Exam 45: Hormones and the Endocrine System

Testosterone is an example of a chemical signal that affects the very cells that synthesise it, the neighbouring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of ________. I. an autocrine signal II. a paracrine signal III. an endocrine signal

Melatonin is secreted by the ________.

Which of the following are properties of steroid hormones? I. Steroid hormones are lipid-soluble and easily cross the phospholipid bilayer. II. Steroid hormones usually exert their effects on target cells through membrane receptor proteins. III. Steroid hormones act on cells close to where they were produced. IV. Steroid hormones regulate gene transcription by binding to intracellular receptor proteins.

Which of the following is not an accurate statement?

Removing which of the following glands would have the most wide-reaching effect on bodily functions of an adult human?

People who suffer from chronic fatigue syndrome (CFS) experience ongoing, debilitating fatigue. In one study, cortisol levels in the saliva during the first hour after waking were measured and compared between CFS patients and people without CFS (controls). The data is summarised in the graph. What can you infer from the data?

The steroid hormone that coordinates moulting in arthropods is ________.

The relationship between the insect hormones ecdysteroid and PTTH is an example of

Prostaglandins are local regulators whose chemical structure is derived from ________.

During mammalian labour and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of ________.

People experiencing chronic stress may be more likely to become sick because ________.

You are dissecting a fish in your biology laboratory section. Your teaching assistant points out a long oval structure and tells you it is an endocrine gland. Which of the following would you then know is a true statement about this structure?

Which of the following has both endocrine and exocrine activity?

What happens in a cell when adenylyl cyclase is activated?

Aspirin and ibuprofen both ________.

If a biochemist discovers a new molecule, which of the following pieces of data would allow her to draw the conclusion that the molecule is a steroid hormone? I. The molecule is lipid-soluble. II. The molecule is derived from a series of steps beginning with cholesterol. III. The molecule acts at a target tissue some distance from where it is produced. IV. The molecule uses a transport protein when in an aqueous solution such as blood.

Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of ________.

If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signalling is occurring?

A cluster of tumour cells that produces and secretes growth factors to induce surrounding cells to grow and divide is showing which type of cell-to-cell signalling?

When a steroid hormone and a polypeptide hormone exert similar effects on a population of target cells, then ________.