Many males with XYY syndrome do perform lower than average on standard intelligence tests and have a greater incidence of behavioral problems. The majority, however, lead normal lives and are indistinguishable from XY males.

The controversy surrounding this research began with a study at Harvard University that began in the early 1960s and ended in 1973 because of pressure from both public and scientific communities. The researchers screened all boys born at a Boston hospital, identifying those with sex chromosomal abnormalities. Because the parents of XYY boys were told of their children’s genetic makeup and the possibility of lower intelligence and bad behavior, critics claimed that the researchers had biased the parents against their sons, causing the parents to treat the children differently. The environment would thus play a greater role than genetics in their behavior. Subsequent research has shown that the original hypothesis is at least partially accurate. There is a disproportionately large number of XYY males in prison populations, and they are usually of subaverage intelligence compared to other prisoners. It must be emphasized, however, that the majority of XYY males show neither low intelligence nor criminal behavior.

Scientists, doctors, geneticists, and psychologists now agree that the extra Y chromosome does cause above-normal height, reading and math difficulties, and, in some cases, severe acne, but the explanation of the high prevalence of XYY men in prison populations has changed its focus from genes to environment. Large body size during childhood, adolescence, and early adulthood will no doubt cause people to treat these individuals differently, and they may in turn have learned to use their size defensively. Aggressive behavior, coupled with academic difficulties, may lead to further problems. Clearly, however, the majority of XYY males do well. The issue would be much easier to resolve if a YY or Y male existed, but because lack of an X chromosome results in spontaneous miscarriage, no YY or Y male embryo could ever survive.

Screening and Diagnosis

Identification of this disorder after a child is born requires that the child receive genetic testing or screening and is often discovered accidentally as a consequence of results from another genetic test. A pregnant woman’s cells can be examined by either amniocentesis or chorionic villus sampling to determine if her child will have XYY syndrome. In amniocentesis, a sample of cells is taken from the amniotic fluid; chorionic villus sampling examines cells in the placenta.

Treatment and Therapy

Men with XYY syndrome may require help in school to deal with learning disabilities and behavioral difficulties. Speech, physical, and occupational therapies can also prove beneficial. The support of family members is another important element in helping men cope with this disorder.

Prevention and Outcomes

There is no cure for XYY syndrome. However, help in school and a supportive family can reduce the educational and behavioral problems associated with the disorder. Most males with XYY syndrome lead normal lives.

Bibliography

Bryant, Daniel M., et al. "Sex Chromosomes and the Brain: A Study of Neuroanatomy in XYY Syndrome." Developmental Medicine & Child Neurology 54.12 (2012): 1149–56. Print.

Chen Harold. “XYY Syndrome.” Atlas of Genetic Diagnosis and Counseling. Totowa: Humana, 2006. Print.

Kim, Ina W., et al. "47 ,XYY an Male Infertility." Rev. in Urology 15.4 (2013): 188–96. Print.

Mader, Sylvia S. Human Reproductive Biology. 3d ed. Dubuque: McGraw-Hill Higher Education, 2005. Print.

Simpson, Joe Leigh, and Sherman Elias. “Sex Chromosomal Polysomies (47,XXY; 47,XYY; 47,XXX), Sex Reversed (46,XX) Males, and Disorders of the Male Reproductive Ducts.” Genetics in Obstetrics and Gynecology. 3d ed. Philadelphia: Saunders, 2003. Print.

Tamarin, Robert H. Principles of Genetics. Boston: McGraw-Hill, 2002. Print.

Templado, C., F. Vidal, and A Estop. "Aneuploidy in Human Spermatoza." Cytogenetic & Genome Research 133.2-4 (2011): 91–99. Print.

Vernice, Mirta, and Anna Cremante. “Life Span Development in XYY.” Life Span Development in Genetic Disorders: Behavioral and Neurobiological Aspects. New York: Nova Biomedical Books, 2008. Print.

Discuss Kurtz' last words in Heart of Darkness. What is their significance? How does Marlow interpret them?

Kurtz’s last words, “The horror! The horror!” have been widely debated by critics and could have multiple meanings. On the surface, it seems that he is referring to the horrors he has witnessed during his time working in the Congo. He is horrified with imperialism and the exploitation of African people and resources. It could also be that he is horrified with himself and what he has become. From the beginning of the novel, Marlow hints at the psychological changes that take place in a person when they travel into the “heart of darkness,” and it seems Kurtz may be horrified at the changes in his mind and the atrocities that has made him capable of. We can gather that Kurtz has been brought to a certain level of insanity from his experience in the Congo, and this could also be what he is referring to with his last words.

Marlow seems to see Kurtz’s last words as a dying man’s last moment of complete clarity before passing. Because Kurtz was able to have such poignant and revelatory last words, Marlow sees him as a “remarkable man.” Marlow is so impressed that Kurtz, on the edge of death, is able to say words that he believes encompasses some kind of great truth. Marlow says:

He had summed up-- he had judged. ‘The horror!’ He was a remarkable man. After all, this was the expression of some sort of belief; it had candor, it had conviction, it had a vibrating note of revolt in its whisper, it had the appalling face of a glimpsed truth-- the strange commingling of desire and hate.

Marlow finds Kurtz so remarkable because even in his last moments he is able to speak truthfully and with conviction- because his beliefs do not falter even in the weakest moment. It is not clear from this whether Marlow believes “the horror” refers to the exploitative acts of imperialism or whether it is Kurtz’s own soul, but it is clear that Marlow admires Kurtz because of them.

Where is Long Walk to Freedom: The Autobiography of Nelson Mandela set? What is the landscape like? What objects are part of the setting?

The book opens in 1918, the year of Mandela's birth, in rural South Africa. More specifically, the setting is the small village of Mvezo.

The narrator notes that Mvezo is a traditional and isolated village, set quite apart from the major events that were playing out in the world at large (most notably World War I, called The Great War here because, of course, people weren't expecting a second one at the time, as well as the terrible epidemic of the flu).

The landscape of this setting is beautiful, and as Mandela introduces it to us, he emphasizes its "rolling hills," its lush valleys, and its many, many "rivers and streams." Thanks to these flowing bodies of water, no matter what time of year it is, the landscape remains green. Mandela goes on to describe the whole region as "rich and temperate," possibly anticipating that many readers in the US will automatically and incorrectly equate Africa with barren deserts.

The lushness and beauty of the landscape might be best summarized by Mandela's recollection that his childhood fostered his "love of the veld, of open spaces, the simple beauties of nature, the clean line of the horizon."

When the story moves to the nearby village of Qunu, the general landscape remains green, grassy, hilly, and full of clear streams.

As for objects important to the setting, you might consider the oxen first. We infer that they are of great value, since Mandela recounts the story of his father being deposed from his political position due to "a complaint against him involving an ox that had strayed from its owner." Other important objects in the environment here include the clusters of huts, made of mud and shaped like beehives; the buckets used to bring water from the streams; the three-legged iron pot in which the narrator's mother prepared food; as well as the "cattle, sheep, goats, and horses" that graze the grassy pastures. The cattle seem to be especially important:

"I discovered the almost mystical attachment that the Xhosa have for cattle, not only as a source of food and wealth, but as a blessing from God and a source of happiness."

The thorn bush seems important, also, as an object in the environment, as it's the reason for Mandela's early shameful encounter with the donkey that so embarrassed him in front of his friends.

Finally, the one-room schoolhouse with the "western-style roof" also emerges as a crucial part of the setting, the place where, despite his mother's reluctance, Mandela first attends school.