REVIEW QUESTIONS FOR THE FIRST EXAM

INTRACELLULAR MESSENGERS

“*” INDICATES MATERIAL COVERED IN CELL BIOLOGY

Explain the importance of intercellular communication.

Discuss the following types of intercellular communication being sure to cover their types of transmission, chemical mediators, where they are found, and how their effects are distributed.

*Describe the structure of a gap junction.

Name the various areas where they might be found.

Explain their role in coordinating contraction of cardiac muscle and the propagation of action potentials in electrical synapses.

Distinguish between electrical and chemical synapses.

Define the term neurotransmitter and briefly discuss their function.

Name some of the neurotransmitters that can also act as hormones.

Explain the importance of local chemical messengers.

Distinguish between autocrine and paracrine mediators.

Define the term cytokine.

Define the term target cell.

Briefly discuss the function of histamines and prostaglandins, as local mediators.

Explain why these local mediators might be considered to be endocrine messengers.

Discuss the term endocrine secretion/hormone.

Explain the difference between endocrine secretions and the other types of secretions.

Name the endocrine glands found in the human body.

Name the tissues that have endocrine cells scattered about in them.

Name the organs that have dual function (endocrine and some other function).

Discuss the differences between the endocrine and nervous systems.

Discuss the relationship between the endocrine and nervous system. Give special attention to the

Discuss the relationship between the hypothalamus, the autonomic nervous system and the pituitary.

Name the hormones that are derived from the amino acid tyrosine.

Name the hormone that is derived from the amino acid tryptophan.

Name the hormones that are classified as catecholamines and draw a flow chart showing their metabolic pathway. Be sure to include the chemical L-dopa.

Explain the medical importance of L-dopa and why it is used rather than dopamine.

Name the hormones that are glycoproteins.

Name the hormones that are peptide hormones.

Discuss the role of eicanosoids in local messaging.

Name the molecule from which eicanosoids are derived.

Very briefly discuss the function of leukotrienes, prostacyclins, and prostaglandins.

Name the steroid hormones.

Name the molecule from which all steroid hormones are formed.

Explain the importance of pregnenolone in the metabolic pathway for making steroids

Explain the difference between protein hormone secretion and steroid hormone secretion.

Define the term homeostasis.

Discuss negative feedback systems and give several examples in the endocrine system of negative feedback systems.

Discuss positive feedback systems and give several examples in the endocrine system of negative feedback systems.

Name the feedback mechanism that controls most endocrine secretions.

Discuss how the action of substances other than hormones can control endocrine secretions.

Discuss how neural control can control endocrine secretions.

Discuss how the activity of another endocrine gland can control the secretion of an endocrine gland.

Define the following terms and how they relate to endocrine secretions: antagonistic effects, synergistic effects and permissive effects.

Give examples where more than one of these factors affect endocrine secretion.

Very briefly discuss how glucose in the blood affects insulin and glucagon secretions.

Very briefly discuss how calcium in the blood affects calcitonin and parathyroid hormone secretion.

Very briefly discuss how adrenal medulla secretions are controlled by neural mechanisms.

Very briefly discuss how the hypothalamus and anterior pituitary control thyroid secretion of thyroid hormone.

Distinguish between long feedback loops and short feedback loops.

Discuss how positive feedback controls the menstrual cycle.

Discuss hormones are carried in the blood stream.

Name the hormones that are carried in a free form.

Name the hormones that are carried bound to plasma proteins.

Name the binding molecules that bind to thyroid hormone.

Name the binding molecules that bind to transcortin.

Discuss how the reversible association between hormone and carrier provide both storage and buffer systems for the hormones.

Explain why the binding is important in maintaining homeostasis.

Explain why the endocrine secretions reach every portion of the body while the nervous system does not.

Discuss the relationship between blood concentration of hormone and the amount that reaches the target tissue.

Discuss the mechanisms of how hormones are metabolized and eliminated by the body

Defend the following statement: Hormones do not cause target cells to do anything new. They only increase of decrease the activity.

Explain upregulation and give examples of where it may occur.

Explain downregulation and give examples of where it may occur.

Compare and contrast the receptors for water soluble and lipid soluble hormones

Name the hormones that bind to membrane receptors and discuss the characteristics that do not allow them to enter the cell.

Name the hormones that bind to intracellular receptors and discuss the characteristics that allow them to enter the cell.

Name the two regions of the cell where intracellular regulators can be found.

Discuss the direct and indirect effects hormones binding to cell membrane receptors can have.

*Discuss the function of g proteins and second messenger systems in hormone function.

Name the hormones that activate G proteins

*Name the two cyclic intracellular mediators.

*Briefly discuss the possible effects of intracellular mediators on the cell.

*Briefly discuss how G proteins regulate membrane channels.

*Briefly discuss how G proteins regulate the synthesis of intracellular mediators.

*Name the enzymes that affected by g proteins.

*Discuss the role of cAMP as intracellular mediator.

Discuss the function of protein kinases

*Discuss the role of cGMP as intracellular mediator.

Explain why intracellular mediators will have different effects in different cells.

*Discuss the function of g proteins and phosphinositol.

Briefly discuss how membrane receptors can directly synthesize an intracellular mediator.

Discuss how some receptors can phosphorlate intracellular proteins.

Discuss the function of intracellular hormone receptors, using Aldosterone as your model.