1. The Human Body: An Orientation
Chapter 1
1.2 Maintaining life

2. Bellwork

3. Life Processes of Humans
Vocabulary
Metabolism:
Chemical process to breakdown large, complex molecules into smaller ones
Energy is released and new materials can be made
give students time to create their own definitions for the note-taker
Responsiveness:
Ability to sense changes and react

4. Life Processes of Humans
Vocabulary
Movement:
Motion of organelles, cells, organs or the whole body
Growth:
An increase in body size
give students time to create their own definitions for the note-taker
Increase in size of cells, number of cells or amount of material surrounding cells

5. Life Processes of Humans
Vocabulary
Differentiation:
Unspecialized cells(stem cells) become specialized
Examples: Stem cells become white blood cells
Stem cells become kidney cells
Etc.
give students time to create their own definitions for the note-taker
Reproduction:
Formation of new cells for growth, repair or replacement.
Production of a new individual

6. Life Processes of Humans
Review
I’m gonna put you in groups of 4, using the slates you’ll answer the following questions
Pay attention, you might see these questions again(hint, hint)

7. Life Processes of Humans
A: Movement B: Metabolism C: Differentiation D: Responsiveness E: Growth F: Reproduction B
________ Chemical processes which involve the breakdown of large complex molecules into smaller ones with a release of energy

8. Life Processes of Humans
A: Movement B: Metabolism C: Differentiation D: Responsiveness E: Growth F: Reproduction C
________ Changes that cells undergo during development from unspecialized to specialized; like bone or muscle

9. Life Processes of Humans
A: Movement B: Metabolism C: Differentiation D: Responsiveness E: Growth F: Reproduction F
________ Formation of new cells for growth, repair, or replacement, or for production of a new individual

10. Life Processes of Humans
A: Movement B: Metabolism C: Differentiation D: Responsiveness E: Growth F: Reproduction D
________ Ability to detect and respond to changes in the environment

11. Life Processes of Humans
A: Movement B: Metabolism C: Differentiation D: Responsiveness E: Growth F: Reproduction A
________ Food passes through the body, change location, blood cells travel around the body

12. Life Processes of Humans
Pick a life process and explain why it’s important to sustaining life

13. Objectives: Part 2 Define homeostasis and explain its importance
Describe the components of a feedback system
Compare the operation of negative and positive feedback systems

14. Bellwork In your own words define Homeostasis: Positive Feedback loop:
Negative Feedback loop:
Systems maintain a relative constant or balanced internal environment
Increases the original stimulus to push the variable farther
Shuts off the original stimulus, or reduces its intensity

15. Homeostasis Homeostasis: Maintenance of a stable environment
A.K.A: a balance
Body’s internal environment stays the same even when the external environment changes
Under control of the nervous system and the endocrine system
Anything underlined is a fill-in the blank on your note-taker

16. Homeostasis
Nervous System: detects changes in the system and sends signals to organs
Endocrine System: produces hormones to correct changes and restore homeostasis
Quick Response
Slow Response

17. Homeostasis Feedback Loops:
cycle of events in which the body is continuously monitored.
Can be positive or negative
Examples: body temperature, blood pressure, blood glucose

18. Homeostasis Feedback Loops Continued 3 Components to a Feedback Loop
Receptor:
A type of sensor that responds to changes in the environment
Sends nerve impulses or chemical signals to the control center
Example: nerve endings in your fingers

19. Homeostasis Feedback Loops Continued 3 Components to a Feedback Loop
Control Center:
What is known as the human control center?
Evaluates and analyzes the information it receives from the receptor and then determines the response
The Brain

20. Homeostasis Feedback Loops Continued 3 Components to a Feedback Loop
Effector:
A body structure(muscle or gland) that acts out the control center’s response to the stimulus
Feedback Loop
(play till first tab)

21. Homeostasis
Have students draw

22. Homeostasis Feedback Loops Continued Negative Feedback Loop:
For example when you get to hot and start sweating
Includes most homeostatic control mechanisms: 99%
Works like a household thermostat
Shuts off the original stimulus, or reduces its intensity
GOING BACK TO NORMAL
Play from 2nd tab to 3rd tab

23. Thermostat is set to 72o, what happens when the temperature drops1.
Thermostat (Receptor) detects drop in temperature ( )
INPUT
Stimuli 4.
Negative feedback occurs as warmer air reaches the thermostat causing it to shut off
Furnace ( ) turns on to release heat
Control Center 2.
Have students think about it and answer it on their note-takers, have them think about what happens at home, then go over it as a class together, next slide will be the low body temperature slide have them do on their own.
OUTPUT
Room temperature increases ( ) 3.
Effector

24. Body ( ) detects a drop in temperature ( ) Receptor Input Stimuli
Use a negative feedback loop to describe what happens when your body temperature drops 1.
Body ( ) detects a drop in temperature
( )
Receptor
Input
Stimuli 4.
Negative feedback occurs your body temperature rises and shivering stops
Brain ( ) sends messages in response to input
control center 2.
Students will fill this out on their own on the notetaker, then we’ll go over it and then play the video; 3rd tab to 4th tab 3.
Heat is generated by muscles ( ) ; so temperature increases
Output
effector

25. Negative Feedback Loop

26. Homeostasis Feedback Loops Continued Positive Feedback Loop:
Not very common
Examples: Blood clotting and giving birth of a baby
Increases the original stimulus to push the variable farther;
Think…MORE MORE MORE
Have students brainstorm how child birth is a positive feedback loop, they can write down their brainstorm ideas on their notetaker then have them share with the class

27. Childbirth stimulus control center effector effector
Stretch receptors in wall of uterus send signals to the brain ( )
Brain causes release of hormone
( )
Uterine smooth muscle contracts more forcefully
( )
stimulus
control center
effector
After brainstorming walk through this with them have them fill it out on their note-taker
Afterwards ask them to highlight or circle what makes this feedback loop a positive feedback loop
More stretch, more hormones, MORE CONTRACTIONS
( )
Loop ends with birth of baby
effector

28. Positive Feedback Loop

29. Feedback
Men experiencing labor
And again....hehehe