1

John Bowne High School Mr. J Zelkind, AP Sci. Dept.

Endocrine System

How Do Organisms Respond to a Changing Environment?

The external environment around an organism is constantly changing. These changes threaten the stabilityof an organism's internal environment. The maintenance of a stable internal environment is called homeostasis. Changes in the external environment can result in a change to an organism's internal environment. An organism must be able to detect and respond to changes. Organisms detect and respond to change in a variety of ways, both at the cellular level and at the organism level. Failure to respond to change can result in an organism's death. Thus, homeostasis is an attempt to maintain internal equilibrium or an even balance in the body for a healthy life.

How is homeostasis related to environmental change?

Mechanisms of Control

The body's internal state does not stay exactly the same all the time. Instead, it varies around a certain average value. To maintain homeostasis, your body has a diversity of feedback mechanisms that detect changes in the body's internal environment and take actions to correct these changes. A feedback mechanism is a process in which the last step in a series of events controls the first step.

A feedback mechanism has three parts:1. A receptor detects a change in the internal environment of the body.2. A control center, such as the hypothalamus in the brain, selects a response to the information received.3. an effector, such as a muscle or gland, carries out the response to the changes.

The two main types of feedback are negative and positive feedback. The table below lists thecharacteristics of negative and positive feedback.

.

Explain: How does the body use feedback mechanisms to maintain homeostasis?

How Does the Body Control Blood Glucose Levels?

2

Two hormones released by the pancreas, insulin and glucagon, control the level of glucose in the blood. Insulin and glucagon are antagonistic hormones. When blood glucose levels are high, insulin lowers blood glucose levels. It causes the liver to convert glucose into glycogen that can be stored for future use. When blood glucose levels drop, glucagon stimulates the liver to break down glycogen into glucose. In this way, blood glucose levels stay within a narrow range.

The pancreas and the liver work together to maintain blood glucose within a very narrow range.

Describe: What are the functions of insulin and glucagon?

Describe: How does your body maintain its blood-glucose level after you have eaten a large meal?

3

4

5

6

7

How does the Endocrine System maintain homeostasis?

Like the nervous system, the endocrine system sends messages to the body's cells. The endocrine system has four main functions:

1- Regulate metabolism2- Maintain salt, water, and nutrient balance in the blood3- Control the body's responses to stress4- Regulate growth, development, and reproduction

The endocrine system uses chemical messengers called hormones. Hormones are substances produced in one part of the body that cause changes in another part of the body. Hormones cause cells to change their activities. These changes generally help the body maintain homeostasis.Hormones are produced by special cells. Often these cells are part of an endocrine gland, an organ that produces and releases hormones directly into the blood stream or into fluid around cells. The major endocrine glands are shown below.

List Name four endocrine glands that are found in both males and females.

8

Recognize Relationships: How do you think the endocrine system and the nervous system work together to maintain the body's homeostasis?

9

10

11

12

13

14

15

John Bowne High SchoolDr. Iannelli, Principal Mr. J Zelkind, AP Sci. Dept. LE Lesson 4-09-19

Aim: How are hormones regulated in the body?

Standard 4Students will understand and apply scientific concepts, principles, and theories pertaining to the physical

setting and living environment and recognize the historical development of ideas in science.

Common Core Learning Standards for Literacy in History/Social Studies, Science, and Technical Subjects:RST.9-10.4, RST.9-10.7, WHST.9-10.2a, WHST.9-10d, WHST.9-10.4.

Instructional objectives: In addition to be provided with the opportunity to read, write, and speak in order to increase literacy….SWBAT:

Understand the regulation of hormones by both negative and positive feedback mechanisms Understand how the feedback mechanisms help maintain homeostasis Understand the regulation of blood glucose and thyroxin in the body

Critical Thinking Questions:1) How does our body regulate the blood glucose levels?2) How does our body regulate the thyroxin levels?3) Why is it important to regulate the hormones?

Vocabulary: Hormones

16

Negative Feedback Regulation Positive Feedback Regulation Homeostasis TSH Thyroid Pituitary Glucagon Glycogen Insulin

Lesson development:

1. Class activity on Thyroxin regulation. Students fill out the loop diagrams for thyroxin and glucose regulation with the help of the activity.

2. Word Warmth Activity. Students use the activity as a self-assessment of their understanding of the concept terms and as an opportunity to learn from each other. (Students take about 5 min to write the definitions of the concept terms and then mingle and help each other to better their understanding).

3. Assessment Activity. Students are given 2 sets of questions (X and Y). They can pick the set (X or Y) they feel more comfortable with to answer first. After answering the question set, they put their best answers on a post-it and post it on the back under appropriate title (X or Y). After everyone has answered at least one question set, they do a gallery walk to read each other’s responses. Based on what they learned, they come back to their seats and make improvements to their responses and/or, use the information to answer the set that they haven’t answered yet. After everyone is finished, students display the green and red disks to demonstrate their understanding of the questions.

Differentiation Techniques:

1-Provide choice to pick the analytical writing task3-Provide extra scaffolding for vocabulary attainment4-Provide extra wait time for oral response to questions5-Use of graphic organizers6-Use more visuals through technology

HW: Regent questions

17

Aim: How does the endocrine system maintain homeostasis?

Key questions:-How do you define homeostasis?-Why is homeostasis important in your life?-How is homeostasis related to environmental change?-How do you define feedback?-What are the three parts of a feedback mechanism?-How is negative & positive feedback different from each other?-How does the body use feedback mechanisms to maintain homeostasis?-How do you define a hormone?-How do all endocrine glands perform their job?

Assessing students’ prior knowledge, understanding, and misconceptions: Explain homeostasisDo Now: Read with comprehension on “How do organism respond to a changing environment?” & answer the question on the bottom of the paragraph.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Development of lesson: Explain negative & positive feedback mechanismsReading comprehension out-loud (volunteer) of the “mechanisms of control”.Students work in pair share-thinking technique to answer the question on bottom of page 1.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Further development of the lesson: Option of developing “How does the body control blood glucose levels?” or solve regent type question on homeostasis on pages 3 to 4.Homework #3: Read with comprehension page 2 on “How does the body control blood glucose levels?” Answer the bottom questions.

18

Aim: How does the endocrine system maintain homeostasis?

Key questions:-How do you define homeostasis?-Why is homeostasis important in your life?-How is homeostasis related to environmental change?-How do you define feedback?-What are the three parts of a feedback mechanism?-How is negative & positive feedback different from each other?-How does the body use feedback mechanisms to maintain homeostasis?-How do you define a hormone?-How do all endocrine glands perform their job?

Assessing students’ prior knowledge, understanding, and misconceptions: Explain homeostasisDo Now: Read with comprehension on “Mechanisms of control” & answer bottom question of page 1.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Development of lesson: Explain negative feedback by using thermostat as an example & positive feedback by using fever by resetting the hypothalamus at a higher body temperature than normally. Introduce the pancreas as an endocrine that secretes insulin & glucagon that work in opposite direction.

Motivation: Show short video of insulin & glucagon

Further development of the lesson: Reading comprehension out-loud (volunteer) of “How does the body control blood glucose level?” & analyze the flow chart. Students work in pair share-thinking technique by answering all questions on page 2 to 6.

Homework #3. Rewrite the flow chart on page 2.

19

Aim: How does the endocrine system maintain homeostasis?

Key questions:-How do you define homeostasis?-Why is homeostasis important in your life?-How is homeostasis related to environmental change?-How do you define feedback?-What are the three parts of a feedback mechanism?-How is negative & positive feedback different from each other?-How does the body use feedback mechanisms to maintain homeostasis?-How do you define a hormone?-How do all endocrine glands perform their job?

Assessing students’ prior knowledge, understanding, and misconceptions: Explain homeostasisDo Now: Read with comprehension on “How does the body control blood glucose levels?” & Answer the bottom three questions.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Motivation: Show short video of insulin & diabetes specially the one as insulin being the key to allow glucose to enter the cell from the blood.

Development of the lesson: Explain a hormone has a particular shape to be received by a special cell membrane receptor, which activates the cell to allow glucose to enter it. Thus, decreasing the glucose level in the blood. Negative & positive feedback mechanisms, & homeostasis.-Students work in pair share-thinking technique on regent type questions on page 5 & 6.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept

Further development: -Students work in pair share-thinking technique on regent type questions on page 4 to 5.

20

Aim: How does the endocrine system maintain homeostasis?

Key questions:-How do you define homeostasis?-Why is homeostasis important in your life?-How is homeostasis related to environmental change?-How do you define feedback?-What are the three parts of a feedback mechanism?-How is negative & positive feedback different from each other?-How does the body use feedback mechanisms to maintain homeostasis?-How do you define a hormone?-How do all endocrine glands perform their job?

Assessing students’ prior knowledge, understanding, and misconceptions: Do Now: Answer all multi-choice questions on page 4.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Motivation: Show short video of insulin & diabetes specially the one as insulin being the key to allow glucose to enter the cell from the blood.

Development of the lesson: Explain homeostasis, feedback mechanism, parts to feedback, negative & positive feedback, endocrine glands, hormone’s specific shape to be received by the specific shape of the hormone receptor on the cell membrane.Reading comprehension out-loud (volunteer) on the endocrine system worksheet, “How can we examine the functioning of the endocrine system?” introduction part & Procedure A for diabetes on page 1.Students work in pair share-thinking technique on the Procedure A diabetes’ problem on page 1.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Further development of lesson: Solve problem for Procedure B for thyroxine on page 2.Reading comprehension out-loud (volunteer)Students work in pair share-thinking technique to answer the problem.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Homework #4. Study the chart on page 8 & solve all problem on page 9 for the endocrine system.

21

Aim: How does the endocrine system maintain homeostasis?

Key questions:-How do you define homeostasis?-Why is homeostasis important in your life?-How is homeostasis related to environmental change?-How do you define feedback?-What are the three parts of a feedback mechanism?-How is negative & positive feedback different from each other?-How does the body use feedback mechanisms to maintain homeostasis?-How do you define a hormone?-How do all endocrine glands perform their job?

Assessing students’ prior knowledge, understanding, and misconceptions: Do Now: Read with comprehension page 5 & analyze the diagram too. Answer the question on the bottom of the page & top of page 6.

Check Point(s) Have students report to each other and/or to the entire class what they have learned as a check on the Progress of the teaching by writing on the smart board. Ask key questions during the check point & scaffolding to develop vocabulary &/or concept.

Motivation: Show short video of endocrine glands.

Development of the lesson: Label the diagram on page 7.Explain homeostasis, negative feedback, & hormones.Design a flow chart describing thyroxin by the thyroid gland of negative feedback. Using arrows to indicate the step process.

(1) Hypothalamus is the command center in the brain to detect the level of the hormone thyroxin & other hormones too. The hypothalamus will secrete Thyroid Releasing Hormone (TRH), when the level of the hormone thyroxin is low in the blood. The TRH stimulate or activates the pituitary gland.

(2) Once the pituitary gland is activated it secretes Thyroid Stimulating Hormone (TSH).(3) The TSH stimulates the thyroid gland in the neck to secrete the hormone thyroxin.(4) The hormone thyroxin has a specific shape that will fit exactly into the receptor for thyroxin on the target cell

membrane and activate the cell to increase the metabolism. At the same time the level of the hormone thyroxin is elevated in the blood.

(5) The elevated level of thyroxin in the blood is detected by the hypothalamus and stops the secretion of Thyroid Releasing Hormone (TRH), this mechanism is called negative feedback.

Check the student’s notebook

Further development of the lesson: Answer regent type questions. Start on page 12 then 11, & 10.