Exam 26: Hormones and the Endocrine System

Oxytocin is a hormone produced by the posterior pituitary gland that causes female uterine muscles to contract during childbirth and female mammary glands to eject milk during nursing. Oxytocin also occurs naturally in males and is involved in movement of sperm and production of testosterone. It has been given the common name of "the love hormone" because oxytocin is linked to human behaviors including sexual arousal and trust. In 2012, The Atlantic (a popular news source) published a brief online news summary that explained that when scientists in Germany gave men who were in a monogamous relationship with a woman a nasal spray containing oxytocin, the men were less attracted to an attractive female stranger than men who were given a nasal spray with no oxytocin. While The Atlantic provided a link to the original scientific study, the summary drew conclusions and stated implications that included the following: 1. In men, oxytocin promotes monogamous relationships because it keeps them from communicating with women who are attractive to them. 2. If a man is unable to obtain a nasal spray with oxytocin, there are other means by which oxytocin release can be stimulated during a monogamous relationship: sexual intercourse, hand-holding, and touching. -What is the main evidence that you would use to decide whether the conclusions and implications that The Atlantic published were valid?

How are hormones distributed to tissues, and what determines which cells hormones will affect?

When the concentration of glucose in the blood rises following digestion of a meal, what is the hormonal response?

Which statement is true?

What is the metabolic abnormality that underlies the characteristic symptoms of diabetes mellitus?

Which step in this figure portraying lipid-soluble hormone action shows transcription in response to the bound hormone-receptor complex?

Which statement regarding endocrine glands is true?

When environmental estrogens trigger premature puberty in girls, the main organs affected are the

High levels of which hormone can suppress the body's immune system?

Which gland is/are located nearest the kidneys?

Which disorder is associated with obesity and occurs because cells of the body fail to respond adequately to insulin?

Which act(s) mainly to regulate salt and water balance?

Which hormone affects the greatest variety of cell types?

Recent studies suggest that flame retardants, chemicals that are used to slow down burning, can mimic estrogen hormones found in the human body. Scientists investigating this phenomenon developed three-dimensional images to show how the chemical structure of certain flame retardants allows the retardants to bind to and inhibit an enzyme (estrogen sulfotransferase) that metabolizes estrogen. Suppose the scientists want to conduct a study of the effects of flame retardants on estrogen levels. In a hypothetical study, the scientists use frogs to test the effects of flame retardants because the frogs' skin is highly permeable and therefore allows for easy absorption of chemicals. The scientists collected 20 wild adult frogs and brought them to a laboratory. Ten of the frogs (group 1: five male and five female) were kept in tanks mimicking their natural environment. The other ten frogs (group 2: five male, five female) were kept in tanks like those of group 1 except they were introduced to low amounts of flame retardants in the shallow water in their tank. Estrogen levels were measured on the first day of the experiment and then every 4 days for 20 days. -Why is group 1 needed in this experiment?

Why must some hormones bind to a membrane receptor on a target cell's surface in order to activate it?

Hormones as a general class are chemicals produced by the endocrine system that

Androgens stimulate

In investigating the role of oxytocin as an antistress hormone, researchers sought to explore the relationship between childhood maltreatment, PTSD (post-traumatic stress disorder) and oxytocin levels. One study measured the level of oxytocin (pg/mL) in people who had and had not experienced childhood maltreatment and who did and did not have PTSD. The results, averaged over many subjects, are these: Levels of oxytocin (pg/mL) in people who had and had not experienced childhood maltreatment and who did and did not have PTSD PTSD No PTSD Childhood maltreatment 983 669 No childhood maltreatment 388 752 -Did this study lend support to the idea that people with PTSD combat stress with higher levels of oxytocin?

Oxytocin is a hormone produced by the posterior pituitary gland that causes female uterine muscles to contract during childbirth and female mammary glands to eject milk during nursing. Oxytocin also occurs naturally in males and is involved in movement of sperm and production of testosterone. It has been given the common name of "the love hormone" because oxytocin is linked to human behaviors including sexual arousal and trust. In 2012, The Atlantic (a popular news source) published a brief online news summary that explained that when scientists in Germany gave men who were in a monogamous relationship with a woman a nasal spray containing oxytocin, the men were less attracted to an attractive female stranger than men who were given a nasal spray with no oxytocin. While The Atlantic provided a link to the original scientific study, the summary drew conclusions and stated implications that included the following: 1. In men, oxytocin promotes monogamous relationships because it keeps them from communicating with women who are attractive to them. 2. If a man is unable to obtain a nasal spray with oxytocin, there are other means by which oxytocin release can be stimulated during a monogamous relationship: sexual intercourse, hand-holding, and touching. -Biologically, why might oxytocin have the nickname "the love hormone"?

In investigating the role of oxytocin as an antistress hormone, researchers sought to explore the relationship between childhood maltreatment, PTSD (post-traumatic stress disorder) and oxytocin levels. One study measured the level of oxytocin (pg/mL) in people who had and had not experienced childhood maltreatment and who did and did not have PTSD. The results, averaged over many subjects, are these: Levels of oxytocin (pg/mL) in people who had and had not experienced childhood maltreatment and who did and did not have PTSD PTSD No PTSD Childhood maltreatment 983 669 No childhood maltreatment 388 752 -A reasonable conclusion from this study would be