The Human Body: An Orientation Chapter 1 1.2 Maintaining life

Bellwork

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

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

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

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)

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

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

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

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

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

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

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

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

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

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

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

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

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

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)

Homeostasis Have students draw

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

Thermostat is set to 72o, what happens when the temperature drops 1. 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

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

Negative Feedback Loop

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

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

Positive Feedback Loop

Feedback Men experiencing labor And again....hehehe