Endocrinology - (ch4) Textbook Flashcards
Study for final
Summarize the shared features of signaling systems.
In terms of endocrine vs nervous, they both communicate by sending signals out to the body. They both use hormones, and they both have receptors for these hormones.
Compare and contrast the major chemical classes of signaling molecules.
The classes are:
1. Proteins
2. Biogenic Amines
3. Steroid Hormones
4. Eicosanoids
Explain how chemical messengers communicate their signals to a target cell.
Compare the general features of signal transduction via intracellular receptors, ligand-gated ion channels, receptor enzymes, and G protein–coupled receptors.
Compare the different signal transduction pathways associated with G protein–coupled receptors.
Outline some of the ways that endocrine systems are organized using selected examples.
Outline some of the major patterns in the evolution of endocrine systems.
Compare and contrast paracrine and endocrine communication in terms of the three main steps of indirect signaling.
Compare and contrast hydrophilic and hydrophobic messengers in terms of the three main steps of indirect signaling.
Are peptide messengers hydrophilic or hydrophobic?
How does this property influence the mechanisms involved in each of the three main steps of indirect signaling?
What is a preprohormone?
What are the three main classes of steroid hormones in vertebrates?
Why are steroids usually bound to carrier proteins when transported in the blood?
Are amines hydrophilic or hydrophobic messengers? How does this affect their release, transport, and signaling?
Outline the ways in which thyroid hormone release, transport, and signaling differ from that of other biogenic amines.
What are eicosanoids?
Name three gaseous signaling molecules, and one function that they share.
Why do some cells respond to a chemical messenger while other cells ignore it?
Compare and contrast receptor up-regulation and down-regulation. How do these phenomena help to maintain homeostasis?
Some hydrophobic messengers alter the expression of only a few genes, while other messengers cause changes in the regulation of thousands of genes. Explain how this can be the case.
Some responses to hydrophobic ligands are termed nongenomic responses. How do they differ from the typical responses to a hydrophobic ligand?
What is the primary response of a cell when a ligand binds to a ligand-gated ion channel?
Which would you predict to be faster, signaling via a ligand-gated ion channel or signaling via an intracellular receptor? Justify your answer
What are the three main parts of a receptor-enzyme?
How do receptor-enzymes amplify incoming signals?
Outline the five main steps in G protein–coupled receptor signaling.
What is a second messenger?
Tell me abt Pineal gland
(Ch 4, “introduction to endocrine systems” - bottom chart).
Tell me abt Hypothalamus(clusters of secretory neurons)
Tell me abt Posterior pituitary (extensions of hypothalamic neurons)
Tell me abt Anterior pituitary gland
Tell me abt Thyroid gland
Tell me abt Parathyroid gland
Tell me abt Thymus gland
Tell me abt Heart (individual cells in atrium)
Tell me abt Liver (various cells)
Tell me abt Stomach and small intestine (various cells)
Tell me abt Pancreas
Tell me abt Adrenal gland (cortex) in mammals; dispersed cells in other vertebrates
Tell me abt Adrenal gland (medulla) in mammals; chromaffin cells in other vertebrates
Tell me abt Corpuscles of Stannius (fish); various tissues in mammals
Tell me abt Kidney (various cells)
Tell me abt Testes (male)
Tell me abt Ovaries (female)
Tell me abt Placenta (pregnant female mammals only)
What are antagonistic pairings? What are the advantages of this organization of control systems?
Compare and contrast negative feedback and positive feedback. Which type of control allows maintenance of homeostasis?
Provide an example of a hormone controlled by a third-order endocrine pathway, and outline each step in the regulatory cascade.
What are the major differences between invertebrate and vertebrate endocrine systems?
How have gene duplications played a role in the evolution of the vertebrate endocrine system? Support your answer with at least two examples.
LO 1 What are the main types of indirect signaling, and what is the primary feature that distinguishes them?
LO 1 What are the three major steps involved in indirect chemical signaling?
LO 2 If the newspaper article in Question #3 were about a peptide hormone, how would your predictions change?
LO 2 You read an article in the newspaper about the discovery of a new steroid hormone. What can you predict about how it is synthesized and/or stored by the signaling cell, how it is transported through the blood, and how it acts on the target cell?
LO 3 From the perspective of the target cell, is there a fundamental difference between a paracrine signal and an endocrine signal? Why or why not?
LO 3 What are the three main domains of a transmembrane receptor, and what are their functions?
LO 4 Compare and contrast the signal transduction cascades initiated by intracellular receptors and G protein–coupled receptors.
LO 4 Compare and contrast the functions of intracellular and transmembrane steroid receptors.
LO 5 Compare and contrast the function of heterotrimeric G proteins and a small soluble G protein such as Ras.
LO 5 What is the difference between signaling through and ?
LO 6 Which classes of chemical messenger are utilized for endocrine communication? Give one example of a hormone from each class.
LO 6 Compare and contrast positive and negative feedback. Provide an example from the endocrine system of vertebrates for each type of feedback.
LO 7 Are the endocrine systems of vertebrates and invertebrates homologous? Justify your answer.
LO 7 Compare and contrast the insulin/glucagon system for blood glucose regulation in vertebrates with the function and regulation of crustacean hyperglycemic hormone (CHH).
Epinephrine and glucagon both act to increase blood glucose, but they act on a different subset of tissues. What characteristics are likely to determine whether a particular tissue responds to epinephrine, glucagon, or to both hormones?
People who do not regularly drink coffee often feel much greater effects when they ingest modest doses of caffeine than do heavy coffee drinkers. Explain at a molecular level why this might be so.
The anticancer drug tamoxifen binds to the estrogen receptor. Tamoxifen inhibits the growth of breast tissue but promotes growth of uterine tissues, thus reducing the risk of breast cancer but potentially increasing the risk of uterine cancer. Explain how the same chemical messenger could have opposite effects in two different tissues.
What are the advantages of a multistep signal transduction pathway in cell-to-cell communication?
Epinephrine binds to a G protein–coupled receptor that signals via . Acetylcholine binds to a G protein–coupled receptor that signals via . You construct a recombinant receptor with the extracellular domain of the acetylcholine receptor and the intracellular domain of the epinephrine receptor, and transfect it into cultured cells. Your preliminary experiments indicate that the receptor is processed correctly, and inserted into the plasma membrane. If you applied acetylcholine to your transfected cells, what would you expect to happen to intracellular cAMP levels? What would happen if you applied epinephrine? Explain your answers.
Why are peptide messengers released by exocytosis? Why are steroid hormones not released in this way?
Why do selective serotonin reuptake inhibitors (SSRIs) affect the response of a target cell to serotonin?
How does increasing the amount of a receptor on a target cell affect the and of the ligand-receptor interaction? What would be the effect of this change on the response of a target cell to the ligand?
Thinking about the evolution of endocrine systems, what evolutionary patterns result in the phenomenon of “endocrine disruption” observed when male fish living in sewage outfalls are feminized by artificial human contraceptives and hormone replacement therapies in the effluent?
What are the major parts of any control system (mechanical or biological)? Choose an example of a biological control system and show how it fits the general description of control systems that you provided.
In insects, the Malpighian tubules are involved in the maintenance of ion and water balance. When a peptide hormone called diuretic hormone is applied to Malpighian tubules isolated from the blood-sucking insect Rhodnius prolixus, the tubule epithelium begins to secrete fluid at a rate of approximately 5 nL/min. The biogenic amine serotonin has similar effects, causing secretion at a rate of approximately 4 nL/min. When both chemical messengers are applied together, however, fluid secretion occurs at a rate of approximately 45 nL/min. Is this an example of additivity, synergism, or antagonism? Justify your answer.
