The Human Body: An Orientation

Chapter 11.2 Maintaining life

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Bellwork Write these vocabulary words on your bell work sheet

9. cephal10. cyto/cyte11. Anatomy12. Physiology13. Metabolism14. Homeostasis15. Tissue

1. a-/an 2. ad3. ana4. anti5. arthr6. auto7. bi8. cata-

Now with a partner define these. You can use your books, or your phone

Quiz: This Friday

1. a-/an

2. ad

3. ana

4. anti

5. arthr

6. auto

7. bi8. cata-

9. cephal-

10.cyto/cyte

11. Anatomy12. Physiology13. Metabolism14. Homeostasis15. Tissue

#1-10 Include a word using the prefix or suffix as an example

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Life Processes of Humans

▪ Vocabulary• Metabolis

m:Chemical process to breakdown large, complex molecules into smaller ones

• Energy is released and new materials can be made

• Responsiveness:

Ability to sense changes and react

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Life Processes of Humans

▪ Vocabulary• Movement

:Motion of organelles, cells, organs or the whole body

• Growth: An increase in body size

• Increase in size of cells, number of cells or amount of material surrounding cells

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Life Processes of Humans

▪ Vocabulary• Differentiati

on:Unspecialized cells(stem cells) become specialized

• Reproduction:Formation of new cells for growth, repair or replacement.

Production of a new individual

• Examples: Stem cells become white blood cells

Stem cells become kidney cells Etc.

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Life Processes of Humans

▪ Review

• Pay attention, you might see these questions again(hint, hint)

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Life Processes of Humans

A: Movement B: Metabolism C: Differentiation

D: Responsiveness E: Growth F: Reproduction

1. ________ Chemical processes which involve the breakdown of large complex molecules into smaller ones with a release of energy

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Life Processes of Humans

A: Movement B: Metabolism C: Differentiation

D: Responsiveness E: Growth F: Reproduction

2. ________ Changes that cells undergo during development from unspecialized to specialized; like bone or muscle

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Life Processes of Humans

A: Movement B: Metabolism C: Differentiation

D: Responsiveness E: Growth F: Reproduction

3. ________ Formation of new cells for growth, repair, or replacement, or for production of a new individual

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Life Processes of Humans

A: Movement B: Metabolism C: Differentiation

D: Responsiveness E: Growth F: Reproduction

4. ________ Ability to detect and respond to changes in the environment

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Life Processes of Humans

A: Movement B: Metabolism C: Differentiation

D: Responsiveness E: Growth F: Reproduction

5. ________ Food passes through the body, change location, blood cells travel around the body

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Life Processes of Humans

▪ Pick a life process and explain why it’s important to sustaining life

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Objectives: Part 2

1. Define homeostasis and explain its importance

2. Describe the components of a feedback system

3. Compare the operation of negative and positive feedback systems

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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

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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

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Homeostasis

▪ Feedback Loops:cycle of events in which the body is continuously monitored.

• Examples: body temperature, blood pressure, blood glucose

• Can be positive or negative

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Homeostasis

▪ Feedback Loops Continued• 3 Components to a Feedback Loop

1. 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

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Homeostasis

▪ Feedback Loops Continued• 3 Components to a Feedback Loop

2. 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

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Homeostasis

▪ Feedback Loops Continued• 3 Components to a Feedback Loop

3. Effector: A body structure(muscle or gland) that acts out the control center’s response to the stimulus

Feedback Loop

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Homeostasis

Homeostasis

▪ Feedback Loops Continued• Negative Feedback Loop:

• Negative Feedback=

• 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

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GOING BACK TO NORMAL

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Thermostat is set to 72o, what happens when the temperature drops

1.

Thermostat (Receptor) detects drop in temperature ( )

2.

Furnace ( ) turns on to release heat

3.

Room temperature increases ( )

4.

Negative feedback occurs as warmer air reaches the thermostat causing it to shut off

INPUT

OUTPUT

Control Center

Stimuli

Effector

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Use a negative feedback loop to describe what happens when your body temperature drops

1.

Body ( ) detects a drop in temperature ( )

2.

Brain ( ) sends messages in response to input

3.

Heat is generated by muscles ( ) ; so temperature increases

4.

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Negative Feedback Loop

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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

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Stretch receptors in wall of uterus send signals to the brain ( )

Childbirth

Brain causes release of hormone( )

Uterine smooth muscle contracts more forcefully( )

More stretch, more hormones, MORE CONTRACTIONS( )

Loop ends with birth of baby

stimulus

control center effector

effector

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Positive Feedback Loop

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Feedback

▪ Men experiencing labor

▪ And again....hehehe