Homeostasis & Immune System Negative Feedback Homeostasis & disease Immune System: Inflammatory response Antibody response Cell mediated response Allergies,

Homeostasis & Immune System• Negative Feedback• Homeostasis & disease• Immune System:

• Inflammatory response• Antibody response• Cell mediated response

• Allergies, AIDS, vaccination, antibiotics

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Mechanism, Thermostat

1. Temperature _______ outdoors.

2. Thermometer registers temperaturedecrease inside

3. Thermostat ____ the furnace for ____

4. Furnace generates _____

5. Temperature ______ inside

6. Temperature _______ the thermostatsetting

7. Thermostat ________ the furnacefor heat

8. Furnace _____ generating heat

9. Temperature _______ inside

1. Temperature decreases outdoors.

2. Thermometer registers temperaturedecrease inside

3. Thermostat calls the furnace for heat

4. Furnace generates heat

5. Temperature increases inside

6. Temperature reaches the thermostatsetting

7. Thermostat does not call the furnacefor heat

8. Furnace stops generating heat

9. Temperature decreases inside

Do Now: It is winter and the temperature in your classroom has dropped to 60ºF, low below 70ºF to which the thermostat is set. The electrician advised you that the thermostat was not working.

Explain how does the thermostat work to regulate the temperature of the room


1. Temperature __________ outdoors.

2. ________ registers body temperature

3. ________ calls the __________ for heat

4. _________ shiver and generate heat

5. Body temperature ___________

6. Body temperature reaches the ______

7. ______ does not call the________ for heat

8. Muscles stop ____________________

9. Body temperature ________________

decreases

Skin

Brain muscles

increases

setting

Brain

shivering

decreases

Muscles

muscles

Your body´s “thermostat” is set at 98ºF (37ºC). How is this temperature maintained when you are in very hot or cold environment.


1. During exercise the CO2 level increases.

2. Heart registers CO2 increase in blood

3. Brain calls the respiratory muscles to speed up

4. Respiration rate increases

5. CO2 level decreases in blood

6. Heart detects CO2 decrease

7. Brain call the respiratory muscles to slow down

8. Respiratory rate decreases

9. CO2 increases in blood

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Mechanism

How Does Homeostasis Work in Plants?

Plants keep their stomata open just enough to allow photosynthesis to take place but not so much that they lose an excessive amount of water.

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Mechanism, Stoma, Guard Cells

1. Which gases do get into stomata?

2. Which gases do get out from stomata?

3. What requirements does a plant need to carry out photosynthesis?

4. How are leaf pores when plant carries out photosynthesis? Why?

5. How are leaf pores when plant doesn’t carry out photosynthesis? Why?

6. State one problem for plant that would result from a malfunction of its stomata.

7. When the guard cells lose water, the stomata are

8. When the guard cells are swollen with water the stomata are

Carbon Dioxide CO2

Oxygen O2, Water Vapor H2O(v)

Carbon dioxide, water, and sunlight

Leaf pores are open. Guard cells are filled up with water

Leaf pores are closed. Guard cells shrink because the lack of water

The plant would not carry out photosynthesis and eventually would die

closed

open

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Mechanism, Stoma, Guard Cells


9. How are leaf pores of stomata when the sun is shining and water is available in the soil:

10. How are leaf pores of stomata when photosynthesis is carrying out and the air is warm:

11. Which picture represents how are leaf pores of stomata

a) when air is hot and dry:b) when photosynthesis slows down:c) when little water is available from the soil:d) when photosynthesis is active:e) at night:

12. What factor regulates the opening and closing of stomata?

13. Why do plants regulate the opening and closing of their stomata? Which is the function of stomata?

open

open

closedclosed

openopen

closed

The presence of water

To control the exchange of gases and the performance of photosynthesis

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Mechanism, Stoma


Objective: Understand What a Negative Feedback Look LikeKey Words: Homeostasis, Negative Feedback, Insulin, Glucagon, Dynamic Equilibrium

1. The role of insulin is

2. The role of glucagon is

3. The line graph is an example of

4. Both, glucagon and insulin, are hormones that work together to

To promote the breakdown of glycogen into glucose.

To increase the glucose level in blood.

To take glucose out of the bloodstream and store it in the liver an muscles.

To decrease the glucose level in blood.

HomeostasisNegative feedbackDynamic Equilibrium

To maintain a constant glucose level in blood


The results of blood tests for two individuals are shown in the data table below. The blood glucose level before breakfast is normally 80–90 mg/100 mL of blood. A blood glucose level above 110 mg/100 mL of blood indicates a failure in a feedback mechanism.

Injection of chemical X, a chemical normally produced in the body, may be required to correct this problem.


1. State a title for the graph:

2. Identify chemical X.

3. Which individuals will most likely need injections of chemical X? Explain your answer

4. State one reason for the change in blood glucose level between 7:00 a.m. and 8:00 a.m.

5. What term refers to the relatively constant level of blood glucose of individual 1 between 9:00 a.m. and 11:00 a.m.?

HomeostasisDynamic equilibrium.

They had breakfast.

Insulin

Glucose level in blood between 7 am to 11 am

Individual #2 because he/she does not produce insulin


1. How do you explain what a negative feedback is?

2. You are doing some exercise. Explain how your body maintains the balance of CO2 level in blood.

3. Give a few examples of negative feedback in living things

A negative feedback is a process that control and maintain stable the vital signs

During exercise CO2 level increases in blood. The body speed up the respiration rate in order to release more CO2 and decreases the CO2 level

•Keeping body temperature near 98 F•Balance CO2 level in blood•Exchange of gases and photosynthesis in plants•Maintenance of glucose level in blood•Maintenance of calcium level in blood


Glucose, glucagon ,fat, increase, skeletal muscles, decrease, insulin, liver, For those who ate breakfast or lunch today, blood glucose levels _____________after eating.The pancreas releases ______________. Insulin stimulates cells throughout the body to take ________ out of the bloodstream. Glucose taken out of the circulation is stored in __________ and ____________________, or converted to _______.Within one or two hours after eating, the level of blood glucose ______________Then, pancreas releases ______________. Glucagon stimulates the cells of the _________ and skeletal muscles to break down complex sugar and increase ____________ levels in the blood. Glucagon also causes fat cells to break down fats so that they can be used for the production of ________________.

Fill in the blanks of the following paragraph. Use the words on the list. The same word can be use more than once.

increasesinsulin

glucose

liver skeletal musclesfat

decreases

liver

glucose

glucose

glucagon


When blood calcium levels are too high, the (gland) _________ secretes (hormone) _________.

(Hormone) _______________ stimulates calcium deposition in the bones. Therefore, calcium leves in blood (increases /decreases) ______________.

If calcium levels drop too low, the (gland) ________________ secretes (hormone) _____________.(Hormone) ________________ stimulates bone cells to release some of the calcium store in bone into the bloodstream. Then, calcium level in blood (increases /decreases) _____________.

thyroidcalcitonin

calcitonin

decreases

parathyroidPTHPTH

increases

Objective: Understand How a Negative Feedback Mechanism WorksKey Words: Homeostasis, Feedback, Parathyroid, Thyroid, PTH, Calcitonin

1.- What is homeostasis?

2.- What is another word for “homeostasis”?

3.- Why is homeostasis constantly threatened?

4.- Explain how does an organism maintain homeostasis?

5.- As an example of maintaining homeostasis, how do organisms readjust body temperature?

6.- Draw a graph that shows a regular pattern of body temperature. Explain what that graph means related to homeostasis.

7.- Describe what is “dynamic equilibrium”.

8.- What can interfere with homeostasis or dynamic equilibrium?

Homeostasis is a state of balance in the body.

Dynamic equilibrium

Because the organism’s external an internal environment is constantly changing

The organism detects changes in the environment and respond with an actionthat return the organism’s system to normal

If temperature is above normal the body sweats, if temperature is below normal the muscles shake

The constant small corrections that keep the internal environment within the limits needed for survival

Microorganism and diseases

Objective: Understand What a Negative Feedback isKey Words: Homeostasis, Feedback, Mechanism, Dynamic Equilibrium

Examples of Feedback Mechanisms to Maintain Homeostasis

Objective: Understand What a Negative Feedback isKey Words: Homeostasis, Feedback, Mechanism, Dynamic Equilibrium

Do Now: List 3 examples of negative feedbacks in living things

How our body regulates a steady body temperature

How stomata regulate photosynthesis

How our body regulates CO2 levels in blood

How a thermostat regulates temperature in a building

Objective: Understand How a Negative Feedback Mechanism worksKey Words: Feedback, Mechanism, Dynamic Equilibrium, Homeostasis

Read pages 895 and 896 on the Biology book and answer the questions below.

1. What is homeostasis:

2. The process in which a stimulus produces a response that opposes the original stimulus is referred to as

3. Fill in the missing label in the diagram to show how a thermostat uses feedback inhibition to maintain a stable temperature in a house

The process by which organisms keep internal conditions relatively constant despite change in the external environment.

Negative feedback

Thermostat senses temperature change and switches off heating system

Thermostat senses temperature change and switches on heating system


What Is Homeostasis? Biology, pages 895-896

4. Is the following sentence true or false? The part of the brain that monitors and controls body temperature is the hypothalamus.

5. The process of maintaining a controlled, stable internal environment is called

6. What happens if nerve cells sense that the core body temperature has dropped below 37 C?

7. What happens if the body temperature rises too far above 37 C?

True

Homeostasis or dynamic equilibrium

The hypothalamus produces chemicals that signal cells throughout the bodyto speed up their activities and produce heat

The hypothalamus slow down cellular activities, minimizing the production of heat


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Homeostasis & Immune System Negative Feedback Homeostasis & disease Immune System: Inflammatory response Antibody response Cell mediated response Allergies,