Physiology Regulation of the Endocrine System ICE

What type of cells secrete releasing hormones? Where are these cells located?

Neurons; in the hypothalamus

What major organ is the hypothalamus part of?

The brain

Based on the model, what circulatory structure do the hypothalamic releasing
hormones use to get to the anterior pituitary?

The hypophyseal portal system

What kind of cells secrete anterior pituitary hormones? Where are the cells that secrete anterior pituitary hormones located?

Epithelial; in the anterior pituitary

What type of cells secrete posterior pituitary hormones?

Neurons

Are these cells (or the nuclei of these cells) actually located in the posterior pituitary gland? Where are they located?

No; in the hypothalamus

Does the posterior pituitary appear to produce any of its own hormones? How do the hormones get from the hypothalamus to the posterior pituitary to be released?

No; they are transported down axons

Is the posterior pituitary actually an endocrine gland? Be able to support your answer based on
evidence in the model.

The posterior pituitary does not actually release its own hormones but can aid in the release of hormones that are produced elsewhere

What hormone is being secreted by the hypothalamus here?

Gonadotropin releasing hormone (GDH)

What is the target tissue for the hypothalamic hormone?

The anterior pituitary

What does the hypothalamic hormone cause the ant. pituitary to do? What is the target
tissue for this hormone?

Produce/release luteinizing hormone (LH); the testes

What does LH cause the testes to do?

Release testosterone

What are the TWO functions of testosterone?

Stimulate male sexual functions and inhibit the hypothalamus

If increasing amounts of testosterone in the blood will inhibit the release of GnRH
from the hypothalamus, what will promote the release of GnRH?

Decreasing testosterone

The process outlined here is an example of a negative feedback loop. As a group
come up with a definition of what a negative feedback loop is

The resulting product inhibits the production of the precursors

GnRH and LH are both examples of tropic hormones. Based on the model, what do these two hormones have in common?

They both stimulate the release of another hormone

Define “tropic hormone”.

A hormone that controls the release of another hormone

Using the model, list the six anterior pituitary hormones in the space below.

Growth hormone (GH), prolactin (PRL), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and adrenocorticotropic hormone (ACTH)

Which anterior pituitary hormones are tropic hormones?

All but prolactin

Explain why the anterior pituitary is often referred to as the “master gland” of the endocrine system.

It releases the precursor for or the hormone itself for most hormones in the body

Fill out the chart!

Draw a negative feedback loop for the following sets of hormones:
Hypothalamus: corticotropin releasing hormone
Anterior Pituitary: adrenocorticotropic hormone
Adrenal gland: cortisol

Draw a negative feedback loop for the following sets of hormones:
Hypothalamus: Thyrotropin releasing hormone
Anterior Pituitary: Thyroid stimulating hormone
Thyroid gland: Thyroid hormones

What hormone(s) has BOTH stimulating (releasing) and inhibiting hormones that control its release? What can you deduce about the importance of regulating this hormone?

GH; it is very important in the body

What hormone appears to have NO releasing hormone? How, then, is it controlled?

PRL; with dopamine

In the Psychiatry course, we will learn about a class of drugs that act as dopamine receptor antagonists. What effect might these drugs have on hormone secretion?

Increased PRL release