Animations: The Endocrine System
Hypothalamus and Pituitary Gland
After viewing the animation, answer these questions:
1. The hypothalamus is sometimes referred to as the master control center . Why? It regulates most endocrine functions of the body.
2. Where in the brain is the hypothalamus located?
At the base of the brain in the anterior portions of the diencephalon.
3. Describe the structure of the hypothalamus.
It consist of several groups of neurons called nuclei each with specific functions.
4. What is the infundibulum? What is its function?
Stalk like that connects the hypothalamus to the pituitary gland.
5. Where is the pituitary gland located? How is it divided?
It sits in the hypophysial of the sphenoid and divided into anterior, and posterior lobes. Each lobes of the pituitary gland interact with the hypothalamus in different ways.
6. What is another name for the anterior pituitary? How is it connected to the hypothalamus? Adenohypophysis, connect by a blood of vessel network known as hypothalamal-hypophysial tract.
7. What travels along this pathway? What is their function? Hormones that are released from the hypothalamus travel through the portal system and regulate activities of the anterior pituitary.
8. What is another name for the posterior pituitary? How is it connected to the hypothalamus?
Neurohypophis is connected to the hypothalamus by neurons that form the hypothalamal- hypophysial tract.
9. What travels along this pathway? How are they transported? What is their destination?
Axons of the neurons transport hormones from the hypothalamus for storage in the posterior pituitary.
10. Name the two classes of hypothalamic hormones that regulate the anterior pituitary. How do they reach the anterior pituitary? What is their function?
Releasing hormones that regulate anterior pituitary via the hypothalamal hypophysial portal system, and stimulate suppress, secretion of anterior pituitary hormones.
11. How do anterior pituitary hormones arrive at their target tissues?
Hormone secrete by the anterior pituitary enter the bloodstream for distribution to their specific target.
12. Describe an example of these hormones and their function.
Thyrotrophin releasing hormones stimulates thycotropic cells of the anterior pituitary to increase secretion of TSHwhich then regulates activity of the thyroid gland.
13. Name the hormones produced by the posterior pituitary. What is the source of posterior pituitary hormones?
Produces no hormones but neurosecretory cells into the hypothalamus synthesize 2 hormones.
14. Name two posterior pituitary hormones. How do they arrive at the posterior pituitary?
ADH and oxytocin that are transported to the posterior pituitary and released into the blood streams via hypothalamal hypophysial.
15. Name the structures that store the posterior pituitary hormones. What causes their release? Where are they released?
Stored in the nerve terminal in the posterior pituitary and released into the blood upon stimulation of the axons.
16. Name the functions of each posterior pituitary hormone.
ACH acts on the kidneys to increase water retention from anal lobes and constricts blood vessels. Oxytocin causes smooth muscle contraction and both female and male reproductive tracts and stimulates mik ejection by the lactating mammary gland.
Hormonal Communication
After viewing the animation, answer these questions:
1. In general, how does hormonal communication begin? What reaction then occurs?
Begins with part of the neuroendocrine system receiving sensory information and reacting by issuing a command to the body in the form of a hormone.
2. How are hormones transported to target cells?
By blood vessels.
3. What occurs when the hormones arrive at their target cells?
They bind to matching receptor on these balls.
4. What then triggers changes in the target cells?
The hormones receptor complexes intracellular receptor mode