Jennifer McFarlane Lorraine Garofalo. Curriculum Expectations E3.1 describe the anatomy and physiology of the endocrine, excretory, and nervous systems,

Jennifer McFarlane Lorraine Garofalo

Curriculum ExpectationsE3.1 describe the anatomy and physiology of the endocrine,

excretory, and nervous systems, and explain how these systems interact to maintain homeostasis

 E3.2 explain how reproductive hormones act in human feedback

mechanisms to maintain homeostasis (e.g., the actions of male and female reproductive hormones on their respective body systems)

 E3.3 describe the homeostatic processes involved in maintaining

water, ionic, thermal, and acid–base equilibrium, and explain how these processes help body systems respond to both a change in environment and the effects of medical treatments (e.g., the role of feedback mechanisms in water balance or thermoregulation; how the buffering

Lesson SequenceLesson 1: Homeostatic Mechanisms

Introduction to Homeostasis: Kidney, Immune System, Nervous System

Lesson 2: Feedback SystemsHuman Body Temperature, Transfer of Energy, Negative

Feedback Loop, Positive Feedback Loop Lesson 3: The Human Urinary System

Overview of the Human Urinary System, Anatomy, Comparison of Male & Female Systems

Lesson 4: Kidney Function and StructureGeneral Structure of the kidney and nephron

Lesson 5: How Blood is Filtered in the KidneyRole of Kidney in Maintaining Homeostasis

Lesson 6: Urine Output and Water Homeostasis

Background Information

How does the body maintain a stable state?The body has developed physiological and biochemical

mechanisms that allow it to maintain its internal environment in a relatively stable state. The body is able to do so in the face of external stresses such as high or low temperatures and internal stresses such as fever and infection.

Homeostasis is a state of balance inside the body, where the body systems work together to keep it functioning normally. The endocrine system keeps this internal balancing act going by releasing chemicals called hormones. This release of hormones is controlled by negative feedback mechanisms.

Video & Virtual Lab: Introduction to HomeostasisVIDEO: Explains homeostasis for students learning the topic for the first time http://www.learnerstv.com/animation/animation.php?ani=241&cat=Biology

GIZMO: As external temperature and internal water and blood sugar levels change, adjust factors to maintain internal stability. http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=519

Negative Feedback LoopA process that detects and reverses deviations from

normal body constants.

3 parts: a receptor, an integrator, and an effector.

start at normal range go beyond normal range return to normal

Sensory Receptors:  found throughout every body organ and tissue.Function is to send nerve impulses (stimuli) to the brain in

response to environmental informationmonitor the body’s internal conditions, such as

temperature, blood pH, blood sugar, and blood pressure, on a continual basis.

Negative Feedback Loop Animation is an interactive online activity which can be used as a

demonstration by the teacher using a projector, or can be an interactive activity for the students if a computer lab is booked.

http://www.khanacademy.org/video/the-kidney-and-nephron?playlist=Biology

Positive Feedback Loop

less common in types of homeostasispositive feedback systems reinforce any

changes -- they move the controlled variable even further away from a steady state, causing a discrete physiological event to be accomplished rapidly.

Bodily Constants

Blood glucose concentration = ~ 100 mg/mL

Blood pressure = ~ 160/106 KPa (120/80 mm Hg)

Body temperature = ~ 37ºC

Blood pH = ~ 7

VIDEO: An excellent review on the Functions and Structure of the Kidney and the Nephron:

http://www.khanacademy.org/video/the-kidney-and-nephron?playlist=Biology

Structure & Function of the Kidney

Kidney Homeostasis

Think-Pair-Share Opening ActivityUsing the next slide, have students

brainstorm on their own, then in pairs, how they think the body responds to the following internal/external stresses.

Students to then share their ideas with the class (teacher facilitates).

How does the body respond

to internal

and external stresses?

thirst high blood pressure

food poisoning abnormal blood composition

Diagnostic AssessmentHave students fill out a KWL chart in pairs

guide instruction and clear up any misconceptions about kidney homeostasis.

What role do the kidneys

play in homeostasis?

The Kidney and Homeostasis

Water Balance Inquiry Activity

The Physiological Effects of Coffee

Physiological Effects of Coffeestudents to design an experiment that allows

them to measure the physiological effect of coffeeStudents to prepare a laboratory report

If it is decided that coffee will not be consumed:Students can research findings on the internet

ORStudents can interview family/friends who drink

coffee

(Activity taken from McGraw-Hill Ryerson, 2002, Biology 12, pp. 118-119)

1. Water BalanceHypothalamus directs the pituitary

gland of the endocrine system to control levels of the hormone vasopressin or antidiuretic hormone (ADH) in the blood

This hormone travels through the blood to the kidneys where it directs the rate of water reabsorption

Increased vasopressin increased ➔water reabsorption

Decreased vasopressin decreased ➔water reabsorption

Fluid Balance GamePURPOSE:To help students gain a better understanding of fluid balance in the nephron To provide students with a fun and kinesthetic learning opportunity

PREPARATION: clear the classroom of desks or use an alternative open space25 sheets of white paper crumbled into balls – represent sodium25 sheets of blue paper crumpled into balls – represents water

GOAL OF GAME:to keep an equal balance of white and blue sheets on your side of the room

Fluid Balance Game ContinuedACTIVITY:1.Split class into 2 groups (room will be split into two halves) 2.Each group will have 9 white balls of paper and 9 blue balls of paper3.The students need to keep the balance by throwing the white sheets of paper over to the other side, or running the blue sheets of paper over to the other side. 4.Teacher will periodically throw in balls of paper to ensure that the students are moving around to maintain the balance.

POST-ACTIVITY JOURNAL REFLECTION:Students to write a reflection about what they learned during the game and how it clarified their understanding of fluid balance

Dehydration Case StudyHow long can we survive without water?

Examine physiological response to dehydration and starvation from the real-life report of a girl discovered 15 days after an earthquake devastated Port Au-Prince, Haiti, in January 2010

Students are asked to work through the pathways of water loss from dehydration as they examine the multiple systems involved in homeostatic responses, and then are asked to calculate whether it is possible for a human to withstand 15 days without water

http://sciencecases.lib.buffalo.edu/cs/files/dehydration.pdf

2. Blood PressureBlood volume is regulated by

the hormone aldosteroneAldosterone affects the rate of

sodium ion reabsorption, which in turn affects the rate of water reabsorption

Increased aldosterone ➔increased water reabsorption

higher blood pressure➔Decreased aldosterone ➔

decreased water reabsorption lower blood pressure➔

3. Blood CompositionUseful materials contained in

the filtrate (glucose, amino acids, etc.) are reabsorbed until the threshold level of the given material is reached

Defined as the maximum amount of material that can be moved across the nephron back into the blood

When the threshold is reached, the remaining material is removed as waste e.g. glucose in diabetes

4. Blood pHShould be close to 7The kidney removes excessively acidic or basic substances from the blood

Four-Corners Activity

Discuss why waste management is an important part of any functioning system – from computers, to cities, to living things.

Urea is the major waste product removed from the kidneysPlaced in the blood by the liver through the detoxification processExcess amino acids are broken down in the liverConverted to ammonia and then to urea

Urine Formation in the Nephron

Urination VideosAn excellent review of Urine Formation: http

://www.learnerstv.com/animation/animation.php?ani=238&cat=biology

A good overview of the Micturition Reflex:http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter26/animation__micturition_reflex.html

Student Activity: Create a Model of the Excretory Filtering System

Taken from p. 343 of Nelson Biology 12 (2003)

Materials: funnel, aquarium charcoal, 2 small beakers, food colouring, non-absorbent cotton, ring stand

Place a small piece of non-absorbent cotton in a funnel. Fill the funnel with aquarium charcoal, and put a small beaker beneath the funnel. Fill a second beaker with about 25 mL of water, and add five drops of food colouring. Pour the coloured water through the funnel and collect it in the beaker beneath as shown in Figure 2.

Compare the colour of the filtered water with the original coloured water. Predict what will happen if the water is filtered once again. Test your prediction. How would you improve the filter?

Urinalysis Virtual Labhttp://biologyonline.us/Online%20A&P/AP%202/Northland/AP2lab/Lab%201%20online/lab4/9.htm

Test urine samples for disease or infectionIdentify symptoms that may lead to a urine testLearn the role of urine tests in monitoring diseasesPerform three analyses:

1) macroscopic observations2) chemstix analysis3) microscopic observations

(*lab can be downloaded from site)

Student MisconceptionsMisconception Fact and/or Guidance

Students may think that when a body is in homeostasis, no change takes place and the internal conditions are stable.

Human body systems are constantly active, constantly monitoring and responding to changing conditions.

“Normal” bodily constants remain the same for all people in all situations.

• Young children, the elderly, and heavy individuals find it more difficult to regulate body temperature making themselves more susceptible to internal and external stress.

• Body temperature also varies with time, place, and activity level.

• “Normal” blood pressure also differs. Children tend to have lower blood pressure than adults, due to the flexibility of their arteries.

They urinary system is an open system allowing entry of any substance from the blood stream.

The blood maintains enclosed in vessels but various substances are allowed to move in and out via filtration.

Students can often be confused by the many ways that the kidneys maintain homeostasis.

“The Kidney and Homeostasis” chart provided in the ‘References’ portion of the Summary is an excellent tool for categorizing the mechanisms the kidney uses to maintain homeostasis. Creating a mind map is also a good way to distinguish the different mechanisms.

Real-Life ApplicationsKidney StonesBright’s DiseaseDiabetes Mellitus and Diabetes InsipidusRenal failureEffects of performance-enhancing drugs on

homeostasisEffects of energy drinks on homeostasisEffects of alcohol and illegal drugs on homeostasisKidney Dialysis DiureticsKidney transplants and wait timesThe effects of chemotherapy on homeostasis

Debate

Should kidney sales be legalized?

Based on the newspaper article:“Why Legalizing Organ Sales Would Help to Save Lives, End Violence” - The Atlantic, Nov. 9/11

http://www.theatlantic.com/life/archive/2011/11/why-legalizing-organ-sales-would-help-to-save-lives-end-violence/248114/

Other ActivitiesCreate a model of the kidney Jigsaw activity with hormones involved in kidney

homeostasisCreate a mind map on kidney homeostasis RAFT writing activity on kidney transplant waiting listPrepare a poster campaign on effects of performance

enhancing drugs and drinks on kidney homeostasisCreate flowcharts for hormonal responsesCreate a song about kidney homeostasisStations about applications of kidney homeostasisWhat foods have an impact on urine odour and colour?

Differentiated Assessment Please refer to previous slides for details:

Diagnostic Assessment (KWL Chart)Think-Pair-ShareStudent-Teacher ConferenceJournal ReflectionGameCreate a ModelLaboratory ReportsCase StudyDebateOral CommunicationWriting AssessmentMind MapFlow ChartsCreate a songTests & Quizzes

Safety ConsiderationsDue to health concerns, it may not be appropriate

for some students to participate in an experiment which involves the consumption of diuretics. Be sure that students do not exceed their normal

coffee intake. Allow the option of students to research the topic or

interview others about the topic

The Fluid Balance Game can be dangerous as it involves students moving around the classroom and throwing objects. The activity should be played in an open area where there is room to move. Ensure that you are supervising the activity at all times.

ResourcesOnline Resources:

Article about how human waste is recycled in Outer Space: http://science.nasa.gov/science-news/science-at-nasa/2001/ast03apr_2Intro to Homeostasis Video: http://www.learnerstv.com/animation/animation.php?ani=241&cat=BiologyMicturition Reflex Video: http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter26/animation__micturition_reflex.htmlOverview of Kidney Filtration Video: http://health.howstuffworks.com/human-body/systems/kidney-urinary/adam-200032.htmInteractive Video of Kidney Function: http://www.kscience.co.uk/animations/kidney.swfNegative Feedback Loop Animation: http://bcs.whfreeman.com/thelifewire/content/chp42/4202s.swfUrination Video: http://www.learnerstv.com/animation/animation.php?ani=238&cat=biology

Resources Continued Intro to Homeostasis GIZMO:

http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=519

Dehydration Case Study: http://sciencecases.lib.buffalo.edu/cs/files/dehydration.pdf

Virtual Urinalysis Lab (can be downloaded from site) – involves testing urine samples for diseases: http://biologyonline.us/Online%20A&P/AP%202/Northland/AP2lab/Lab%201%20online/lab4/9.htm

Introduction to Homeostasis Video: http://www.learnerstv.com/animation/animation.php?ani=241&cat=biology

Urine Formation chart: http://www.clickandlearn.org/Bio/Gr12Bio/Homestasis.htm

Textbook:  Blake, et al. Biology 12. Toronto: McGraw-Hill Ryerson, 2002.