Module 2 The Endocrine System

In This Module

 

This module addresses how the endocrine system contributes to homeostasis by studying the following lessons.

 

 

Lesson 1—Structure and Organization of the Endocrine System

 

In the big picture you were introduced to Emily and her struggle with FMEN1 disorder. You yourself may experience stress when you are cramming for exams, or are worried about a friend in crisis. When the exam or the crisis has passed, you calm down and your endocrine system returns to normal. In Emily’s case, her body experiences constant stress with no relief in sight. You both have the same endocrine glands, but what causes the difference in communication?

In order to explore these concepts, you will investigate the following focusing question:

• How is the endocrine system organized, and how do its parts communicate with each other and with other various parts of the body?

Lesson 2—Who is in Charge?

 

 

Much as the brain is the boss of the nervous system, the endocrine system needs a master or a boss in order to ensure homeostasis. The kingpin of the operation is the hypothalamus/pituitary gland complex. If the pituitary/hypothalamus complex was not doing its job, your life would quickly unravel. You would not be able to develop or function normally. Your growth might be stunted, and your voice would never change if you were a boy.

 

In this lesson you will explore the following question:

• Who is the boss of the endocrine system, and how is control of the endocrine system managed?

Lesson 3—The Adrenal Gland

 

 

When you studied the sympathetic nervous system in Module 1, you learned about the “flight or fight” reaction: the tendency in stressful situations to either run away or stay and work through the stressful situation. Imagine watching a horror movie and anticipating the feeling of being scared out of your skin. If your life were a horror movie, you would constantly be on edge—anxious and just waiting to be scared. It would be like going through life with a constant adrenaline rush. How long do you think that you could last through that?

 

In this lesson you will focus on the following question:

 

• How does the adrenal gland and its secretions affect the body?

 

Lesson 4—The Thyroid and Parathyroid Glands

 

Chilly? Hot? Overweight? Lethargic? Hyperactive? These are different symptoms of two opposite types of thyroid disorders: Hyperthyroidism [hyper means over activity] and Hypothyroidism. [hypo means under activity] If you have hyperthyroidism you may always feel too hot, you may experience weight loss, you may find it difficult to concentrate, and you may be jittery and hyperactive. If you have hypothyroidism you might always be cold, you may be overweight, you likely have a tendancy to feel tired and lethargic, and you may have trouble staying awake.

 

To understand the role of the thyroid gland in the functioning of the endocrine system we will explore the following focusing question:

• How do the thyroid and parathyroid glands contribute to homeostasis?

Lesson 5—The Pancreas

 

 

It is just before lunch, you are feeling hungry, tired, light-headed, and you are worried about a big exam in the afternoon. This is stress! What do you grab to eat? Are you the quick candy bar type or the protein-based tuna sandwich type?  Which one do you think would get rid of those symptoms you are experiencing, and get you through the exam without a complete collapse or meltdown? This situation deals specifically with the pancreas and how it manages blood sugar levels. For a diabetic this is a daily balancing act, and one that can have very serious consequences if it is not regulated.

 

To understand the role of the pancreas in the endocrine system, you will investigate the following focusing question:

• How does the pancreas contribute to homeostasis?

Lesson 6—Bringing it all Together

 

The endocrine system responds to stimuli by using chemical messengers in the blood to control metabolic processes in the body. Your body is kept in balance because your nervous system responds to immediate stimuli or crises while your hormonal system maintains long term stability.

 

This lesson will explore how the nervous and endocrine systems complement one another and communicate with each other to maintain homeostasis and ensure your well being by investigating the following focusing question:

• How are the nervous and endocrine systems interdependent, and how are they different?