1. Lesson 1: Homeostasis

2. Lesson Objectives
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.

3. Starter Q1: What happens when you do exercise? Q2: Why?
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Starter
Q1: What happens when you do exercise? Q2: Why?

4. Running You begin to sweat. You begin to breathe more heavily.
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Running
You begin to sweat. You begin to breathe more heavily.

5. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Control
Your body is trying to maintain a constant internal environment. This is called Homeostasis. Why?

6. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Question
What is the equation for respiration? Glucose + Oxygen  Carbon Dioxide + Water

7. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Homeostasis
Conditions inside your body need to be kept steady so that cells can function properly. Therefore, a balance between what goes in and what comes out needs to be maintained.

8. Homeostasis – Example 1 Levels of Carbon Dioxide.
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Homeostasis – Example 1
Levels of Carbon Dioxide.
Respiration in cells produced carbon dioxide constantly, which needs to be removed. Too much can lower the pH and make it too acidic.
Lower pH would therefore affect enzymes.
It is removed in the air we breathe out.

9. Homeostasis – Example 2 Urea. Produced by the liver.
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Homeostasis – Example 2
Urea.
Produced by the liver.
Made of excess amino acids, from eating too much protein.
It is poisonous if it build up.
Filtered by kidneys.
Removed in urine along with water and salt.
Stored in bladder.

10. Homeostasis – Example 3 Water and Ions:
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Homeostasis – Example 3
Water and Ions:
Water is lost through breathing, sweating and urine.
Ions are lost in sweat and urine. (sweat tastes salty due to sodium ions)

11. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
How?
The body regulates the environment through a process called ‘negative feedback’.
The body detects a change in the environment.
This triggers a response that counteracts the change (e.g. rise in body temperature causes a response which lowers the body temperature).
Therefore, the internal environment stays at the norm (the level that cells work best)
This only works within certain limits – if the change is too great then it may not be possible to counteract – hyperthermia, heatstroke.

12. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Negative Feedback
Increase from normal level detected
Response counteracts the increase
Body
Temperature
Normal Level
Decrease from normal level detected
Response counteracts the decrease
Time

13. Body temperature Q: What is normal body temperature? A: 37C
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Body temperature
Q: What is normal body temperature?
A: 37C
Q: What chemicals help to aid digestion?
A: Enzymes
Q: At what temperature, do enzymes work best?

14. Body temperature This can rise due to: Exercise Fevers due to disease
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Body temperature
This can rise due to:
Exercise
Fevers due to disease
External temperature changes.

15. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Body temperature
37C is body temperature and it needs to be kept constant. If it rises too much enzymes will become denatured and no longer work, cell may die, etc.
The brain has its own personal thermostat – contains receptors sensitive to blood temperature – thermoregulatory centre.
It also receives feedback from the skin – can detect changes as small at 0.5C.

16. To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
Your skin

17. When you get too COLD! Hairs (B) stand up on end
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
When you get too COLD!
Hairs (B) stand up on end
(to trap air which provides an insulating layer)
2. Very little sweat is produced
3. Blood vessels near surface constrict (C)
(so less heat can be transferred from the blood to the surroundings).
4. You shiver
(movement generates heat in the muscles)
5. You can put on more clothes.

18. When you get too HOT! Hairs lie flat Lots of sweat (E) is produced
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
When you get too HOT!
Hairs lie flat
Lots of sweat (E) is produced
(when sweat evaporates it transfers heat from you to the environment)
Blood vessels close to the surface (F) of the skin dilate (open) to allow more blood to the surface.
(transfers heat from the blood to the surroundings)
4. You may take off clothes to help cool down.

19. Review Objectives
To know how to keep conditions inside your body constant.
To know how to get rid of waste products.
To know how the body monitor temperature.
Keywords: Homeostasis, Liver, Urea, Kidney, Thermoregulatory centre,
I still feel unsure. I need some more help to understand.
I feel ok. I need to do some more work to check my understanding.
I am happy and feel I understand and can explain the main points.

20. Book Pages Honors Pages (Cornell Notes and Vocabulary Pages)
Homeostasis, Kidneys, Liver: Pg , , , Pg 982
Respiratory System: Pg
Honors Pages (Bookwork)
HKL: Pg 896#2, Pg 917# 2,12, Pg 989 # 1,2,5 and Pg 993 # 7,10,23-25
Resp Sys: Pg 963 # 1-4, Pg 967#8-10, 23-25

21. Book Pages College Prep Pages (Cornell Notes and Vocabulary Pages)
Homeostasis, Kidneys, Liver:
Tiger Book (Class): Pg 918 – 919,
Eyeball Book (Home): Pg 593, 596, , 640, ,
Respiratory System:
Tiger Book (Class): Pgs 895 – 900
Eyeball Book (Home): Pg
College Prep Pages (Bookwork)
HKL:
Tiger Book (Class): Pg 924 #s 1-5, Pg 919 # 4, Pg 926 #
Eyeball Book (Home): Pg 705 # 1-2, Pg 708 #1-3, Pg 700#2, Pg 650 #5, Pg 596 # 1,3,4 Pg 606 #2, 20
Respiratory:
Tiger Book (Class): Pgs 900 #s 1-3, 5, Pg 902 #s 10-12
Eyeball Book (Home): Pg 671 # 1-3, Pg 669 #1-3, Pg 672 # 6,7,14